ROTARY DRAW MACHINE

Abstract

A rotary draw machine to facilitate bending a tube between leading and trailing tangents thereof to a target bend angle is disclosed. A die-set defines a rotary bend die that is actuatably rotatable to bend the tube. A linear carriage assembly is pivotably coupled to the die-set to support the tube and feed the tube to the die-set. First and second rotation sensors are positioned to sense rotation at the respective leading and trailing tangents. A controller is operably coupled to the die-set and connected to the first and second rotation sensors. The controller is configured to cause tube bending and then release of the tube from the die-set, to receive data indicative of leading and trailing angles from the respective first and second rotation sensors, and then cause bending of the tube to compensate for spring back based on an initial bend angle, and the leading and trailing angles.

Claims

1. A rotary draw machine to facilitate bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, comprising: a die-set to receive the tube and defining a rotary bend die that is actuatably rotatable to bend the tube; a linear carriage assembly pivotably coupled to the die-set to support the tube and feed the tube to the die-set via the leading tangent; a first rotation sensor positioned to sense rotation of the tube at the leading tangent; a second rotation sensor positioned to sense rotation of the tube at the trailing tangent; and a controller operably coupled to the die-set, and connected to the first and second rotation sensors, the controller configured to cause rotation of the rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location, cause release of the tube from the die-set to allow spring back of the tube, receive data indicative of a leading angle of the leading tangent from the first rotation sensor, after spring back of the tube, and a trailing angle of the trailing tangent from the second rotation sensor, and cause rotation of the rotary bend die, in response to the data, to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.

2. The rotary draw machine of claim 1, wherein the first rotation sensor is mounted to the die-set so as to co-move with the tube as the rotary bend die rotates.

3. The rotary draw machine of claim 1, wherein the second rotation sensor is mounted to the rotary draw machine so as to remain stationarily mounted during movement of the rotary bend die and the linear carriage assembly.

4. The rotary draw machine of claim 1, wherein the first and second rotation sensors are rotary encoders, each of the first and second rotation sensors defining a corresponding shaft drivably coupled to a corresponding panel that is positioned to contact the tube for measuring rotation of the tube.

5. The rotary draw machine of claim 1, wherein the first and second rotation sensors include a rotary encoder defining a shaft drivably coupled to a panel that is configured to adheringly contact the tube to measure rotation of the tube.

6. The rotary draw machine of claim 1, wherein the first and second rotation sensors include a rotary encoder defining a shaft drivably coupled to a magnetic panel that is positioned to magnetically contact the tube to magnetically couple to the tube to measure rotation of the tube.

7. The rotary draw machine of claim 1, wherein the second die angle is indicative of the first die angle augmented with a spring back angle, and the controller is further configured to determine the spring back angle based on at least a difference between the leading angle and the trailing angle.

8. The rotary draw machine of claim 1, wherein the controller is configured to cause release of the tube from the die-set to allow spring back of the tube by rotating the rotary bend die by a retraction angle to retract the tube to disengage the tube from the rotary bend die, the second die angle being based on the first die angle, the retraction angle, the leading angle, and the trailing angle.

9. The rotary draw machine of claim 1, wherein the linear carriage assembly is actuatably pivoted to the die-set and operably coupled to the controller, the controller configured to, after release of the tube from the die-set, cause positioning of the linear carriage assembly relative to the die-set to facilitate bending of the tube for compensating for spring back.

10. The rotary draw machine of claim 9, wherein the data is indicative of the leading angle and the trailing angle after positioning the linear carriage assembly relative to the die-set.

11. The rotary draw machine of claim 1, further comprising a third rotation sensor configured to sense rotation of the linear carriage assembly relative to the die-set and connected to the die-set, wherein the linear carriage assembly is actuatably pivoted to the die-set and operably coupled to the controller, the data is a first data, and the controller is further configured to receive second data indicative of a pivot angle between the linear carriage assembly and the die-set, and after release of the tube from the die-set, cause positioning of the linear carriage assembly relative to the die-set in response to the second data to facilitate bending of the tube for compensating for spring back.

12. The rotary draw machine of claim 1, wherein the linear carriage assembly is actuatable to translate the tube along the linear carriage assembly, and the controller is further configured to cause translation of the tube along the linear carriage assembly to feed the tube to the die-set.

13. The rotary draw machine of claim 1, wherein the first and second rotation sensor are mounted on carriage assemblies that allow actuatable positioning of the first and second rotation sensors to dispose the first and second rotation sensors against the tube for sensing of rotation of the tube.

14. The rotary draw machine of claim 1, wherein the controller is further configured to determine if spring back of the tube has ended based on data received from the first rotation sensor.

15. A method for bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, comprising: causing rotation of a rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location; causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube; after causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube, receiving data indicative of a leading angle, indicative of rotation of the tube at the leading tangent, and a trailing angle, indicative of rotation of the tube at the trailing tangent; and causing rotation of the rotary bend die to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.

16. The method of claim 15, wherein receiving the data indicative of the leading angle and the trailing angle includes receiving the data from at least one rotary encoder defining a shaft drivably coupled to the tube.

17. The method of claim 15, wherein the leading angle is indicative of rotation of the tube at the leading tangent relative to rotation of the rotary bend die, the second die angle is indicative of the first die angle augmented with a spring back angle, and the method further comprising: determining the spring back angle based on at least a difference between the leading angle and the trailing angle.

18. The method of claim 15, wherein the rotary bend die is part of a die-set, a linear carriage assembly being actuatably pivotably coupled to a die-set to support the tube and feed the tube to the die-set via the leading tangent.

19. The method of claim 18, further comprising: after causing rotation of the rotary bend die to retract the tube to disengage the tube, causing positioning of the linear carriage assembly relative to the die-set to facilitate bending of the tube for compensating for spring back.

20. The method of claim 19, wherein the data is indicative of the leading angle and the trailing angle after positioning the linear carriage assembly relative to a die-set of the rotary bend die.

21. The method of claim 19, wherein the data is first data, the method further comprising: receiving second data indicative of a pivot angle between the linear carriage assembly and the die-set, wherein causing positioning of the linear carriage assembly relative to the die-set is in response to the second data.

22. The method of claim 18, wherein the linear carriage assembly is actuatable to translate the tube along the linear carriage assembly, the method further comprising: causing translation of the tube along the linear carriage assembly to feed the tube to the die-set.

23. The method of claim 15, further comprising: determining if spring back of the tube has ended based on the data.

24. A non-transitory computer-readable medium having stored thereon machine interpretable instructions which, when executed by one or more processors, cause the one or more processors to perform the method of claim 15.

25. A kit for a rotary draw machine to facilitate bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, the rotary draw machine comprising a die-set to receive the tube and defining a rotary bend die that is actuatably rotatable to bend the tube, the rotary draw machine comprising a linear carriage assembly pivotably coupled to the die-set to support the tube and feed the tube to the die-set via the leading tangent, the kit comprising: a first rotation sensor suitable to be positioned to sense rotation of the tube at the leading tangent; a second rotation sensor suitable to be positioned to sense rotation of the tube at the trailing tangent; and a controller suitable to be operably coupled to the die-set, and suitable to be connected to the first and second rotation sensors, the controller configured to, when operably coupled to the die-set and connected to the first and second rotation sensors, cause rotation of the rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location, cause release of the tube from the die-set to allow spring back of the tube, receive data indicative of a leading angle of the leading tangent from the first rotation sensor, after spring back of the tube, and a trailing angle of the trailing tangent from the second rotation sensor, and cause rotation of the rotary bend die, in response to the data, to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.

26. The kit of claim 25, wherein the first and second rotation sensors are rotary encoders, each of the first and second rotation sensors defining a corresponding shaft drivably coupled to a corresponding panel suitable to be positioned to contact the tube for measuring rotation of the tube.

27. The kit of claim 26, wherein the first and second rotation sensors include a rotary encoder defining a shaft drivably coupled to a panel suitable to adheringly contact the tube to measure rotation of the tube.

28. The kit of claim 25, wherein the first and second rotation sensors include a rotary encoder defining a shaft drivably coupled to a magnetic panel suitable to be positioned to magnetically contact the tube to magnetically couple to the tube to measure rotation of the tube.

29. The kit of claim 25, wherein the second die angle is indicative of the first die angle augmented with a spring back angle, and the controller is further configured to, when operably coupled to the die-set and connected to the first and second rotation sensors, determine the spring back angle based on at least a difference between the leading angle and the trailing angle.

30. The kit of claim 25, wherein the controller is further configured to, when operably coupled to the die-set and connected to the first and second rotation sensors, cause release of the tube from the die-set to allow spring back of the tube by rotating the rotary bend die by a retraction angle to retract the tube to disengage the tube from the rotary bend die, the second die angle being based on the first die angle, the retraction angle, the leading angle, and the trailing angle.

31. The kit of claim 25, wherein the linear carriage assembly is actuatably pivoted to the die-set and configured to be operably coupled to the controller, the controller is further configured to, when operably coupled to the die-set and connected to the first and second rotation sensors, after release of the tube from the die-set, cause positioning of the linear carriage assembly relative to the die-set to facilitate bending of the tube for compensating for spring back.

