Device for imparting a torsional force onto a wire

Abstract

A device for imparting a torsional force onto a wire has a base and a support mounted so as to be rotatable with respect to the base around an axis of rotation. The axis of rotation coincides with a wire path extending through the base and the support. Further, a wire clutching device is mounted on the support and adapted to engage at a wire guided along the wire path, and a rotation mechanism is provided which is adapted for rotating the support with respect to the base.

Claims

1. A device for imparting a torsional force onto a wire, having a base, a support mounted so as to be rotatable with respect to the base around an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support, a wire clutching device mounted on the support and adapted to engage at a wire guided along the wire path, and a rotation mechanism which is adapted for rotating the support with respect to the base.

2. The device of claim 1 wherein the wire clutching device is a pair of rolls which are mounted on the support, the rolls being arranged on opposite sides of the wire path, at least one of the rolls having a wire reception groove.

3. The device of claim 2 wherein a biasing device is provided for biasing the two rolls against each other.

4. The device of claim 1 wherein the rotation mechanism comprises a gear adapted for converting a movement of the wire along the wire path into a rotation of the support with respect to the base.

5. The device of claim 4 wherein the gear is a bevel gear with a ring gear connected to the base and a pinion mounted rotatably on the support.

6. The device of claim 5 wherein two mounting positions for the pinion are provided on the support.

7. The device of claim 6 wherein a motor current sensor is provided.

8. The device of claim 4 wherein the gear is a worm drive.

9. The device of claim 4 wherein an intermediate gear wheel is provided which is mounted in a sliding guide.

10. The device of claim 4 wherein a torque limiter is associated with the rotation mechanism.

11. The device of claim 1 wherein the rotation mechanism comprises a drive motor mounted on the base and adapted for rotating the support with respect to the base.

12. The device of claim 11 wherein a coupling device is provided for connecting the motor to the support.

13. The device of claim 12 wherein the coupling comprises an application device for urging a drive wheel connected to the drive motor, against a driven surface associated with the support.

14. A system with a container in which an amount of wire is contained in the form of a coil consisting of a plurality of loops of wire, a device for imparting a torsional force onto a wire, the device being mounted above the wire, the device having a base, a support mounted so as to be rotatable with respect to the base around an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support, a pair of rolls which are mounted on the support, the rolls being arranged on opposite sides of the wire path, at least one of the rolls having a wire reception groove, and a rotation mechanism which is adapted for rotating the support with respect to the base, the system further comprising at least one wire feeder which is arranged downstream of the device for imparting a torsional force onto the wire.

15. The system of claim 14 wherein a retainer is arranged on the coil of wire.

16. The system of claim 15 wherein the wire feeder arranged downstream of the device for imparting a rotation onto the wire is an auxiliary wire feeder, and wherein a main wire feeder is provided downstream of the auxiliary wire feeder.

17. A system with a container in which an amount of wire is contained in the form of a coil consisting of a plurality of loops of wire, a device for imparting a torsional force onto a wire, the device being mounted above the wire, the device having a base, a support mounted so as to be rotatable with respect to the base around an axis of rotation, the axis of rotation coinciding with a wire path extending through the base and the support, a pair of rolls which are mounted on the support, the rolls being arranged on opposite sides of the wire path, at least one of the rolls having a wire reception groove, and a rotation mechanism which is adapted for rotating the support with respect to the base, the rotation mechanism comprising a drive motor for rotating the support with respect to the base, the system further comprising at least one wire feeder which is arranged downstream of the device for imparting a torsional force onto the wire, and a control for controlling the speed of rotation of the drive motor of the rotation mechanism, the control comprising a torque detection for limiting the torsional force applied on the wire.

