US3538516A - Adjustable artificial leg for temporary use - Google Patents

Description

Nov. 10, 1970 J. a. BAILEY ErAL 3,538,516

ADJUSTABLE ARTIFICIAL LEG FOR TEMPORARY USE Filed Oct. 20, 1967 5 Sheets-Sheet 1 LEI-1. ED 17 wafmiwv J. G. BAILEY HAL 3,538,516

ADJUSTABLE ARTIFICIAL LEG FOR TEMPORARY USE Filed Oct. 20,1967 5 Sheets-Sheet 2 Nov. 10, 1970 3,538,516

ADJUSTABLE ARTIFICIAL LEG FOR TEMPORARY USE Filed Oct. 20, 1967 J. G. BAILEY ETA;

5 Sheets-Sheet 3 No'v." IUfIW BAlLEY mum. j 3,538,516

, ADJUSTABLE ARTIFICIAL LEG FOR' TEMPORARY USE Filed Oct. 20. 19s? SSheets-Sheet Nov 16, 1970 J. a. BAILEY ETAL 3,5

v ADJUSTABLE ARTIFICIAL LEG FOR TEMPORARYv USE Filed Oct. 20, 1967 5 Sheets-Sheet 5 5Q 576 3 I 70+ 57 57 -D 1 58 i I: j i- 59 United States Patent 3,538,516 ADJUSTABLE ARTIFICIAL LEG FOR TEMPORARY USE John G. Bailey, Bristol, George J. Wyers, Coseley, Peter Spear, Wolverhampton, and Anthony W. Gregory, Codsall, England, assignors to Rubery, Owen and Company Limited, Darlaston, Wednesbury, Staifordshire, England, a British company Filed Oct. 20, 1967, Ser. No. 676,781 Claims priority, application Great Britain, Oct. 20, 1966, 46,951/66; Jan. 19, 1967, 2,855/67 Int. Cl. A61f 1/04, 1 08 US. Cl. 3-21 Claims ABSTRACT OF THE DISCLOSURE An artificial leg for temporary use after an above-knee amputation is formed by a number of co-operating interengaged parts incorporating means for relative adjustment between parts of the leg transversely, angularly and rotationally to allow the leg to be adjusted over a period of time to accommodate bodily changes in the wearer and then to be used as a template or pattern for a permanent leg.

This invention relates to improvements in artificial legs.

After a leg has been amputated the patient usually has to wait for a considerable time before being fitted with a hand-made sheet metal leg of which the dimensions are copied from the patients own leg. For a period after the amputation, usually about six months, bodily changes take place in the patient which necessitate modifications of the artificial leg and these are expensive and timeconsuming.

One object of our invention is to eliminate or reduce the waiting period before a patient can be fitted with an artificial leg.

Basically, our invention comprises an artificial leg intended for temporary use after an amputation and incorporating means for relative adjustment between the parts of the leg transversely, angularly and rotationally, whereby the leg over a period of, say, six months, can be adjusted until it provides the maximum comfort and convenience to the patient. At the end of that period the multi-component temporary leg can be replaced by a simple single-component permanent leg of which the geometry duplicates that of the temporary leg and which can be made relatively light weight as it need not incorporate any means of adjustment. The multi-component adjustable leg can then be used for another patient.

Transverse and angular adjustments of the lower leg member relative to the socket for the stump in two directions relative to each other are conveniently provided by an assembly comprising a number of super-imposed blocks in sliding engagement with each other, the engaging surfaces which provide the angular adjustments being curved to a substantial radius. After adjustment the blocks are clamped by bolts or screwed pins and preferably the outer ends of the clamping bolts or pins or parts adjacent to their outer ends are slidably engaged in slots in axially extending guiding flanges which are stationary relative to the co-operating blocks which are clamped by the bolts or pins so that separation or opening of the blocks under angularly directed or olfset stresses is prevented.

