The present disclosure is related to a support apparatus for supporting a patient. More particularly, the present disclosure relates to a support apparatus including a surgical table and a limb support coupled to the surgical table.
Often, when a patient is sedated for a surgery, the patient is supported by and secured to braces or supports coupled to a surgical table. Sometimes, unique supports are provided for a patient's extremities such as arm boards, leg supports, hand boards, stirrups, and boots.
Supports known in the art sometimes secure patients to resist patient movement. Such supports can sometimes allow excessive patient movement relative to the supports. The position and orientation of supports is often adjusted during surgery to improve access to a surgical site or to move portions of the patient's body such as bones, muscles, tendons, and ligaments to evaluate the surgical results.
The present application discloses one or more of the features recited in the appended claims and/or the following features which, alone or in any combination, may comprise patentable subject matter:
According to a first aspect of the present disclosure, a limb support comprises a spar, a limb rest, and a coupler. The spar is configured to be supported from a patient support apparatus and adjustable relative to the patient support apparatus, the spar having a longitudinal axis. The coupler is interposed between the limb rest and the spar, the coupler includes a release that is selectively actuable to (i) release the limb rest to rotate about a first axis that is offset from the longitudinal axis of the spar to a plurality of orientations relative to the spar, and (ii) release the coupler relative to the spar to allow the coupler to move along the longitudinal axis of the spar.
In some embodiments, the coupler includes a release mechanism that is acted upon by the release to permit rotation of the limb rest about the first axis. In some embodiments, the release mechanism includes an actuator that moves along the first axis when the release is actuated. In some embodiments, the release moves in a direction that is perpendicular to the first axis. In some embodiments, the release mechanism includes a locking plate that is disengaged by the actuator. In some embodiments, the release mechanism includes guides to maintain an orientation of the locking plate. In some embodiments, the guides are positioned on a base member that is secured to the spar. In some embodiments, the guides preclude rotation of the locking plate when the release is actuated and when the release is not actuated. In some embodiments, the locking plate includes anti-rotation features that engage to prevent rotation of the limb rest when the release is not actuated. In some embodiments, the anti-rotation features are disengaged to thereby allow rotation of the limb rest when the release is actuated.
In some embodiments, actuation of the release causes movement of a linkage that causes the coupler to be released from the spar to allow movement of the coupler along the spar. In some embodiments, the linkage transfers motion from a first plunger to cause longitudinal movement of a release member in a direction perpendicular to the movement of the first plunger. In some embodiments, the linkage further comprises an actuator that is pivotable about a second axis that is perpendicular to the first axis. In some embodiments, the linkage comprises a cam that is pivotable about the second axis. In some embodiments, the actuator is secured to the cam. In some embodiments, the cam comprises an axle that has an axis that is collinear with the second axis. In some embodiments, the cam comprises an eccentric that is secured to the axle and rotates therewith. In some embodiments, the eccentric includes a lobe that is offset from the second axis. In some embodiments, the linkage comprises a second plunger that moves between a first position when the release is not actuated and a second position when the release is actuated. In some embodiments, the lobe engages the second plunger. In some embodiments, rotation of the cam about the second axis causes the lobe to move the plunger to release the coupler from the spar.
In some embodiments, the coupler includes a clamp that is selectively actuated to engage the spar to prevent movement of the coupler along the spar. In some embodiments, the clamp is released when the release is actuated. In some embodiments, the second plunger moves to cause the clamp to release the spar.
In some embodiments, the coupler further comprises a rotation lock that prevents rotation of the limb rest about the longitudinal axis of the spar.
In some embodiments, the coupler further comprises a collar that supports the clamp.
In some embodiments, the rotation lock prevents movement of the clamp relative to the collar.
In some embodiments, the rotation lock is releasable to permit rotation of the clamp relative to the collar.
In some embodiments, the rotation lock is adjustable to allow the clamp to be adjusted to a plurality of positions relative to the collar.
In some embodiments, the spar and the collar include a plurality of interengageable anti-rotation elements that cooperate to prevent rotation of the collar about the axis of the spar.
