GB790053A - Improvements in or relating to leg-supporting apparatus and artificial legs - Google Patents

Abstract

790,053. Leg supports. REHNBERG, H. E. Jan. 10, 1955 [Aug. 23, 1954], No. 672/55. Class 81 (2). A support for a natural or an artificial leg comprises three rigid members for connection to the thigh, leg and foot respectively, and articulated at the level of the knee and the ankle, the knee articulation having a locking system which prevents relative movement between the thigh and leg members when in alignment, a mechanism controlled by forward pivoting of the leg member relative to the foot member automatically unlocking the knee articulation to permit raising of the foot and forward swinging of the leg restoring alignment between the leg and thigh members. On the outside of a leg a thighsupporting rod 2 is pivoted at the knee on a member 4 to a leg-supporting rod 3. The legsupporting rod 3 is also pivoted at the ankle on a member 18 to a rod 16 secured to a shoe 1c. Similar rods and joints are provided at the inner side of the leg and are connected to the outer rods 2, 3, 16 by transverse straps 1; la, 1b, straps or ties (not shown) also being provided to receive the device on the leg. An upper shank 6 slidable along the outer thigh-supporting rod 2 is provided at its lower end with a socket 5 which caps a bevelled extension 3a of the legsupporting rod 3 to lock the knee joint. The socket 5 in locking position abuts against the upper end of a lower shaft 11 which is slidable on the outer leg-supporting rod 3 so that a bevelled surface 14a of a member 14 at the lower end of the shaft 11 engages a bevelled surface 16a on an upwardly-directed extension of the rod 16 secured to the shoe 1c, to hold the angle joint in locked position. In taking a step the ankle joint is bent so that the bevelled surfaces 14a, 16a ride over one another to raise the lower shank 11 against a spring 15. The upper end of the shank 11 pushes the socket 5 and upper shank 6 upwardly against a spring 10 so that the socket 5 clears the extension 3a of the legsupporting rod 3 thus unlocking the knee joint and enabling the knee to bend. As the leg straightens at the end of a step the rods 2, 3, 16 are again in line so that the joints lock under the action of the springs 10, 15. A manually operable locking member 8 slidable on the outer thigh-supporting rod 2 secures the joints in locked position if desired. The rods may be adjustable in length.