JPH10165430A - Knee joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a knee joint with which a user doesn't stumble. SOLUTION: The front end of the joint lower part 1 and the middle part of the joint upper part 7 with a socket receiving part 6 at the top front are pivotally connected by a support arm 4. A slanting lever 9 pivotally connecting the rear end part of the joint lower part 1 and the rear end part of the joint upper part 7 is made a four-joint link mechanism making the upper connecting point slant backward from the vertical base line of the lower connecting point in a standing phase. The top end of a cylinder vertically installed on the lower part of the joint is resiliently brought into contact with the lower lever part of the slanting lever 9 to make a bent knee fixing means which keeps the slanting lever usually aslant backward and disperses load on front and rear of the lower part of the joint. The artificial joint also has a folding mechanism which releases the bent knee fixing when the slanting lever 9 interlocked with the upper part 7 of the joint which moves forward as the weight moves when the leg is kicked out exceeds the vertical base line, and an automatic lower leg pipe swing mechanism which returns the slanting lever 9 slanting forward in a playing phase by resilience of the cylinder to swing the lower leg pipe when the leg is moved toward the normal leg. Therefor, toe returning action after kicking out is automatically carried out and smooth walking can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knee joint for a skeletal prosthesis which obtains a knee bending close to a natural gait when walking.

[0002]

2. Description of the Related Art Generally, a knee joint used for a skeletal prosthesis for a thigh is, for example, a drum type brake between an upper joint (an upper joint) where a socket for a cut end is attached and a lower joint (a lower joint) where a crus pipe is attached. There is known a safety type in which a mechanism is interposed so that a brake is activated when weight is applied in walking motion. That is, the pivot shaft provided on the joint upper side is connected to the front position of the split drum portion provided with a slit for brake disposed between the joint upper part and the joint lower part, and the knee joint shaft provided on the joint lower part side at the rear position. They are connected (see Japanese Patent Publication No. 52-43232).

[0003]

However, in the conventional knee joint in which a drum type brake mechanism is arranged between the upper part and the lower part of the joint as described above, the effectiveness of the brake (joint fixation) depends on one side of the slit of the split drum. It is determined by the pressing force caused by the weight applied to the (upper joint side). That is, the effectiveness of the brake in this case depends on the weight of the wearer. What's particularly bad about this mechanism is that the brakes work once and the joints are fixed when the weight shifts while walking, and then the brake drum is loosened and the joints are released, and then the pendulum starts to swing. Due to the gradual movement, the swinging operation of the lower leg side pipe during walking is slow, and the so-called kicking phenomenon in which the toe hits the ground is likely to occur, and if not used, safety is lacking. Of course, the movement of the knee joint is not a smooth movement that matches walking, but it is an unnatural gait and has a defect that allows a third party to use the prosthesis at a glance.

In view of the above-mentioned circumstances, the present invention provides a brake mechanism interposed between a lower part of a joint and an upper part of a joint, in which an upper and lower part of the joint is connected to a front and rear support arm and an inclined lever body which always receives a spring pressure and is always inclined rearward. A simple configuration that releases the knee bending fixation by tilting the front of the tilting lever body along the upper part of the joint that moves when the weight shifts during kicking out, and the movement of the tilting lever body that automatically returns in the swing phase is swinging out of the lower leg pipe It is an object of the present invention to provide a knee joint that solves the above problems.

[0005]

SUMMARY OF THE INVENTION The present invention provides a joint prosthesis in which a lower leg axis is shifted backward from a lower leg axis, and a joint receiving portion provided with a socket receiving portion at a front lower end of a lower joint and a front upper end connecting a lower leg pipe. The upper intermediate point is pivotally connected by a pair of support arms, and the upper lever is connected to the rear end of the lower joint and the rear end of the upper joint. The rear end is tilted backward from the vertical base line to form a four-joint link mechanism as a whole, and the upper end of a cylinder vertically mounted below the joint is elastically contacted with the lower lever portion of the tilt lever body, and the tilt lever body is Knee bending fixation means that always keeps it backward and distributes the load around the lower part of the joint,
A middle bending mechanism that can release the knee bending fixation at a forward tilt position exceeding the vertical base line parallel to the axis of the crus pipe, with the inclined lever body interlocking with the upper part of the joint receiving a forward load due to weight shift at the time of kicking; And a lower leg pipe-side automatic swing-out mechanism that swings the lower leg pipe to return the tilting lever body, which is tilted forward, to the swinging phase in which the weight shifts, and then returns the middle bend by popping the cylinder.