32. The kit of claim 31, wherein the data is indicative of the leading angle and the trailing angle after positioning the linear carriage assembly relative to the die-set.

33. The kit of claim 25, wherein the controller is further configured to determine if spring back of the tube has ended based on data received from the first rotation sensor.

Description

DESCRIPTION OF THE DRAWINGS

[0024] Reference is now made to the accompanying drawings, in which:

[0025] FIG. 1 is a rear perspective view of a rotary draw machine, in accordance with an embodiment.

[0026] FIG. 2A is a front perspective view of a rotary draw machine, in accordance with an embodiment.

[0027] FIG. 2B is a top plan view of the rotary draw machine, in accordance with an embodiment.

[0028] FIG. 2C is a front elevation view of the rotary draw machine, in accordance with an embodiment.

[0029] FIG. 2D is a right-side elevation view of the rotary draw machine, in accordance with an embodiment.

[0030] FIG. 3 is an enlarged perspective view of a rotary draw machine, in accordance with an embodiment.

[0031] FIG. 4 is an enlarged perspective view of a rotary draw machine, in accordance with an embodiment.

[0032] FIG. 5A is a perspective fragmented view of a rotary draw machine with two rotary encoders mounted to contact a tube, in accordance with an embodiment.

[0033] FIG. 5B is a rear elevation fragmented view of a rotary draw machine with two rotary encoders mounted to contact a tube, in accordance with an embodiment.

[0034] FIG. 5C is a right elevation fragmented view of a rotary draw machine with two rotary encoders mounted to contact a tube, in accordance with an embodiment.

[0035] FIG. 5D is a left elevation fragmented view of a rotary draw machine with two rotary encoders mounted to contact a tube, in accordance with an embodiment.

[0036] FIG. 6A is a schematic plan view of the rotary draw machine in an initial stage of operation, in accordance with an embodiment.

[0037] FIG. 6B is a schematic plan view of the rotary draw machine in a bending stage of operation, in accordance with an embodiment.

[0038] FIG. 6C is a schematic plan view of the rotary draw machine in a retraction stage of operation, in accordance with an embodiment.

[0039] FIG. 7A is a schematic plan view of a rotary draw machine in a first stage of operation, in accordance with an embodiment.

[0040] FIG. 7B is a schematic plan view of a rotary draw machine in a second stage of operation, in accordance with an embodiment.

[0041] FIG. 7C is a schematic plan view of a rotary draw machine in a third stage of operation, in accordance with an embodiment.

[0042] FIG. 7D is a schematic plan view of a rotary draw machine in a fourth stage of operation, in accordance with an embodiment.

[0043] FIG. 7E is a schematic plan view of a rotary draw machine in a fifth stage of operation, in accordance with an embodiment.

[0044] FIG. 7F is a schematic plan view of a rotary draw machine in a sixth stage of operation, in accordance with an embodiment.

[0045] FIG. 7G is a schematic plan view of a rotary draw machine in a seventh stage of operation, in accordance with an embodiment.

[0046] FIG. 8A is a side elevation view of a rotary encoder assembly that is mountable on an arm of a rotary bend die, in accordance with an embodiment.

[0047] FIG. 8B is a perspective view of a rotary encoder assembly that is mountable on an arm of a rotary bend die, in accordance with an embodiment.

[0048] FIG. 8C is a front elevation view of a rotary encoder assembly that is mountable on an arm of a rotary bend die, in accordance with an embodiment.

[0049] FIG. 9A is a side elevation view of a rotary encoder assembly that is mountable on a table supporting a rotary bend die, in accordance with an embodiment.

[0050] FIG. 9B is a perspective view of a rotary encoder assembly that is mountable on a table supporting a rotary bend die, in accordance with an embodiment.

[0051] FIG. 9C is a front elevation view of a rotary encoder assembly that is mountable on a table supporting a rotary bend die, in accordance with an embodiment.

[0052] FIG. 10 is a schematic block diagram of a controller of a rotary draw machine, in accordance with an embodiment.

[0053] FIG. 11 is a schematic flow chart of a method for operating a rotary draw machine, in accordance with an embodiment.

[0054] FIG. 12 is a schematic flow chart of a method for bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, in accordance with an embodiment; and

[0055] FIG. 13 illustrates a block diagram of a computing device, in accordance with an embodiment of the present application.

DETAILED DESCRIPTION

[0056] The following disclosure relates to kits, devices, systems, methods, and computer-readable media for achieving bending of tubes to achieve high accuracy bends. In particular, the disclosure relates to tube bending using rotary bend dies, e.g. as implemented in rotary draw machines. While it is conceived that a common use for aspects herein is bending of metal tubes, bending of tubes of other appropriate materials may be possible.

[0057] The disclosure describes a rotary draw machine to facilitate bending a tube between leading and trailing tangents thereof to a target bend angle. Such rotary draw machines comprise a die-set to receive the tube, and a linear carriage assembly pivotably coupled to the die-set to support the tube. The die-set defines a rotary bend die that is actuatably rotatable to bend the tube. The linear carriage assembly is used to feed the tube to the die-set via the leading tangent.

[0058] The rotary draw machine is equipped with leading and trailing rotation sensors 144, 146, positioned to sense rotation at the respective leading and trailing tangents. A controller is operably coupled to the die-set and connected to the leading and trailing rotation sensors 144, 146. The controller is configured to cause tube bending and then release of the tube from the die-set, to receive data indicative of leading and trailing angles from the respective leading and trailing rotation sensors 144, 146, and then cause bending of the tube to compensate for spring back based on an initial bend angle, and the leading and trailing angles.

[0059] The rotary draw machine, e.g. a controller thereof, may execute a method for bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, described in various aspects herein.

[0060] Existing tube bending machines may be retrofitted with leading and rotation sensors, controllers, and/or other components to achieve one or more of the rotary draw machines disclosed herein. For example, leading and rotations sensors may be provided as part of a kit for the tube bending machine. The kit may include the controller and/or other components. The kit may include a non-transitory computer-readable medium that has stored thereon machine interpretable instructions, e.g. for loading on to a pre-existing controller of the tube bending machine. The machine interpretable instructions, when executed by one or more processors, may cause the one or more processors to execute one or more steps of methods described herein. In some embodiments, machine interpretable instructions may be downloadable from a web server for loading on to a computer-readable medium, e.g. a computer-readable medium of the controller.

[0061] Aspects disclosed herein may facilitate fast, cost-effective, and high accuracy bending of tubes. For example, cost-effective lower-end tube bending machines may be used to achieve such bending. For example, automation of bending and spring back compensation may be fully automated by aspects disclosed herein, lowering labor and skill requirements, as well as allowing faster bending of tubes. Other advantages may be apparent to a skilled person, such advantages being implied or expressly described in the disclosure.

[0062] Aspects of various embodiments are described in relation to the figures.

[0063] FIG. 1 is a rear perspective view of a rotary draw machine 100, in accordance with an embodiment.

[0064] FIG. 2A is a front perspective view of a rotary draw machine 100, in accordance with an embodiment.

[0065] FIG. 2B is a top plan view of the rotary draw machine 100, in accordance with an embodiment.

[0066] FIG. 2C is a front elevation view of the rotary draw machine 100, in accordance with an embodiment.

[0067] FIG. 2D is a right-side elevation view of the rotary draw machine 100, in accordance with an embodiment.

[0068] FIG. 3 is an enlarged perspective view of a rotary draw machine 100, in accordance with an embodiment.

[0069] FIG. 4 is an enlarged perspective view of a rotary draw machine 100, in accordance with an embodiment.

[0070] FIG. 5A is a perspective fragmented view of a rotary draw machine 100 with two rotary encoders 170 mounted to contact a tube 102 via corresponding panels 172, in accordance with an embodiment.

[0071] FIG. 5B is a rear elevation fragmented view of a rotary draw machine 100 with two rotary encoders 170 mounted to contact a tube 102 via corresponding panels 172, in accordance with an embodiment.

[0072] FIG. 5C is a right elevation fragmented view of a rotary draw machine 100 with two rotary encoders 170 mounted to contact a tube 102 via corresponding panels 172, in accordance with an embodiment.

[0073] FIG. 5D is a left elevation fragmented view of a rotary draw machine 100 with two rotary encoders 170 mounted to contact a tube 102 via corresponding panels 172, in accordance with an embodiment.

[0074] Referring to FIG. 1, FIGS. 2A-2D, FIGS. 3-4, and FIGS. 5A-5D, the rotary draw machine 100 facilitates bending of a tube 102 that extends from a leading end 104 to a trailing end 106, such ends being so named in accordance with the direction, along and relative to the tube 102 itself, in which the tube 102 is drawn during bending.

[0075] While FIG. 1 shows a straight tube, it is understood that tubes of various open or closed, straight or curved, shapes may be bent accordingly to aspects disclosed herein. For example, in some cases the leading and trailing ends 104, may be substantially similar (a closed tube or substantially closed tube).

