Otto Bock Orthopaedische Industrie Besitz- Und Verwaltungs-kommanditgesel

Otto Bock Orthopaedische Industrie Besitz-und Verwaltungs-kommanditgesell

Otto Bock Orthopaedische Industrie Besitzund Verwaltungs-kommanditgesells

Manfred Krukenberg

Helmut Wagner

Karl Becker

The invention relates to a brake joint for a prosthesis, in particular, to a brake-action knee joint for a leg prosthesis. There is an upper joint part, a lower joint part, and a joint shaft for pivotally connecting the upper and lower joint parts. The joint shaft is connected to the lower joint part in a rotatably fixed manner and is designed as a brake shaft. The joint shaft is surrounded by a brake arrangement, which bears upon the joint shaft it and is arranged in a cylindrical recess, which, together with the joint shaft, forms an annular chamber in a clamping part forming a central joint part. The upper joint part is mounted to the clamping part in an articulated manner via a pivot pin in such a way that the upper joint part, when loaded, impacts on the clamping part and thus the brake arrangement and thereby exerts a braking action on the joint shaft. To improve the brake arrangement, the invention proposes that the brake arrangement be formed by needle rollers, which are arranged with their axes parallel to the joint shaft. The needle rollers surround the joint shaft about its entire circumference and comprise an inner needle-roller ring, which bears on the joint shaft, and an outer needle-roller ring, which bears on the outer circumferential surface of the annular chamber and whose needle rollers engage like teeth between the inner needle rollers, and by an indexing wedge which sits on the upper joint part. When the upper joint part is loaded, in an approximately radial direction of action relative to the joint shaft, the indexing wedge presses apart two adjacent inner needle rollers in the circumferential direction of the joint shaft.

Prosthesis brake joint

A prosthetic brake joint includes an upper joint portion, a lower joint portion, and a joint shaft which pivotably connects the two joint portions together. The joint shaft, designed as a brake shaft, is connected to the lower joint portion for fixed rotation with the lower joint portion. A brake bushing surrounds and rotates about the joint shaft and operates as a bearing. The brake bushing is connected to a clamping or support portion for fixed rotation with the clamping or support portion. The upper joint portion is mounted to the clamping or support portion in an articulated manner via a pivot axle. Under loading, the upper joint portion impacts the clamping or support portion and thus the brake bushing, and thereby exerts a braking force on the joint shaft. The brake bushing is surrounded by an annular brake chamber which is filled with an incompressible medium. The annular brake chamber communicates, for purposes of fluid exchange, with a closed hollow space integrated in the clamping or support portion. A pressure piston supports the upper joint portion and protrudes into the closed hollow space to impact the incompressible medium which compresses the brake bushing against the joint shaft to brake rotation of the prosthetic knee joint.

Prosthetic brake joint

A below-knee prosthesis with a rigid, bowl-shaped outer shaft having a closed distal end, and with a flexible inner shaft which is fitted therein in a removable manner and which likewise has a closed distal end and also an air chamber which can be inflated via a valve. To improve the wearing comfort a) the inner shaft is designed as a soft silicone shaft which can be rolled over the stump of the prosthesis user and which completely surrounds the stump and bears against it; b) the air chamber of the inner shaft completely surrounds the distal end of the stump and extends only over a small partial length of the inner shaft; c) a connector plug is secured on the distal end of the inner shaft and communicates with the air chamber via a through-bore to permit air exchange; d) an insertion opening adapted to the connector plug and receiving it in a detachable manner is provided in the distal end of the outer shaft; and e) a flexible tube is connected to the insertion opening, and its tube end guided to the outside is connected to an exhaust valve and a pump.

Below-knee prosthesis

A brake-action knee joint for a leg prosthesis includes a closed displacer chamber which concentrically surrounds the joint pin over its circumference, at least partially, is preferably filled with hydraulic oil, and is arranged in the associated end of the central part of the joint. The joint pin is designed as a rotary piston and is connected in torsionally rigid fashion to the upper part of the joint. The joint pin divides the closed displacer chamber into an extension chamber and a flexion chamber, which are connected to one another by way of an oil line which can be completely or partially closed by a valve plunger. The valve plunger is mounted in the central part of the joint in such a way as to be displaceable counter to the action of a valve-plunger spring pushing it into its open position and, when the central part of the joint is pivoted in the direction of flexion about the rocker pin arranged in the lower part of the joint, is pushed into its closed position by an adjusting device provided in the lower part of the joint.

Growing community of inventors

Duderstadt, Germany

Manfred Krukenberg