In a skeletal prosthesis in which the lower leg axis is displaced rearward from the lower leg axis, a pair of supporters are provided for the front end of the lower joint, which connects the lower leg pipe, and the middle part of the upper joint, which is provided with a socket receiving portion above the front end. The tilted lever body pivotally connected by the arm and pivotally connected to the rear end of the lower part of the joint and the rear end of the upper part of the joint is such that the upper connection point is behind the vertical base line of the lower connection point in the standing phase. A four-bar linkage is formed as a whole with a rear inclination, and the upper end of a cylinder vertically mounted on the lower part of the joint is resiliently abutted against the lower lever part of the inclination lever body. Knee bending fixing means dispersed around the lower part, knee bending at the forward leaning position exceeding the vertical base line parallel to the axis of the lower leg pipe in conjunction with the upper part of the joint receiving the front load due to weight shift at the time of kicking out Fixed Bending mechanism, and automatic swinging of the lower leg pipe as the swinging of the lower leg pipe, in which the tilting lever body, which is tilted forward, is returned by the popping of the cylinder in the swing phase, which shifts the weight to the healthy foot side, and the operation of returning the middle bending is the swing of the lower leg pipe By sliding the mechanism and the sliding-type knee bending restricting operation shaft that is horizontally inserted in the middle of the tilting lever body, the amount of protrusion of the brake piece perpendicular to the tilting lever body is switched to release the front tilting rotation restriction and release the upper part of the joint. And a sitting knee bending mechanism that can be turned over.

In this case, the amount of protrusion of the brake piece is changed by a push screw which is screwed into the operation shaft, and the center bending angle is finely adjusted.

As described above, the knee joint has a lower joint and an upper joint, the front and rear portions of which are connected with the support arm and the tilt lever body to form a four-bar linkage as a whole. Is a rear slope from the vertical base line of the lower connection point, and is a knee bending fixing means that distributes the load applied to the upper part of the joint to the front and rear positions of the lower part of the joint.In the standing phase, the lower part of the joint and the upper part of the joint cause knee breakage. You can maintain a safe posture (stick-and-foot state). At the time of weight change at the time of so-called kicking (a state in which a load is applied to the toe), which shifts from the standing phase to the swing phase, which is a walking motion, the upper part of the joint in which the socket receiving portion is arranged at the upper front end receives the front load and moves forward. Accordingly, the support arm and the tilt lever body exhibiting a link mechanism are also deformed by forward rotation. At this time, the inclined lever body rotates against the thrust of the cylinder received by the lower lever portion.

When the tilting lever body rotates forward and reaches a forward tilting position exceeding a vertical base line (vertical line of the lower connecting point) parallel to the axis of the lower leg pipe, load distribution to the rear is lost and the front of the vertical base line is eliminated. Since the load is shifted to the side, the fixed balance is lost, and the knee bending and fixing are released, resulting in knee bending in which the inclined lever body is further inclined forward. That is, the lower part of the joint rotates backward, and the lower leg pipe side bends backward to form a knee.

[0010] Thereafter, when the weight shifts to the healthy foot side, which is the swing phase, when the preload applied to the upper part of the joint is eliminated and the tilted lever body tilts forward, the lower lever part projecting forward from the lower connection point has a cylinder lever. , The tilting lever body returns to the lower connecting point as a fulcrum and returns to the original rear tilting position. This operation is an operation in which the lower part of the joint at which the lower connection point is arranged rotates, and the lower leg pipe integrally provided at the lower part of the joint is swung out. That is, the lower leg pipe side is automatically swung forward to obtain a smooth gait. In this state, if the tilting lever body interlocking with the swinging of the lower leg pipe side returns to the original rearward tilting state beyond the vertical base line as described above, the load is dispersed to the front and rear positions under the joint as described above, and the knee is moved. It becomes an extended knee bending fixation.