[0076] A resulting bend is associated with a target bend angle generally positioned at a bend location 110 of the tube 102. The bend formed in such a manner may be defined by an arc of the tube 102 disposed between opposing non-bent portions of the tube 102 referred to herein as the leading tangent 114 and the trailing tangent 116. A distance between the leading tangent 114 and the leading end 104 may be shorter than a shortest distance between the trailing tangent 116 and the leading end 104. Analogously, a distance between the trailing tangent 116 and the trailing end 106 may be shorter than a shortest distance between the leading tangent 114 and the trailing end 106.

[0077] As referred to herein, tube may refer to a generally tubular body that is elongated along a longitudinal direction thereof. It is understood that a common application of the aspects disclosed herein will be directed to bending of relatively rigid, hollow, and cylindrical tubes since these types of tubes are widespread in the automotive industry and may also be more susceptible to spring back compared to other types of tubes, which are also envisaged. For example, in various embodiments, a tube may have a circular or non-circular transverse section, lateral to the longitudinal direction, with such transverse section being varying or non-varying along the tube. In various embodiments, a tube may be hollow or solid.

[0078] As shown in FIGS. 1, 2A-2D, the rotary draw machine 100 generally comprises a die-set 112 to receive the tube 102, a linear carriage assembly 126 to support the tube 102, and a controller 128 operably coupled to the die-set 112 to operate the die-set 112 to achieve desired bending of the tube 102. The controller 128 is shown schematically in FIG. 1 and is understood to be provided also in the embodiment(s) in FIGS. 2A-2D, 3-4, 5A-5D.

[0079] As referred to herein, the controller 128 may include circuitry, microprocessors, logic gates, and/or other types of components. In various embodiments, the controller 128 may be configured to control the rotary draw machine 100 by one or more feedback and/or feedforward control loops. For example, in some embodiments, the controller 128 may be configured, via lower level or inner control loops thereof, to achieve desired operation of actuators, such as operation of a (rotary and/or linear) motor to achieve a prescribed translation or rotation of a component of the rotary draw machine 100. For example, in some embodiments, the controller 128 may be configured, via higher level or outer control loops thereof, to determine target movement of components of the rotary draw machine 100, such as by determining target translations or rotations of such components.

[0080] The die-set 112 may be positioned at a front end 134 of the rotary draw machine 100 and the linear carriage assembly 126 may be positioned at a rear end 136 of the rotary draw machine 100.

[0081] The linear carriage assembly 126 is pivotably coupled to the die-set 112 to support the tube 102. In various embodiments, linear carriage assembly 126 is actuatably pivoted to the die-set 112 and operably coupled to the controller 128. The linear carriage assembly 126 is configured to feed the tube 102 to the die-set 112, for bending, via the leading tangent 114. In various embodiments, the linear carriage assembly 126 may be pivoted to the die-set 112 via a table 140 or other fixture supporting the die-set 112 in place during bending. The linear carriage assembly 126 may be configured to pivot about the table 140 as the tube 102 is drawn into the rotary draw machine 100 for bending. Advantageously, such pivoting may mitigate clamping requirements for the rotary draw machine 100.

[0082] The die-set 112 includes a rotary bend die 118 that is actuatably rotatable to bend the tube 102. In various embodiments, the rotary bend die 118 may also be referred to as a bend die, or bend former. The rotary bend die 118 is suitable to rotate about an axis thereof, relative to the table 140, to bend the tube 102.

[0083] A circumferential end of the rotary bend die 118 defines a depressed or concave portion extending circumferentially around the rotary bend die 118. The depression may be arcuate and may be adapted to a shape of the tube 102 so as to allow the tube 102 to be received into the depression to engage with the rotary bend die 118 for bending of the tube 102 therealong.

[0084] The rotary bend die 118 may be drivably coupled to a rotary bend die 118 motor or other actuator to allow rotation of the rotary bend die 118 around its axis, e.g. a central axis thereof, to cause bending of the tube 102 when the tube 102 is engaged with the rotary bend die 118. The rotary bend die 118 may be operably coupled to the controller 128. For example, the controller 128 may be configured to actuate the rotary bend die 118 during one or more stages of operation of the rotary draw machine 100 to selectively rotate the rotary bend die 118 so as to bend the tube 102 at the bend location 110 to a nominal bend angle or towards a target bend angle of the tube 102. For example, the rotary bend die 118 motor may be caused to rotate around an axis thereof by a predetermined angle by the controller 128. The predetermined angle of rotation of the rotary bend die 118 motor may be associated with the target or nominal bend angle. The rotary bend die 118 may be coupled to a control circuit and one or more sensors (e.g. encoders or other sensors for measuring rotation of the motor) for controlling rotation thereof.

[0085] As referred to herein, the die angle may be the angle of rotation of the rotary bend die 118 about its own axis from a reference (or zero) angle, such reference angle being taken to be the angle of the rotary bend die 118 prior to bending of the tube 102 and while the rotary bend die 118 is engaged with the tube 102 for bending the tube 102.

[0086] In some embodiments, the controller 128 may be configured to control rotation of the rotary bend die 118 based on a sensed or inferred angular position and/or rotation rate of the rotary bend die 118 and/or the rotary bend die motor. In various embodiment, the controller 128 may be configured to control rotation of the rotary bend die 118 by controlling power supplied to the rotary bend die motor.

[0087] In various embodiments, the die-set 112 may include a counter die 120 positioned opposite to the rotary bend die 118 so as to allow the tube 102 to be at least partially sandwiched between the rotary bend die 118 and the counter die 120.

[0088] The counter die 120 may be mounted on guide(s), e.g. rail(s), to allow translation thereof. The counter die 120 may be drivably coupled to a counter die motor to drive the counter die 120 towards and away from the tube 102. The counter die 120 may be operably coupled to the controller 128. For example, the controller 128 may be configured to cause translation of the counter die 120 to selectively engage with and release the tube 102.

[0089] The die-set 112 may include a hook-arm 122. The hook-arm 122 may be positioned in front of the rotary bend die 118 so as to receive the tube 102 into a hook defined by the hook-arm 122. The hook-arm 122 is coupled to the rotary bend die 118 so as to co-move (co-rotate) with the rotary bend die 118 as the rotary bend die 118 rotates to bend the tube 102. The hook-arm 122, while engaged with the tube 102, may prevent the tube 102 from springing back after a bend. As the rotary bend die 118 continues to retract, the tube 102 continues to be engaged with the hook-arm 122 as long as the tube 102 continues to spring back. The hook-arm 122 may be released or disengaged from the tube 102 after bending by retracting the rotary bend die 118 further after the tube 102 has finished springing back.

[0090] In various embodiments, there may be provided a pressure die, a clamp, a wiper, or other components for clamping the tube 102 in position for bending and/or applying pressure during a bend to achieve a well-defined bend of the tube 102. For example, a clamp die may be provided to retain the tube 102 in position during bending such that release of the clamp die may be required to release the tube 102.

[0091] In various embodiments, a pressure die, a clamp, a wiper, and/or other component(s) may be operably coupled to the controller 128 via corresponding motor(s) or other type of actuation mechanism to allow for control of the pressure die, the clamp, the wiper, and/or the other component.

[0092] In some embodiments, the rotary draw machine 100 may include a mandrel for being received in the tube 102.

[0093] The linear carriage assembly 126 may comprise a linear guide 138, such as a rail or other type of guide, defining a linear path extending from the rear end 136 towards the front end 134. In various embodiments, the linear carriage assembly 126 may be actuatable to allow selective positioning of the tube 102 relative to the table 140 and/or the linear carriage assembly 126.

[0094] In various embodiments, a chuck 130, or other type of structure for holding and supporting the tube 102, may be engaged with the linear guide 138. The chuck 130 may be configured to receive the tube 102 to support the tube 102 as the chuck 130 is translated along the linear guide 138. In some embodiments, the chuck 130 may be drivably coupled to a chuck motor or other actuator to facilitate actuatable translation of the chuck 130 along the linear guide 138. In various embodiments, the chuck motor may be operably coupled to the controller 128. For example, the controller 128 may be configured to actuate the chuck motor during one or more stages of operation of the rotary draw machine 100 to selectively position the tube 102 relative to the rotary draw machine 100.

[0095] A hinge 132 may couple the linear carriage assembly 126, e.g. via the linear guide 138, to the die-set 112, e.g. via the table 140. In some embodiments, the hinge 132 may be actuatable to cause rotation of the linear carriage assembly 126. In some embodiments, the hinge 132 may be drivably coupled to a hinge motor for rotating the linear carriage assembly 126 about the hinge 132. In various embodiments, the hinge motor may be operably coupled to the controller 128. For example, the controller 128 may be configured to actuate the hinge motor during one or more stages of operation of the rotary draw machine 100 to selectively position the linear carriage assembly 126 relative to the table 140.

