LOCKABLE PIVOTAL CONNECTION DEVICE

Abstract: A lockable pivotal connection device which is relatively compact and suitable for use as a joint in an artificial limb such as an artificial leg for replacing a leg amputated close to the original joint. The lockable pivotal connection device, includes a cylindrically bored housing member (2) and, rotationally housed in said housing member bore (3), a cam member (7) with a generally periphery and an annular lock member (4), with the annular lock member (4) pivotally interconnecting the housing member (2) and cam member (7) relative to one another about a rotary pivot axis formed by the longitudinal axis of the cylindrical bore (3). The annular lock member (4) is housed in the housing member bore (3) with the outer periphery of the lock member (4) adjacent the inner periphery of the housing member bore (3) so that the housing member (2) is rotatable about the lock member (4), which lock member (4) has at least three bearing members (5) movably housed in apertures (6) opening radially through the inner and outer peripheries of the lock member (4) at peripherally spaced locations therearound. The cam member (7) has a generally circular periphery with, spaced around the cam member periphery, at least three substantially planar, concave or convex cam faces (8), which cam member (7) is housed in the lock member (4) with the outer periphery of the cam member adjacent the inner periphery of the lock member (4) with the bearing members (5) in contact with the respective cam faces (8). Means (11, 12) are provided, on or engageable with the lock member (4) whereby the lock member (4) can be rotatably displaced to a limited extent between at least two positions to rotate the annular lock member (4) in either direction to a limited extent about the rotary pivot axis relative to the housing and cam members (2, 7) so that with the lock member (4) in one of said at least two positions, the housing member (2) may rotate relative to the cam member (7) about the lock member (4) in either direction, and with the lock member (4) in the other of said at least two positions, the lock member (4) is rotatively displaced relative to the cam and housing members (7, 2) causing the bearing members (5) to be displaced by the lock member (4) along and up their respective cam faces (8) towards and into wedged locking engagement between the inner periphery of the housing member cylindrical bore (3) and the respective cam faces (8) to stop rotary movement of the housing member (2) relative to the cam member (7) in the direction of said other position but not in the opposite direction towards said one position.

Description: "LOCKABLE PIWTALCONNECTION DEVICE" This invention relates to a lockable pivotal connection device particularly, but not exclusively, suitable for use.as a joint in an artificial limb such as an artificial leg and concerns an artificial limb having such a device. - There is a need for a relatively compact lockable pivotal connection device particularly for use with artificial limbs to replace limbs amputated close to the original joint. According to the present invention there is provided a lockable pivotal connection device-, including a cylindrically bored housing member, and.rotationally housed in said housing member bore, a cam member with a generally circular periphery and an annular lock member, with the annular lock member pi otally -interconnecting the housing member and cam member for rotary pivo¬ tal movement of the housing member and cam member relative to one another about a rotary pivot axis formed by the longitudinal axis of the cylindrical bore, wherein the annular lock member is housed in the housing member bore with the outer periphery of the lock member adjacent the inner periphery of the housing member bore.so that the housing member is rotatable about the lock member, which lock member has at least three bearing members movably housed in apertures opening radially through the inner and outer peri¬ pheries of the lock member at peripherally spaced locations there¬ around, and the cam member has a generally circular periphery with, spaced around the cam member periphery, at least three sub- stantially planar, concave or convex cam faces, which cam member is housed in the lock member with the outer periphery of the cam member adjacent the inner periphery of the lock member and with the bearing members in contact with the respective cam faces, and means being provided, on or engageable with the lock member whereby the lock member can be rotatably displaced to a limited extent between at least two positions to rotate the annular lock member in either ^ direction to u limited extent about the rotary pivot axiu relative to the houning and cam members, εo that with the lock member • in one of ε.