One practical form of artificial leg in accordance with our invention is illustrated by way of example in the accompanying drawings in which:

FIG. 1 is a rear elevation of the complete leg;

Patented Nov. 10, 1970 "ice FIG. 2 is a vertical section of the leg on the line 22 of FIG. 1;

FIG. 3 is a perspective view of the foot and ankle;

FIG. 4 is a perspective view of the above-knee assembly and the upper part of the lower leg member, with the leg straight;

FIG. 5 is a similar perspective view but showing the lower leg member moved angularly through an angle of slightly more than FIG. 6 is a perspective view similar to FIG. 4, but showing angular and lateral displacement of the lower leg member relative to the upper part of the above-knee assembly;

FIG. 7 is a diagrammatic perspective View of the component parts of the above-knee assembly separated;

FIGS. 8 and 9 are elevations of the parts shown in FIG. 7 assembled and viewed from two directions at right angles to each other;

FIG. 10 is a vertical section of the assembly on the line 1010 of FIG. 9; and

FIG. 11 is a plan of the assembly shown in FIG. 8.

The artificial leg illustrated comprises six main components, a socket 10 to receive the stump of the wearers leg, an above-knee adjustable assembly 11, a knee-joint 12, a lower leg member 13, an adjustable ankle joint 14, and a foot '15. I

The leg illustrated is intended for a wearer having a short stump and the socket 10 is attached by rigid metal straps or bars 16 to a plate 17 secured to the upper mem ber of the assembly 11. The length of the straps or bars depends on the length of the stump, and if the amputation is only a short distance above the knee the socket may be secured directly to the plate 17.

The lower leg member 13 is a tube of square or other rectangular cross-section and is conveniently made of aluminum or light alloy. Advantages of a tube of square cross-section are that it provides flat straight datum faces between the knee joint and the foot, facilitates the mounting of the knee joint, and can readily accommodate a release mechanism or a damper for controlling movement of that joint.

For appearance the tube may be provided with a shaped plastic or other cover.

A fitting 18 mounted in the lower end of the tube 13 has an axially projecting part-spherical boss '19 engaging in a complementary socket in a plate 21 secured to the upper face of the ankle part of the foot 15. A bolt 22 passing vertically through the foot is screwed into a nut 23 located in the boss 19 and having a part-spherical end engaging the inner face of the boss. Rotation of the nut is prevented by a cross-pin 24. The fitting 18 has a radially projecting annular flange 25, and angularly spaced set screws 26 screwed through this flange bear on the upper face of the plate 21.

Thus by slackening the bolt 22 the foot can be rotated about the axis of the leg tube 13 and by means of the set-screws 26 the foot can be adjusted angularly in any direction about the centre of the boss 19 on the lower end of the tube.

The foot 15 may be a rigid one-piece member or the front part 27 may be separate in which case it is flexibly attached to the main part by a strap 28 and a rubber or other sole 29 secured by adhesive to the foot.

At its upper end the lower leg member 13 is pivotally connected by a transverse pin 31 to a plate 32 forming the lower part of the above-knee assembly, the plate having spaced downwardly extending lugs 33 between which the tube fits, and the pin 31 passing through the lugs and through a fitting 34 pinned or otherwise secured to the tube.

The knee joint formed by the pin 31 is normally locked by a transversely slidable member 35 guided on a headed pin 36 screwed into the plate 32. The locking member has at its inner end a Wedge-shaped nose held by a spring 37 in engagement with the inclined face 38 of a lug on the fitting 34. With this arrangement the locking member automatically takes up any Wear in the hinge-pin and prevents rattle.

The locking member is adapted to be retracted by a rocking lever or trigger 39 which can be actuated by the wearer of the leg through a cord or other control member to allow the lower leg to articulate for sitting down.

The member 32 is referred to above as a plate but it is actually a die-cast member forming the bottom element of the adjustable above-knee assembly shown more particularly in FIGS. to 10.