In addition, the maximum knee bending such as sitting (about 18
(0 ° bending), when the sliding-type knee bending restricting operation shaft, which is horizontally inserted, is pushed into one side of the middle part of the inclined lever body,
An axial braking piece which abuts on one side of the operating shaft and has a constant amount of protrusion in the orthogonal direction (rotation direction) is switched to the deep groove of the receiving groove on one side, and the braking piece is retracted into the deep groove and retracted. Therefore, the amount of protrusion is small, and the contact interval of the brake piece to the inner wall of the joint lower part becomes large. That is, the rotation of the tilting lever body can be released by the amount of protrusion of the braking piece. If the upper connecting point of the tilting lever body takes a large turn deeper into the front than the upper connecting point on the support arm side, the upper part of the joint is in the middle. The upper portion of the support arm of the section rotates in reverse with the upper connection point as a fulcrum. In this state, the forwardly inclined tilting lever body is converted into a standing operation by the resilient pushing of the cylinder in contact with the lower lever portion, so that the upper part of the joint further pivots around the upper connection point as a fulcrum and easily reverses, The socket receiving portion at the upper end of the upper portion of the joint is the maximum knee bending with respect to the lower leg pipe side. In other words, the knee bending braking mechanism is a sitting knee bending mechanism in which the joint upper and lower joints have a maximum bending of about 180 ° and are suitable for sitting.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A knee joint according to the present invention will be described below with reference to the drawings of one embodiment.

FIG. 1 shows an embodiment of a knee joint in a skeletal prosthesis which adopts a so-called axial position stabilization (a setting in which the knee axis of the prosthesis is always located behind the weight line) for stabilizing the knee. Reference numeral 1 denotes a joint lower part for connecting the lower leg pipe 3 to the lower end tubular part 2.
The lower end of a pair of support arms 4 is connected to both sides of the front end of the support arm 4 by a pivot 5, and the upper end of the support arm 4 is disposed upward. A pivot 8 is connected to the intermediate portion, and an inclined lever body 9 is fitted to a rear end of the joint lower part 1 with a clevis part 1a formed in the center of the joint lower part and connected with a pivot 10 and an upper end of the inclined lever body 9 Is fitted to a clevis part 7a formed at the rear end of the joint upper part 7 and connected by a pivot 11, and the four-point link mechanism 12 is formed by four-point connection of the support arm 4 and the inclined lever body 9, which are provided in the front-rear direction. . In this case, the inclination of the inclination lever body 9 is
Upper connection point a (position of pivot 11 at rear end of joint upper part 7)
Is slightly behind the vertical base line f which is parallel to the axis e of the lower leg pipe 3 on the joint lower part 1 side raised from the lower connecting point b of the inclined lever body 9 (position of the pivot 10 at the rear end of the joint lower part 1). The center portion 1b of the joint lower portion 1 is provided at the lower end lever portion 13 formed at the inclined position after shaking (for example, the inclination angle α is set to 8 ° or more) and formed at the lower part of the inclined lever body 9 and formed on the front hook.
Armature 14a of spring type cylinder 14 vertically mounted on
And the upper connecting point a of the inclined lever body 9 always faces rearward in the standing phase, and the load applied to the joint upper part 7 is distributed to the front and rear positions of the joint lower part 1 by the support arm 4 and the inclined lever body 9. The knee bending fixing means 15 is constituted. However, the adjustment of the pressure of the cylinder 14
The compression of the spring 14c mounted on the cylindrical portion 14b is performed by changing the degree of screwing of the feed screw 14e into the receiving piece 14d fitted to the lower end of the cylindrical portion 14b.