-id at least two positions, the housing member may rotate relative to the cam member about the lock member in either 5 direction, and v t-h the lock member in the other of .said at least two positions, the lock member is rotatively displaced relative to the cam and housing members causing the bearing members to be displaced by the lock member along and up their respective cam faces towards and into wedged locking engagement between 10 the inner periphery of the housing member cylindrical bore and the respective cam faces to stop rotary movement of the housing member relative to the cam member in the direction of said other position but not in the opposite direction towards said one position. ^= Ailvantageously the outer periphery of the lock member is in rotary slidable contact with the inner periphery of the housing member bore and/or the outerperiphery of the cam member is in slidable contact with the inner periphery of the lock, member. Preferably the device includes a base member to which the 20 cam member is fixedly attached, the annular lock member is in the form of a ring and the cam member is in the form of a disc or plate. Conveniently the device includes a cover plate fixedly attachable to the cam member plate and to the base member so that the cover plate, cam member plate and base member are rota- 25 tionally fixed relative to one another and so that the housing member cylindrical bore is closed at least partially at one end by the base member and at the other end by the cover plate to retain the cam member plate and lock member ring in the cylindri ¬ cal bore between the cover plate and base member. 30 Conveniently the means whereby the lock member can be rotatably displaced is a projection on one side of the lock member and extending in a direction parallel to the rotary , pivot axis, engageable in a corresponding slot provided either in the cover plate or in the base member, which projection and 35 slot are dimensioned such that the projection can be displaced , . WIPO ,* in the slot to a limited extent between the said at least two positions to rotate the lock member in either direction to a limited extent about the rotary pivot axis relative to the cover plate and cam member plate. Alternatively the means whereby the lock member ring can be rotatably displaced is a groove in, lever or cam on, at least one side of the lock ring member or a radial cutout in the housing member. Advantageously the lock member is rotatably displace- able to a limited extent between three positions, namely a median position corresponding to said one position, a first end position, corresponding to said other position, on ' one side of the median position and a second end position on the other side of the median position, so that with the lock member in the second end position, the lock member is displaced relative to the cam and • housing members in the opposite direction to that in the first end position causing the bearing members to be displaced by the lock member along and .up their respective cam faces, in the opposite direction to that in the first end position, towards and into wedged locking engagement between the inner periphery of the housing member cylindrical bore and the respective cam faces to stop rotary movement of the- housing member relative to the cam member in the direction of the second end position but not in the opposite direction of the first end position. Preferably the bearing members are resiliently biassed in the direction of said other or first end positions and/or said second end position. Conveniently the bearing members are resiliently biassed towards the cam faces and away from the inner periphery of the housing member cylindrical bore. Advantageously each bearing member is resiliently biassed by at least one spring housed in a corresponding recess in the lock member on the trailing side of the bearing member with res¬ pect to the other or first end position and communicating with the associated bearing member aperture. Conveniently two such springs are provided for each bearing member located one on each side of the bearing member with respect to the first and second end positions. Preferably the bearing members are ball or roj shaped. " ° QMpI ~$>i Conveniently the cover plate is attached to the cam member plate and base member by at least two screws passing through the cover plate and cam member plate and engaging in threaded bores in the base plate. Advan ageous y the housing .meisber is cylindrical in chape with the bore opening uninterruptedly through one end of the housing member and opening via a reduced diameter aperture through the other end of the housing member. Suitably the ether end of the housing may be formed separate from the housing member but fixedly attachable thereto to -rotate therewith. Conveniently the annular lock member has the shape of a ring carrying three or more bearing members in the foim of rollers. Preferably the cam member is substantially cylindrical in form with a i duced diameter end portion one end of ωhich, ωhen the cam member and lock member are housed in the housing member bore, projects out of the housing