LENGTH ADJUSTABLE CRUTCH

Abstract

An adjustable length crutch including at least one support portion to support at least a portion of the weight of a user, a leg portion associated with the at least one support portion and having a foot adapted to abut the ground in use to balance the user and a length adjustment mechanism to adjust the separation between the at least one support portion and the foot to adjust the effective length of the crutch.

Claims

1. An adjustable length crutch including at least one support portion to support at least a portion of the weight of a user, a leg portion associated with the at least one support portion and having a foot adapted to abut the ground in use to balance the user and a length adjustment mechanism to adjust the separation between the at least one support portion and the foot to adjust the effective length of the crutch.

2. An adjustable length crutch as claimed in claim 1 wherein the length adjustment mechanism includes a screw drive system to adjust the effective length of an extendible leg assembly.

3. An adjustable length crutch as claimed in claim 2 wherein the length adjustment mechanism includes a toggle switch with an extend position and a retract position on either side of a home or locked position, operation of the toggle switch activating the screw drive system.

4. An adjustable length crutch as claimed in claim 2 wherein the screw drive mechanism includes an onboard electrical motor.

5. An adjustable length crutch as claimed in claim 4 wherein the screw drive mechanism includes a drive cog driven rotatably by the electrical motor, a closed loop drive belt, and driven cog provided adjacent to the drive cog and separated therefrom, connected by the drive belt.

6. An adjustable length crutch as claimed in claim 5 wherein the driven cog is larger in diameter than the drive cog which will increase the torque available at the driven cog.

7. An adjustable length crutch as claimed in claim 5 wherein the drive cog and the driven cog are both toothed cogs and a toothed drive belt is provided.

8. An adjustable length crutch as claimed in claim 5 wherein the driven cog rotates an upper portion of a threaded rod.

9. An adjustable length crutch as claimed in claim 8 wherein a lower portion of the threaded rod is provided with a guide which is fixed to the threaded rod.

10. An adjustable length crutch as claimed in claim 5 wherein the screw drive mechanism includes a threaded rod mounted within a hollow leg tube of fixed length with a hollow extendible leg mounted about the threaded rod and within the hollow leg tube.

11. An adjustable length crutch as claimed in claim 10 wherein the hollow extendible leg is provided with a guide boss at an upper end that is mounted about the threaded rod and at least a portion of the guide boss abuts an inner surface of the hollow leg tube.

12. An adjustable length crutch as claimed in claim 11 wherein a bore is provided through the guide boss and the bore is threaded to engage with the threaded rod so that rotation of the threaded rod causes translation of the guide boss along the threaded rod which extends and retracts the hollow extendible leg.

13. An adjustable length crutch as claimed in claim 1 further including a receiving tube provided in the at least one support portion into which a lower end of a forearm support is insertable.

14. An adjustable length crutch as claimed in claim 13 wherein the receiving tube is mounted relative to the leg portion.

15. An adjustable length crutch as claimed in claim 10 wherein the speed at which extension occurs is adjustable and similarly, the speed at which retraction occurs may be adjustable as well by providing a threaded portion of a different pitch at an lower and/or upper end of the threaded rod.

16. An adjustable length crutch as claimed in claim 1 further including an alarm actuator with an associated communications pathway to allow a user of the crutch to alert others in an emergency.

17. An adjustable length crutch as claimed in claim 16 wherein the actuator is a button or switch or similar and actuation causes an alarm to be issued or to transmit a signal to a remote location.

18. An adjustable length crutch as claimed in claim 16 wherein the crutch is provided with a unique identifier allowing identification of the user if the actuator is triggered.

19. An adjustable length crutch as claimed in claim 16 wherein the crutch is provided with a positioning device in order that the location of the crutch can be ascertained at any time.

20. An adjustable length crutch as claimed in claim 1 further including an attitude sensing device to actuate an alarm or signal should the crutch be placed in an angle that indicates that the person has fallen.

21. An adjustable length crutch as claimed in claim 20 wherein a manual deactivation of the alarm or signal is provided such that the operator can disable the attitude sensor trigger as required.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0107] Various embodiments of the invention will be described with reference to the following drawings, in which:

[0108] FIG. 1A is a front view of an adjustable length crutch according to one embodiment of the present invention in the extended condition.