Reference numeral 16 denotes a sliding-type knee bending restricting operation shaft which is inserted into a horizontal shaft hole 17 formed in a rear intermediate portion of the inclined lever body 9. A guide long groove 18 having a shallow groove portion 18a and a deep groove portion 18b is formed in the direction (see FIGS. 10A and 10B), and an axial type brake inserted into an orthogonal shaft hole 19 formed in the inclined lever body 9 in the guide long groove 18 is provided. Receiving the end of the piece 20, the tip of the brake piece 20 is
Protruding from the front surface 9a of the camera, and the amount of protrusion (projection length) can be switched. The structure of the brake piece 20 includes a main shaft portion 20a having a buffer member 21 disposed at a tip thereof, and a main shaft portion 20b screwed to a rear shaft portion of the main shaft portion 20a. The front portion of the base shaft portion 20b is received by the front surface of the flange-shaped partitioning step portion 26 provided in the middle of the coil spring 22.
The orthogonal shaft hole 19 is received by the rear surface of the partition step portion 26 through the
, And the end of the brake piece 20 is constantly brought into contact with the guide long groove 18. The base shaft portion 20b includes:
Before the horizontal insertion work of the operation shaft 16 arranged in the horizontal shaft hole 17,
It is inserted from the protrusion adjusting and guiding hole 19 ′ communicating with the orthogonal shaft hole 19 and screwed with the main shaft portion 20 a. In addition, the rear end surface of the base shaft portion 20b of the braking piece 20 is provided with the shallow groove portion 1 of the guide long groove 18.
At the position 8a, a push screw 23 for fine adjustment of the protrusion width, which is screwed from behind the shallow groove portion 18a, is brought into contact with the push screw 23 as a fine adjustment mechanism of the protrusion amount. However, the tip of the push screw 23 has an arc shape,
This does not hinder the switching of the brake pieces 20 that come into contact with each other when sliding horizontally.

In this case, the base end of the braking piece 20 (the base shaft portion 20)
b) Switching of the operation shaft 16 causes the deep groove portion 18 of the guide long groove 18 to be changed.
In the position facing b, the amount of protrusion of the tip is minimized, the inclination degree at which the inclined lever body 9 comes into contact with the inner contact surface 1c of the joint lower part 1 is maximized, and the upper connection point a of the inclined lever body 9 is connected to the lower connection point. A sitting knee bending mechanism 24 that wraps around the line connecting the point b and the upper connection point c of the support arm 4 forward from the line connecting the point b to the upper connection point c of the support arm 4 (the pivot 8) as a fulcrum. Be composed. With the above overall configuration, the knee joint 25 can obtain a natural gait.

The operation of the knee joint 2 will now be described.
In use of the lower part 5, the lower leg pipe 3 having a well-known foot 27 attached to the lower end thereof is inserted into the lower end cylindrical part 2 of the joint lower part 1, and the tightening screw 29 of the split groove part 28 provided at the lip is screwed in and tightened. And one. Further, a socket part 30 to which a cut end (not shown) is fitted is attached to the socket receiving part 6 at the upper part of the front end of the joint upper part 7 by using a known attaching member 31. In the femoral skeletal prosthesis configured in this manner, the axis e
Are located behind the load axis g on the socket portion 30 side, and the axial position is stabilized (see FIG. 1).

Here, during walking, the load applied to the joint upper part 7 in the standing phase is such that the supporting arm 4 exhibiting the four-bar linkage mechanism 12 and the upper connecting point a are connected to the vertical base line f (lower thigh pipe) of the lower connecting point b. (Line parallel to the axis e of No. 3), and the transmission is distributed to the front and rear positions of the joint lower part 1 by the rearwardly inclined inclination lever body 9, so that the knees are fixed (stick feet). That is, a force that pushes backward is applied to the tilt lever body 9 that is inclined backward from the vertical base line f of the lower connection point b, and is stable (fixed) in balance with the force of the support arm 4 that pushes forward.
In addition, at this time, the buffer piece 32 arranged in the intermediate frame portion of the joint upper part 7 comes into contact with the front surface 9a of the inclined lever body 9 and becomes immobile, so that the joint lower part 1 does not receive the force of bending backward with respect to the joint upper part 7. The knee is not bent (see FIGS. 1 to 3, 7, and 9A). At this time, the brake piece 20 is slid laterally on one side with the knee bending restricting operation shaft 16 (FIGS. 4, 5 and 5).
7), the shallow groove portion 18 of the guide long groove 18 of the operation shaft 16.
a, and the braking piece 20 is set in such a manner that the tip thereof protrudes from the front surface 9a of the inclined lever body 9 by a predetermined length.