[0096] The linear carriage assembly 126 may be supported at a first end by table 140 and may be supported by a wheeled leg at a second end opposite to the first end. The wheeled leg may comprise a wheel that is suitable to rotate about an axis substantially parallel to the linear guide 138 to allow pivoting of the linear carriage assembly 126 about the table 140, to which it may be hingably attached.

[0097] In various embodiments, a rotation sensor 148 of the rotary draw machine 100 may be connected to the die-set 112. The rotation sensor 148 may be configured to sense rotation of the linear carriage assembly 126 relative to the die-set 112.

[0098] In some embodiments, the linear carriage assembly 126 may be actuatable to allow selective rotation of the linear carriage assembly 126 about the table 140. In some embodiments, the wheel may be drivably coupled to a wheel motor for driving the wheel to allow selective positioning of the linear carriage assembly 126 relative to the table 140. In various embodiments, the wheel motor may be operably coupled to the controller 128. For example, the controller 128 may be configured to actuate the wheel motor to position the tube 102 and/or the linear carriage assembly 126 during one or more stages of operation of the rotary draw machine 100 to selectively position the linear carriage assembly 126 relative to the table 140.

[0099] As the tube 102 is bent by the die-set 112, the tube 102 may be drawn away from the rear end 136 towards the front end 134 as it is fed to the die-set 112. During such drawing, the tube 102 may pull on the chuck 130 to slide the chuck 130 along the linear guide 138 while supporting the tube 102.

[0100] The rotary draw machine 100 includes a leading rotation sensor 144 and a trailing rotation sensor 146. The leading rotation sensor 144 is positioned to sense rotation of the tube 102 at the leading tangent 114. The trailing rotation sensor 146 is positioned to sense rotation of the tube 102 at the trailing tangent 116.

[0101] The leading rotation sensor 144 may be mounted to the die-set 112 so as to co-move with the tube 102 as the rotary bend die 118 rotates. In various embodiments, the leading rotation sensor 144 may be mounted to the hook-arm 122 so that it moves with the leading tangent 114 as the tube 102 is bent.

[0102] The trailing rotation sensor 146 may be mounted to the rotary draw machine 100 so as to remain stationarily mounted during movement of the rotary bend die 118 and the linear carriage assembly 126 during bending.

[0103] The leading rotation sensor 144 may be mounted on a carriage assembly that allows actuatable positioning of the leading rotation sensor 144 to dispose the leading rotation sensor 144 against the tube 102 for sensing of rotation of the tube 102.

[0104] For example, the leading rotation sensor 144 may be operably coupled to the controller 128 to allow control of positioning of the leading rotation sensor 144. The carriage assembly may define a linear guide rail slidably engaged with a carriage. For example, the leading rotation sensor 144 may be attached to (or held by) a holder that is slidably engaged to allow sliding of the leading rotation sensor 144 along a length of the carriage assembly. A motor may be coupled to the leading rotation sensor 144 to allow positioning thereof along the length of the carriage assembly. For example, the motor may allow driving the holder along the length of the carriage assembly. The motor may be operably coupled to the controller 128 to allow positioning of the leading rotation sensor 144. The controller 128 may be configured to position the leading rotation sensor 144 away from the tube 102 in a stage of operation of the rotary draw machine 100 and to position the leading rotation sensor 144 against the tube 102 in another stage of operation of the rotary draw machine 100. For example, the carriage assembly may be oriented lateral to the rotary bend die 118 and/or the trailing tangent 116 of the tube 102 so that movement of the leading rotation sensor 144 along the length of the carriage assembly causes movement thereof to and away from the tube 102.

[0105] The trailing rotation sensor 146 may be mounted on a carriage assembly that allows actuatable positioning of the trailing rotation sensor 146 to dispose the trailing rotation sensor 146 against the tube 102 for sensing of rotation of the tube 102.

[0106] For example, the trailing rotation sensor 146 may be operably coupled to the controller 128 to allow control of positioning of the trailing rotation sensor 146. The carriage assembly may define a linear guide rail slidably engaged with a carriage. For example, the trailing rotation sensor 146 may be attached to (or held by) a holder that is slidably engaged to allow sliding of the trailing rotation sensor 146 along a length of the carriage assembly. A motor may be coupled to the trailing rotation sensor 146 to allow positioning thereof along the length of the carriage assembly. For example, the motor may allow driving the holder along the length of the carriage assembly. The motor may be operably coupled to the controller 128 to allow positioning of the trailing rotation sensor 146. The controller 128 may be configured to position the trailing rotation sensor 146 away from the tube 102 in a stage of operation of the rotary draw machine 100 and to position the trailing rotation sensor 146 against the tube 102 in another stage of operation of the rotary draw machine 100. For example, the carriage assembly may be oriented lateral to the rotary bend die 118 and/or the trailing tangent 116 of the tube 102 so that movement of the trailing rotation sensor 146 along the length of the carriage assembly causes movement thereof to and away from the tube 102.

[0107] In some embodiments, the leading and/or trailing rotation sensor(s) 144, 146 may include one or more rotary encoders 170. Each rotary encoder 170 may define an encoding portion coupled to a panel 172 via a shaft 174. The shaft 174 may be drivably coupled to the panel 172. The panel 172 may be positioned to contact the tube 102 for measuring rotation of the tube 102. As the tube 102 rotates, the panel 172 may be pushed by the tube 102 to cause alignment therebetween, which may cause commensurate rotation of the shaft 174 that is detected by the encoding portion.

[0108] The panels 172 may be suitable to contact the tube 102 and, as such, may be referred to as contactors. In various embodiments, the panels 172 may be planar and/or plate-like. Each panel 172 may be rigidly coupled to its respective shaft 174 so that rotation of the panel 172 causes corresponding rotation in the shaft 174. For example, each panel 172 may be configured to rotate about an axis defining the respective shaft 174, e.g. an axis defining the longitudinal direction of the shaft 174.

[0109] In various embodiments, panel(s) 172 of the leading and/or trailing rotation sensors 144, 146 may be configured to adheringly contact the tube 102 to measure rotation of the tube 102.

[0110] In some embodiments, the panel 172 may be a magnetic panel 172 suitable for magnetic coupling to suitable metal or magnetizable tubes. The magnetic panel 172 may be positioned to magnetically contact the tube 102 to magnetically couple to the tube 102 to measure rotation of the tube 102. In some embodiments, the panel 172 may be electromagnetic. In some embodiments, the controller 128 may be operably connected to the panel 172 to selectively energize the panel 172 or to selectively encourage adherence of the panel 172 to the tube 102. Advantageously, this may allow the rotary encoder(s) 170 to closely follow the rotation of tangent(s) 114, 116 of the tube 102 as the tube 102 is bent.

[0111] In some embodiments, a resilient member may be coupled to the panel 172 to push the panel 172 against the tube 102 to adhere the panel 172 on to the tube 102. For example, a spring may be disposed against the panel 172 to push the panel 172 against the tube 102 once it is positioned against the tube 102 so as to be depressed against the tube 102.

[0112] In some embodiments, a motor mounted onto the rotary draw machine 100 may be coupled to a pusher to push the panel 172 against the tube.

[0113] The controller 128 may be operably and/or communicatively coupled to the leading and trailing rotation sensors 144, 146. For example, the leading and trailing sensors may transmit data indicative of measured angles of the tube 102. For example, the controller 128 may be configured to receive such data. For example, the controller 128 may be configured to reset rotation sensors and/or cause rotation sensors to calibrate and/or re-calibrate.

[0114] FIG. 6A is a schematic plan view of the rotary draw machine 100 in an initial stage of operation, in accordance with an embodiment.

[0115] In the initial stage of operation, the tube 102 is inserted into the hook-arm 122 and the counter die 120 pressed the tube 102 against the rotary bend die 118. The leading and trailing rotation sensors 144, 146 may be positioned against the tube 102 to measure rotation of the leading and trailing tangents 114, 116. For example, the controller 128 may be configured to cause the leading and trailing rotation sensors 144, 146 against the tube 102.

[0116] FIG. 6B is a schematic plan view of the rotary draw machine 100 in a bending stage of operation, in accordance with an embodiment.

[0117] In the bending stage of operation, the rotary bend die 118 is rotated, about its own axis and in an angular direction (shown as a clockwise rotation in FIG. 6B), to a (first or nominal) die angle to bend the tube 102 at the bend location 110. The controller 128 may cause the rotary bend die 118 to rotate to the nominal die angle 152. The nominal die angle 152 may be associated with the target bend angle. In some embodiments, the nominal die angle 152 may be equal to the target bend angle. In some embodiments, the nominal die angle 152 may be proportional to the target bend angle. In some embodiments, the nominal die angle 152 may be greater than the target bend angle so as to compensate for anticipated spring back of the tube 102. For example, the nominal die angle 152 may be specified by augmenting the target bend angle.

[0118] As the rotary bend die 118 rotates, the tube 102 bends, and the linear carriage assembly 126 may pivot about the die-set 112 (and the rotary bend die 118). While the rotary bend die 118, and counter die 120, are engaged with the tube 102, the leading rotation sensor 144 may remain in contact with the leading tangent 114 of the tube 102. Since the leading rotation sensor 144 may be mounted to co-move with the rotary bend die 118, the leading rotation sensor 144 may co-rotate with the leading tangent 114 of the tube 102 and the leading tangent 114 may not rotate relative to the leading rotation sensor 144. As such, a rotation may not be registered at the leading rotation sensor 144.

