Abstract: The disclosure relates to a technology of a manual lock mechanism for manually switching over the oscillating motion of an upper member and a lower member at a knee joint between a locked condition and an unlocked condition. More particularly, the disclosure aims at a simple structure of the manual lock mechanism and a size reduction of the knee joint or an artificial leg including the manual lock mechanism. For these purposes, one of oscillating shafts for swingingly coupling the upper and lower members is regulated. Therefore, the manual lock mechanism includes an oscillating shaft including an irregular part and a lock member for regulating the movement of the oscillating shaft. The lock member can be switched over between a locked condition where the lock member is in contact with the irregular part of the oscillating shaft and the unlocked condition where it is separate from the irregular part.

Abstract: A technology for making the sensation at use of prosthetic limbs utilizing a hydraulic cylinder and a spring cylinder as comfortable as at use of those utilizing a pneumatic cylinder and further for improving walk following properties. In particular, the arrangement of drag generating means, such as a hydraulic cylinder and a spring cylinder, per se is specified. Accordingly, the resistance produced by the drag generating means in accordance with an increase of knee angle is increased. The first torque T1 at the first stage of initial period of bend of knee joint is made small, while the second torque T2 at the second stage of final period of the further advanced bend of knee joint is made large, thereby satisfying a relation of T1?T2, as different from conventional ones.

Abstract: There is provided a prosthetic limb having a flexible knee brake function, which is designed such that it can be mechanically detected which part of the foot the load of the wearer is imposed on. In a thigh prosthetic limb (10), a joint upper member (12) including a knee plate (120) and a joint lower member (14) including a base bracket (22) integral with the frame (140) are operated to bend the knee. In the housing member (24), there are provided not only a knee axis but also a hydraulic brake circuit. There is a link mechanism (50) which allows a small relative motion between the housing member (24) and the base bracket (22) on the main body part side. The link mechanism (50) has an instantaneous center between the toe and the heel part of the prosthetic limb.

Abstract: A selector valve capable of maintaining a closed position for a while even if an operating force to a valve element (80) is eliminated when the selector valve (10) is switched from a closed position (braking state) to an open position. The valve element (80) of the selector valve (10) receives an operating force from the outside and a returning force in the opposite direction of the operating force by a valve spring (90). Accordingly, the valve element (80) opens and closes the valve by making the first end (801) of the valve element (80) seat on/unseat from a valve seat (48) on the housing (20) side according to the presence or absence of the operating force. A first port (31) and a second port (32) on both sides of the valve seat (48) are connected or cut off from each other by the opening and closing. The valve element (80) is formed in a stepped structure, and receives a force based on a difference in pressure receiving area by the stepped structure which results from the pressure of hydraulic fluid.

Abstract: A selector valve capable of maintaining a closed position for a while even if an operating force to a valve element (80) is eliminated when the selector valve (10) is switched from a closed position (braking state) to an open position. The valve element (80) of the selector valve (10) receives an operating force from the outside and a returning force in the opposite direction of the operating force by a valve spring (90). Accordingly, the valve element (80) opens and closes the valve by making the first end (801) of the valve element (80) seat on/unseat from a valve seat (48) on the housing (20) side according to the presence or absence of the operating force. A first port (31) and a second port (32) on both sides of the valve seat (48) are connected or cut off from each other by the opening and closing. The valve element (80) is formed in a stepped structure, and receives a force based on a difference in pressure receiving area by the stepped structure which results from the pressure of hydraulic fluid.

Abstract: There is provided a prosthetic limb having a flexible knee brake function, which is designed such that it can be mechanically detected which part of the foot the load of the wearer is imposed on. In a thigh prosthetic limb (10), a joint upper member (12) including a knee plate (120) and a joint lower member (14) including a base bracket (22) integral with the frame (140) are operated to bend the knee. In the housing member (24), there are provided not only a knee axis but also a hydraulic brake circuit. There is a link mechanism (50) which allows a small relative motion between the housing member (24) and the base bracket (22) on the main body part side. The link mechanism (50) has an instantaneous center between the toe and the heel part of the prosthetic limb.

Abstract: There is provided an air-cylinder apparatus for use in a prosthetic limb capable of effectively adjusting the pressure characteristics over a wide range of walking speed. A second chamber 82 defined by a piston 113 is increased in pressure by air confined therein in accordance with the bending motion of the knee. Air is restricted from flowing out of the second chamber 82 by a constant throttle valve 140. In addition, the second chamber 82 is divided into plural chambers 821, 822 in accordance with increase in bending angle of the knee and air is restricted from flowing out of the newly divided chambers 821, 822 by throttle valves corresponding thereto. The division of the second chamber 82 is achieved by mutual engagement between a projection 1140b on the piston side and a recess 1127 on the bottom part of a cylinder body.

Abstract: There is provided a prosthetic leg with an extension auxiliary mechanism 1100 capable of generating an extension torque only when an angle of bending of the knee is small. A knee joint 80 of a thigh prosthesis 170 is of a multi-axis structure, and a front and a rear link 130, 150 together with an upper thigh member 110 and a lower thigh member 120 constitutes a constrained chain. An extension auxiliary mechanism 1100 having a compression spring is supported between the lower thigh member 120 and the rear link 150. An extension torque generated by the extension auxiliary mechanism 1100 is determined by a product of a force caused by biasing of the compression spring and a distance from a line of action of the force to the center of rotation of the rear link 150. Here, at a stage where the bending angle of the knee exceeds, for example, 15 degrees, an axis of the compression spring is brought generally into alignment with a connecting portion 170O between the rear link 150 and the lower thigh member 120.

Abstract: An artificial limb provides for positional relation between a first pin for rotatably connecting one end of an air cylinder device to a lower member and a second pin for rotatably connecting the other end of the air cylinder device to an upper member. The attaching position of the second pin is set to satisfy certain predetermined conditions when an artificial limb is in a completely extended state. The position of an air cylinder device (particularly, the attaching position of the second pin) is changed in conformity with a walking speed which is variable in phase such as normal walking, quick walking, and running with small steps. The artificial limb further comprises a pin position change capable of changing the position of a second pin rotatably connected to an upper member in conformity with variation of walking speed.