MOTION IMPARTING LEG FOR ROCKING A BED

Abstract

A motion imparting leg for imparting an oscillating or reciprocating rectilinear motion to a bed for rocking the bed is provided. The motion imparting leg comprises a base, an upper member movable relative to the base for imparting the oscillating or reciprocating rectilinear motion, a linear shaft motor for driving movement of the upper member, a position sensor for determining the position of the linear shaft motor or the position of the upper member, and a motor controller for controlling the linear shaft motor based on data from the position sensor.

Claims

1. A motion imparting leg for imparting an oscillating or reciprocating rectilinear motion to a bed for rocking the bed, the motion imparting leg comprising: a base; an upper member movable relative to the base for imparting the oscillating or reciprocating rectilinear motion; a linear shaft motor for driving rectilinear movement of the upper member, the linear shaft motor comprising a fixed part and a moving part spaced apart from each other, the moving part being rectilinearly movable relative to the fixed part; a position sensor for determining a position of the linear shaft motor or a position of the upper member; and a motor controller for controlling the linear shaft motor based on data from the position sensor.

2. The motion imparting leg as claimed in claim 1, wherein the upper member is disposed above or attached to the linear shaft motor.

3. The motion imparting leg as claimed in claim 1, wherein a rectilinear travel path of the upper member extends along a length of the fixed part of the linear shaft motor.

4. The motion imparting leg as claimed in claim 1, wherein the upper member is adapted to be displaced in a horizontal plane for allowing rotation and translation of the upper member relative to the base.

5. The motion imparting leg as claimed in claim 4, wherein: the upper member includes flexible or resilient member for enabling displacement of the upper member; or the whole upper member is a flexible or resilient member.

6. The motion imparting leg as claimed in claim 1, further comprising a rectilinear motion assembly disposed between and coupled to the moving part of the linear shaft motor and the upper member.

7. The motion imparting leg as claimed in claim 6, wherein the flexible or resilient member is the part of the upper member coupled to the rectilinear motion assembly; a fastener is provided for securing the rectilinear motion assembly and the upper member together; or the rectilinear motion assembly includes a groove for receiving at least part of the moving part of the linear shaft motor.

8. The motion imparting leg as claimed in claim 6, wherein the rectilinear motion assembly comprises a carriage and linear slider assembly, the linear slider assembly including a first slider element connected to each side of the carriage and a second slider element connected to the base and disposed between the linear shaft motor and each first slider element.

9. The motion imparting leg as claimed in claim 8, wherein each first slider element is substantially T-shaped having a first member and a second member extending perpendicularly from a center of the first member, and wherein each second slider element is substantially U-shaped having two arms connected together, the second member of the first slider element being disposed between the arms of the second slider element.

10. The motion imparting leg as claimed in claim 6, wherein an arrangement of magnets or electromagnets is provided to the rectilinear motion assembly for supporting weight applied on the upper member and for maintaining the rectilinear movement of the rectilinear motion assembly.

11. The motion imparting leg as claimed in claim 10, wherein the rectilinear motion assembly comprises a carriage and linear slider assembly, the linear slider assembly including a first slider element connected to each side of the carriage and a second slider element connected to the base and disposed between the linear shaft motor and each first slider element, and, wherein at least one first carriage magnet and at least one second carriage magnet are provided to each first slider element, and at least one base magnet is provided to each second slider element.

12. The motion imparting leg as claimed in claim 11, wherein the at least one first carrier magnet is disposed to a lateral side of the at least one base magnet, and the at least one second carriage magnet is disposed above or below the at least one base magnet.

13. The motion imparting leg as claimed in claim 11, wherein the at least one first carriage magnet and the at least one second carrier magnet are spaced apart from the at least one base magnet.

14. The motion imparting leg as claimed in claim 1, wherein the position sensor is mounted under the linear shaft motor.

15. The motion imparting leg as claimed in claim 1, wherein the upper member of each motion imparting leg is removably coupled to a bed frame or leg of a bed, wherein the motion imparting legs are attached around the periphery of the bed frame.

16. A kit of parts comprising a plurality of motion imparting legs as claimed in claim 1.

17. The kit of parts as claimed in claim 16, further comprising a central control hub for connection to each motion imparting leg, the central control hub synchronising the rectilinear motion of the motion imparting legs.

18. A motion imparting device for imparting an oscillating or reciprocating rectilinear motion to an object, the motion imparting device comprising: a base; an upper member movable on a motion path relative to the base for imparting the oscillating or reciprocating rectilinear motion to the object; and a drive or guide structure positioned at least partially between the base and the upper member; wherein the upper member is displaceable in a horizontal plane independently of its movement along the motion path, allowing for at least one of rotation or translation of at least part of the upper member relative to the base and the drive or guide structure.