In some embodiments, the coupler includes a selectively engageable brake to prevent movement of the coupler along the longitudinal length of the spar. In some embodiments, when the rotation lock is disengaged, the brake may be disengaged to permit movement of the coupler along the longitudinal length of the spar. In some embodiments, the brake comprises an elastomeric pad.
According to a second aspect of the present disclosure, a limb support comprises a support structure, a limb rest, and a coupler. The support structure is configured to be mounted to a patient support apparatus and includes a spar having a longitudinal axis and a guide tube having a longitudinal axis that is parallel to the longitudinal axis of the spar. The limb rest is configured to support the limb of a patient supported on the patient support apparatus. The coupler is supported from the spar and supports the limb rest. The coupler has a single release that is manually actuable to permit a user to move the release between a locked position and a released position, wherein when the release is in the released position the limb rest is simultaneously adjustable relative to the spar with at least two degrees of freedom.
In some embodiments, when the release is in the released position, the limb rest is simultaneously adjustable relative to the spar with at least four degrees of freedom.
In some embodiments, when the release is in the released position, the limb rest is simultaneously adjustable relative to the spar in at least three degrees of freedom.
In some embodiments, the release is only operable to lock three of the four degrees of freedom.
In some embodiments, the coupler comprises a floating lock member, a biased locking assembly, a fixed lock member, a plurality of wedge members, a plurality of fixed plates, and a shaft engaged with at least one fixed plate. The floating lock member engages the wedge members and the wedge members engage the fixed lock member such that the wedge members induce a load between the wedge members and the fixed plates such that the load of the biased locking assembly is transferred through the wedge members to the plates, the plates thereby inducing a load in the shaft.
In some embodiments, the release is operable to disengage the floating lock member from the wedge members so as to reduce the load induced in the shaft.
In some embodiments, the load induced in the shaft is operable to lock the coupler to the spar.
In some embodiments, the reduction in the load in the shaft releases the coupler from the spar such that the coupler is moveable along the longitudinal axis of the spar.
In some embodiments, the wedge members are coupled together by a bias structure that urges the wedge members to engage the floating lock member and fixed lock member.
In some embodiments, the bias structure coupling the wedge members is insufficient to prevent movement of the limb rest relative to the spar.
In some embodiments, the coupler includes a carriage that is supported on the spar, the carriage including a frame and a lock moveable relative to the frame, the lock being pivoted relative to the frame to secure the carriage to the spar when the load is induced in the shaft.
In some embodiments, the carriage further includes a bias member that is configured to resist the load induced in the shaft. In some embodiments, the load induced in the shaft overcomes the bias of the bias member of the carriage when the load is induced in the shaft by the biased locking assembly. In some embodiments, the bias of the bias member is sufficient to release the lock of the carriage when the load in the shaft is removed.
In some embodiments, the release includes a cam that is rotated to cause the floating lock member to disengage the wedge members.
In some embodiments, the limb rest is rotatable about a third axis, regardless of the position of the release.
In some embodiments, the release is manually actuable between a released position permitting movement of the limb rest about the first axis, about the second axis, and along the spar, and a locked position preventing movement of the limb rest about the first axis, about the second axis, and along the spar.
In some embodiments, the release is configured such that manual actuation achieves a mechanical advantage that overcomes the bias of the biased locking assembly.
In some embodiments, rotation of the coupler about the longitudinal axis of the spar is precluded by a guide member. In some embodiments, the coupler includes a carriage that engages the spar. In some embodiments, the carriage also engages the guide member. In some embodiments, the carriage includes a bias member that biases at least a portion of the carriage into engagement with the guide member. In some embodiments, the carriage further includes at least one needle bearing that engages the guide member. In some embodiments, the carriage includes at least one bearing member that is biased to engage the guide member.
In some embodiments, at least one wedge member includes a feature that limits the range of motion of the limb rest about the first axis.
In some embodiments, the spar further includes a release trigger operable to release the spar for adjustment of the spar relative to a patient support apparatus.