[0109] FIG. 1B is a front view of the adjustable length crutch as illustrated in FIG. 1A in the contracted condition.

[0110] FIG. 2A is a front view of an adjustable length crutch according to a second embodiment of the present invention in the extended condition.

[0111] FIG. 2B is a front view of the adjustable length crutch as illustrated in FIG. 2A in the contracted condition.

[0112] FIG. 3 is a perspective view of the adjustable length crutch as illustrated in FIG. 2A.

[0113] FIG. 4 is a perspective view of a length adjustable crutch, according to the invention, in a compact configuration.

[0114] FIG. 5 is a perspective view of the length adjustable crutch showing a leg portion of a frame of the crutch being moved to an extended position.

[0115] FIG. 6 is a perspective view of the length adjustable crutch which has been adjusted to an operative configuration.

[0116] FIG. 7 is a perspective view of a variation of the length adjustable crutch of FIG. 5 and showing a control assembly fitted to the frame.

[0117] FIG. 8 is a perspective view of the length adjustable crutch of FIG. 6 to show more clearly a cover used to conceal part of the control assembly.

[0118] FIG. 9 is a perspective view, on an enlarged scale, of a handle of the control assembly identified with letter “A” in FIG. 8.

[0119] FIG. 10 is an isometric view of an alternative, walking stick embodiment of the present invention in the contracted condition.

[0120] FIG. 11 is an isometric view of the embodiment of the present invention illustrated in FIG. 10 in the extended condition.

[0121] FIG. 12 is an isometric view of an alternative embodiment of the present invention in the contracted condition.

[0122] FIG. 13 is an isometric view of the embodiment of the present invention illustrated in FIG. 12 in the extended condition.

[0123] FIG. 14 is a sectional view of an alternative embodiment using a screw drive system, without forearm support and in the extended condition.

[0124] FIG. 15 is a detailed isometric section view of the handle and control assembly of an alternative embodiment.

[0125] FIG. 16 is a sectional view of an alternative embodiment using a screw drive system, without forearm support and in the retracted condition.

[0126] FIG. 17 is a detail view of the portion from FIG. 16 identified by Reference letter B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0127] According to a particularly preferred embodiment, an adjustable length crutch is provided. A pair of alternative preferred embodiments illustrated, the first preferred embodiment illustrated in FIGS. 1A and 1B and the second preferred embodiment illustrated in FIGS. 2A, 2B and 3.

[0128] Referring firstly to the common features of the crutch as illustrated in all Figures, the adjustable length crutch 10 includes an upper assembly 11 including a hand support 12 and an underarm support 13 to support a portion of the weight of a user, and a leg 14 having a foot 15 adapted to abut the ground in use to balance the user associated upper assembly 11. A length adjustment mechanism is provided to adjust the separation between the supports 12, 13 and the foot 15 to adjust the effective length of the crutch 10.

[0129] The upper assembly 11 of the crutch 10 includes a pair of spaced apart struts 16 with the underarm support 13 at an upper end and extending between the struts 16. The underarm support 13 is fixed and also functions to space the struts 16 at the upper end. The hand support 12 extends between the struts 16 approximately at arm's length downwardly from the underarm support 13. The hand support portion will usually be temporarily fixed relative to the struts 16, but the hand support 12 is be movable in order to adjust in the spacing between the hand support 12 and the underarm support 13.

[0130] According to this configuration, the struts 16 of the upper assembly 11 taper towards each other at a lower end as illustrated. A guide portion 17 is provided at or adjacent the lower end of the upper assembly 11 in order to receive and/or guide the leg 14.

[0131] Turning now to the specific embodiment illustrated in FIGS. 1A and 1B, the length adjustment mechanism has a threaded or helical operation and the components of the length adjustment mechanism therefore adapted for this purpose. In particular, the components of the length adjustment mechanism include a threaded rod 18, an electric drive motor 19 to rotate the threaded rod 18 in both directions, and a telescopic leg 14 associated with the threaded rod 18 and which extends and attracts relative to the upper assembly 11 upon rotation of the threaded rod 18 by the electric motor 19.

