GB2338899A

GB2338899A - Connector for orthoses or prostheses

Info

Publication number: GB2338899A
Application number: GB9814298A
Authority: GB
Inventors: Colin Dix
Original assignee: ORTHO EUROP Ltd; Ortho Europe Ltd
Current assignee: ORTHO EUROP Ltd; Ortho Europe Ltd
Priority date: 1998-07-01
Filing date: 1998-07-01
Publication date: 2000-01-12
Also published as: GB9814298D0

Description

Connector for orthoses or prostheses The present invention relates to a connector for attaching prostheses or orthoses.

Many systems have been previously proposed to attach orthoses and protheses to the human body. One previously proposed system involves the attachment of a sock on the residual limb or stump at the end of which is placed a connection member. The connection member is a pin that is screwed into the end of the sock and has a series of projections or serrations. The orthosis or prosthesis is then joined to the limb through a joint attached in a receptor for the limb. The joint comprises a spring loaded catch mechanism. The catch mechanism clicking out over each successive projection on the pin and locks into an appropriate indentation on the pin.

This system has presented problems in the past. A first of which is the pin not being adjustable in position on the stump sock, with the result that it is unable to cope with variations in the stump volume.

These may have various causes and result in the prosthesis or orthosis being unable to attach or alternatively clicking slightly into an indentation but not fully securing.

The first aim of the present invention is to provide a system whereby this problem may be overcome.

Accordingly a first aspect of the present invention is directed to a pin for a ratchet connection for an

orthosis or prosthesis, in which the pin is lockably adjustable in length. This enables the user of the stump sock to adjust the position of the pin if the stump volume increases or decreases thus ensuring comfort of connection and proper connection of the orthosis or prosthesis. This is especially vital with regard to walking where there can be disastrous consequences for failure to properly attach the prosthesis.

In the preferred embodiment the pin is equipped with a locking member which ensures that it is adjustably locked in a set position. Preferably the locking member is a locking nut which works on the same thread that the pin works on. This has the advantage that it is a simple addition to the pin with the result that it can easily be added to existing socks without need for purchase of a new orthosis or prosthesis.

A second problem encountered in the existing system is that when the pin is pushed into the latch or catch mechanism, the catch mechanism is moveable in a plane perpendicular to the pin. This results in the problem that the pin can be stuck in the mechanism in position without therefore creating great difficulty for the removal of the prosthesis.

Accordingly a second aspect of the present invention is directed to a connector for an orthosis or prosthesis comprising a body containing a moveable catch or latch which is urged by a spring against a stop, the catch being movable in a direction perpendicular to a

connection pin attached to a stump sock in which the catch is moveable in one direction only when the connection pin is inserted and held by the catch. This provides the advantage that when the pin is pushed into the connector there is no movement possible of the catch other than in the intended backwards and forwards movement as the projections on the pin pass. This ensures that the catch does not lock onto the pin stopping removal of the prosthesis or orthosis.

In a preferred embodiment the catch is retained by a projecting member which also ensures the movement in only one direction. This provides the advantage that the mechanism for retaining the catch in the body and restricting its movement is the same, thus lowering the number of parts required.

Preferably the catch is a tubular part.

Advantageously the catch is equipped with a groove which accommodates the projecting member and retains it.

In the preferred embodiment the projecting member is a grub screw. The advantage is that this is a readily removable part to enable it to be made to the connector.

An example of a connector made in accordance with the present inventions is now described below with reference to the accompanying drawings in which Figure 1 shows an exploded view of the parts of the connector; Figure 2 shows a cross section through the connector with the pin attached;

Figure 3 shows various views of the inner body of the connector; Figure 4 shows the action of the pin with regard to prior art devices; Figure 5 shows various views of the casing for the catch; Figure 6 shows various views of the catch; Figure 7 shows various views of the plunger for the catch; Figure 8 shows various views of the outer body for the joint attachment; Figure 9 shows the universal joint to join the intended limb onto the connector; Figure 10 shows the pin for the stump sock; and Figure 11 shows the locking nut for the pin.

Figure 1 shows an exploded view of the parts that create the connector for the prosthetic limb. A pin 10 is provided which will be attached to the stump sock of the residual limb. The pin 10 has a screw thread 12 at one end, which screws into a stump sock (not shown). The other end of the pin 10 has a series of projections or serrations 14 for engagement in the connector. The pin 10 is further equipped with a locking nut 16 which locks it to a set position in the stump sock. This has the advantage that the length of the pin 10 can be varied depending upon the volume of the stump.

The connector comprises the inner body 18 which contains a through hole in which is inserted a casing 20.

Inside the casing 20 is a compression spring 22.

Pressed against the compression spring 22 is a catch 24 attached by a screw thread to a plunger 26. An inner casing 18 is held against an outer casing 28 by an O-ring 30. The outer casing 28 is attached at its bottom to a universal joint 32. The universal joint 32 is held there by bolts 34 which engage inside the body 28. The catch 24 is held in the casing 20 by a grub screw 36 which is screwed in by an Allen key.