In a third aspect of the present disclosure, a limb support comprises a spar configured to be supported from a patient support apparatus and adjustable relative to the patient support. The spar has a longitudinal axis. The limb support also comprises a limb rest and a coupler interposed between the limb rest and the spar. The coupler includes a release that is selectively actuable to (i) release the limb rest to rotate about a first axis that is offset from and parallel to the longitudinal axis of the spar to a plurality of orientations relative to the spar, (ii) release the limb rest to rotate about a second axis orthogonal to the first axis to a plurality of orientations, and (ii) release the coupler relative to the spar to allow the coupler to move along the longitudinal axis of the spar.
In some embodiments, the release is biased to a locked position to prevent movement of the limb rest relative to the spar.
In some embodiments, the release includes a biased locking assembly that urges a floating lock member to engage a wedge member into engagement with a fixed lock member to urge the release into a locked condition preventing movement of the limb rest about the first and second axis and preventing movement of the coupler along the longitudinal axis of the spar.
In some embodiments, the floating lock member engages two wedge members; the two wedge members each engaging the fixed lock member in the locked condition.
In some embodiments, the wedge members each engage a fixed plate such that the load of the bias member is transferred through the wedge members to the plates, the plates cooperating to induce a load in a shaft.
In some embodiments, the load on the shaft is transferred to a lock that engages the spar to secure the coupler to the spar.
In some embodiments, the release includes a cam that is rotated to cause the floating lock member to disengage the wedge members.
In some embodiments, the limb rest is rotatable about a third axis, regardless of the position of the release.
In some embodiments, the release is manually actuable between a released position permitting movement about the first axis, about the second axis, and along the spar, and a locked position preventing movement about the first axis, about the second axis, and along the spar.
In some embodiments, the release is configured such that manual actuation achieves a mechanical advantage that overcomes the bias member.
In some embodiments, rotation of the coupler about the longitudinal axis of the spar is precluded by a guide member. In some embodiments, the coupler includes a carriage that engages the spar. In some embodiments, the limb support further comprises an elongate guide member that is parallel to the spar and the carriage further engages the guide member. In some embodiments, the carriage includes a bias member that biases at least a portion of the carriage into engagement with the guide member. In some embodiments, the carriage further includes at least one needle bearing that engages the guide member. In some embodiments, the carriage includes at least one bearing member that is biased to engage the guide member.
In some embodiments, at least one wedge member includes a feature that limits the range of motion of the limb rest about the first axis.
In some embodiments, the floating lock ring includes a first annular surface that engages one or more wedge members, the fixed lock ring includes a second annular surface that engages one more wedge members, and wherein the one or more wedge members are free to move relative to the first and second annular surfaces when the release is in the released position.
In some embodiments, the coupler further comprises a floating lock member, a biased locking assembly, a fixed lock member, a wedge member, a fixed plate, and a shaft engaged with the fixed plate, wherein the floating lock member engages the wedge member to induce a load between the wedge member and the fixed plate such that the load of the biased locking assembly is transferred through the wedge member to the plate, the plate inducing a load in the shaft.
In some embodiments, the release is operable to disengage the floating lock member from the wedge member so as to reduce the load induced in the shaft. In some embodiments, the load induced in the shaft is operable to lock the coupler to the spar. In some embodiments, the reduction in the load in the shaft causes the coupler to release the coupler from the spar such that the coupler is moveable relative to the spar.
In some embodiments, the coupler further comprises a floating lock member, a biased locking assembly, a fixed lock member, a plurality of wedge members, a plurality of fixed plates, and a shaft engaged with at least one fixed plate, wherein the floating lock member engages the wedge members and the wedge members engage the fixed lock member such that the wedge members induce a load between the wedge members and the fixed plates such that the load of the biased locking assembly is transferred through the wedge members to the plates, the plates inducing a load in the shaft.
In some embodiments, the release is operable to disengage the floating lock members from the wedge member so as to reduce the load induced in the shaft. In some embodiments, the load induced in the shaft is operable to lock the coupler to the spar. In some embodiments, the reduction in the load in the shaft causes the coupler to release the coupler from the spar such that the coupler is moveable relative to the spar.