[0132] The electric drive motor 19 is associated with a guide arm 20 extending laterally between the struts 16 of the upper assembly 11. The electric drive motor 19 is a lightweight motor, preferably one which is powered by batteries 30 which are located in or on the underarm support 13. Activation of the electric drive motor 19 causes rotation of the threaded rod 18.

[0133] According to this embodiment, each of the portions of the telescopic leg member 14 are provided with an internally threaded portion (not shown) adapted to engage with the threaded rod 18 in order to extend and retract. Typically, extension of the innermost telescopic member is actuated initially by rotation of the threaded rod 18 relative to the internally threaded portion. Once the innermost telescopic member has reached the limit of its movement, the further rotation of the threaded rod 18 may disengage from the internally threaded portion of the innermost member and continued rotation will then extend the next innermost telescopic member and so on until the telescopic leg member reaches the desired length or the limit of its extension. Retraction of the telescopic leg member will preferably occur in the opposite manner.

[0134] According to the second preferred form illustrated in FIGS. 2A, 2B and 3, the length adjustment mechanism includes a pair of hydraulic rams 21 associated with an extendable and retractable scissor drive assembly 22 which is in turn associated with the leg 14. According to this embodiment, the leg 14 is of a fixed length and is extended and retracted to the desired position by the scissor drive assembly 22. The hydraulic rams 21 force the extension and retraction of the scissor drive assembly 22.

[0135] Each of the hydraulic rams 21 is mounted in a pivotal fashion to a cross piece 23 provided in association with the upper assembly. The hydraulic rams 21 are each associated with the scissor drive assembly 22.

[0136] The scissor drive assembly 22 includes a plurality of pairs of arm members 24, the arm members 24 of each pair connected to each other approximately centrally along their length. Each end of each arm member 24 is then attached to an end of an arm member 24 of an adjacent pair which are similarly connected to each other. The end of each of the uppermost pair of arm members 24 is attached to one of the rams 21 via an intervening pivotably mounted plate 25.

[0137] The lowermost pair of arm members 24 is associated with the leg member via intervening members 26.

[0138] The rams 21 of this configuration are provided between a pair of cross-piece members 23 which are attached to and interposed between the struts 16 provided as a part of the upper assembly 11.

[0139] Again referring to both embodiments, the extension and retraction (and typically the speed of extension and retraction) of the leg 14 is actuated by a depressible or button or switch 27. Normally, the actuation button 27 is associated with the hand support 12 so as to be conveniently located for a user when the crutch is in use.

[0140] A further embodiment of the crutch of the present invention is illustrated in FIGS. 4 to 9. According to this embodiment, the crutch has frame which is divided into a lower portion 110 and an upper portion 111 which is foldable about a hinge point 118 relative to the lower portion 110 to reduce the effective length of the crutch when in the use condition.

[0141] Further, the lower portion has an associated extendable leg 112 which is extendable and retractable relative to the lower portion of the frame. The extendable leg illustrated is provided with a rubber foot 121 in order to minimise slippage.

[0142] The upper portion 111 can be locked into at least the use condition in which it is substantially coplanar with the lower portion of hundred and 10 of the frame utilising a locking means which is normally provided at the hinge point 118. According to an alternative embodiment, the upper portion may be complete removal from the lower portion.

[0143] The upper portion 111 of the frame has a pair of spaced apart substantially parallel frame members 113. The upper portion is also provided with a shaped shoulder rest 114 which he is adapted to be received in an underarm region when the crutch is used. As illustrated in FIGS. 4 and 5, the frame members 113 each receive an elongate member 115 which is received telescopically within the frame member 113.

[0144] The elongate member 115 and the respective frame member 113 can be moved relative to one another in order to adjust the effective length of the upper portion 111 of the frame and are then typically releasably locked to one another to at least temporarily fix the effective length. A variety of methods may be used to lock the members together but typically, a biased pin or button extends outwardly from the elongate member 115 and is received in one of a series of openings spaced over the length of the frame member 113.