19. The motion imparting device as claimed in claim 18, wherein the upper member is displaced in the horizontal plane.

20. The motion imparting device as claimed in claim 18, wherein the upper member includes a flexible or resilient member for enabling displacement or stretching or twisting of the upper member in the horizontal plane; or the upper member comprises rubber or another elastomeric material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0100] FIG. 1 shows a perspective view of a first embodiment of a motion imparting leg according to the first aspect of the present disclosure;

[0101] FIG. 2 shows a perspective view of the motion imparting leg of FIG. 1 without a base;

[0102] FIG. 3 shows perspective view of the motion imparting leg of FIGS. 1 and 2 with a better view of its linear shaft motor;

[0103] FIG. 4 shows a cross-sectional view of the motion imparting leg of FIGS. 1 to 3;

[0104] FIG. 5 shows a perspective view of a second embodiment of the motion imparting leg according to the first aspect of the present disclosure;

[0105] FIG. 6 shows a perspective view of the motion imparting leg of FIG. 5 without a base;

[0106] FIG. 7 shows a perspective view of the motion imparting leg of FIGS. 5 and 6 with a better view of its linear shaft motor;

[0107] FIG. 8 shows a cross-sectional view of the motion imparting leg of FIGS. 5 to 7;

[0108] FIG. 9 shows a perspective view of an upper member and a top of a rectilinear motion assembly of the first and second embodiments; and

[0109] FIG. 10 shows a perspective view of the first and the second embodiments with a shroud attached.

DETAILED DESCRIPTION

[0110] A first embodiment of a motion imparting leg (or device) for imparting an oscillating or reciprocating rectilinear motion to a bed for rocking a bed is generally indicated at 10, as can be seen in FIGS. 1 to 4. A second embodiment of the motion imparting leg (or device) is generally indicated at 100, as can be seen in FIGS. 5 to 8. The same references will be used for similar features in both embodiments.

[0111] In the first and second embodiments, the motion imparting leg 10, 100 comprises a rectangular and planar base 12 and an upper member 14 movable relative to the base 12. In use, the base 12 is in contact with the floor and the upper member 14 is coupled to a bed frame or a leg of the bed for imparting the oscillating or reciprocating rectilinear motion to the bed.

[0112] A linear shaft motor 16 is provided above the base 12. The linear motor 16 comprises a fixed part 16a and a moving part 16b which rectilinearly slides along the fixed part 16a in direction A-A, indicated in FIGS. 2 and 6. The movement of the moving part 16b directly drives the rectilinear movement of the upper member 14. Therefore, there is no need for rotational movement of a motor to be translated into rectilinear movement to drive the movement of the upper member 14. This reduces the number of components required for the motion imparting leg 10, 100 and allows the design to be simpler and more compact than previous designs.

[0113] The linear shaft motor 16 can be more clearly seen in FIG. 3.

[0114] The fixed part 16a of the linear shaft motor 16 is a shaft which extends along the longitudinal length of the base 12. The moving part 16a is a rectangular block with an aperture extending through its length, wherein the fixed part 16a extends through. The moving part 16b includes a coil disposed within the block and cylindrically wound around the aperture. The fixed part 16a includes a plurality of magnets disposed along the length of the shaft.

[0115] There is a gap between the fixed part 16a and the moving part 16b. This means that there is no contact or friction between the fixed 16a and moving 16b parts at any point particularly when the moving part 16b slides along the fixed part 16a. This provides the linear shaft motor 16 with high precision, noise-free and zero cogging features.

[0116] The length of the moving part 16b is shorter than the fixed part 16a. This allows the moving part 16b to rectilinearly slide along the fixed part 16a.

[0117] Each end of the fixed part 16a i.e. each end of the shaft is connected to a block 18 mounted to the base 12. This allows the linear shaft motor 16 to be supported and spaced away from the base 12.

[0118] A rectilinear motion assembly is coupled to and substantially surrounds the moving part 16b of the linear shaft motor 16.

[0119] The rectilinear shaft assembly includes a carriage 20 and a linear slider assembly.

[0120] The carriage 20 forms a top of the rectilinear motion assembly. The carriage 20 includes a groove which receives substantially half of the moving part 16b of the linear shaft motor 16.

