Locking damper positioner

Abstract

A damper positioner includes a lead screw to move the damper blade and a screw lock selectively engageable with the screw to permit rotation of the screw but prevent unintended rotation.

I (we) claim: 
     
         1 . An apparatus for adjusting a blade of a damper, said blade affixed to an axle rotatably mounted in a frame of said damper, said apparatus comprising:
 (a) a lever affixed to said axle proximate a first end of said lever;   (b) an elongate screw comprising a head portion, said screw in threaded engagement with a first anchor affixed to said lever remote from said first end, said screw rotatable but axially restrained in a second anchor affixed to said frame, rotation of said screw rotating said axle; and   (c) a screw lock selectively engageable with said screw to selectively restrain rotation of said screw.   
     
     
         2 . The apparatus of  claim 1  wherein said screw lock comprises a body defining a socket having a shape complementary to a shape of said head portion and axially movable relative to said screw to selectively engage said head portion in said socket, said body rotationally restrained. 
     
     
         3 . The apparatus of  claim 2  further comprising a resilient member urging axial movement of said body and engagement of said socket with said head portion of said screw. 
     
     
         4 . The apparatus of  claim 2  wherein said head portion includes a facet and said socket includes a complementary facet. 
     
     
         5 . The apparatus of  claim 2  wherein said head includes a hexagonal portion and said socket defines a hexagon. 
     
     
         6 . The apparatus of  claim 2  wherein said body is rotationally restrained by a pin affixed to said body and slidably engaging said second anchor. 
     
     
         7 . The apparatus of  claim 2  wherein said body includes a peripheral facet slidably engaged with one of said frame and said second anchor. 
     
     
         8 . The apparatus of  claim 1  wherein said head portion of said screw comprises:
 (a) a first portion engageable by a tool for rotating said screw; and 
 (b) a conical second portion tapering to an end of said head portion to guide said tool into engagement with said first portion. 
 
     
     
         9 . The apparatus of  claim 7  wherein said head portion includes a third portion separating said first portion and said conical second portion, said third portion facilitating manual rotation of said screw. 
     
     
         10 . An apparatus for selectively constraining rotation of a screw in an anchor, said screw including a head, said apparatus comprising:
 (a) a body defining a socket having a shape complementary to a portion of said head of said screw, said body axially slidable on said screw but rotationally restrained by said anchor; and   (b) a resilient member urging said body toward said head to engage said head in said socket, engagement of said head and said socket restraining rotation of said screw relative to said body.   
     
     
         11 . The apparatus of  claim 10  wherein said head portion includes a facet and said socket includes a complementary facet. 
     
     
         12 . The apparatus of  claim 10  wherein said head includes a hexagonal portion and said socket defines a hexagon. 
     
     
         13 . The apparatus of  claim 10  wherein said body is rotationally restrained by a pin affixed to said body and slidably engaging said anchor. 
     
     
         14 . The apparatus of  claim 10  wherein said body includes a peripheral facet slidably engaged with said anchor.