In some embodiments, the wedge members are coupled together by a bias structure that urges the wedge members to engage the floating lock member and fixed lock member. In some embodiments, the bias structure coupling the wedge members is insufficient to cause the wedge members to prevent movement of the limb rest relative to the spar.
In some embodiments, the coupler includes a carriage that is supported on the spar, the carriage including a frame and a lock moveable relative to the frame, the lock being biased relative to the frame to secure the carriage to the spar when the load is induced in the shaft.
In some embodiments, the carriage further includes a bias member that is configured to resist the load of the shaft. In some embodiments, the load of the shaft overcomes the bias of the bias member of the carriage when the load is induced in the shaft. In some embodiments, the bias of the bias member is sufficient to release the lock of the carriage when the load in the shaft is removed.
In some embodiments, the release includes a cam that is rotated to cause the floating lock member to disengage the wedge member.
According to a fourth embodiment of the present disclosure a coupler is configured to support a limb rest relative to a support structure. The coupler includes a release that is selectively actuable to (i) release the limb rest to rotate about a first axis, (ii) release the limb rest to rotate about a second axis orthogonal to the first axis to a plurality of orientations, and (ii) release the coupler for movement along the longitudinal axis of the support structure.
In some embodiments, the release is biased to a locked position to prevent movement of the limb rest relative to the support structure.
In some embodiments, the release includes a biased locking assembly that urges a floating lock member to engage a wedge member into engagement with a fixed lock member to urge the release into a locked condition preventing movement of the limb rest about the first and second axes and preventing movement of the coupler relative to the support structure.
In some embodiments, the floating lock member engages two wedge members; the two wedge members each engaging the fixed lock member in the locked condition.
In some embodiments, the wedge members each engage a fixed plate such that the load of the bias member is transferred through the wedge members to the plates, the plates cooperating to induce a load in a shaft.
In some embodiments, the load on the shaft is transferred to a lock that engages the support structure to secure the coupler to the support structure.
In some embodiments, the release includes a cam that is rotated to cause the floating lock member to disengage the wedge member.
In some embodiments, a limb rest mounting plate is rotatable about a third axis, regardless of the position of the release.
In some embodiments, the release is manually actuable between a released position permitting movement about the first axis, about the second axis, and along the support structure, and a locked position preventing movement about the first axis, about the second axis, and along the support structure.
In some embodiments, the release is configured such that manual actuation achieves a mechanical advantage that overcomes the bias member.
In some embodiments, the coupler includes a guide channel configured to engage a guide member of the support structure to maintain an orientation of the coupler as it moves along the spar.
In some embodiments, the coupler includes a carriage that is configured to engage the support structure.
In some embodiments, the carriage configured to engage the guide member.
In some embodiments, the carriage includes a bias member that is configured to bias at least a portion of the carriage into engagement with the guide member.
In some embodiments, the carriage further includes at least one needle bearing configured to engage the guide member.
In some embodiments, the carriage includes at least one bearing member that is biased to engage the guide member.
In some embodiments, at least one wedge member includes a feature that limits the range of motion of the limb rest about the first axis.
In some embodiments, the floating lock ring includes a first annular surface that engages one or more wedge members, the fixed lock ring includes a second annular surface that engages one more wedge members, and wherein the one or more wedge members are free to move relative to the first and second annular surfaces when the release is in the released position.
In some embodiments, the coupler further comprises a floating lock member, a biased locking assembly, a fixed lock member, a wedge member, a fixed plate, and a shaft engaged with the fixed plate, wherein the floating lock member engages the wedge member to induce a load between the wedge member and the fixed plate such that the load of the biased locking assembly is transferred through the wedge member to the plate, the plate inducing a load in the shaft.
In some embodiments, the release is operable to disengage the floating lock member from the wedge member so as to reduce the load induced in the shaft.
In some embodiments, the load induced in the shaft is configured to lock the coupler to the support structure.
In some embodiments, a reduction in the load in the shaft is configured to release the coupler from the support structure such that the coupler is moveable relative to the support structure.