The upper surface 41 of the member 32 which incorporates an upstanding parallel-sided guiding rib 42 is formed with a cylindrical concave curvature of large radius. It engages with the complementarily curved convex underside 43 of a block 44 which incorporates a parallel-sided groove 45 to receive the rib 42.

A parallel-sided groove 46 with a flat base is formed in the upper face of the block 44 and slidably receives a complementary rib 47 on the underside of an intermediate member 48 for relative sliding movement in a straight line between the block 44 and the intermediate member 48.

The upper surface 49 of the member 48 is formed with a cylindrical concave curvature of large radius, the center of curvature being at right angles to that of the surface 41 of the member 32. The surface 49 engages slidably with the complementarily curved convex undersurface of an upper block 52. The surface 49 incorporates a parallel-sided upstanding rib 53 which engages slidably in a complementary groove 54 in the underside of the block 52, the rib 53 and groove 54 being at right angles to the rib 42 and groove 45.

Finally, there is a parallel-sided groove 55 with a flat base in the upper surface of the block 52 which slidably receives a downwardly projecting complementary rib 56 on the underside of a top member 57 for relative sliding movement in a straight line between that member and the block 52, that movement being in a direction at right angles to the sliding movement between the block 44 and the intermediate member 48.

*It will be appreciated that relative movements between the various parts of the assembly described above provide for transverse and angular adjustments in two directions at right angles to each other of the bottom member 32 which carries the lower leg relative to the top member 57 to which the stump is attached. By a combination of the various adjustments the axis of the lower leg can be moved transversely in any direction relative to the stump and its angular disposition can be adjusted in any direction within the limits imposed by the means for connecting the parts of the assembly.

As shown in the diagrammatic exploded view (FIG. 7) the parts of the assembly are held together and clamped after adjustment by bolts 58, 59.

The bolt 58 passes through a hole 61 in the block 52, a straight slot 62 in the top member 57, and a slot 63 in the rib 53, which slot 63 is curved to the same radius as the co-operating surfaces 49 and 51.

The bolt 59 which is at right angles to the bolt 58 passes through a hole 64 in the lower 'block 44, a straight slot 66 in the rib 47 on the intermediate member 48, and a slot 65 in the rib 42 on the member 32, the slot 65 in the rib 42 being curved to the same radius as the cooperating surfaces 41 and 43.

Assuming the top and bottom surfaces of the assembly to be initially parallel and horizontal and at right angles to an imaginary vertical axis passing through the center of the assembly, sliding movement of the member 57 relative to member 52 and of the intermediate member 4 48 relative to the member 43 provide horizontal displacement of the member 57 relative to the member 32 in two directions at right angles to each other without affecting the parallelism of the top and bottom surfaces of the assembly.

Sliding movement of the member 52 relative to the intermediate member 48 and of the member 44 relative to the member 32 produce angular adjustment in two directions at right angles to each other of the lower member 32 to which the lower leg member is pivoted and the upper member 57 which is secured to the plate 17 on the lower end of the socket 10.

In the practical construction shown in FIGS. 4, 5 and 6 the intermediate member 53 is formed with upwardly and downwardly extending flanges 67, 68 which are at right angles to each other and bear on the outer faces of the adjacent blocks and incorporate arcuate slots 69, 71 for the bolts. Each bolt has an enlarged cylindrical portion 72 adjacent to its head which is guided in a slot 69 or 71 and provides a shoulder bearing on the block to be clamped.

The provision of the flanges 67 and 68 prevents separation or opening of the blocks under angularly directed or offset stresses.

If desired graduations may be provided on some of the parts of the assembly for convenience in making and recording adjustments.

As shown more particularly in FIGS. 5 and 6 the plate 17 to which the socket 10 is secured by screws 73 is itself secured to the upper member 57 of the adjustable aboveknee assembly by screws 74 passing through arcuate slots 75 in the plate so that the assembly carrying the knee joint, lower leg, and foot can be adjusted rotationally relative to the stump to vary the position of the axis of the knee joint relative to the axis of the stump.