[0145] The lower portion 110 of the frame includes at least a pair of frame members 116 which are substantially parallel over the majority of the height of the lower portion 110 with a divergent section towards the upper end of the lower portion 110. In practice, a pair of substantially parallel frame members 116 will be provided and a pair of divergent frame members 117 will also be provided attached together using a support 119. A support 119 will also typically be provided at a lower end of the lower portion in order to maintain the separation of the parallel frame members 116.

[0146] The hinge point for attachment of the upper portion 111 is located at or adjacent free end of the divergent frame members 117 of the frame members 116.

[0147] The lower portion 110 of the frame includes a handle or hand rest 125 at an upper portion thereof. The hand rest typically extends substantially horizontally between the divergent frame is 117 of the frame members 116.

[0148] The extendable leg 112 is received between the substantially parallel frame members 116.

[0149] The extendable leg 112 has an outer sleeve which is substantially hollow and tubular. The outer sleeve covers and protects the fluid extension mechanism which is best illustrated in FIG. 7.

[0150] The preferred embodiment of the fluid extension mechanism includes an extendable and retractable gas strut 120. The gas strut 120 includes a cylinder 122 and a piston including a rod 123 located therein. Between the piston and the cylinder 122 is a quantity of pressurised gas which extends the rod 123 by acting on the piston when the actuated to release the rod 123 and the rod 123 can be pushed back into the cylinder 122 using force applied to the foot 121 of the extendable leg 112 which is coaxially located about the rod 123.

[0151] A guide sleeve 124 is provided in the lower support 119 located at the bottom end of the lower portion 111 of the frame. The extendable leg 112 therefore moves between an extended condition illustrated in FIG. 6 and a retracted condition illustrated in FIG. 8.

[0152] Controlling the extension and retraction of the gas driven rod is an actuation mechanism which is associated with the hand rest 125. The hand rest 125 is best illustrated in FIG. 9. The hand rest includes a number of actuation buttons adapted to be used to control the extension of the extendable leg 112.

[0153] According to the illustrated embodiment, a pair of buttons 126 may be provided on the hand rest 125 at each lateral end of the hand rest 125 and which are movable between a position which actuates extension of the gas strut and a second position which actuates retraction. These buttons 126 are typically rocker buttons and biased into a neutral position between the two actuation positions.

[0154] The actuation buttons are connected to the gas strut using a connection conduit 129 which extends from the hand rest 125 to an upper end of the gas strut 120 as illustrated in FIGS. 6 and 7 in particular. The connection conduit 129 is typically protected by a cover 128 which extends on both sides of the crutch between the divergent frame members 117 and also has a closed upper end.

[0155] In an alternative embodiment, two actuation buttons are provided and two unlocking buttons are provided on the hand rest 125.

[0156] Normally, the unlocking buttons are adapted to unlock the extendable leg 112/rod 123 to allow extension thereof. Typically the unlocking buttons are biased into the locking condition which in turn locks of the extendable leg 112/rod 123 into position (whether extended or retracted). The unlocking buttons typically located on a lower side of the hand rest 125 in order to prevent accidental actuation by a user when placing a load on the upper side of the hand rest 125 which will be the typical location for the load when the crutch is in use.

[0157] According to one preferred embodiment, an unlocking button is provided on each lateral end of the hand rest 125 so that the crutch can be used in either the left or right-hand with an unlocking button located adjacent a user's forefinger.

[0158] Similarly, a pair of actuation buttons normally provided on or in an upper surface of the hand rest 125 at each lateral end of the hand rest 125 again so that the buttons are adjacent a user's hand in the use condition.

[0159] The actuation of the extendable leg 112/rod 123 is therefore preferably a two-part process wherein an unlocking button must be depressed before the actuation button is depressed in order to unlock the extendable leg 112/rod 123 and then actuate the gas strut 120. Typically this same process is required to extend the extendable leg 112/rod 123 as well as to retract the extendable leg 112/rod 123.

[0160] As mentioned previously, the preferred gas strut mechanism may be provided with a thread on the rod with a matching thread on an inner surface of the cylinder in order to control the rate of extension and retraction and also to provide the crutch with increased load-bearing capabilities.