It is to be noted that the rear inclination of the inclined lever body 9 is set at an inclination angle α of 8 ° or more rearward with respect to a vertical base line f starting from the lower connection point b as shown in FIG. When the angle is 8 ° or less, the supporting force applied to the lower connection point b is small and the balance is poor. In this state, the knee is fixed by bending with only a small front load. Unraveling, resulting in rapid knee bending and a lack of safety.

In this state, in the operation from the stance phase to the free leg phase, if a preload is applied to the joint upper part 7 integral with the socket part 30 in accordance with the weight shift during the kick-out period in which a load is applied to the toe, The upper part 7 is shifted forward, and the support arm 4 and the inclined lever body 9 which are linked to the joint upper part 7 are also rotated forward. At this time, the upper connection point a of the tilt lever body 9 of the joint upper part 7 also shifts forward, and the axis h of the tilt lever body 9 itself tilts forward with its lower connection point b as a fulcrum.

Here, the knee axis (center of rotation of the knee) is maintained until the upper connection point a of the inclined lever body 9 on the joint upper part 7 side reaches the vertical base line f raised from the lower connection point b on the joint lower part 1 side.
Is behind the weight line and the load is dispersed at the front and rear positions of the joint lower part 1 so that the knee is not bent and the fixed state is maintained (see FIGS. 7 and 8). Next, when the upper connection point a (axis h) of the inclined lever body 9 reaches the vertical base line f or exceeds the upper connection point a, the load is all applied forward,
The rotation of the tilt lever body 9 acts as the center bending mechanism 33 to release the knee fixation and change to a bent state.

That is, when the weight shift is further continued due to the above-mentioned preload, the tilt lever body 9 tilts forward, and when the upper connecting point a exceeds the vertical base line f parallel to the axis e of the lower leg pipe 3, the tilt lever The rearward load distribution by the body 9 is eliminated, and the entire load is shifted forward from the knee axis. In this case, the tilt lever body 9 has a cylinder 14
To fall forward and rotate against the thrust-up. When the tilt lever body 9 is tilted forward, the support arm side of the link structure also rotates interlockingly, so that the load on the joint upper part 7 is applied to the front of the joint lower part 1, and the bending thereof releases the knee bending fixation. Thus, the so-called middle bend in which the lower leg pipe 3 side faces rearward (see FIGS. 11 to 13 and C in FIG. 9). At this time, the rotation of the tilting lever body 9 is restricted by the brake piece 20 orthogonally projecting from the front surface of the tilting lever body 9 when the brake piece 20 is mounted on the frame receiving surface 1
It stops until it comes into contact with c and does not lead to unnecessary bending of the knee.

Of course, since the knee bending angle slightly varies depending on the patient's foot habit, taste, and the like, the angle can be finely adjusted. For example, FIG. As shown in FIGS. 10A and 10B, the amount of protrusion of the brake piece 20 projecting from the front surface of the inclined lever body 9 may be adjusted. A tool (not shown) such as a screwdriver is inserted through a protrusion adjustment and guide hole 19 ′ through which the operation shaft 16 provided at the intermediate rear portion of the tilt lever body 9 can be seen. When the screw is extended, the push screw 23 moves back and forth to the position of the shallow groove portion 18a of the guide long groove 18, so that the base end of the brake piece 20 facing the shallow groove portion 18a is pushed to adjust the amount of protrusion, and the contact position of the inclined lever body 9 is adjusted. And fine adjustment of the tilt angle is made.