It will be appreciated that with a leg as described above adjustments can be readily made to deal with changes in the balance and walking of the patient during a period of, say, six months after which no further appreciable bodily changes will take place and the leg should be as convenient and comfortable as it is possible to make it.

The adjustable leg with all the final adjustments is then used as a model or template for the permanent leg which, so far as the patient is concerned, will be identical with the adjustable leg except that it can be considerably lighter as it will not incorporate any adjustable parts.

In one method of doing this, the lower leg tube is clamped in a suitable fixture and adjustable probes, fingers or the like are employed to measure and establish the positions in space relative to the leg tube of a number of points on the other parts of the leg sufficient to allow the production of a simple permanent leg conforming exactly to the temporary leg as finally adjusted to suit the patient.

The adjustable leg can then be used for other patients.

The adjustable leg can be fitted very soon after amputation has taken place so that the mental and physical effects on the patient of being without a leg are minimised.

We claim:

1. An artificial leg for temporary use after an aboveknee amputation and comprising: a socket for the leg stump, an adjustable above-knee assembly, means connecting said assembly to the socket, a lower leg member, a hinge joint connecting said lower leg member to said above-knee assembly, a foot, and an adjustable ankle joint connecting said foot to the lower end of said lower leg member, said above-knee assembly embodying a plurality of co-operating members slidable relative to each other in directions substantially at right angles to the axis of the leg and having respectively planar and cylindrically curved complementary surfaces, said co-operating members having relative sliding movement between, selected ones of said members to produce transverse and angular displacement of the lower leg member relative to the -socket in two directions at right angles to each other, and

means for locking said co-operating members in selected positions of adjustment.

2. An artificial leg as defined in claim 1 wherein said locking means for said above-knee assembly includes bolts arranged at right angles to one another and extending through said co-operating members.

3. In an artificial leg embodying a socket for a leg stump, a knee-joint, a lower leg member connected to said knee-joint, and a foot connected to the lower end of said lower leg member, means for providing transverse and angular adjustment in two directions of the lower leg member relative to the socket comprising: an above-knee assembly incorporating a first block secured to said socket, a second block, co-operating surfaces on the underside of the first block and the upper side of the second block in guided sliding engagement for relative sliding movement between said blocks in a single plane, a third block, co-operating complementary cylindrically curved surfaces on the underside of the second block and the upper side of the third block, said surfaces being in guided sliding engagement, a fourth block, co-operating surfaces on the underside of the third block and the upper side of the fourth block in guided sliding movement in a single plane and in a direction at right angles to the guided sliding movement between the first and second blocks, a fifth block carrying a hinge joint for the lower leg member defining said knee-joint, co-operating complementary cylindrically curved surfaces on the underside of the fourth block and the upper side of the fifth block for guided sliding movement between said blocks, the axis of curvature of said surfaces being at right angles to that of the cylindrically curved co-operating surfaces on the second and third blocks, and means for locking said blocks in selected positions of adjustment.

4. An artificial leg as defined in claim 3 wherein said means for locking said blocks of said above-knee assembly includes first and second bolts each passing through three blocks and being at right angles to each other.

5. An artificial leg as defined in claim 3 wherein said blocks are provided with co-operating guiding ribs and grooves on their engaging surfaces.

References Cited UNITED STATES PATENTS 2,897,512 8/1959 Sackett 322 3,273,168 9/1966 Gardner et al 321 XR 3,414,908 12/1968 Waggott et a1 3-2l XR 3,422,462 1/ 1969 Finnieston 321 FOREIGN PATENTS 478,219 9/1915 France. 978,586 12/1964 Great Britain.

RICHARD A. GAUDET, Primary Examiner R. L. FRINKS, Assistant Examiner US. Cl. X.R. 3-26, 31

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