Double acting torque chuck

Abstract

A self-locking chuck for engaging the hollow core of a tubular roll of material includes a center trunnion having a central axis of rotation and a plurality of flat peripheral surfaces. A rotatable cage surrounds the trunnion and has a plurality of apertures in which moveable lug members are loosely retained. Each of the moveable lug members has an outer surface for engaging the inside of the hollow core and an inner arcuate surface defining a radial space opposite each flat peripheral surface portion of the trunnion. A plurality of cylindrical rollers extend through the radial space between each of the moveable lug members and each respective flat peripheral surface. In response to torque applied to the chuck, the cage rotates, forcing the rollers to move along the flat surfaces so as to bear against the inner lug surfaces. This creates a camming action which operates in either direction causing the chuck to self lock by forcing the lugs radially outwardly to engage the inside of a hollow core.

1 . A self locking chuck for engaging the hollow core of a tubular roll of material comprising: 
 a. a center trunnion having a central axis of rotation and a plurality of flat peripheral surfaces;    b. a rotatable cage surrounding the trunnion and having a plurality of apertures for receiving moveable lug members;    c. said moveable lug members having each an outer surface for engaging the hollow core and an inner surface defining a radial space with respect to each flat peripheral surface of said trunnion;    d. a roller assembly for forcing the lug members in a radially outward direction in response to torque in either direction comprising first and second synchronizing rings positioned at each end of said cage, said rings having first and second sets of recesses for holding a plurality of rotatable cylindrical roller bars extending between said first and second synchronizing rings, the roller bars being disposed each respectively in the radial space between each said flat peripheral surface and the inner arcuate surface of each of said lug members.    
   
   
       2 . The self-locking chuck of  claim 1  wherein each inner arcuate surface has a radius of curvature which has a center displaced from said central axis of rotation.  
   
   
       3 . The self-locking chuck of  claim 1  wherein the lug members are held loosely in the cage retained by flange elements at the corners of said lug members.  
   
   
       4 . A self-locking chuck for engaging the hollow core of a tubular roll of material comprising: 
 a. a center trunnion having a central axis of rotation and a plurality of flat peripheral surfaces;    b. a cage surrounding the trunnion and rotatable with respect thereto;    c. a plurality of lugs enclosed in the cage and radially moveable therein, each lug having an outer surface for engaging the hollow core and an inner surface, said inner surface having a radius of curvature, with a center offset from said central axis of rotation of said trunnion;    d. a plurality of roller bearing elements interacting between the inner surface of each lug and a respective flat peripheral surface to expand said lugs radially in response to torque in either direction.    
   
   
       5 . The self-locking chuck of  claim 4  wherein said roller bearing elements are cylindrical roller bars extending axially with respect to said trunnion.  
   
   
       6 . The self-locking chuck of  claim 5  further including a pair of synchronizing rings having apertures for receiving opposite ends of said roller bars.  
   
   
       7 . The self-locking chuck of  claim 5  wherein the lug members are held loosely in the cage retained by flange elements at the corners of said lug members.  
   
   
       8 . The self-locking chuck of  claim 4  wherein there are three roller bearing elements.  
   
   
       9 . The self-locking chuck of  claim 1  wherein there are three cylindrical roller bars.  
   
   
       10 . The self-locking chuck of  claim 2  wherein the radius of curvature of each inner surface is smaller than a radius of the chuck at the outer surfaces of the lug members.