JPS6240577Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a prosthetic leg, particularly a mechanism for changing and adjusting the angle of elevation of the ankle.

An example of a prosthetic leg in which the ankle joint moves slightly in the upward and downward direction is shown in FIG.

In the prosthesis shown in Figure 6, the lower leg (A) and foot (B) are connected by a joint (C), and a soft elastic piece (H) is interposed and fixed in the play gap (D) formed at the joint, so that it is normal even when the angle of elevation is changed. In addition, in order to fix the elevation angle to the desired angle, a wedge is driven in, and it is difficult to drive the wedge in by oneself.

This invention solves the conventional problem of adjusting the elevation angle of the foot, and its purpose is to create a prosthetic leg that allows the elevation angle of the ankle to be easily adjusted at any time and also allows fine adjustment.

In this invention, a ball screw shaft is rotatably supported in the lower leg, a ball nut is attached to this, and the ball nut and the front part of the foot are connected by a link. It is characterized by a built-in stopper that stops the rotation of.

An embodiment of this invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a thigh socket, and 2 is a lower leg connected via a joint 3.

The lower leg part 2 is made of a pipe and has a second pipe at its lower end.
The ball screw shaft 4 is shown enlarged in Fig. 3.
are supported by upper and lower bearing stands 6 and 7 which are fixed by pillars 5. Reference numeral 8 denotes a spiral groove formed in the ball screw shaft, and this groove has a semicircular cross section into which the ball 9 fits 1/2.

A ball nut 10 is attached to the ball screw shaft 4.

The lower bearing pedestal 7 has a mounting part 13 which is connected to a mount 12 fixed to a foot part 11, and is connected with a pin 14 to form an ankle joint.

Link 15 between ball nut 10 and mounting base 12
It is connected with.

A stopper 16 made of a transverse shaft rod is passed through the lower leg 2 at a portion corresponding to the upper end of the ball screw shaft 4 so as to be freely advanced and retracted, and a coil spring 17 is interposed to provide constant resilience in the backward direction.

The upper end of the ball screw shaft 4 and the stopper 16 have a semicircular cross section, and since their flat surfaces face each other, the ball screw shaft cannot rotate, but as shown in FIG. 4, the stopper 16 can be moved forward. A semicircular recess 18 is formed in the flat surface at the portion corresponding to the upper end of the ball screw shaft in this position, and the ball screw shaft can be rotated in this position.

This device has the above-mentioned structure. Normally, the ball screw shaft is prevented from rotating by the stopper, so the ankle joint does not move. However, when the stopper is moved forward, the ball screw shaft becomes rotatable. When stepping force is applied to the tip of the foot, the link tries to push up the ball nut, and the ball nut rises while rotating the ball screw shaft. When the toe of the foot reaches the desired elevation angle, release the pressure on the stopper and it will be fixed at that elevation angle, making it easier to climb up the slope.On the other hand, if you apply pressure to the heel side, it will move to the depression angle position and climb the slope. It is easier to descend or sit down, and even when stepping on shoes with different heel heights, the angle of elevation can be adjusted simply by operating the stopper on the lower leg and applying force to the foot, compared to the conventional wedge. Not only is the operation much easier than driving, but it also has excellent effects such as being able to finely adjust the elevation angle as desired.

[Brief explanation of the drawing]

FIG. 1 is a side view of an example of the prosthetic leg according to the present invention, FIG. 2 is an enlarged partially cutaway side view of the main parts of the same, FIG. 3 is a front view of the same, FIG. The figure is an enlarged sectional view taken along the - line, and FIG. 6 is a side view of the main parts of an example of a conventional prosthetic leg. 2...Lower leg, 4...Ball screw shaft, 10...
Ball nut, 11...foot, 12...mounting base,
15...link, 16...stopper, 18...
Hollow.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a prosthetic leg in which the foot is connected to the lower leg, a ball screw shaft is rotatably supported in the lower leg, a ball nut is attached to this, and the ball nut and the front of the foot are connected. This prosthetic leg is characterized in that the closer portions are connected by links, and a stopper for stopping the rotation of the ball screw shaft is incorporated in the lower leg. (2) The stopper is a horizontal bar with a semicircular cross section, and the surface of the portion of the ball screw shaft that intersects with the stopper is flat so as to be in surface contact with the flat surface of the stopper,
The prosthetic leg according to claim 1, wherein a semicircular recess is formed in the flat surface of the stopper in the forward position to allow rotation of the ball screw shaft.