[0121] The linear slider assembly includes two sets of a first slider element 22a, 122a and a second slider element 22b, 122b which form sides of the rectilinear motion assembly. A first set is disposed on one side of the linear shaft motor 16 and a second set is disposed on the opposite side of the linear shaft motor 16.

[0122] Each first slider element 22a, 122a is in a form of a sliding block and each second slider element 22b, 122b is in a form of a shaped guide which is mounted to the base 12.

[0123] In the first embodiment, each first slider element 22a includes a recess extending along its length which is shaped and sized to receive its corresponding second slider element 22b. A top of each first slider element 22a is coupled to the end of the carriage 20 and is provided substantially on top of the second slider element 22b.

[0124] In the second embodiment, the first slider elements 122a are T-shaped elements. Each first slider element includes a first member and a second member extending perpendicularly from the centre of the first member to form the T-shape.

[0125] The second slider elements 122b are U-shaped elements. Each second slider element 122b includes two arms which are connected together at one of their ends to form the U-shape.

[0126] An outer surface of one of the arms of each U-shaped second slider element 122b abuts the base 12. The second member of the T-shaped first slider element is disposed between the arms of its corresponding second slider element. The first slider elements 122a do not abut or contact the base 12.

[0127] One first carrier magnet 24 is disposed within an aperture in each end of the first member of each T-shaped first slider element 122a. This can be seen more clearly in FIG. 7. One second carrier magnet 26 is disposed to each face of the second member of each T-shaped first slider element 122a. One base magnet 28 is disposed to an inner face of each arm of each U-shaped second slider element 122b. This allows the first carriage magnets 24 to be disposed to a lateral side of its corresponding base magnet 28 and help maintain the rectilinear movement of the rectilinear motion assembly. The second carriage magnets 26 and the base magnets 28 together allow the weight of the bed to be supported by motion imparting leg 100.

[0128] A gap is provided between the first 24 and second 26 carriage magnets, and the base magnets 28. The gap between the magnets of the first slider elements 122a and second slider elements 122b means that there is no contact or friction between the first slider elements 122a and second slider elements 122b. This helps to prevent wear of the rectilinear motion assembly, and no servicing or maintenance is required.

[0129] The magnets can be more clearly seen in FIG. 7. The magnets can be permanent magnets and/or electromagnets.

[0130] In both embodiments, the linear slider assembly supports the carriage 20 and ensures that, in use, the weight from the bed is transferred to the base 12 of the motion imparting leg. This allows the motion imparting leg 10, 100 to support heavier beds, as each leg can support more weight.

[0131] The linear slider assembly extends in a direction parallel to the fixed part 16a of the linear shaft motor 16. The rectilinear movement of the linear slider assembly is parallel to the rectilinear movement of the linear shaft motor 16.

[0132] The upper member 14 is coupled to the carriage 20. The upper member 14 is a rectangular and planar member which sits at the top of the carrier 20. The upper member 14 covers substantially the whole top surface of the carriage 20. The rectilinear motion assembly allows the upper member 14 to move in a rectilinear motion along the length of the fixed part 16a of the linear shaft motor 16.

[0133] A flexible or resilient member or layer 30 such as a rubber layer is provided between the upper member 14 and the carriage 20 of the rectilinear motion assembly. This can be more clearly seen in FIG. 9.

[0134] The flexible or resilient member 30 is coupled to the upper member 14 and the carriage 20 using adhesive. However, other coupling devices may be used, for example, galvanization. The flexible or resilient member 30 allows the upper member to rotate and translate in relation to the carriage 20.

[0135] This is useful for example, when the motion imparting leg 10, 100 is provided to the bed with other motion imparting legs. The rotation in B-B direction and translation in CC and D-D direction of the upper member 14 means that all the motion imparting legs attached to the bed do not have to be perfectly aligned with each other. This is because the upper member 14 can move slightly to align itself with the upper members of the other motion imparting legs.

[0136] A fastener 32 i.e., a screw extends through the upper member 14, the flexible or resilient member 30 and the carriage 20 for further securing them together.

[0137] A shroud 34 is provided for enclosing the components of the motion imparting leg 10, 100, as can be seen in FIG. 10. The shroud 34 is connected to the upper member 14 through fasteners such as a bolts or screws which extend through apertures in the upper member 14.

[0138] In this embodiment, a linear encoder 36 is mounted to the base 12 and disposed within the space between the base 12 and the linear shaft motor 16. However, in other embodiments, the linear encoder 36 may be disposed anywhere between fixed (e.g. base) and moving components (e.g. upper member, rectilinear motion assembly) of the motion imparting leg 10, 100, for example.

