J. E. Hanger and Company Limited

J. E. Hanger & Company Limited (british Company)

John E Cooper

Alun Wilcox

A turntable for an artificial limb provides a rotatable joint which enables the limb to be turned into the cross-legged position. The turntable includes two relatively rotatable plates and axially moveable means for locking one plate relative to the other in one position.

Turntable for artificial limb

An alignment device is provided for an artificial limb and comprises first and second end plates fastenable to respective upper and lower parts of the limb in a predetermined angular and axial position. A flexible sleeve fastened between the end plates forms therewith an internal cavity for containing a body of settable fluid. When the fluid body is in a flowable state relative movement between upper and lower parts of the limb during alignment thereof are accommodated by flexion of the sleeve. When the fluid body is in a solidified state it establishes a rigid mechanical linkage between the end plates, thereby preventing relative movement of the upper and lower parts. Angular alignment between an end plate and an adjoining part of the limb is provided by pegs on one of said parts engaging sockets on the other of said parts. Radially flanged ends of the end plate and the adjoining part of the limb abut, and a releasable clamping band encircles the abutting flanges to hold said end plate and said adjoining part axially together. Cavity is air filled prior to use, and passages lead through at least one end plate to the internal cavity for introduction of hardenable material therein. Breather passages are provided for outflow of air from the cavity. The invention also provides a method for manufacturing an artificial limb, by fitting a temporary mechanical alignment device between a stump socket and lower parts of the limb, releasing a mechanism of the temporary alignment device, adjusting the relative positions of the stump socket and the lower parts in a jig, reclamping the alignment device and removing the limb from the jig so that the patient can test the limb. A permanent alignment device having the structure above described is fitted when the correct alignment has been obtained.

Alignment device and method of artificial limb manufacture

A hip joint for a prosthetic leg has first and second members pivoted together by a pin through the first member. The pin includes an outer spool-like spindle roatable in a bearing in said first member and an inner spool-like spindle rotatable in a bearing in the outer spindle and carrying pivots for the second member. The inner spindle has an axis skew to the outer spindle so that firstly an angle may be set between the pivot axis of the joint and said first member by adjusting the relative angular positions of the inner and outer spindles and secondly an attitude of said pivot axis may be set by adjusting the angular position of the outer spindle relative to the first member. The hip joint may have a buffer assembly that contacts an abutment on the first member at a contact line or plane to define a rearward limit of swing of the second member. The buffer assembly may have a first adjustment mechanism by which a limit of swing of the second member can be set and a second adjustment mechanism by which a line or plane or action of the buffer assembly can be aligned with the abutment on the first member. A stride limiter carried by the second member is also described.

Hip joint for prosthetic leg

A shift device for a prosthetic limb comprises: first and second plates having adjoining flat faces in sliding contact. Spaced parallel ribs on an outer face of each plate define a slideway. Guides in the slideways of the first and second plates enable the plates to move generally at right angles to one another. The guides include first and second guide bars slideably received in the respective slideways. One or more longitudinal slots in each slideway permit limited relative translational movement of the plates. Clamping screws pass through each slot of each of the first and second plates into the guide bar in the slideway of the other plate. The clamping screws are releasable to allow relative movement of the plates and on re-tightening immobilize the plates.

Shift device for a prosthetic limb

A compact and lightweight knee joint for a prosthetic leg that can be locked or released with low operating forces comprises upper and lower members interconnected by a pin at a posterior location. A latch pivoted to one of the members for rotation about a vertical axis releasably locks into a recess in the other member to hold the joint in its extended position. The upper member has depending cheeks between which a head of the lower member is received. Adjoining horizontal faces of the upper and lower members are planar and a pad of elastomeric material attached to one of the planar surfaces serves as an extension stop buffer. The latch is blade-like and of bell-crank shape. It fits into slots in the anterior edge of each cheek and is pivoted in one of the slots with an anterior lever thereof spanning between the slots and with a latch head thereof fitting into the other slot. A cable release is fitted to the medial/lateral lever for release of the latch. The cable passes through a bore in the pin and an internal spring urges the latch towards its locking position.

Artificial knee

A first member of an artificial limb such as a tube socket has a generally rhombic flange formed with throughholes grouped into an anterior-posterior pair and a medial/lateral pair spaced at 90 degree intervals about the axis of socket. The lower face of the flange carries a ball formation of a ball and socket articulation. A second member in the form of ankle attachment plate has a concave seat that accepts the ball and threaded bores conforming to the through holes. The first and second members are held together by clamping screws received in the bores that fit onto washers having spherical lower faces that articulate on seats. The resulting alignment device is simple to manufacture and preserves angular position when an adjacent pair only of the clamping screws are removed. A similar alignment device having a cylindrical projection articulating in a cylindrical seat under the control of a single pair of clamping screws provides for heel height adjustment.

Alignment device for artificial limbs

A prosthetic foot comprises a hollow elastomeric cosmesis having a relatively large internal space, a keel of relatively stiff or rigid material, and a stiffener of glass reinforced plastics fitted between keel and instep region of the cosmesis. Front and rear snubbers extend from keel and front and rear stiffeners being portions of stiffener extend from under the keel with radiused ends resting on the sole of the cosmesis. During ambulation the stiffeners provide a primary path by which ground reaction is transmitted to the keel, but ground reaction bringing the stiffeners into contact with the snubbing means is transmitted to the keel via an overload path through the snubbing means.

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Leatherhead, United Kingdom

John E Cooper