Clamping freewheel and its use for a prosthetic part
View Patent ↗In a clamping freewheel having a sleeve ( 5 ) which encloses a shaft ( 7, 9 ) and in which the shaft ( 7, 9 ) is mounted in an axially displaceable manner, having rolling elements ( 6 ) which are arranged in chambers, formed between shaft ( 7, 9 ) and sleeve ( 5 ), in such a way that they roll in a first direction for a relative rotation between shaft ( 7, 9 ) and sleeve ( 5 ), whereas a torque acting in the opposite direction leads to the clamping of the rolling elements ( 6 ) in their chamber, having a transmission element ( 11 ) arranged on the shaft ( 7, 9 ), and having an actuating element ( 16 ) for the axial displacement of the transmission element ( 11 ) arranged on the shaft ( 7, 9 ), the function of the axial displacement is separated from the function of the clamping by virtue of the fact that the shaft ( 7, 9 ) consists of a hollow shaft piece ( 7 ) and an inner piece ( 9 ) axially displaceable therein, but mounted in a rotationally locked manner, and that the actuating element ( 16 ) and the transmission element ( 11 ) are arranged on the inner piece ( 9 ). As a result, the initiation of the axial displacement becomes independent of the clamping forces. A preferred field of application of the clamping freewheel consists in locking a linearly movable prosthetic part.
1. A clamping freewheel having a sleeve ( 5 ) which encloses a shaft ( 7 , 9 ) and in which the shaft ( 7 , 9 ) is mounted in an axially displaceable manner, having rolling elements ( 6 ) which are arranged in chambers formed between shaft ( 7 , 9 ) and sleeve ( 5 )in such a way that said rolling elements roll in a first direction for a relative rotation between shaft ( 7 , 9 ) and sleeve ( 5 ), whereas a torque acting in the opposite direction leads to the clamping of the rolling elements ( 6 ) in their chamber, said clamping freewheel further having a transmission element ( 11 ) arranged on the shaft ( 7 , 9 ) and having an actuating element ( 16 ) for the axial displacement of the transmission element ( 11 ) arranged on the shaft ( 7 , 9 ), wherein the shaft ( 7 , 9 ) comprises a hollow shaft piece ( 7 ) and an inner piece ( 9 ) axially displaceable therein, but mounted in a rotationally locked manner, and wherein the actuating element ( 16 ) and the transmission element ( 11 ) are arranged on the inner piece ( 9 ), wherein the inner piece ( 9 ) is of a profiled design which deviates from the circumference of a circle and the hollow shaft piece ( 7 ) has a complementary inner profile ( 8 ) to said profiled design of said inner piece ( 9 ) whereby the inner piece ( 9 ) and the hollow shaft piece ( 7 ) are rotationally locked and whereby axial displacement of said inner piece ( 9 ) is made independent of said clamping of said rolling elements.
2. The clamping freewheel as claimed in claim 1 , wherein the axial displacement of the inner piece ( 9 ) is effected against the restoring force of a spring ( 13 ).
3. The clamping freewheel as claimed in claim 1 , wherein the transmission element is a gear.
4. The clamping freewheel of claim 1 wherein said profiled design is polygonal.
5. A prosthetic device comprising
a prosthesis shank ( 23 ) including a liner ( 26 ) and a locking pin ( 31 ), and
a clamping freewheel engaging said locking pin through a transmission element ( 11 ), said clamping freewheel having a sleeve ( 5 ) which encloses a shaft ( 7 , 9 ) and in which the shaft ( 7 , 9 ) is mounted in an axially displaceable manner, having rolling elements ( 6 ) which are arranged in chambers formed between shaft ( 7 , 9 ) and sleeve ( 5 ) in such a way that said rolling elements roll in a first direction for a relative rotation between shaft ( 7 , 9 ) an sleeve ( 5 ), whereas a torque acting in the opposite direction leads to the clamping of the rolling elements ( 6 ) in their chamber, wherein said transmission element ( 11 ) of said clamping freewheel is arranged on the shaft ( 7 , 9 ) and having an actuating element ( 16 ) for the axial displacement of the transmission element ( 11 ) arranged on the shaft ( 7 , 9 ), wherein the shaft ( 7 , 9 ) comprises a hollow shaft piece ( 7 ) and an inner piece ( 9 ) axially displaceable therein, but mounted in a rotationally locked manner, and wherein the actuating element ( 16 ) and the transmission element ( 11 ) are arranged on the inner piece ( 9 ), wherein the inner piece ( 9 ) is of a profiled design which deviates from the circumference of a circle and the hollow shaft piece ( 7 ) has a complementary inner profile ( 8 ) to said profiled design of said inner piece ( 9 ) whereby the inner piece ( 9 ) and the hollow shaft piece ( 7 ) are rotationally locked and whereby axial displacement of said inner piece ( 9 ) is made independent of said clamping of said rolling elements.
6. The prosthetic device as claimed in claim 5 , wherein the axial displacement of the inner piece ( 9 ) is effected against the restoring force of a spring ( 13 ).
7. The prosthetic device as claimed in claim 5 , wherein the transmission element is a gear.
8. The prosthetic device of claim 5 wherein said profiled design is polygonal.