Thereafter, in the swing phase in which the weight shifts to the healthy foot side in the walking motion, the preload applied to the joint upper part 7 is eliminated, and the tilted lever body 9 that has tilted and rotated is thereby moved forward. Since the push-up action of the cylinder 14 is constantly applied to the lower lever portion 13 of the hook fold, the inclined lever body 9 is rapidly returned to the original rearward inclined position with the lower connecting point b as a fulcrum. You. This means that the joint lower part 1 rotates forward when viewed from the joint upper part 7 side. The rotation of the joint lower part 1 causes the lower leg pipe 3 connected to the lower end to be automatically swung forward, so that a foot trip without a kick trip can be obtained. That is, the lower leg lever 13 provided with the lever portion 13 and the cylinder 14 having a constant thrust-up force constitute a lower leg pipe side automatic swing-out mechanism 34. Since the tilt lever body 9 and the supporting arm 4 provided together form a four-bar linkage 12,
Following the rotation of the tilt lever body 9, the support arm 4 also
It can move with the lower connection points c and d as fulcrums.

In this state, the tilting lever body 9 that rotates and returns.
Is a vertical base line f of a lower connection point b similar to the above.
If it returns more backward, the original knee bending fixation is performed.

When the knee bending is desired to be maximized (about 180 ° bending) such as when sitting or cross-legging, the knee bending restrictor which is laterally inserted through the inclined lever body 9 disposed at the rear part of the knee joint 25 is desired. If the user slides the operation shaft 16 in the opposite direction to the above, the position of the operation shaft 16 that receives the braking shaft 20 in the guide long groove 18 on one surface is shifted from the shallow groove portion 18a to the deep groove portion 18b. Since the brake shaft 20 falls into the deep groove portion 18b, the amount of protrusion of the brake shaft 20 is minimized (FIG. 16).
reference).

In this state, for example, if the lower leg pipe 3 is bent and rotated to forcibly rotate the tilt lever body 9 forward against the rebound of the cylinder 14, the tilt lever body 9 projects in the rotation direction. Since the braking piece 20 to be driven is small, the maximum forward tilt is made, and the upper connection point a wraps forward from a line connecting the upper connection point c and the lower connection point a of the support arm 4, and the upper joint 7 of the support arm 4 The support arm 4 is also rotated around the lower connection point d as a fulcrum, and the upper connection point c of the support arm 4 is shifted from the upper connection point a of the inclined lever body 9. When moving backward, the pushing force of the cylinder 14 applied to the lower lever portion 13 acts on the tilt lever body 9, and the upper connection point a of the tilt lever body 9 moves to the upper front of the upper connection point c of the support arm 4. Become like That is, after the tilting lever body 9 has tilted forward to some extent, it once rises to the return state, so that the joint upper part 7 is forcibly inverted (about 180 ° rotation) by this operation.

That is, as the reversing knee bending operation, the operation shaft 16 is displaced and the position of the shallow groove portion 18a of the guide long groove 18 is switched to the position of the deep groove portion 18b (FIGS. 14, 10A, B, 1).
6), the amount of protrusion of the brake shaft 20 is minimized. In this state, if the lower leg pipe 3 is manually bent or a large front load is applied to the socket portion 30 to move the joint upper portion 7 deep forward, the inclined lever body 9 is greatly inclined forward. When the upper connecting point a of the inclined lever body 9 goes deeper than a line connecting the lower connecting point b and the upper connecting point c on the support arm 4 side, the support arm 4 conversely uses the upper connecting point d as a fulcrum and the upper connecting point c side becomes The support arm 4c moves rearward and tilts rearward, and the lower lever portion 13 of the tilt lever body 9 that has turned downward against the rebound of the cylinder 14 is pushed up and the tilt lever body 9 rises. 4 and acts as a sitting knee bending mechanism 24 with the upper connecting point c of 4 being a fulcrum. Actually, the joint lower part 1 is inverted to the joint upper part 7 side, and the crus pipe 3 wraps around to obtain the maximum knee bending (FIG. 1).
5, see FIG. 16).