member reduced diameter end aperture ωhich provides a bearing for the reduced diameter end portion. The cam member reduced diameter end portion may be rotatably secured in the housing member aperture by a circlip engaged around the reduced dismster end portion on the outer side of the housing member end ωall ωith respect to the cam member. Additionally the device may include an axially bored cover plate fixedly atta¬ chable to the substantially cylindrical cam member at the end thereof remote from the reduced diameter .end portion, to abut • the housing member -end through uihich the bore opens uninterrup- tedly, to close the latter. Advantageously the rotary moυsrr.ent can be applied to the outer periphery of the housing member . Conveniently rotary movement may be applied to the substan¬ tially cylindrical cam ΓΠ=.Γ.DΞΓ uia a shaft keyed to the ca~ σsm er ωhich is mounts--, on the shaft. The invention also contemplates the provision of an artifi¬ cial limb including- at least one lockable pivotal connection device as aforesaid, as a joint. Conveniently the limb includes mechanical, electrical, pneumatic or hydraulic means τor displacing the projection, and hence the lock member between the first, second and median posi¬ tions. Advantageously the artificial limb is in the form of a leg. For a better understanding of the .present invention and to shoω hoω the same may be carried into effect, reference will noi be made, by ωay of example, to the accompanying drawings, in ωhich :- Figure is a side vieω taken on the line A-A -in Figure 3 of the lockable pivotal connection device according to a first embodiment of the invention, Figure 2 in a vieω from above of the device of Figure 1 Figure 3 is a cross-sectional vieω of Figure 1 taken on the line B-3, Figure A is an exploded perspective vieω of a slightly modified version of the device of Figures 1 to 3, Figure 5 is an exploded side vieω of a lockable pivotal connecting device according to a further embodiment of the present invention, Figure 6 is a plan vieω taken on the line F-F of Figure 5, iQure 7 is a σlan vieu« tanen on the line G-G of Fiαure 5 , and Figure 8 is an exploded perspective vieω of the device of Figures 5 to 7. A lockable pivotal connection device according to a first ejπbodiπent of the 5 invention as shown in Figures 1 to 3 and the modified version of Figure 4 of the accompanying draωings, includes a base member 1, a housing member 2, an annular lock member in the form of a ring 4 and a cam member in the form of a plate 7. The base member 1 and housing member 2 at least partially overlap and are pivotally interconnected 10 at the overlapping region via the lock member ring 4 and cam member plate 7 ωhich are housed in a cylindrical bore 3 in the housing member 2. The members 1 and 2 are rotatively pivotal relative to one another about a rotary pivot axis formed by the . longitudinal axis of the cylindrical bore 3. 5 The annular lock member ring 4 is made of any convenient material such as bronze or brass and housed in the cylindrical Λ bore 3 with the outer periphery a of the ring 4 adjacent to and preferably in rotary slidable contact with the inner periphery of the cylindrical bore 3 so that the housing member 2 is rotatable about 20 the ring 4. This ring 4 has at least three bearing members 5, conven¬ iently in the form of balls as illustrated, movably housed in apertures 6 opening radially through the inner and outer peripheries of the ring 4 at peripherally spaced locations therearound. Of course, if desired, more than three bearing members 5 may be 25 provided. The cam member plate 7 has a generally circular periphery with, spaced around the plate periphery, at least three substantially planar, concave or convex cam faces 8. As illustrated the ' faces 8 are planar. Of course the same number of cam faces 8 should be r-r- provided as are bearing members 5 for cooperation therewith. The cam plate 7 is housed in the lock ring 4 with the outer periphery of the cam plate 7 adjacent to and preferably in peripheral slidable contact with the inner periphery 4b of the ring 4 and with the bearing members 5 in contact with the respective cam faces 8 as shown ' in Figure 1 of the drawings. A cover plate 9 is fixedly attachable to " the cam plate 7 and to the base member 1 in any convenient manner such as by tωo screωs 10, so that the cover plate 9, cam plate 7 and base member 1 are rotationally fixed relative to one another and so that the housing member cylindrical bore 3 is closed at least partially at one end by the base member 1 and at the other end by the cover plate 9 to retain the cam plate 7 and lock ring 4 in the cylindrical bore 3 betωeen the cover plate 9 and base member 1 as shoωn in Figures 1 to 3. Means are provided for rotatably displacing the lock member ring 4. In this embodiment the means is a projection 11 provided on one side of the lock ring 4 to extend in a direction parallel to the rotary pivot axis of the device and engage in