[0119] The panel 172 of the trailing rotation sensor 146 may rotate as the rotary bend die 118 rotates so as to cause a rotation to be registered at the trailing rotation sensor 146, as the trailing rotation sensor 146 remains stationarily mounted. This rotation may represent rotation of the trailing tangent 116 relative to the die-set 112 or the table 140 the die-set 112 is mounted on.

[0120] FIG. 6C is a schematic plan view of the rotary draw machine 100 in a retraction stage of operation, in accordance with an embodiment.

[0121] In the retraction stage of operation, the tube 102 is released from the die-set 112 to allow spring back of the tube 102 after bending. The controller 128 may cause release of the tube 102 from the die-set 112. In some embodiments, the tube 102 may be released by rotating the rotary bend die 118 at least partially in a reverse angular direction (shown as a counterclockwise rotation in FIG. 6C). In some embodiments, the controller 128 is configured to cause release of the tube 102 from the die-set 112 to allow spring back of the tube 102 by rotating the rotary bend die 118 by a retraction angle 158 to retract the tube 102 to disengage the tube 102 from the rotary bend die 118. For example, a magnitude of the retraction angle 158 may be equal to a portion of the nominal die angle 152. In some embodiments, the counter die 120 or other type may be moved away from the tube 102 in the retraction stage of the operation.

[0122] In some embodiments, the rotary bend die 118 may be rotated in the reverse angular direction at least until the tube 102 has substantially fully sprung back. In the embodiment shown in FIGS. 7A-7G, until the tube 102 has substantially fully sprung back, the tube 102 continues to reverse bend, i.e. unbend or bend opposite to the initial bend, substantially along with such retraction of the rotary bend die 118 and consequently also does not cause the leading rotation sensor 144 to register a rotation. As such, the leading rotation sensor 144 registers or begins registering rotation of the tube 102 only when the tube 102 has substantially fully sprung back while the rotary bend die 118 continues to retract. For example, the leading rotation sensor 144 registering or beginning to register rotation of the tube 102 indicates that the rotary bend die 118 has been retracted sufficiently to release the tube 102. It is understood that, in various embodiments, the leading rotation sensor 144 may register a small rotation even while the tube 102 is still springing back. For example, if the rotary bend die 118 is rotated faster than the rate at which the tube 102 relaxes or spring backs, the leading rotation sensor 144 may register a small rotation corresponding to the lag or delay between the retraction of the rotary bend die 118 and the response of the tube 102. As such, the angular velocity (rotation rate) of the rotary bend die 118 may be based on the material characteristics of the tube 102, the magnitude of the bend angle, and/or other variables that impact the relaxation rate of the tube 102. Consequently, the rotary bend die 118 may stop rotation when the tube 102 completes springing back. For example, detection of springing back of the tube 102 by a controller 128 may be used to determine when the tube 102 has fully sprung back so as to control the rotary bend die 118 to stop and/or start rotation based on the behaviour of the tube 102. In various embodiments, the rotary bend die 118 may be retracted or rotated in the reverse angular direction only up to a position wherein the tube 102 is on the verge of engagement (or disengagement) with the die-set 112. For example, if the rotary bend die 118 is further rotated in the reverse angular direction beyond the position at which the tube 102 has fully relaxed or sprung back, the rotary bend die 118 is further disengaged from the tube 102 (or is further away from engagement with the tube 102). Advantageously, in various embodiments, such further disengagement may not have significant impact on accuracy of subsequent bending (or re-bending) operations since the spring back angle may be determined based on a difference between a rotation registered by the leading rotation sensor 144 and a rotation registered by the trailing rotation sensor 146.

[0123] As the tube 102 is released from the die-set 112, the tube 102 may spring back away from the angle to which the tube 102 was initially bent and/or the linear carriage assembly 126 may be perturbed or rotated from the position it assumed upon bending of the tube 102. After spring back, the tube 102 may define a bend 108 (resting bend or bend in a relaxed state of the tube 102).

[0124] As the tube 102 springs back during retraction of the rotary bend die 118, the panel 172 of the leading rotation sensor 144 may be substantially rotationally stationary. As the rotary bend die 118 continues to retract after the tube 102 comes to a rest after spring back of the tube 102, the tube 102 pushes the panel 172 of the leading rotation sensor 144 so as to register or sense rotation at the leading rotation sensor 144. The leading tangent 114 of the tube 102 is then angled at a leading angle 154 relative to the rotary bend die 118, e.g. hook-arm 122 and other rotating parts of the die-set 112. The controller 128 then receives data indicative of the leading angle 154 of the leading tangent 114 from the leading rotation sensor 144.

[0125] In various embodiments, the controller 128 may be configured to determine if the tube 102 has completed springing back, i.e. spring back of the tube 102 has ended, based on the data received from the leading rotation sensor 144. For example, the controller 128 may determine that spring back of the tube 102 has completed based on the leading rotation sensor 144 showing a non-zero rate of change of rotation registered by the leading rotation sensor 144.

[0126] In some embodiments, the retraction angle 158 is based on the data received from the leading rotation sensor 144. For example, the retraction angle 158 may be determined based on the position of the rotary bend die 118 when the controller 128 determines that spring back of the tube 102 has ended.

[0127] After spring back of the tube 102 is completed, the trailing tangent 116 of the tube 102 is angled at a trailing angle 156 relative to the die-set 112, e.g. relative to a table 140 upon which the die-set 112 is mounted. The controller 128 then receives data indicative of the trailing angle 156 of the trailing tangent 116 from the trailing rotation sensor 146.

[0128] In various embodiments, as the tube 102 springs back during retraction of the rotary bend die 118, the linear carriage assembly 126 may rotate so as to cause the tube 102 to push the panel 172 of the trailing rotation sensor 146 so as to register a rotation at the trailing rotation sensor 146, such rotation being associated with the trailing angle 156.

[0129] In various embodiments, the controller 128 may be configured to determine a spring back angle of the tube 102 based on data indicative of the leading angle 154 and trailing angle 156. In some embodiments, the controller 128 may be configured to determine the spring back angle based on at least a difference between the leading angle 154 and the trailing angle 156.

[0130] As will be described further, if the spring back angle and/or the leading angle 154 are greater than a predetermined threshold or tolerance, the rotary draw machine 100 may then re-enter the bending stage of operations wherein the tube 102 is bent by rotating the rotary bend die 118 to a (second or correction) die angle. For example, the controller 128 may be configured to evaluate the spring back angle and then cause the rotary draw machine 100 to re-enter the bending stage of operation.

[0131] The correction die angle 150 may be configured to correct the bend of the tube 102 to reduce or eliminate the change in bend angle due to spring back, i.e. re-bend the tube 102 based on the spring back angle to achieve a bend angle closer to the target bend angle. In various embodiments, the controller 128 may be configured to cause rotation of the rotary bend die 118, in response to data received indicative of the leading and trailing angles 154, 156, to the correction die angle 150 to bend the tube 102 to at least partially compensate for spring back.

[0132] The rotary bend die 118 may start at a zero die angle, may then rotate to the nominal die angle 152, may then rotate to a die angle equal to the nominal die angle 152 minus the retraction angle 158, and then rotate to a correction die angle 150. In various embodiments, the rotary bend die 118 may retract again, the controller 128 may then receive further data indicative of another spring back of the tube 102 to determine another correction die angle 150, and the rotary bend die 118 is rotated based on this other correction die angle 150. In an analogous manner, the rotary draw machine 100 may repeatedly cause retraction of the rotary bend die 118 and (corresponding repeated) re-bending of the tube 102 based on (corresponding repeated) measurement of leading and trailing angles 154, 156 until a determined spring back of the tube 102 falls below a predetermined threshold (or tolerance) or when the difference between the nominal die angle 152 and the retraction angle 158 is greater than the target bend angle, which may indicate that the tube 102 is over bent.

[0133] In some embodiments, the correction die angle 150 is indicative of the nominal die angle 152 augmented with a spring back angle.

[0134] In various embodiments, the correction die angle 150 may be based on the nominal die angle 152, the leading angle 154, and the trailing angle 156. In some embodiments, the correction die angle 150 may also be based on the retraction angle 158.

[0135] In some embodiments, the rotary bend die 118 retracts while (e.g. only while) the tube 102 continues to spring back and stops retracting when the tube 102 stops springing back, e.g. as determined based on leading and/or trailing rotation sensors 144, 146. For example, in some such embodiments, the correction die angle 150 may be:

[00001]${}_{comp}+\left({}_{nom}-{}_{ret}+{}_{lead}-{}_{trail}\right)$ [0136] where .sub.nom is the nominal die angle 152, .sub.ret is the retraction angle 158, .sub.lead is the leading angle 154, .sub.trait is the trailing angle 156, and .sub.comp is an additive compensatory factor. For example, in some such embodiments, the correction die any may be:

[00002]${}_{\mathrm{comp}}\left({}_{nom}-{}_{ret}+{}_{lead}-{}_{trail}\right)$ [0137] where .sub.comp is a multiplicative compensatory factor. In some embodiments, .sub.comp=0 or .sub.comp=1. In various embodiments, the compensatory factors may be based on tube material.