[0161] According to a further preferred embodiment illustrated in FIGS. 10 to 13, the crutch includes a gripping portion 200 and a length adjustable leg 201. The leg is extended to an extended position from a retracted position thereby adjusting the length of the crutch. A mechanism which causes the leg portion to extend and a control assembly through which the mechanism can be operated are provided in a control housing 202.

[0162] The gripping portion 200 of the crutch of the embodiments illustrated in FIGS. 10 to 13 is substantially L-shaped with a handle 203 to be received and held by a user, in the user's palm with the user's fingers and thumb wrapped thereabouts.

[0163] In use, the handle is located relative to a user's palm such that the handle can support the thenar and hypothenar eminences of the user's hand with the user's fingers located underneath the handle portion on one side of the handle portion and user's thumb wrapped about the handle portion from the opposite side of the handle portion. The handle portion will therefore be shaped accordingly.

[0164] An actuator switch 204 is located on an underside of the handle 203 recessed into the handle in order to prevent accidental actuation. The actuator switch is located at a forward or free end of the handle 203 in order to be operated by a user's forefinger or thumb.

[0165] The actuator switch of the illustrated embodiment is a toggle switch biased into a central, inactive position and which is capable of movement to either or both of the left and right actuation positions. Movement of the toggle switch to the left (all right) will actuate extension of the crutch and movement of the toggle switch in the opposite direction will allow retraction. In the retraction position, the toggle switch simply unlocks the leg allowing a user to apply force to the leg in order to force retraction.

[0166] The opposite end of the handle 203 is provided with a depending portion 205. As illustrated in FIGS. 10 to 13, the depending portion is angled relative to the handle 203 at an angle slightly less than 90°.

[0167] The depending portion 205 is at least partially hollow with an opening 206 provided into the depending portion 205 substantially coaxial with the depending portion 205 through the upper surface of the handle 203. A cover member is provided for this opening.

[0168] The leg portion 201 of the embodiment illustrated in FIGS. 10 to 13 is provided as a telescoping upper, outer leg portion 207 and lower inner leg portion 208.

[0169] According to a preferred embodiment illustrated in FIGS. 10 to 13, a control housing 202 is provided between the gripping portion 200 and the leg portion 201 with the upper leg portion 207 is attached to a lower side of the control housing 202 allowing the mechanism within the control housing 202 to drive extension of the leg portion 201. Preferably, the upper leg portion is received at least partially within an annular mounting collar 209.

[0170] The lower leg portion can be provided with a shock absorber 210 at a lower end of the lower leg for absorption of shock when the leg portion 201 is extended and the crutch is in use, or alternatively, to buffer the final movement of the lower leg 208 wherein the lower leg is being retracted.

[0171] A foot 211 is provided at the lower end of the lower leg portion 208. In the preferred embodiment, the foot includes a foot platform 212 with a large effective area and a plurality of arms 213 with non-slip rubber caps 214 extending laterally and then downwardly from the foot platform 212.

[0172] The extendable leg portion 201 is mounted to one side of the foot platform 212, adjacent one side edge using a ball joint 215 allowing support to be provided closer to the user's body then if the leg portion 201 was more centrally mounted on the platform 212.

[0173] In this embodiment, the crutch includes a mechanism to cause the leg portion to move to the extended position from a retracted position thereby adjusting length of the crutch. The control mechanism is typically contained within a control housing 202 which is a central component of the crutch located typically relative to the gripping portion 200 as discussed above.

[0174] The control housing 202 is generally rectangular, extending forwardly beneath the handle 203 of the gripping portion 200 approximately as far as the free end of the handle 203. Accordingly, the length of the control housing is preferably coaxial with the handle portion and located beneath the handle portion. Typically, the control housing is of minimal width, again approximating the width of the handle portion.

[0175] The control housing typically houses the actuator to cause extension of the leg such that when the actuator switches operated into either the extension or retraction position, this allows a drive system to move or drive the movement of the leg as required.

[0176] Typically, the drive system is either hydraulic or pneumatic. Therefore, when the actuator switch is switched to the extension position, electrical power provided from a preferred the battery (which can be rechargeable or replaceable) within the control housing is provided to the pump in order to drive a fluid to extend the lower leg relative to the upper leg.