The maximum knee bending state is normal (walking state).
In the case of returning to the above, the lower leg pipe 3 side is rotated by manually extending or the like, and the upper connecting point a of the inclined lever body 9 of the joint upper part 7 is rotated by the return rotation of the inclined lever body 9. Accordingly, the joint 7 moves backward from the line connecting the lower connection point b and the upper connection point c on the side of the support arm 4, and the inverted joint upper part 7 returns to its original position, and is attached to the joint upper part 7. The axis g of the part 30 is located ahead of the axis e of the crus pipe 3 and returns to the axially stable state. In addition, if the operation 16 of the tilt lever body 9 is shifted in the opposite direction to the above and the braking piece 20 is returned so that the tip thereof projects a predetermined amount, walking using a normal swinging mechanism can be performed.

[0029]

As described above, in the knee joint of the present invention, the joint lower part and the joint upper part are connected at the front and rear parts by the supporting arm and the tilting lever body which form a four-bar linkage, and the tilting of the tilting lever body is performed in the standing phase. It is assumed that the upper connecting point is backward inclined from the lower connecting point,
In addition, the cylinder end vertically mounted on the lower part of the joint is elastically contacted with the lever at the lower end of the inclined lever body to make the inclined lever body always rearward inclined, and the load received at the upper part of the joint is distributed and applied to the front and rear positions of the lower part of the joint. As a result, in the stance phase, the knee axis inherent to the skeletal prosthesis is securely bent and fixed with the knee axis positioned behind the weight line, and a stable stance phase is obtained without inadvertent bending.

If a forward load is applied to the socket part due to a weight shift at the time of kicking when a load is applied to the toe due to the walking movement from the standing phase to the free leg phase, the upper part of the joint is also rotated forward together with the supporting arm and inclined with the supporting arm. The lever body is also deformed forward and the load is dispersed to the front and rear positions under the joint until the upper connection point of the tilt lever body reaches the vertical base line of the lower connection point (a line parallel to the axis of the lower leg pipe). Although it is kept, when the upper connecting point of the inclined lever body exceeds the vertical base line, the load shifts forward so that the so-called knee bending fixation is released, and at that stage, the center bending is performed for the first time, so the reliable kicking out it can.

In the swing phase in which the weight shifts to the healthy foot side, the tilted lever body that is tilted forward automatically returns to the original tilted rearward due to the popping of the cylinder. An automatic swinging mechanism that swings out provides a safe walking motion without kicking stumbling and a natural gait. For this reason, the use of prostheses is not understood, and the wearer of the prostheses becomes the gospel.

Further, the tilting lever body is provided with a sliding-type knee bending restricting operation shaft which is inserted in the horizontal direction and fine adjustment of the projecting amount of the brake piece restricts the forward tilting, so that adjustment after assembly is possible. As a result, a knee bending angle that is suitable for the patient can be selected by fine adjustment of the amount of protrusion of the brake piece.

Further, knee bending should be maximized (about 18
(0 ° bending), the handling can also be done by simply shifting the operation axis of the horizontal insertion through the inclined lever body that serves as the knee bending mechanism. It is automatically switched, and the upper connecting point of the inclined lever body enters ahead of the axis of the support arm, and the joint lower part and the joint upper part are turned around by 180 ° to be able to sit.

In addition, the present invention is composed of a combination of a very small number of parts such as a joint lower part and a joint upper part, a support arm, an inclined lever body and a cylinder, so that the overall structure is finished compactly, the weight of the knee joint is reduced, and the skeleton is improved. It has an effect that is optimal for knee joints for prostheses. The configuration of the cylinder may be a hydraulic cylinder or the like in addition to the spring-type cylinder as shown.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment in which the knee joint of the present invention is mounted on a skeletal prosthesis.

FIG. 2 is a perspective view showing a main part of a knee joint.

FIG. 3 is a side view of the knee joint.

FIG. 4 is a front view of the knee joint.

FIG. 5 is a rear view of the knee joint.

FIG. 6 is a perspective view in which a knee joint is separated.

FIG. 7 is a sectional view of a knee joint.

FIG. 8 is an explanatory diagram showing a state in which a load is applied to a toe that shifts from the standing phase to the free leg phase, and the upper connecting point of the inclined lever body reaches a vertical base line of the upper connecting point parallel to the axis of the lower leg pipe;

FIG. 9 is a diagram showing a load state applied to the tilt lever body,
(A) is an explanatory view of a load state in a standing phase in which the knee is bent and fixed; (B) is an explanatory view of a load state when the inclined lever body reaches a vertical base line of a lower connection point; () Is an explanatory view in which the inclination lever body has moved forward beyond the vertical base line and the load has moved forward.