[0138] The additive/multiplicative compensatory angles may be determined based on predicted spring back and/or may be based on the nominal die angle 152 and the target bend angle, e.g. additive/multiplicative compensatory angles may be negative angles to account for predetermined spring back represented in the difference between the nominal die angle 152 and the target bend angle.

[0139] In some embodiments, the linear carriage assembly 126 may be repositioned after rotation of the rotary bend die 118 to the nominal die angle 152, e.g. between retraction and bending stages of operation. It is found to be important for bend accuracy to reposition the linear carriage assembly 126 after bending so it assumes an initial orientation, i.e. an orientation at the start of the last bending operation, since the location where the linear carriage assembly 126 pivots is offset from the bend location. As such, the controller 128 may be configured to, after rotation of the rotary bend die 118 to the nominal die angle 152, cause positioning of the linear carriage assembly 126 relative to the die-set 112 to facilitate bending of the tube 102 for compensating for spring back. For example, the linear carriage assembly 126 may be positioned at a zero position. In some embodiments, the data is indicative of the leading angle 154 and the trailing angle 156 after positioning the linear carriage assembly 126 relative to the die-set 112.

[0140] In some embodiments, the controller 128 may be configured to receive data indicative of a pivot angle 142 between the linear carriage assembly 126 and the die-set 112. The pivot angle 142 may be indicative of the rotation of the linear carriage assembly 126 relative to the die-set 112 and/or table 140 in an angular direction. For example, pivot angle 142 may be determined by the rotation sensor 148. After rotation of the rotary bend die 118 to the nominal die angle 152, the controller 128 may cause positioning of the linear carriage assembly 126 relative to the die-set 112 in response to the data indicative of the pivot angle 142 to facilitate accurate bending of the tube 102 for compensating for spring back. For example, the controller 128 may cause the linear carriage assembly 126 to pivot back to its original position, i.e. cause the linear carriage assembly 126 to rotate by the pivot angle 142 in a reverse angular direction.

[0141] FIG. 7A is a schematic plan view of a rotary draw machine 100 in a first stage of operation, in accordance with an embodiment.

[0142] In the first stage of operation the tube 102 is loaded in the chuck 130, the counter die 120 is open or positioned away from the tube 102, and the leading and trailing rotation sensors 144, 146 are not in contact with the tube 102.

[0143] FIG. 7B is a schematic plan view of a rotary draw machine 100 in a second stage of operation, in accordance with an embodiment.

[0144] In the second stage of operation, the tube 102 is positioned so that the start of the first bend (the bend location 110) is lined up in the die, the linear carriage assembly 126 is positioned to a centre position (e.g. positioned so that the tube 102 is in alignment with the counter die 120 and is tangent to the rotary bend die 118), and the leading and trailing rotation sensors 144, 146 are positioned in contact with the tube 102, and the counter die 120 is closed. When the counter die 120 is closed, the tube 102 is clamped between the rotary bend die 118 and the counter die 120. Panels 172 of the leading and trailing rotation sensors 144, 146 may be positioned to contact the tube 102.

[0145] FIG. 7C is a schematic plan view of a rotary draw machine 100 in a third stage of operation, in accordance with an embodiment.

[0146] In the third stage of operation, the tube 102 is bent to an approximate target bend angle by rotation of the rotary bend die 118 to the nominal die angle 152. In this stage of operation, the linear carriage assembly 126 is rotated about die-set 112 and/or table 140 by the bend die force. During the third stage of operation, the leading and trailing rotation sensors 144, 146 remain in contact with the tube 102.

[0147] For example, the approximate target bend angle, the nominal die angle 152 and/or parameters relating to such quantities may be displayed to a user on a graphical user interface.

[0148] For example, in FIG. 7C, the tube 102 is shown bent to an initial target bend angle of 45 degrees.

[0149] FIG. 7D is a schematic plan view of a rotary draw machine 100 in a fourth stage of operation, in accordance with an embodiment.

[0150] The fourth stage of operation may involve retraction to measure the bend angle.

[0151] In the fourth stage of operation, the linear carriage assembly 126 may be moved to zero/straight position. The rotary bend die 118 may be rotated back until the hook-arm 122 loses contact with the tube 102. For example, loss of contact (disengagement) of the tube 102 from the hook-arm 122 (and/or the rotary bend die 118) may be determined by the controller based on data received from the encoder.

[0152] After the rotary bend die 118 is retracted, the bend angle may be determined or estimated based on data, indicative of the leading and trailing angles 154, 156, received by the controller 128. In the example shown in FIG. 7D, the bend angle is about 40 degrees. For example, a resulting spring back may be about 5 degrees.

[0153] For example, the measured bend angle and/or parameters thereof may be displayed to a user on a graphical user interface.

[0154] FIG. 7E is a schematic plan view of a rotary draw machine 100 in a fifth stage of operation, in accordance with an embodiment.

[0155] The fifth stage of operation may be a compensation stage of operation.

[0156] In the fifth stage of operation, the rotary bend die 118 is rotated to bend the tube 102 to compensate for spring back. The controller 128 may cause the rotary bend die 118 to rotate to a predetermined angle (the correction die angle 150) to compensate for spring back. As described previously, the correction die angle 150 may be based on a bend angle, e.g. as determined the measured angles in the fourth stage of operation illustrated in FIG. 7D. As the rotary bend die 118 is rotated, the linear carriage assembly 126 may be pushed by the bend force and the leading and trailing rotation sensors 144, 146 may maintain contact with the tube 102.

[0157] For example, the compensatory bend angle and/or parameters thereof may be displayed to a user on a graphical user interface.

[0158] FIG. 7F is a schematic plan view of a rotary draw machine 100 in a sixth stage of operation, in accordance with an embodiment.

[0159] In the sixth stage of operation, the bend angle of the tube 102 may be measured after the compensatory bend. The linear carriage assembly 126 may be moved (pivoted) back to a zero/straight position. The rotary bend die 118 may be retracted. For example, the rotary bend die 118 may be retractingly rotated only or at least until the tube 102 has finished springing back. In various embodiments, the rotary bend die 118 may be retractingly rotated until the leading rotation sensor 144 starts registering rotation, e.g. until the panel 172 of an encoder of the leading rotation sensor 144 starts rotating/moving. For example, that the leading rotation sensor 144 is not registering rotation may imply that the hook-arm 122 is pushing on the tube 102, which may be the case until the tube 102 stops springing back. The bend angle may then be measured based on rotations registered (or recorded) by the leading and trailing rotation sensors 144, 146. For example, the controller 128 may determine the bend angle.

[0160] For example, the resulting bend angle and/or parameters thereof may be displayed to a user on a graphical user interface.

[0161] For example, the bend angle shown in FIG. 7F is approximately 45 degrees, which may be substantially equal to the target bend angle.

[0162] In some embodiments, the tube 102 may be overbent. The measured angle of the bend may exceed the target bend angle such that additional bends by the same rotary bend die 118 would not bring the bend closer to the target bend. When the measured angle of the bend exceeds the target bend angle, the controller 128 may terminate further bending and alert the user. For example, the controller 128 may transmit a signal to a graphical user interface to generate a visual alert to the user to remove the tube 102.

[0163] FIG. 7G is a schematic plan view of a rotary draw machine 100 in a seventh stage of operation, in accordance with an embodiment.

[0164] The seventh stage operation may be a termination stage of operation. The counter die 120 may be moved away from the tube 102 to release the tube 102. The linear carriage assembly 126 may be positioned to release the tube 102 from the rotary bend die 118. For example, the linear carriage assembly 126 may be rotated to release the tube 102 from the rotary bend die 118.

[0165] If an additional bend is required, the chuck 130 may move to the starting position of the next position and rotate to achieve the orientation of the next bend, and the linear carriage assembly 126 would move to the zero/straight/centre positioned so as to be ready for the next bend. Alternatively, if no additional bends are required, the tube 102 may be removed from the chuck 130.

[0166] It is understood that several cycles of measuring and bending, as described in relation to the stages illustrated above, may be achieved before a bend is complete. In various embodiments, measuring and bending may be achieved automatically or fully automatically by means of the controller 128, and various sensors, as described above. For example, in some embodiments, steps may automatically be taken to achieve a high accuracy bend, without user intervention, once the tube 102 is loaded into the rotary draw machine 100 and the parameters of the desired or target bend are provided to the controller 128. For example, parameters of the desired or target bend may be provided by means of a graphical user interface, which generates signals, indicative of the desired or target bend (and parameters thereof), that are then received by the controller 128.