18. The system of claim 17 wherein the wire is a welding wire from an aluminum alloy comprising magnesium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings,

(2) FIG. 1 shows a cross section of a container containing a wire coil,

(3) FIG. 2 shows a perspective view of the container of FIG. 1,

(4) FIG. 3 shows the container of FIG. 1 with entangled wires,

(5) FIG. 4 shows a system according to the invention in a side view,

(6) FIG. 5 shows a container provided with a device for imparting a torsional force onto the wire according to the invention,

(7) FIG. 6 shows a first embodiment of the device for imparting a torsional force onto a wire in an exploded view,

(8) FIG. 7 shows a perspective view of the device shown in FIG. 6,

(9) FIG. 8 shows a top view of the device of FIG. 6,

(10) FIG. 9 shows a second embodiment of the device for imparting a torsional force onto a wire in an exploded view,

(11) FIG. 10 shows the device of FIG. 9 in a perspective view,

(12) FIG. 11 shows the device of FIG. 9 in a side view,

(13) FIG. 12 shown the device of FIG. 9 in a top view,

(14) FIGS. 13a) through f) show different gear drives,

(15) FIG. 14 shows a third embodiment of the device for imparting a torsional force onto a wire in an exploded view,

(16) FIG. 15 shows the device of FIG. 14 in a perspective view,

(17) FIG. 16 shows the device of FIG. 14 in a side view,

(18) FIG. 17 shown the device of FIG. 14 in a top view,

(19) FIG. 18 shows a fourth embodiment of the device for imparting a torsional force onto a wire in an exploded view,

(20) FIG. 19 shows a side view of the device of FIG. 18,

(21) FIG. 20 shows a perspective view of the device of FIG. 18, and

(22) FIG. 21 shows a side view of an alternative of the device of FIG. 18.

(23) In FIG. 1, a container 1 is shown in which a large quantity of wire 2 is contained in the form of a coil 3. Coil 3 consists of a plurality of loops formed from the wire 2.

(24) Wire 2 can be a welding wire. It can also be any consumable wire which is used for 3D printing, for metallization, etc.

(25) Wire 2 is withdrawn from container 1 through an upper opening of the container. A cover or a dome 4 can be placed on top of the container 1, with the main purpose of dome 4 being to prevent contamination of the interior of container 1 during the time period when the wire is being consumed.

(26) In order to prevent loops of wire from falling into the interior of coil 3, a retainer 5 is placed on the upper surface of coil 3. The main purpose of retainer 5 is to exert a braking force onto the wire and to create friction with its weight.

(27) As can be seen in FIG. 3, it might occur that some loops of the wire fall into the interior of coil 3 despite the presence of the retainer. Should the loops entangle, the wire can no longer be withdrawn from container 1.

(28) FIG. 4 shows a system according to the invention, which prevents loops from falling into the interior of coil 3 and from becoming entangled.

(29) An important element of the invention is a device 10 for imparting a torsional force onto the wire 2. Generally speaking, device 10 rotates the wire around its own axis, thereby offsetting some of the residual stress in the wire and also ensuring that the loops of wire remain in their position within container 1.

(30) Downstream of device 10, a wire feeder 6 can be arranged which advances the wire into a wire guide 7 and towards the place where the wire is being consumed, for example to a welding robot. A main wire feeder can be used close to the welding robot so that wire feeder 6 is an auxiliary wire feeder.

(31) Device 10 is arranged close to container 1. In the embodiment shown, device 10 is placed on dome 4 (please see in particular FIG. 5).

(32) In FIGS. 6 to 8, a first embodiment of device 10 for imparting a torsional force onto the wire will be explained.

(33) Device 10 comprises a base 12 and a support 14. Support 14 is mounted so as to be rotatable with respect to base 12 around an axis 16 which coincides with a wire path along which wire 2 is guided through device 10. A wire inlet guide 15 is attached to support 14.

(34) A roller bearing 18 is used for mounting support 14 on base 12.

(35) A wire clutching device 20 is mounted on support 14. It here consists of two rolls 22 arranged on opposite sides of wire path 16, with both rolls 22 each having a wire reception groove 24.

(36) Wire reception grooves 24 have a width and depth adapted to the dimension of the particular wire so as to tightly engage the wire. When wire feeder 6 withdraws the wire from the container, the wire passes through the wire pass 16 between the two adjacent rolls 22, with rolls 22 being entrained or rotated by the wire.

