Adjustable linear friction device

Abstract

An adjustable linear friction device for exercising the forearm, wrist and hand, comprising: a disc rotatably mounted on a housing, with a circumferential edge and opposed faces; a friction band extending between an anchor and biasing means, the friction band disposed against the circumferential edge of the disc; a shaft extending outwardly from the opposed faces, with handles on the shaft for rotating the shaft to effect rotation of the disc. Rotating the disc in a first direction results in a first normal friction between the friction band and the circumferential edge, and rotating the disc in a second and opposite direction results in a second, different normal friction. The device can be used to exercise the forearm and wrist joint in supination/pronation, extension/flexion, and radial/ulnar deviation motions through the full range of motion.

1 . A device for exercising forearm, wrist and hand, the device comprising: 
 a housing;    a discoid member having a circumferential edge and opposed faces, the discoid member rotatably mounted on the housing;    an anchor member on the housing adjacent the circumferential edge of the discoid member;    biasing means connected to the housing adjacent the circumferential edge of the discoid member and spaced from the anchor member,    an elongate friction member extending between the anchor member and the biasing means, the elongate friction member disposed against the circumferential edge of the discoid member, the elongate friction member having a first end attached to the anchor member and a second end attached to the biasing means;    a shaft extending outwardly from at least one of the opposed faces; and    handle means on the shaft for rotating the shaft to effect rotation of the discoid member;    such that actuation of the handle means effecting rotation of the discoid member in a first direction results in a first normal friction between the elongate friction member and the circumferential edge, and actuation of the handle means effecting rotation of the discoid member in a second and opposite direction results in a second normal friction between the elongate friction member and the circumferential edge.    
   
   
       2 . The device of  claim 1  further comprising adjusting means on the housing connecting the biasing means to the housing, the adjusting means connected to the biasing means for selectively adjusting biasing effected by the biasing means, thereby selectively adjusting normal friction between the elongate friction member and the circumferential edge.  
   
   
       3 . The device of  claim 2  wherein the biasing means comprise first and second extension springs, and the adjusting means comprise: 
 a threaded adjustment bolt mated with the housing;    a nut threaded onto the threaded adjustment bolt, such that rotating the threaded, adjustment bolt causes the nut to move axially along the threaded adjustment bolt;    projections extending outwardly from the nut;    a bar for connecting to the second end of the elongate friction member; and    the first and second extension springs connected at respective first ends to the projections and at respective second ends to the bar,    such that rotating the threaded adjustment bolt in a first direction causes the nut to move away from the discoid member, increasing the normal friction between the elongate friction member and the circumferential edge.    
   
   
       4 . The device of  claim 1  wherein the biasing means comprise an extension spring.  
   
   
       5 . The device of  claim 1  wherein the anchor member is a post extending from the housing at least partially past the circumferential edge of the discoid member.  
   
   
       6 . The device of  claim 1  wherein the elongate friction member is a band composed of material sufficient to effect a desired coefficient of friction between the elongate friction member and the circumferential edge of the discoid member.  
   
   
       7 . The device of  claim 1  wherein the elongate friction member is in direct contact with the circumferential edge along greater than half of the extent of the circumferential edge.  
   
   
       8 . The device of  claim 1  wherein the shaft extends generally perpendicularly from the at least one of the opposed faces.  
   
   
       9 . The device of  claim 1  wherein the shaft extends outwardly from each of the opposed faces.  
   
   
       10 . The device of  claim 1  wherein the handle means are disposed generally parallel to the opposed faces of the discoid member and generally perpendicular to the shaft.  
   
   
       11 . The device of  claim 1  wherein the handle means are disposed generally perpendicular to the opposed faces of the discoid member and generally parallel to the shaft.  
   
   
       12 . The device of  claim 1  further comprising vertical support means.  
   
   
       13 . The device of  claim 12  wherein the vertical support means comprise a base member and a generally vertical mast extending upwardly therefrom, the generally vertical mast connected to the housing.