FIG. 10 is a view showing an operation shaft for restricting sliding knee bending;
(A) is a perspective view seen from the guide long groove side, and (B) is a cross-sectional view.

FIG. 11 is an explanatory view showing a state in which the skeletal prosthesis is bent and fixed while the knee is bent.

FIG. 12 is a side view of the knee joint.

FIG. 13 is a sectional view of the knee joint.

FIG. 14 is a rear view of the knee joint after sliding the knee bending operation shaft.

FIG. 15 is an explanatory diagram of a knee joint in which an upper part of a joint is inverted.

FIG. 16 is a sectional view of the knee joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint lower part 3 Lower leg pipe 4 Support arm 6 Socket receiving part 7 Joint upper part 9 Inclined lever body 12 Four-node link mechanism 13 Lower lever part 14 Cylinder 15 Knee bending fixing means 16 Knee bending regulating operation shaft 18 Guide long groove 20 Brake piece 24 Seated knee bending mechanism 25 Knee joint 33 Center bending mechanism 34 Lower leg pipe side automatic swing-out mechanism

Claims (3)

[Claims] In a skeletal prosthesis in which a lower leg axis is displaced rearward from a lower leg axis, a pair of supports are provided at a front end portion of a lower portion of the joint connecting the lower leg pipe and an intermediate portion of a joint upper portion provided with a socket receiving portion at an upper portion of the front end. The tilted lever body pivotally connected by the arm and pivotally connected to the rear end of the lower part of the joint and the rear end of the upper part of the joint is such that the upper connection point is behind the vertical base line of the lower connection point in the standing phase. A four-bar linkage is formed as a whole with a rear inclination, and the upper end of a cylinder vertically mounted on the lower part of the joint is resiliently abutted against the lower lever part of the inclination lever body. Knee bending fixing means dispersed around the lower part, knee bending at the forward leaning position exceeding the vertical base line parallel to the axis of the lower leg pipe in conjunction with the upper part of the joint receiving the front load due to weight shift at the time of kicking out Fixation A crimp pipe side swing-out mechanism, in which the tilting lever body that tilts forward in the swing phase, which shifts the weight to the healthy foot side, is returned by the popping of the cylinder, and the operation to return the middle-fold is to swing the crus pipe. And a knee joint. 2. In a skeletal prosthesis in which the lower leg axis is displaced rearward from the lower leg axis, a pair of supports are provided at the front end of the lower joint to which the lower leg pipe is connected and the middle part of the upper joint where a socket receiving portion is provided above the front end. The tilted lever body pivotally connected by the arm and pivotally connected to the rear end of the lower part of the joint and the rear end of the upper part of the joint is such that the upper connection point is behind the vertical base line of the lower connection point in the standing phase. A four-bar linkage is formed as a whole with a rear inclination, and the upper end of a cylinder vertically mounted on the lower part of the joint is resiliently abutted against the lower lever part of the inclination lever body. Knee bending fixing means dispersed around the lower part, knee bending at the forward leaning position exceeding the vertical base line parallel to the axis of the lower leg pipe in conjunction with the upper part of the joint receiving the front load due to weight shift at the time of kicking out Fixation A crimp pipe side swing-out mechanism, in which the tilting lever body that tilts forward in the swing phase, which shifts the weight to the healthy foot side, is returned by the popping of the cylinder, and the operation to return the middle-fold is to swing the crus pipe. Further, by sliding the sliding-type knee bending restricting operation shaft horizontally inserted into the middle of the tilt lever body, the amount of protrusion of the brake piece orthogonal to the tilt lever body is switched, the front tilt rotation restriction is released, and the upper part of the joint is inverted. A knee joint, comprising: a sitting knee bending mechanism that allows free movement. 3. The knee joint according to claim 2, wherein the brake piece changes a protruding amount with a push screw screwed into the operation shaft to finely adjust the bending angle.