(37) Device 10 further comprises a rotation mechanism 26 which is adapted for rotating the support with respect to the base. Rotation mechanism 26 is here formed from a gear, in particular a bevel gear 28, which comprises a ring gear 30 fixedly provided on base 12, and a pinion 32 which is mounted on support 14.

(38) Pinion 32 is connected via a gear drive 34 to one of rolls 22. Thus, when the rolls 22 are entrained by the wire, rotation of the rolls is transmitted via the gears to pinion 32, which engages into ring gear 30. Accordingly, support 14 is rotated with respect to base 12 when the wire is drawn through device 10.

(39) As rolls 22 tightly engage the wire, rotation of support 14 and accordingly of wire clutching device 22 imparts a torsional force onto the wire.

(40) The amount of torsional force to be applied onto the wire largely depends from characteristics of the wire. For some wires, it has been found out that applying 1.5 revolutions of wire clutching device 20 per loop of withdrawn wire provides good results. The ratio of revolutions per length of withdrawn wire can be adapted by selecting the size of rolls 22 and the transmission ratio of rotation mechanism 26.

(41) It has been found out that wire clutching device 20 should rotate in the same direction in which the withdrawn wire rotates within container 1. As an example, when looking into container 1 from the top and the wire is withdrawn in a clockwise direction, wire clutching device 20 should also rotate in a clockwise direction.

(42) In order to be able to adapt device 10 to both possible winding directions of the coil in container 1, two amounting positions for pinion 32 are possible. As can be seen in FIG. 8, a mounting position 36 is provided for mounting pinion 32 on the opposite side, thereby changing the direction of rotation.

(43) In order to prevent excessive torsional force from being applied to the wire, a torque limiter can be provided somewhere in the rotation mechanism 20. The torque limiter could be formed by spring-loaded friction disks or a similar mechanism.

(44) A second embodiment of device 10 is shown in FIGS. 9 to 12. For the components known from the first embodiment, the same reference numerals are being used, and reference is made to the above comments.

(45) The general difference between the first and the second embodiment is that in the second embodiment, the rotation mechanism 26 comprises a worm drive 29, formed from a worm gear 31 fixedly provided on base 12, and a screw gear 33 mounted on support 14.

(46) Screw gear 33 is connected via gear drive 34 to one of rolls 22. Thus, when the rolls 22 are entrained by the wire, rotation of the rolls is transmitted via the gears to screw gear 33 which engages into worm gear 31 and, when being rotated, rotates support 14 with respect to base 12.

(47) In a manner similar to the first embodiment, the sense of rotation can be reversed by mounting gear drive 34 on the opposite side of support 14.

(48) It is also possible to exchange gear drive 34 by an electric motor so as to be able to rotate support 14 with respect to base 12 independent from a fixed transmission ratio of wire pay out vs. rotation of the support.

(49) The second embodiment allows to conveniently change the transmission ratio from rolls 22 to screw gear 33, as will be explained in the following with reference to FIG. 13.

(50) In FIG. 13a, a small diameter container 1 with a small diameter coil 3 is shown. For converting the rotation of rolls 22 into a suitable rotation of screw gear 33, a large gear wheel 34a (please see FIG. 13b) is mounted on the axis on which roll 22 is mounted, with gear wheel 34a driving via an intermediate gear 34b a small gear wheel 34c drivingly connected to screw gear 33.

(51) In FIG. 13c, a medium diameter container 1 with a medium diameter coil 3 is shown. For converting the rotation of rolls 22 into a smaller rotation of screw gear 33 (per length unit of withdrawn wire), a medium gear wheel 34a (please see FIG. 13d) is mounted on the axis on which roll 22 is mounted, with gear wheel 34a driving via an intermediate gear 34b a medium gear wheel 34c drivingly connected to screw gear 33.

(52) In FIG. 13e, a large diameter container 1 with a large diameter coil 3 is shown. For converting the rotation of rolls 22 into an even smaller rotation of screw gear 33, a small gear wheel 34a (please see FIG. 13f) is mounted on the axis on which roll 22 is mounted, with gear wheel 34a driving via an intermediate gear 34b a large gear wheel 34c drivingly connected to screw gear 33.