[0139] A motor controller (not shown) is connected to the linear encoder 36. The motor controller controls the speed of the linear shaft motor 16 based on positional data from the linear encoder 36. The motor controller also controls the speed of the motor 16 based on the desired motion or position path, for example, as received from a control hub.

[0140] When a plurality of motion imparting legs is retrofitted to a standard bed, the bed will oscillate or reciprocate back and forth in a horizontal plane, i.e. in a direction substantially parallel to the floor.

[0141] A central hub (not shown) for controlling and providing power to the motion imparting legs can be provided. The central hub can be connected to each motion imparting leg by cabling. The cabling provides a route for data communication and power.

[0142] The central hub receives data and/or signals from each motion imparting leg. The central hub may send commands, signals, data and/or information to each motion imparting leg. The central hub can be configured to synchronise the motion of the legs.

[0143] A safety system is provided and configured to determine unexpected operation of the motion imparting leg 10, 100. For example, the safety system may be used to determine if there is a decoupling, either complete or partial, between the rectilinear motion of components and the linear shaft motor 16. For example, decoupling may occur when the linear shaft motor displacement or movement is blocked by an obstacle, or when motor burns out, or when connection wires are disconnected.

[0144] If a decoupling has been determined, the motor controller generates a warning signal which is transmitted to the central hub. The central control hub may then generate a shutdown signal which is transmitted to all of the motion imparting legs 10, 100.

[0145] In some embodiments, the safety system uses data from the linear encoder 36 to determine if there is a decoupling. In other embodiments, the safety system uses data from the linear encoder 36 plus a monitored electrical value of the linear shaft motor 16, such as current.

[0146] The safety system is configured to determine excessive rectilinear motion. That is to say, the safety system determines that the upper member 14 has moved further than one end of its defined motion or travel path length. The safety system may use the rectilinear motion of other components, such as the rectilinear motion assembly or shroud 34, to infer the motion of the upper member 14.

[0147] The safety system includes two optical switches 38, 138 connected to the motor controller. Each optical switch 38, 138 is disposed towards an end of the linear slider assembly, specifically the second slider element 22b, 122b. Each optical switch 38, 138 has a switch gate comprised of two pillars with a light path disposed therebetween.

[0148] A blade 40, 140, or similar switch trigger, is disposed on either end of the first slider element 22a, 122a. Each blade 40, 140 extends out from the first slider element 22a, 122a towards an optical switch 38, 138. The blade 40, 140 actuates the optical switch 38, 138 by interrupting the light path in the switch gate.

[0149] During normal operation of the motion imparting leg 10, 100, the blades 40, 140 will not actuate the optical switches 38, 138.

[0150] If the optical switches 38, 138 are actuated, the motor controller generates a warning signal which is transmitted to the central hub. The central control hub may then generate a shutdown signal which is transmitted to all of the motion imparting legs 10, 100.

[0151] The optical switches 38, 138 may also be used in a method of calibrating a motion imparting leg 10, 100. The method will now be described with reference to the embodiments discussed above, however it is applicable to other types of motion imparting legs.

[0152] To calibrate the motion imparting leg 10, 100 and determine the maximum extent of possible rectilinear motion, the linear shaft motor 16 drives the rectilinear motion assembly until a blade 40, 140 actuates an optical switch 38, 138. The actuation of the optical switch 38, 138 is indicative of the end of the rectilinear motion path. The motor controller records positional data indicative of the end of the motion path.

[0153] Once one end has been recorded, the motion imparting leg 10, 100 undergoes the same steps but reverses the direction of the linear shaft motor 16 to determine the other end of the rectilinear path.

[0154] With both ends being recorded the extent of possible rectilinear motion, i.e. the maximum motion or travel path length, is determined and the rectilinear motion assembly is moved back towards a central position, i.e. about equal distance between both ends.

[0155] In the current embodiment, the optical switches 38, 138 are not to be triggered during normal operation of the motion imparting leg 10, 100. This means that the actual motion or travel path length has to be less than the maximum motion or travel path length so that the blades 40, 140 do not trigger the optical switches 38, 138.

[0156] In the current embodiment, the actual motion path length is 4 mm smaller than the maximum motion path length, that is to say there is a margin of 2 mm at either end.

[0157] The motion imparting leg may be supplied as a pre-calibrated unit. That is, the end user may not need to perform any calibration prior to installing/using the leg.

[0158] Although the first and second embodiments both include a linear shaft motor, other types of motor or motion path defining devices may be used to drive or cause or allow the rectilinear movement of the upper member.

[0159] The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present disclosure as defined by the appended claims.