[0167] It is understood that during the bending operations described above, whenever a bend angle is measured that exceeds the target bend angle such that the bend angle may not be brought closer to the target bend angle by further bending of the tube 102, the rotary draw machine 100 may terminate bending operations and alert the user, e.g. via the graphical user interface. For example, the rotary draw machine 100 may move the counter die 120 away from the tube 102, retract the rotary bend die 118, and/or configure other components of the rotary draw machine 100 so as to allow release of the tube 102 from the rotary draw machine 100.

[0168] FIG. 8A is a side elevation view of a (leading) rotary encoder assembly 164 that is mountable on an arm of a rotary bend die 118, in accordance with an embodiment.

[0169] FIG. 8B is a perspective view of a rotary encoder assembly 164 that is mountable on an arm of a rotary bend die 118, in accordance with an embodiment.

[0170] FIG. 8C is a front elevation view of a rotary encoder assembly 164 that is mountable on an arm of a rotary bend die 118, in accordance with an embodiment.

[0171] FIG. 9A is a side elevation view of a (trailing) rotary encoder assembly 166 that is mountable on a table 140 supporting a rotary bend die 118, in accordance with an embodiment.

[0172] FIG. 9B is a perspective view of a rotary encoder assembly 166 that is mountable on a table 140 supporting a rotary bend die 118, in accordance with an embodiment.

[0173] FIG. 9C is a front elevation view of a rotary encoder assembly 166 that is mountable on a table 140 supporting a rotary bend die 118, in accordance with an embodiment.

[0174] Referring to FIGS. 8A-8C, 9A-9C, the rotary encoder assemblies 164, 166 may each include a corresponding rotary encoder 170 coupled to a corresponding panel 172 via a corresponding shaft 174. Each of the rotary encoders 170 and the panels 172 are mounted on to a respective holder, which includes a corresponding carriage assembly. Each carriage assembly defines a corresponding rail and a carriage to allow slidable engagement therebetween to allow sliding of the rotary encoder 170 (and panel). Each holder includes a corresponding plate that is sandwiched between a rotary encoder 170 and a panel 172. Each plate defines an aperture or opening for receiving the shaft 174 coupling the rotary encoder 170 and the panel 172.

[0175] One or more motors may be coupled to the rail(s) and carriage(s) to allow motorized sliding engagement. Such one or more motors may be coupled to the controller 128 to allow selective sliding of the rotary encoder 170 along sliding direction(s).

[0176] Referring to FIGS. 8A-8C, the holder may define a C-shaped clamp and/or cup for engaging with the die-set 112. The C-shaped clamped extends outwardly from one side of the holder to form a receiving portion to receive the hook-arm 122.

[0177] Referring to FIGS. 9A-9C, the holder may extend laterally away from the rail and carriage (lateral to a sliding direction of the rotary encoder 170) to space the rotary encoder 170 away from the rail and carriage. The holder include may include a plurality of openings to allow for coupling with the table 140 and/or the die-set 112.

[0178] FIG. 10 is a schematic block diagram of a controller 128 of a rotary draw machine 100, in accordance with an embodiment.

[0179] A nominal bend angle module 1020 of the controller 128 may receive an input 1010. The input 1010 may be data indicative of a target bend angle 1006, a threshold 1008, and/or other desired bend properties. In various embodiments, the data may be received via a graphical user interface, or other input device. For example, a user may specify the target bend angle 1006 and/or threshold 1008 using an input device so as to cause the nominal bend angle module 1020 receives the same.

[0180] The nominal bend angle module 1020 may determine a nominal bend angle based on the target bend angle. In some embodiments, the nominal bend angle is the same as the target bend angle. In some embodiments, the nominal bend angle may be smaller than or larger than the target bend angle. In various embodiments, the nominal bend angle may be based on multiplying the target bend angle by a multiplicative compensation factor and/or by augmenting the target bend angle by an additive compensation factor. The nominal bend angle may be an angle suitable for achieving the target bend angle or bringing a tube bend closer to the target bend angle. In some embodiments, the nominal bend angle may be at least partially determined based on how many times, and/or how many angular degrees, the tube 102 has already been bent at the bend location 110.

[0181] A nominal die angle module 1030 receives the nominal bend angle from the nominal bend angle module 1020. The nominal die angle module 1030 may generate a nominal die angle 152 based on the nominal bend angle. In some embodiments, the nominal die angle 152 is the same as nominal bend angle.

[0182] A rotary die actuator 1040 receives the nominal die angle 152 from the nominal die angle module 1030. The rotary die actuator 1040 causes rotation of the rotary bend die 118 to achieve the nominal die angle 152. The rotary die actuator 1040 is connected in feedback to allow the rotary bend die 118 to rotated to an angle equal to the nominal die angle 152 so as to bend the tube 102.

[0183] The nominal bend angle module 1020 and a retraction angle module 1060 may detect when the rotary bend die 118 has rotated to the nominal die angle 152 based on a residual between the nominal die angle 152 and a rotary die actuator angle (provided the rotary die actuator 1040).

[0184] In some embodiments, a differentiator 1050 may receive data indicative of the leading angle 154 from the leading rotation sensor 144 (leading sensor 1070). The retraction angle module 1060 may receive data indicative of the rate of change of the leading angle 154 from the leading sensor 1070.

[0185] Once the nominal die angle 152 is achieved (the residual is zero, near zero, and/or below a predetermined threshold, e.g. threshold 1008), the retraction angle module 1060 may supply a retraction angle (e.g. an incremental retraction angle) to the nominal die angle module to cause the rotary die actuator 1040 to retract the rotary bend die 118 while the rate of change of the leading angle 154 is zero, or below a predetermined threshold, e.g. threshold 1008. For example, while the tube 102 is springing back in commensurate response to the retracting rotary bend die 118, the numerical output of the differentiator 1050 may remain substantially equal to zero to the extent that the rate of retraction of the rotary bend die 118 does not substantially exceed the maximum rate of spring back of the tube 102, and may be substantially non-zero, or above a predetermined threshold, e.g. threshold 1008, when the tube 102 stops springing back in response to a continuing retraction of the rotary bend die 118. Such predetermined thresholds may be based on the accuracy, precision, and/or sensitivity of the rotation sensors being used. For example, the rotary bend die 118 may be stopped from rotating when the tube 102 stops springing back, e.g. as indicated by a substantially non-zero rotation registered at the leading rotation sensor 144. For example, the retraction angle module 1060 may keep causing, via the nominal die angle 1030, the rotary die actuator 1040 to retractingly rotate the rotary bend die 118 by incremental values until the differentiator registers a rate of change of the leading angle 154 that is indicative of stopping of spring back of the tube 102.

[0186] In some embodiments, a comparator may be used instead of the differentiator 1050. For example, the comparator may indicate when the leading angle 154 changes, such change indicating the stopping of springing back of the tube 102.

[0187] Once the retraction angle module 1060 stops causing retraction of the rotary die actuator, the nominal bend angle module 1020 may receive data indicative of a new or second nominal bend angle. The second nominal bend angle may be based on a sum of the die angle after retraction and the difference between the leading angle 154, from the leading sensor 1070, and the trailing angle 156, from a trailing sensor 1080 (trailing rotation sensor 146).

[0188] The nominal die angle module 1030 then receives the (new or second) nominal bend angle from the nominal bend angle module 1020. The nominal die angle module 1030 specifies a new or second nominal die angle for the rotary die actuator 1040. In some embodiments, the new or second nominal die angle may adjust the second nominal bend angle based on a (multiplicative or additive) compensation factor.

[0189] For example, the target bend angle may be 45 degrees, the first nominal die angle may be 45 degrees based on an additive compensation of zero degrees, and the retraction angle 158 may be 5 degrees, i.e. the rotary bend die 118 is at 40 degrees after retraction. The difference between the leading angle 154 and the trailing angle 156 may be 8.77 degrees. In some embodiments, the second nominal bend angle may then be equal to the sum of the die angle after retraction and the difference between the leading angle 154 and the trailing angle 156, i.e. 48.77 degrees. In some embodiments, the second nominal bend angle may be greater than the first nominal bend angle. In some embodiments, the second nominal die angle may be the second nominal bend angle adjusted based on a comparison with the target bend angle. In some embodiments, the second nominal die angle may be the same as the second nominal bend angle.

[0190] In an example bending process, to achieve a target bend angle of 45 degree, the first nominal bend angle was set to 45 degrees. After completion of the first bending operation and subsequent spring back of the tube, the bend angle achieved was found to be 39.2 degrees. The second nominal bend angle was then set to 48.77 degrees. After completion of the second bending operation and subsequent spring back of the tube, the bend angle achieved was found to be 43.724 degrees. The third nominal bend angle was then set to 49.5994 degrees. After completion of the third bending operation and subsequent spring back of the tube, the bend angle achieved was found to be 44.71928 degrees. The bending process was then stopped as the desired bend accuracy was achieved. It is understood that the bending process could be continued to achieved greater accuracy.