In some embodiments, the coupler further comprises a floating lock member, a biased locking assembly, a fixed lock member, a plurality of wedge members, a plurality of fixed plates, and a shaft engaged with at least one fixed plate, wherein the floating lock member engages the wedge members and the wedge members engage the fixed lock member such that the wedge members induce a load between the wedge members and the fixed plates such that the load of the biased locking assembly is transferred through the wedge members to the plates, the plates inducing a load in the shaft.
In some embodiments, the release is operable to disengage the floating lock member from the wedge member so as to reduce the load induced in the shaft.
In some embodiments, the load induced in the shaft is configured to lock the coupler to the support structure.
In some embodiments, the reduction in the load in the shaft is configured to release the coupler from the support structure such that the coupler is moveable relative to the support structure.
In some embodiments, the wedge members are coupled together by a bias structure that urges the wedge members to engage the floating lock member and fixed lock member.
In some embodiments, the bias structure coupling the wedge members is insufficient to cause the wedge members to prevent movement of the limb rest support plate relative to the support structure.
In some embodiments, the coupler includes a carriage that is configured to be on the support structure, the carriage including a frame and a lock moveable relative to the frame, the lock being biased relative to the frame to the secure the carriage to the support structure when the load is induced in the shaft.
In some embodiments, the carriage further includes a bias member that is configured to resist the load of the shaft.
In some embodiments, the load of the shaft overcomes the bias of the bias member of the carriage when the load is induced in the shaft.
In some embodiments, the bias of the bias member is sufficient to release the lock of the carriage when the load in the shaft is removed.
In some embodiments, the release includes a cam that is rotated to cause the floating lock member to disengage the wedge member.
In some embodiments, the limb rest support plate is rotatable about a third axis, regardless of the position of the release.
In some embodiments, the release is manually actuable between a released position permitting movement of the limb rest support plate about the first axis, about the second axis, and along the support structure, and a locked position preventing movement of the limb rest support plate about the first axis, about the second axis, and along the support structure.
In some embodiments, the release is configured such that manual actuation achieves a mechanical advantage that overcomes the bias member.
Additional features, which alone or in combination with any other feature(s), including those listed above and those listed in the claims, may comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.
The detailed description particularly refers to the accompanying figures in which:
A limb support configured as a leg support 10 mountable to a patient support apparatus (not shown) and for positioning the leg of a patient in a number of different positions is shown in
The spar 16 is supported relative to the mount 12 by a counterbalancing gas spring 18 which assists in supporting the weight of a patient's leg when the leg support 10 is in use or the position is being adjusted. A handle 20 positioned on a distal end of the spar 16 relative to the mount 12 is configured to be used by a user to position the spar 16 and includes a release trigger 22 that, when gripped by a user, causes the lockable multi-axis coupler 14 to be released to allow the spar 16 to move relative to the mount 12. Movement of the spar 16 relative to the mount 12 is facilitated in the pitch axis 24, roll axis 26, and yaw axis 28 as suggested in
The illustrative leg support 10 is configured to support a patient's left leg. In many cases, a second leg support that is a mirror duplicate of the leg support 10 will be used to support the right leg of a patient. The present disclosure includes an adjustable coupler 30 that permits of adjustment of the relative position and orientation of a limb rest 32 relative to the spar 16. As will be explained in further detail below, the adjustable coupler 30 permits discrete adjustment of the position of the limb rest 32 about the spar 16 that provides additional roll axis adjustment of the limb rest 32. Still further, the limb rest 32 may be rotated about an axis 34 shown in
Referring to
In addition, the downward movement of the plunger 42 is transferred to an actuator 46 which acts on a plunger 48 to move the plunger 48 between the first position shown in
Referring again to
To explain in further detail, the coupler 30, shown in an exploded view in
A lock plate 78 is supported on a spring 80 which is trapped between lock plate 78 and a base 82 of the coupler 30. The spring 80 biases the lock plate 78 upwardly and, through the lock plate 78 biases the plunger 42 in the direction opposite the arrow 74. This bias urges the release 36 to the first position shown in
