Prosthetic locking device

Abstract

A device is provided to lock the residual limb of an amputee into a prosthesis. The device is comprised of rolling elements within a tapered housing which accepts a smooth plunger, such as a wire, cable, or rod connected to a suspension sleeve, with minimal resistance while opposing removal of the plunger from the locking device until the rolling elements have been retracted with a release mechanism. The nature of this device allows it to compensate for irregularities or wear in the plunger while continuing to securely lock the prosthesis to the sleeve. This locking device will function properly with a certain amount of misalignment between the lock and the plunger.

What is claimed is:  
     
         1 . A prosthetic locking device in a prosthetic socket for receiving a substantially smooth plunger attached to a prosthetic sleeve comprising: 
 (a) a lock housing having a proximal opening for introduction of a plunger, and having a tapered interior expanding distally from the opening;    (b) a rolling element housed within the tapered interior;    (c) a lift to bias the rolling element toward the proximal opening;    (e) a release mechanism which moves the rolling element distally from the proximal opening when activated.    
     
     
         2 . The prosthetic locking device of  claim 1  having a plurality of rolling elements housed within the tapered interior.  
     
     
         3 . The prosthetic locking device of  claim 2 , where the rolling elements are of a form selected from the group consisting of spherical, cylindrical, ellipsoidal and columnar.  
     
     
         4 . The prosthetic locking device of  claim 1 , where the rolling element is made from material selected from the group consisting of austenitic stainless steel, titanium, and brass.  
     
     
         5 . The prosthetic locking device of  claim 1 , where the release mechanism is selected from the group consisting of a linearly actuated cam, radially actuated cam, pin-hinged linkage, gear-to-gear system, and gear-to-rack system.  
     
     
         6 . The prosthetic locking device of  claim 1 , further comprising an actuation button connected to said release mechanism and extending from the lock housing.  
     
     
         7 . The prosthetic locking device of  claim 6 , wherein the actuation button comprises a draw member connected to the release mechanism that can be pulled to actuate the release mechanism.  
     
     
         8 . A prosthetic locking device in a prosthetic socket for receiving a plunger mounted on a prosthetic sleeve comprising: 
 (a) a lock housing having an exterior, a tapered interior, with a top interior portion, and an opening passing through the top interior portion to the exterior;    (b) a substantially smooth rolling element housed within said tapered interior;    (c) a spring biasing said rolling element towards the top portion of the tapered interior;    (d) a release mechanism which moves the rolling element away from the top portion of the tapered interior when activated.    
     
     
         9 . The prosthetic locking device of  claim 8  having a plurality of rolling elements housed within the tapered interior.  
     
     
         10 . The prosthetic locking device of  claim 9 , where the rolling elements are of a form selected from the group consisting of spherical, cylindrical, ellipsoidal and columnar.  
     
     
         11 . The prosthetic locking device of  claim 8 , where the rolling element is made of materials selected from the group consisting of austenitic stainless steel, titanium, and brass.  
     
     
         12 . The prosthetic locking device of  claim 8 , where the release mechanism is selected from the group consisting of a linearly actuated cam, radially actuated cam, pin-hinged linkage, gear-to-gear system, and gear-to-rack system.  
     
     
         13 . The prosthetic locking device of  claim 8 , further comprising an actuation button connected to said release mechanism and accessible from the lock housing.  
     
     
         14 . A method of attaching a prosthetic sleeve having a plunger to a prosthetic socket fitted with the prosthetic locking device of  claim 1  comprising the steps of: 
 (a) guiding the plunger into the proximal opening of the lock housing;  
 (b) pushing the plunger into the tapered interior and contacting the rolling element therein;  
 (c) applying sufficient force on the plunger to urge the rolling element distally from the opening and the tapered interior wall such that the rolling element is moved distally from the opening sufficiently that the width of the tapered interior increases sufficiently to permit the plunger to pass by the rolling element;  
 (d) continuing to urge the plunger through the prosthetic locking device to the desired depth;  
 (e) biasing the rolling element toward the proximal opening thereby biasing the rolling element against both the tapered interior and the plunger.  
 
     
     
         15 . The method of  claim 15 , wherein the rolling elements are of a form selected from the group consisting of spherical, cylindrical, ellipsoidal and columnar.  
     
     
         16 . The method of  claim 15 , wherein the plunger is in a form selected from the group consisting of solid wire, rod, tube, and stranded flexible wire.  
     
     
         17 . A method of detaching a prosthetic sleeve having a longitudinally smooth plunger passing through the opening to the top interior portion of the lock housing and engaged in the locking device of  claim 8 , comprising the steps of: 
 (a) activating the release mechanism to move the rolling element retainer away from the top opening;    (b) continuing the distal movement of the rolling element retainer until the width of the tapered interior is sufficient that the rolling element does not simultaneously contact both the tapered interior and the longitudinally smooth plunger;    (c) withdrawing the plunger out through the top opening.    
     
     
         18 . The method of  claim 18 , wherein the release mechanism is actuated by pulling a draw member connected to the release mechanism.  
     
     
         19 . The method of  claim 18 , wherein the plunger is in a form selected from the group consisting of solid wire, rod, and stranded flexible wire.  
     
     
         20 . A prosthetic locking device in a prosthetic socket for receiving a substantially smooth plunger attached to a prosthetic sleeve comprising: 
 (a) a lock housing having a top proximal opening for introduction of a substantially smooth plunger, and having an interior with a top portion, a conically tapered intermediate portion expanding distally away from the top portion, and a bottom portion    (b) a rolling element retainer having a base with a central opening, positioned within the interior of the clutch lock housing and also having a cam element;    (c) at least three spherical rolling elements positioned upon the base of the rolling element retainer outward of the central opening;    (d) a compressible spring biasing the rolling element retainer toward the proximal opening;    (e) a release mechanism which engages the cam element and moves the rolling element retainer distally from the proximal opening when activated.