a corresp¬ onding slot 12 provided in the cover plate 9. Alternatively although not shoωπ, the projection 11 may be replaced .by a groove in, lever or cam.on at least one side of the lock ring 4 or a radial cutout in the housing member 2. The projection 11 and slot 12 are dimensioned such that the projection can be displaced in the recess to a limited extent betωεen a median position M, a first end position E- on one side of the median position Fl and a second end position E _ on the other side of the median position M to rotate, fche ring 4 in either direction to a limited extent about the rotary pivot axis relative to the cover plate 9, cam plate 7 and bass member 1 , as indicated diagrammatically in Figure 1. Thus to operate the device of the present invention, partic¬ ularly the device of the embodiment of Figures 1 to 4, the pro e- ction 11 can be displaced in the slot 12 In any convenient partner such as by mechanical, electrical, pneumatic or hydraulic means, - .not shoωn so that ωith the projection 11 and ring 4 in the median position M the housing member 2 may rotate or be rotated relative to the base member 1 about the ring 4 in either direction D _. or D- as shoωn in Figure 1. On displacing the projection 11, and thus the ring 4, into the first end position E.. the ring 4 is displaced relative to the cam plate 7 causing the bearing members 5 to be displaced by the ring 4 along and up their respective cam faces 8 toωards and into ωedged locking engagement betωeen the inner ■ periphery of the housing member cylindrical bore 3 and the respe- ctive cam faces 8 to stop rotary movement of the housing member 2 relative to the base member 1 in the direction D_. but not in the opposite direction D_. Similarly displacing the projection 11, and thereby the ring 4, into the second end position E- displaces the ring 4 relative to the cam plate 7 in the opposite direction to that in the first end position E-. causing the bearing members 5 to be displaced by the ring 4 along and up their respective cam faces 8, in the opposite direction to that in the first end position E. , towards and into ωedged locking engagement betωeen the inner peri¬ phery ' of the housing member cylindrical bore 3 and the respective cam faces 8 to stop rotary movement of the housing member 2 relative to the base member 1 in the direction D_ but not in the opposite direction 0 1 . Thus in this way the device may be operated to alloω the members 1 and 2 to rotate in either a clockwise or anti-clockωise direction or to prevent rotation betωeen the members 1 and 2 in a clockwise or anti-clockwise direction as required. This is particularly desirable when the device is used as a joint in an artificial limb, such as an artificial leg, and it can be locked and unlocked simply by moving the projection 11 in any convenient manner by mechanical, electrical, pneumatic or hydraulic devicesuhich may be, in turn, activated by a sensor or sensors. As can readily be understood the energy required to actuate the device by moving the projection 11 is relatively small as indeed the locking force is not provided by the actuating force. The locking force, once the device is actuated, is provided by, in effect, a wedging action of the bearing members 5 in to a taper:.rig opening defined by the inner periphery of the cylind¬ rical bore 3 in the housing member 2 and the associated cam face 8. In effect movement of the lock ring 4 towards the end ' positions E 1 or E_ moves the bearing ' members 5 from the median position M in which they have sufficient clearance between the cam face 8 and inner periphery of the cylindrical bore 3 of the housing member 2 not to impede rotation of the housing member 2 about the ring 4, into a position where they are forced into ' the tapering opening or gap between the inner periphery of the bore 3 and the associated cam face 8 so as to jam or wedge by friction between the inner periphery of the bore 3 and the cam face 8 and thus lock the housing member 2 against rotation in the direction which tends to force the bearing members 5 further into the tapering opening or gap between the inner periphery of the bore 3 and the cam face 8. Of course movement of the housing member 2 in the opposite direction will not be impeded as this will tend to displace the bearing members 5 back out of the tapering opening -or gap between the inner periphery of the bore 3 and the cam face 8 and thus out of wedging contact therewith. Alternatively, although not illustrated, the projection 11 and slot 12 may be dimensioned such that the projection can be displaced in the slot to a limited extent between one pos¬ ition corresponding to the median position M and another position corresponding to, for example, the first end position E.. In this way a device may be produced wheh can be locked against rotary movement of the housing member 2 relative to the base member 1 in one direction only, such as in the direction D, but not D-. Of course the device