Referring to
While the movement of the lock plate 78 permits the adjustment of the limb rest support plate 94 about axis 34, a separate linkage 116 transfers the movement of the plunger 42 in the direction of axis 34 to movement of the plunger 42 along an axis 118 which is perpendicular to axis 34. The linkage 116 includes the actuator 46 and a cam 120 which is supported on trunnions 122 and 124 formed in the base 82. The actuator 46 is a u-shaped member with two legs 126 and 128 that are secured to the cam 120 by pins 130, 130. The cam 120 includes an axle 132 and an eccentric 134 secured to the axle 132. Rotation of the cam 120 about an axis 136 of the axle 132 causes the eccentric 134 to rotate as suggested in
The plunger 42 includes a shaft 142 that has a cross-hole 144 through which a pin 146 (shown in
The plunger 48 being pinned to the leg 52 and free to move within an relative to the arm 88, effects movement of leg 52 relative to leg 50 to overcome the bias of the web 148. Thus, as the eccentric 134 rotates, a lobe 172 of the eccentric 134 engages the head 56 of plunger 48 to move the plunger 138 along axis 118 and cause the clamp 54 to release. The eccentric 134 is rotated by the action of a bottom surface 175 of the lock plate 78 on the actuator 46 to thereby cause the linkage 116 to pivot about the axis 136 as the plunger 42 is urged downwardly. Rotation of the eccentric 134 about the axis 136 in the direction of arrow 176 shown in
It should be noted that the action of releasing both the locking mechanism 44 and the linkage 116 result from the cooperation of the actuator 46 and the lock plate 78. However, in other embodiments, the clamp release could be omitted by omitting the linkage 116 and having only a rotation release as described relative to locking mechanism 44. Similarly, locking mechanism 44 could be omitted and the plunger 42 could act directly on the actuator 46 such that an embodiment of the coupler 30 could include only the linkage 116 that releases the clamp 54.
Heretofore, the clamp 54 has been described as having a constant relationship relative to the collar 58. In the illustrative embodiment, the orientation of the clamp 54 about the axis 240 of the spar 16 is adjustable to a number of locations by releasing a clamp lock 174 and rotating the clamp 54 about the axis 240 of spar 16 as indicated by arrow 176 in
In another embodiment shown in
As shown in
Referring now to
The collar 333 further includes an elastomeric pad 386 supported in the housing 360. The pad 386 is deformable under a load to cause frictional interference between the collar 333 and the spar 316 to prevent movement of the collar 333 and, thereby, the coupler 330 along the spar 316. The weight of the limb rest 332 and, when a patient is present, the weight of a patient's limb, are supported in cantilever from the collar 333 creating a moment that is supported by the pad 386. The pad 386 deforms under the load causing friction between the pad 386 and a surface of the channel 312 which causes resistance against movement of the coupler 330 along the spar 316.
To move the collar 333 and, thereby, coupler 330 along the spar 316, a user squeezes the grip 382 of the handle 370 to disengage the block 378 from the channel 314. The user then manually lifts the limb rest 332 to unload the pad 386. Once the pad 386 is unloaded, the frictional resistance of movement along the spar 316 is removed and the coupler 330 is moveable to a new position on the spar 316. Once the coupler 330 is positioned appropriately, the user lowers the limb rest 332 to re-load the pad 386 and releases the grip 382 to cause the anti-rotation block 378 to re-engage channel 314.
Another embodiment of a limb support configured as a leg support 410 mountable to a patient support apparatus (not shown) and for positioning the leg of a patient in a number of different positions is shown in
The spar 416 is supported relative to the mount 12 by a counterbalancing gas spring 418 which assists in supporting the weight of a patient's leg when the leg support 410 is in use or the position is being adjusted. A handle 420 positioned on a distal end of the spar 416 relative to the mount 12 is configured to be used by a user to position the spar 416 and includes a release trigger 422 that, when gripped by a user, causes the lockable multi-axis coupler 14 to be released to allow the spar 416 to move relative to the mount 12. Movement of the spar 416 relative to the mount 12 is facilitated in the pitch axis 24, roll axis 26, and yaw axis 28 as suggested in
The illustrative leg support 410 is configured to support a patient's left leg. In many cases, a second leg support that is a mirror duplicate of the leg support 410 will be used to support the right leg of a patient. The present disclosure includes an adjustable coupler 430 that permits of adjustment of the relative position and orientation of a limb rest 432 relative to the spar 416.