Figure 2 shows a cross-section through the assembled connector. As can be seen the catch 24 locks against the projections 14 on the pin 10. The catch 24 is urged against these projections 14 by spring 22. The catch 24 surrounds the pin 10 and has an angled catch surface 38 which engages of indentations of the projections 14. As can be seen the catch 24 is retained in the casing 20 by the grub screw 36 which projects into a groove 40 in the intended upper surface of the catch 24. The catch 24 is disengaged from the pin 10 by pressing in the plunger 26 against the force of the spring 22. The pin 10 can pass completely through the inner body 18 and the outer body 28 of the connector and also passes through the joint 32.

The inner body 18 is held within the outer body 28. The connector attaches to a receptacle (not shown) made of a material such as fibreglass for the residual limb. The orthotic or prosthetic limb is then attached to universal joint 32 by a known method.

Figure 3 shows the inner body 18 of the connector in

cross section and perspective views. From these it can be seen that it has a through hole 42 to accept the casing 20 it also has a hole 44 perpendicular to the hole 42 to accept the grub screw 36 which also retains the casing 20. The inner body 18 is preferably made of plastics material.

Figure 4 shows a schematic view of the prior art catch 22 and the catch according to one aspect of the present invention. As can be seen in Figure 4a and b the prior art catch 22 was able to rotate in the casing 20 and depending upon how it rotated it would jam on one of the projections 14 of the pin 10 stopping removal of the prosthesis or orthosis. However, Figure 4c shows the catch 22 according to one aspect of the present invention in which the presence of the grub screw 36 in a groove 46 in the top of the catch stops rotation of the catch 22.

Figure 5 shows the casing 20 to hold the catch 22.

As can be seen it has a through hole 48 into which the pin 10 fits and a further hole 50 next to it through which the grub screw 36 screws. Thus the casing 20 is retained by the grub screw 36 in the inner body 18. The casing 20 is preferably made of stainless steel.

Figure 6 shows the catch 22. The catch 22 has a through hole 50, to accommodate the pin 10, the side of which in the direction of horizontal movement has the angled catch surface 38. The facing surface is purely vertical. The catch 22 is equipped with a thread screw head 52 at one side for attaching to the plunger 26. The

top surface of the catch 22 has a groove 46 in it. The groove 46 has an abutment surface 54 on its inner surface so that the catch 22 is retained inside the casing 20 by the grub screw 36. The catch 22 is preferably made of stainless steel.

The plunger 26 is shown in Figure 7 and has at one end a screw threaded hole 56 for joining to the catch 22 and at the other end a groove 58 on its flat surface to accept the head of a screwdriver or similar such tightening tool.

Figure 8 shows the outer body 28. The outer body 28 is preferably made of aluminium alloy. The outer body 28 has on its intended lower surface six spaced apart screw holes 60 for holding the universal joint 32. The outer body 28 has a hole 62 through its middle in order to fit the inner body 18. It has a through hole 64 perpendicular to the through hole 62 to accept the casing 20.

Figure 9 shows standard universal joint 32, in this case a pyralock. This is equipped with six holes 66 to join it by bolts 64 to the outer body 28 and has a through hole 68 through which the pin 10 will fit. The joint 32 is preferably made from titanium.

Figure 10 shows the pin 10 in closer detail. A through hole 66 can be seen which allows tightening of the pin 10 in the stump sock. Figure lOa shows the projections or serrations 14 blown up whereby it can be seen that each projection 14 has an angle to its outer

edge, in this case preferably 72.50 from its perpendicular surface and a shaped inner edge next to the perpendicular surface of 48 . This facilitates better locking of the catch 22 to the pin.

Figure 11 shows the locking nut 16 in greater detail from which it can be seen that it has two flat edges 68 parallel to each other to enable the attachment of a spanner.

Claims

CLAIMS 1. A pin for a ratchet connection for an orthosis or prosthesis, in which the pin is lockably adjustable in length.
2. A pin according to claim 1 in which it is equipped with a locking member which ensures that it is adjustably locked in a set position.
3. A pin according to claim 2, in which the locking member is a locking nut which works on the same thread that the pin works on.
4. A connector for an orthosis or prosthesis comprising a body containing a moveable catch or latch which is urged by a spring against a stop, the catch being movable in a direction perpendicular to a connection pin attached to a stump sock in which the catch is moveable in one direction only when the connection pin is inserted and held by the catch.
5. A connector according to claim 4, in which the catch is retained by a projecting member which also ensures the movement in only one direction.
6. A connector according to claim 5, in which the catch is equipped with a groove which accommodates the projecting member and retains it.
7. A connector according to claim 5 or claim 6, in which the projecting member is a grub screw.
8. A connector according to any one of claims 4 to 8, in which the catch is a tubular part.

<Desc/Clms Page number 10>
9. A pin for connector substantially as described herein and shown in Figures 1,2, 10 and 11 of the accompanying drawings.
10. A connector substantially as described herein with reference to Figures 1 to 9 of the accompanying drawings.