could be made so that the projection 11 is moveable between the one or median position M and another or second end position E~ to stop movement in the direction D 2 but not D,. One way of providing this limited operation would be to put a stop, removable or fixed, on the device of Figures 1 to 4 in any convenient manner to prevent the projection 11 being moved other than between the median position M and one only of the end positions E. or E.,. Indeed the means for moving the pro¬ jection 11 may be made operable so as to be capable of moving the projection ]] between the πiedi i position M and only one of the end positions E. , E... In the embodiment of Figures 1 to 4 the bearing members 5 may be loosely housed in the apertures 6 in the ring 4 as shown in Figures 1 to 3 or may be resiliently biassed so as normally to urge the lock ring 4 towards the median position M of the projection 11 as shown in Figure 4. Additionally the bearing members 5 may b.e resiliently biassed towards .the cam faces 8 and away from the inner periphery of the housing member cylind- rical bore 3. As illustrated in Figure 4 the bearing members 5 are each provided with two biassing coil springs 13 housed in corresponding recesses 14 in the ring 4 and communicating with and one on either side of the associated bearing member aperture 6. If desired only one such spring 14 can be provided and one such recess 14 located on one side of the associated DΞ: r-irn member 5 in the peripheral direction of the ring 4. Such one spring 14 is located on the trailing side of the bearing member 5 with respect to the other position of the projection 11 so as to urge the bearing member in the direction of- the other position of the projection 11 towards the tapering opening or gap between the inner periphery of the bore 3 and cam face 8. This alternative is for use when the device is capable of restric¬ ting rotary movement in one direction only by having a lock ring 4 moveable only between said one and other positions. Alternatively the resilient bias may be provided by a pad or pads of elastic material instead of springs. In the embodi¬ ment of Figures 1 to 4 the cover plate 9 is attached to the cam plate 7 and base member 1 by at least two screws 10 passing 1 ? through the plates 7 and 9 and engaging in threaded bores 15 provided in the base plate 1. Moreover 'the slot 12 for the pro¬ jection 11 is provided in this cover plate 9. The embodiment of the invention illustrated in Figures 5 to 8 is basically similar to that of Figures 1 to 4 and like parts will not be redescribed in detail. However in the embodi¬ ment of Figures 5 to 8 the housing member 2 is cylindrical in shape ωith the -bore 3 opening uninterruptedly through one end IB of the housing member 2 and opening via a reduced diameter aperture 17 through the other end 18 of the housing member 2. As illustrated in Figure 9 the end 18 may be formed separate from the remainder of the member 2 and fixedly attached thereto for rotation therewith such as by peripheral tabs 18a engaging in corresponding recesses 2b in the adjacent end face of the member 2. The lock member also is in the form of a ring 4 carr- ' ying at- least three and preferably six bearing members in the form of rollers 5 ωith locating springs 13 housed in apertures 6. The cam member 7 is substantially cylindrical in form having six cam faces 8, preferably planar, peripherally spaced therear¬ ound as illustrated In Figures 5 and 7. As shoωn in Figure 9 these faces 8 may be of reduced length relative to the rotational axis through the member 7 to provide an improved free running surface for the member 7 in the member 4. This cam member 7 is axially bored at 19 for mounting on a shaft, not shoωn, to ωhich the cam member 7 may be connected via a key In keyωay 20. A reduced diameter end portion 21 is provided on the cam member 7 so that one end of the portion 21 , when t e cam member 7 and lock member 4 are housed in the bore 3, projects out of the hou- sing member aperture 17 ωhich provides a bearing for the portion 2 . The portion 21 is secured in the the housing member aperture 17 by a clrclip 22 fitted in a corresponding groove 23 around ξ ≤Ai OMPI IPO . >J ' the portion 21 on the outer side of the wall- 18 ωith respect to the cam member 7.' In the embodiment of Figures 5 to 8 the slot 12, in ωhich the projection 11 is engaged, is provided through the cover plate 9 as shoωn in Figures 7 and 9. Also in this embodiment the cover plate 9 is axially bored to correspond to the diameter of the bore 19 and fixedly attached, .in any convenient manner, to the cam member 7 at the end thereof remote from the portion 21 to abut the housing member end 16 to close the bore 3 ωith the cam member 7 and lock member 4 therein. Rotary movement can be applied to the outer periphery of the housing member 2. To this end the member 2 may be force fitted or clamped into or on to a part conπεctible for example to an artificial limb component such as that