Referring to
A general understanding of the operation of the coupler 430 may be best understood by reference to
Referring now to
Referring to
The release 436 also affects a third degree of freedom in that the release controls the locking of the coupler 430 to the spar 416. A carriage 474 of the coupler 430 is supported on the spar 416 then moves relative to the spar 416 and a guide rod 476 to vary the distance between the limb rest 432 and the mount 12 which results in the variation of the distance of the limb support relative to a patient support apparatus to which the leg support 410 is mounted in use. The guide rod 476 and spar 416 are each coupled to a fixed coupler 580 positioned at one end of the guide rod 476. The fixed coupler 580 is also engaged by a rod end 582 of the gas spring 18. The spar 416 and guide rod 476 are coupled at an end of the guide rod 476 opposite the fixed coupler 580 by a mount 584. The mount 584 secures the handle 420, the guide rod 476, and the spar 416. The release trigger 422 extends through the spar 416 as shown in
Referring to
A shaft 488 extends through the fixed lock ring 468, the fixed plates 470, 472, the wedge plates 462, 464, the tubular shaft 486, engaging a pair of bearings 564, 566 positioned in the tubular shaft 486 and shaft 488 and is secured to the lock 480 by a pin 490. The shaft 488 is secured on the opposite end by a thrust bearing 492 and a lock nut 494 which is adjusted to provide a preload on the lock 480 that is sufficient to secure the carriage 474 to the spar 416 when the release 436 is in the position shown in
The bias member 484, illustratively embodied as a helical spring, resists the load induced in the shaft 488. However, in normal operating conditions the load induced in the shaft 488 is a multiple of the load of the bias member 484 such that the bias member 484 is overcome by the load of the shaft 488 and compresses. When the handle 438 is moved to a released position, such as that shown in
The frame 478 of carriage 474 does not directly engage the guide tube 476, but the carriage 474 engages with the guide tube 476 through a pair of needle bearings 500, 502. The needle bearing 500 is secured to the frame 478 by a fastener 504 such that the needle bearing 500 is fixed relative to the frame 478. The needle bearing 500 to is secured to a floating arm 506 which is pivotably connected to the frame 478 and pivotable about an axis 508. A bias member 510, illustratively embodied as a helical spring, engages the floating arm 506 urging the floating arm 506 to pivot about the axis 508 to engage the needle bearing 502 with the guide shaft 476. A load is induced in the bias member 510 by a set screw 512 which is threaded into the frame 478 to create a preload in the bias member 510 sufficient to keep the needle bearing 500 to engaged with the guide shaft 476. This arrangement eliminates the need for close tolerance machining and establishes an appropriate load in the needle bearings 500, 502. The engagement of the needle bearings 500, 502 with the guide tube 476 resists the rotation of the coupler 430 about the spar 416 when a load is placed on the limb rest 432.
Unlike the embodiment of limb support 10, leg support 410 is not adjustable about the spar 416, but role about the axis 435 is facilitated by clearance in the wedge plates 462, 464 which each have a respective slot 514, 516 which permit a limited amount of role about the axis 435 when the release 436 is moved to the released position, such as that shown in
The coupler 430 includes a bearing structure 530 that is positioned in the fixed lock ring 468. The bearing structure 530 includes an outer bearing housing 532 that is positioned through an aperture 534 in the fixed lock ring 468 best seen in
Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims.
This application is a continuation of U.S. patent application Ser. No. 15/473,784, filed Mar. 30, 2017, and to U.S. Provisional Application Ser. No. 62/316,626, filed Apr. 1, 2016, each of which are expressly incorporated by reference herein.
Number | Date | Country | |
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62316626 | Apr 2016 | US |
Number | Date | Country | |
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Parent | 15473784 | Mar 2017 | US |
Child | 17092492 | US |