(53) Intermediate gear 34b is mounted in a sliding guide 35 which allows to quickly adapt the gear ratio to different pack dimensions (and the corresponding loop diameter inside the pack).

(54) A dust cover 17 closes device 10 so as to prevent dust and dirt from entering into device 10 and container 1.

(55) A third embodiment of device 10 is shown in FIGS. 14 to 16. For the components known from the first and second embodiments, the same reference numerals are being used, and reference is made to the above comments.

(56) The general difference between the first and second embodiments and the third embodiment is that the first and second embodiments are “passive” devices in which the torsional force applied onto the wire is generated by the movement of the wire itself while in the second embodiment, the torsional force is actively generated by a motor.

(57) The third embodiment also uses a worm drive 29 formed from a worm gear 31 and a screw gear 33. Here, worm gear 31 is fixedly connected to support 14 while screw gear 33 is mounted on base 12.

(58) A motor 40 is provided for driving (via a suitable reduction gear) screw gear worm 33.

(59) Rolls 22 are mounted on support 14 so as to be rotatable. They are biased with an adjustable force against each other.

(60) In the third embodiment, device 10 is controlled by a control which can be incorporated into wire feeder 6. It is also possible to implement the control separately.

(61) When wire is withdrawn from container 1, electric motor 40 is operated so as to rotate wire clutching device 20 in the correct direction, thereby exerting a torsional force onto the wire.

(62) The amount of rotation of wire clutching device 20 per length unit of withdrawn wire can very conveniently be controlled via the control. In order to prevent that excessive torsional forces are exerted onto the wire, the motor current of motor 40 can be controlled. Should excessive torsional forces are being built up in the wire, the motor current increases as a higher force is required to rotate the wire. In such event, the speed of operation of motor 40 can be reduced or stopped, or it is possible to deactivate biasing device 46 so that support 14 can freely rotate, thereby releasing the torsional tension in the wire. Subsequently, biasing device 46 can be reactivated, and operation of motor 40 can be resumed.

(63) The advantage of the third embodiment is that many of its components can be used both for a passive device as per the second embodiment and for the active device as per the third embodiment.

(64) A fourth embodiment of device 10 is shown in FIGS. 17 to 20. For the components known from the previous embodiments, the same reference numerals are being used, and reference is made to the above comments.

(65) The general difference between the third embodiment and the fourth embodiment is that in the fourth embodiment, there is no intermeshing gear connection between the motor and the support (thus a positive connection) but a friction-based connection.

(66) Rotating mechanism 26 here comprises a drive motor 40 (an electric motor) which drives a drive wheel 42. Electric motor 40 together with drive wheel 42 are mounted on a carrier 44 which is pivotably connected to base 12.

(67) An application device 46 which is here in the form of a solenoid, is mounted on base 12 and is adapted for urging carrier 44 together with motor 40 and drive wheel 42 in a direction towards support 14. More specifically, application device 46 presses drive wheel 42 against a cylindrical driven surface 48 of support 14.

(68) Drive wheel 42 can be provided with an O-ring 50 or some other friction enhancing element in order to ensure that support 14 can be rotated by motor 40.

(69) Wire clutching device 20 of the fourth embodiment basically corresponds to the first embodiment in as it contains two rolls 22 which are urged against each other and against the wire passing through between the rolls. A biasing device 52 is here provided which allows changing the force with which the two rolls are pressed against each other.

(70) When wire is withdrawn from container 1, electric motor 40 is operated so as to rotate wire clutching device 20 in the correct direction, thereby exerting the desired torsional force onto the wire. At the same time, biasing device 46 is activated so as to ensure that the power of motor 40 is transmitted to support 14.

(71) In FIG. 21, an alternative to the embodiment of FIGS. 17 to 20 is shown. Here, drive wheel 42 is connected to support 14 via a belt or rubber ring 60, thereby avoiding the need for a biasing device.