[0177] Once the limit of extension is reached, a lock (not shown) can preferably engage either automatically will be engaged manually by the user. Once the lock has been engaged, manual disengagement is preferably preferred.

[0178] When the actuator is switched to the retraction position, then the pump can either operate in reverse at a given (adjustable) speed to reduce the length of the crutch at a controlled speed or in a controlled manner or alternatively, the lock will be disengaged and the user can be required or able to exert force on the handle portion to drive retraction of the leg.

[0179] The crutch of the preferred embodiment may include an optional support 216 which is attachable to the crutch to provide additional support stability. The support will normally be attached utilising an extension portion with one end of the extension portion attached into the opening 206 in the handle 203 of the gripping portion 200 (once the cover has been removed). Typically, a part of the extension portion will extend down into the depending portion of the gripping portion for stability.

[0180] The extension portion illustrated in FIGS. 12 and 13 is a length adjustable multipart portion. Length adjustment of this portion is provided in the form of a pin 217 for location in aligned or alignable openings in the upper 218 and lower 219 telescoping components of the extension portion.

[0181] The extension portion illustrated in FIGS. 122 and 13 is provided with a collar or cuff 220 at an upper end to receive a user's forearm or alternatively, a pad or similar could be provided to be received in a user's armpit area.

[0182] In an alternative form illustrated in FIGS. 14 to 17, the drive system can be a screw drive system. In a preferred embodiment, the handle 140 and control assembly 141 are integrated into a single housing and the handle 140 includes a toggle switch 142 with an “extend” position and a “retract” position on either side of a home or “locked” position. Operation of the toggle switch 142 activates an onboard electrical motor 143 to rotate a drive cog 144 in the desired direction. The motor is typically powered by a rechargeable on board battery 156. The drive cog 144 mounts a closed loop drive belt 145, preferably a toothed drive belt. A driven cog 146 is provided adjacent to the drive cog 144 and separated therefrom but connected by the drive belt 145. As illustrated in FIGS. 25 to 17, the driven cog 146 is larger in diameter than the drive cog 144 which increases the torque available at the driven cog 146. The driven cog 146 is also a toothed cog.

[0183] As shown in FIG. 17 in particular, the driven cog 146 rotates an upper portion of a threaded rod 147 which is a part of an extendible leg assembly 150. The upper portion of the threaded rod 147 is not threaded but the bulk of the length of the threaded rod 147 is threaded. A lower portion of the threaded rod 147 is provided with a guide 148 which is fixed to the threaded rod 147 and abuts an inner surface of a hollow leg tube 149.

[0184] The threaded rod 147 is mounted within a hollow leg tube 149 of fixed length which extends from the control assembly 141. A hollow extendible leg 151 is mounted about the threaded rod 147 and within the hollow leg tube 149. The hollow leg tube 149 is made of metal and is circular in cross-section.

[0185] The hollow extendible leg 149 is provided with a guide boss 152 at an upper end that is mounted about the threaded portion of the threaded rod 147 and at least a portion of the guide boss 152 abuts an inner surface of the hollow leg tube 149. A threaded bore is provided through the guide boss 152 to engage with the threaded portion of the threaded rod 147. Rotation of the threaded rod 147 will therefore preferably cause translation of the guide boss 152 along the threaded rod 147 which extends and retracts the hollow extendible leg 151, which in this embodiment illustrated, has a rubber or similar foot 153 (rather than the four legged assembly illustrated earlier but which can be used).

[0186] A receiving tube 154 is also preferably provided in the handle 140 accessible using the opening described above. When the preferred cover is removed, a lower end of a forearm support 216 can be inserted into the receiving tube 154. As shown in FIG. 17 best, he receiving tube 154 is attached to a housing 155 that is attached to the hollow leg tube 149 and surrounds the guide boss 152 and the upper end of the drive mechanism. The handle portion of the device is also attached to the receiving tube 154. The receiving tube 154 is preferably made of metal in order to provided additional strengthening and rigidity to the device allow significant forces to be transmitted to the leg assembly 150.

[0187] In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0188] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.