attached to the stump of the amputated limb. Similarly rotary movement may be 'applied to the cam member 7 via the shaft keyed thereto at 20. For artificial limb use, ωith the housing member 2 secured to the artificial limb component attachable to the stump of the amputated limb, the member 7 can be secured to the artificial limb itself via the shaft on ωhich the member 7 is mounted. In Figure 8 the lock ring 4 and cam member 7 have been shoωn slightly displaced angularly ωith respect of Figures 7 to 7, for convenience. The small size of the device of the invention allows its thickness to be kept to a minimum and thus allows it to be fitted beside or below the stump of an amputated limb. This makes the device particularly useful as a joint where the space between the stump of the amputated limb and the joint of the artificial liπb is limited. gTJREA F < OMH

Claims: CLAIMS: 1. A lockable pivotal connection device, including a cylindr- ically bored housing member and, rotationally housed in said housing member bore, a cam member with a generally circular periphery and an annular lock member, with the annular lock member pivotally interconnecting the housing member and cam member for rotary pivotal movement of the housing member and cam member relative to one another about a rotary pivot axis formed by the longitudinal axis of the cylindrical bore, wherein the annular lock member is housed in the housing member bore with the outer periphery of the lock member adjacent the inner periphery of the housing member bore so that the housing member is rotatable about the lock member, which lock member has at least three bearing members movably housed in apertures opening radially through the inner and outer peripheries of the lock member at peripherally spaced locations theraround, and the cam member has a generally circular periphery with, spaced around the cam member periphery, at least three substantially planar, concave or convex cam faces, which cam member is housed in the lock member with the outer periphery of the cam member adjacent the inner periphery of the lock member and the bearing members in contact with the respective cam faces, and means being provided on or engageable with the lock member whereby the lock member can be rotatably displaced to a limited extent between at least two positions to rotate the annular lock member in either direction to a limited extent about the rotary pivot axis relative to the housing and cam members, so that with the lock member in one of said at least two positions, the housing member may rotate relative to the cam member about the lock member in either direction, and with the lock member in the other of said at least two positions, the lock member is rotatively displaced relative to the cam and housing members causing the bearing members to be displaced by the lock member along and up their respective cam faces towards and into wedged locking engagement between the inner periphery of the housing member cylindrical bore and the respective cam faces to stop rotary movement of the housing member relative to the cam member in the direction of said other position but not in the opposite direction towards said one position. 2. A device according to claim 1, wherein the outer periphery of the lock member is in rotary slidable contact with the inner periphery of. the housing member bore and/or the outer periphery of the cam member is in slidable contact with the inner periphery of the lock member. 3. A device according to claim 1 or claim 2, including a base member to which the cam member is fixedly attached, with the annular lock member being in the form of a ring and the cam member in the form of a disc or plate. 4. A device according to claim 3, including a cover plate fixedly attachable to the cam member plate and to the base member so that the cover plate, cam member plate and base member are rotationally fixed relative to .one another and so -that the housing member 'cylindrical bore is closed at least partially at one end by the base member and at the other end by the cover plate to retain the cam member plate and lock member ring in the cylindrical bore between the cover plate and base member. 5. A device according to claim 4, wherein the cover plate is attached to the cam member plate and base member by at least two screws passing through the cover plate and cam member plate and engaging in threaded bores in the base plate. 6. A device according to claim 1 or claim 2, wherein the housing member is cylindrical in shape with the bore opening uninterruptedly through one end of the housing member and open¬ ing via a reduced diameter aperture through the other end of the housing member. 7. A device according to claim 6, wherein the other end of the housing is formed separate from the housing member but fixedly attachable thereto to rotate therewith. 