[0191] As an example, for the first bending operation discussed above, the retraction angle .sub.ret was 6.3 degrees, the leading angle .sub.lead was 0.5 degrees and the trailing angle .sub.trait was 0.027 degrees. In the first bending operation, the spring back of the first bend is the difference between the first nominal bend angle and the first achieved bend angle, i.e. 45 degrees39.2 degrees=5.8 degrees. The retraction angle .sub.ret of 6.3 degrees is greater than the spring back angle of 5.8 degrees by 0.5 degrees since the rotary bend die 118 is rotated so as to release the tube 102 and allow detection of the same by the leading rotation sensor 144. As an example, for the second bending operation discussed above, the retraction angle .sub.ret was 5.546 degrees, the leading angle .sub.lead was 0.5 degrees and the trailing angle .sub.trail was 0.031. Similarly, in the first bending operation, the spring back of the second bend is the difference between the second nominal bend angle and the second achieved bend angle, i.e. 48.77 degrees43.724 degrees=5.046 degrees. The retraction angle .sub.ret of 5.546 degrees is greater than the spring back angle of 5.046 degrees by 0.5 degrees since the rotary bend die 118 is rotated so as to release the tube 102 and allow detection of the same by the leading rotation sensor 144. The trailing angle 156 may be random and may vary for every bend.

[0192] After the rotary die actuator 1040 causes a second bending rotation of the rotary bend die 118, the process is repeated. In this manner, the bend is brought closer to the target bend via successive bends. The repeating bending processes described above may be stopped when spring back is sufficiently small, e.g. as measured by the difference between the leading angle 154 and trailing angle 156, and/or when the bend is sufficiently closed to the target bend, e.g. as measured by the angle of the rotary bend die 118 when retracted to the point of no spring back.

[0193] Repeated bending to achieve the target bend angle allows for successively smaller bending operations, which necessarily limits the amount of spring back possible on successive bending operations. As such, repeated bends allow the spring back to be pushed below a predetermined threshold, e.g. threshold 1008.

[0194] FIG. 11 is a schematic flow chart of a method 1100 for operating a rotary draw machine 100, in accordance with an embodiment.

[0195] For example, the controller 128 may be operably coupled to the die-set, and connected to the first and second rotation sensors 144, 146, so as to cause execution of the method 1100.

[0196] Step 1102 of the method 1100 may include causing rotation of the rotary bend die 118 to a first die angle associated with the target bend angle to bend the tube 102 at the bend location.

[0197] Step 1104 of the method 1100 may include causing release of the tube 102 from the die-set to allow spring back of the tube 102,

[0198] Step 1106 of the method 1100 may include receiving data indicative of a leading angle 154 of the leading tangent 114 from the first rotation sensor, after spring back of the tube 102, and a trailing angle 156 of the trailing tangent 116 from the second rotation sensor.

[0199] Step 1108 of the method 1100 may include causing rotation of the rotary bend die 118, in response to the data, to a second die angle to bend the tube 102 to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle 154, and the trailing angle 156.

[0200] In some embodiments of the method 1100, the second die angle may be indicative of the first die angle augmented with a spring back angle, and the controller 128 may be further configured to determine the spring back angle based on at least a difference between the leading angle 154 and the trailing angle 156.

[0201] In some embodiments of the method 1100, the controller 128 may be configured to cause release of the tube 102 from the die-set to allow spring back of the tube 102 by rotating the rotary bend die 118 by a retraction angle 158 to retract the tube 102 to disengage the tube 102 from the rotary bend die 118, the second die angle being based on the first die angle, the retraction angle 158, the leading angle 154, and the trailing angle 156.

[0202] In some embodiments of the method 1100, the linear carriage assembly 126 may be actuatably pivoted to the die-set and operably coupled to the controller 128, and the controller 128 may be configured to, after rotation of the rotary bend die 118 to the first die angle, cause positioning of the linear carriage assembly 126 relative to the die-set to facilitate accurate bending of the tube 102 for compensating for (or to at least partially compensate for) spring back. Some embodiments of the method 1100, may include positioning or repositioning the linear carriage assembly 126 to a zero position or to a position of the linear carriage assembly 126 at the start of the initial bend.

[0203] In some embodiments of the method 1100, the data may be indicative of the leading angle 154 and the trailing angle 156 after positioning the linear carriage assembly 126 relative to the die-set.

[0204] Some embodiments of the method 1100 may include a third rotation sensor 148 configured to sense rotation of the linear carriage assembly 126 relative to the die-set and connected to the die-set, and the linear carriage assembly 126 is actuatably pivoted to the die-set and operably coupled to the controller 128, and the data is a first data. In some embodiments of the method 1100, the controller 128 may be further configured to receive second data indicative of a pivot angle 142 between the linear carriage assembly 126 and the die-set, and, after rotation of the rotary bend die 118 to the first die angle, cause positioning of the linear carriage assembly 126 relative to the die-set in response to the second data to facilitate bending of the tube 102 for compensating for spring back.

[0205] In some embodiments of the method 1100, the linear carriage assembly 126 may be actuatable to translate the tube 102 along the linear carriage assembly 126, and the controller 128 may be further configured to cause translation of the tube 102 along the linear carriage assembly 126 to feed the tube 102 to the die-set.

[0206] In some embodiments of the method 1100, the controller 128 may be further configured to determine if spring back of the tube 102 has ended (and/or occurred) based on data received from the first rotation sensor, as described earlier.

[0207] FIG. 12 is a schematic flow chart of a method 1200 for bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, in accordance with an embodiment.

[0208] Step 1202 of the method 1200 may include causing rotation of a rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location.

[0209] Step 1204 of the method 1200 may include causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube.

[0210] Step 1206 of the method 1200 may include, after causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube, receiving data indicative of a leading angle, indicative of rotation of the tube at the leading tangent, and a trailing angle, indicative of rotation of the tube at the trailing tangent.

[0211] Step 1208 of the method 1200 may include causing rotation of the rotary bend die to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.

[0212] In some embodiments of the method 1200, step 1206 may include receiving the data from at least one rotary encoder defining a shaft drivably coupled to the tube.

[0213] In some embodiments of the method 1200, the leading angle may be indicative of rotation of the tube at the leading tangent relative to rotation of the rotary bend die, and the second die angle may be indicative of the first die angle augmented with a spring back angle. Some embodiments of the method 1200 may further include a step of determining the spring back angle based on at least a difference between the leading angle and the trailing angle.

[0214] In some embodiments of the method 1200, the data may be indicative of the leading angle and the trailing angle after positioning the linear carriage assembly relative to a die-set of the rotary bend die.

[0215] In some embodiments of the method 1200, the rotary bend die may be part of a die-set, and a linear carriage assembly may be actuatably pivotably coupled to the die-set to support the tube and feed the tube to the die-set via the leading tangent.

[0216] Some embodiments of the method 1200 may include a step of, after causing rotation of the rotary bend die to the first die angle, causing positioning of the linear carriage assembly relative to the die-set to facilitate bending of the tube for compensating for spring back.

[0217] In some embodiments of the method 1200, the data may be a first data. Some embodiments of the method 1200 may include a step of receiving second data indicative of a pivot angle between the linear carriage assembly and the die-set, wherein causing positioning of the linear carriage assembly relative to the die-set is in response to the second data.

[0218] In some embodiments of the method 1200, the linear carriage assembly may be actuatable to translate the tube along the linear carriage assembly. Some embodiments of the method 1200 may include a step of causing translation of the tube along the linear carriage assembly to feed the tube to the die-set.

[0219] Some embodiments of the method 1200 may include a step of determining if spring back of the tube has ended (and/or occurred) based on data received from the first rotation sensor, as described earlier.

[0220] FIG. 13 illustrates a block diagram of a computing device 1300, in accordance with an embodiment of the present application.

[0221] As an example, the controller, a graphical user interface, the system illustrated in FIG. 10, and/or other related systems, computing devices, servers, and/or client devices may be implemented using the example computing device 1300 of FIG. 13.

[0222] The computing device 1300 may include at least one processor 1302, memory 1304, one or more I/O interfaces 1306, and one or more network communication interfaces 1308.

[0223] In various embodiments, the processor 1302 may be a microprocessor or microcontroller, a digital signal processing (DSP) processor, an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, a programmable read-only memory (PROM), or combinations thereof.

[0224] The memory 1304 may include a computer memory that is located either internally or externally such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM).

[0225] The I/O interface 1306 may enable the computing device 1300 to interconnect with one or more input devices, such as a keyboard, mouse, camera, touch screen and a microphone, or with one or more output devices such as a display screen and a speaker.

[0226] The networking interface 1308 may be configured to receive and transmit data sets, for example, to a target data storage or data structures. The target data storage or data structure may, in some embodiments, reside on a computing device or system such as a mobile device.

[0227] A system of one or more computers, or computing devices, may be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs, or computing devices, may be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

[0228] As can be understood, the examples described above and illustrated are intended to be exemplary only.

[0229] The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. For example, while various motors are described herein to actuate parts of rotary draw machine, it is understood that, in some embodiments, one or more (or all) of such motors may be substituted or augmented with non-motor actuating means. Yet further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.