8. A device according to claim 6 or claim 7, wherein the annular lock member has the shape of a ring carrying three or more bearing members in the form of rollers. OMPI ' 9. - A device according to any one of claims 6 to 8, wherein the cam member is substantially cylindrical in form with a reduced diameter end portion one end of which, when the cam member and lock member are housed in the housing member bore, projects out of the housing member reduced diameter end aper¬ ture which provides a bearing for the reduced diameter end portion. 10. A device according to claim 9, wherein the cam member reduced diameter end portion is rotatably secured,in the housing member aperture by a circlip engaged around the reduced diame¬ ter end portion on the outer side of the housing member end wall with respect to the cam member. 11. A device according to claim 10, including an axially bored cover plate fixedly attachable to the substantially cylin- drical cam meπ ar at the end thereof remote from the reduced diameter end portion to abut the housing member end through which the bore opens uninterruptedly, to close the latter. 12. A device according to claim 11, wherein the rotary move¬ ment can be applied to the outer periphery of the housing member. 13. A device according to claim 11, wherein rotary movement may be applied to the substantially cylindrical cam member via a shaft keyed to the cam member which is mounted on the shaft. 14. A device according to claim 4 or claim 11, wherein the means whereby the lock member can be rotatably displaced is a projection on one side of the lock member and extending in a direction parallel to the rotary pivot axis, engageable in a corresponding slot provided either in the cover plate or in the base member, which projection and slot are dimensioned such that the projection can be displaced in the slot to a limited extent between the said at least two positions to rotate the lock member in either direction to a limited extent about the rotary pivot axis relative to the cover plate and cam member 15 * A device according to claim 4, wherein the means whereby the lock member ring can be rotatably displaced is a groove in, lever or cam on, at least one side of the lock ring member or a radial- cutout in the housing member; 16; A device according to claim 14, wherein the lock member is rotatably displaceable to a limited extent between three positions, namely a median position corresponding to said one e position, a first end position, corresponding to said other position, on one side of the median position and a second end position on the other side of the median position, so that with the lock member in the second end position, the lock member is displaced relative to the cam and housing members in the 10 opposite direction to that in the first end position causing the bearing members to be displaced by the lock member along and up their respective cam faces, in the opposite direction to that in the first end position, towards and into wedged locking engagement between the inner periphery of the housing 5 member cylindrical bore and the respective cam faces to stop rotary movement of the housing member • relative to the cam member in the direction of the second end position but not in the opposite direction of the first end position. 17. A device according to claim 14 or claim 16, wherein the 0 bearing members are resiliently biassed in the direction of said other or first end positions and/or said second end posi¬ tion. 18. A device according to claim 17, wherein the bearing mem¬ bers are resiliently biassed towards the cam faces and away 5 from the inner periphery of the housing member cylindrical bore. 19. A device according to claim 17 or claim 18, wherein each bearing member is resiliently biassed by at least one spring housed in a corresponding recess in the lock member on the 0 trailing side of the bearing member with respect to the other or first end position and communicating with the associated bearing member aperture. 20. A device according to claim 19, wherein two such springs are provided for each bearing member located one on each side 5 of the bearing member with respect to the first and second end positions. _OMPl _ 21. A device according to claims 17 to 20, wherein- he bearing members are ball or roller shaped. 22. An artificial limb including a ' least one lockable pivotal connection device according to any one of claim 1 to 21, as a joint. 23. An artificial limb according to claim 22, including mec¬ hanical, electrical, pneumatic or hydraulic means for displacing the projection, and hence the lock member between the first, second and median positions. 24. An artificial limb according to claim 22 or claim 23, in the form of a leg. 25. A lockable pivotal connection device, substantially as hereinbefore described with reference to Figures 1 to 3, Figure 4 or Figures 5 to 8 of the accompanying drawings.

Inventors: PECK ANTHONY LEONARD, PECK, ANTHONY, LEONARD
Applicants: PECK ANTHONY LEONARD, PECK, ANTHONY, LEONARD
Application year: 1984
Main classification: A61F2
IPC codes: A61F2, A61F5, F16C11