Pivot structure for adjustably suspending equipment from a ceiling track

Abstract

A pivot structure as part of a framework for temporarily suspending equipment such as a movie screen from a ceiling track can include an oblong beam adjustably mounted to the track. The pivot structure can include a housing having a cylindrical bearing for rotatively mounting a spindle. A pair of separately actuatable brakes can clamp the spindle in a locked position. Each brake can include a barrel having a concavity in its outer cylindrical surface which when driven against the spindle discourages its rotation.

What is claimed is: 
     
         1 . A pivot structure comprises:
 a housing comprising a bearing;   a spindle being rotatable within said bearing about a spindle axis;   a first brake comprising a first concavity contacting said spindle to discourage rotation of said spindle when said first brake is in a first locked position; and,   a first mechanism for releasably driving the first concavity against the spindle.   
     
     
         2 . The structure of  claim 1 , wherein said first brake further comprises:
 a substantially cylindrical first barrel wherein said first concavity is set into a side surface of said first barrel.   
     
     
         3 . The structure of  claim 2 , wherein said first brake further comprises:
 a first jackscrew engaging a threaded bore in said first barrel.   
     
     
         4 . The structure of  claim 3 , wherein said first brake further comprises:
 said first barrel slidingly engaging a first cylindrical bore in said housing.   
     
     
         5 . The structure of  claim 4 , wherein said first brake further comprises:
 said first cylindrical bore extending along a first axis; and,   wherein said first axis is substantially perpendicular to said spindle axis.   
     
     
         6 . The structure of  claim 5 , which further comprises:
 a second brake comprising a second concavity contacting said spindle to discourage rotation of said spindle when said second brake is in a second locked position; and,   a second mechanism for releasably driving the second concavity against the spindle.   
     
     
         7 . The structure of  claim 6 , which further comprises:
 a substantially cylindrical second barrel wherein said second concavity is set into a side surface of said second barrel;   a second jackscrew engaging a threaded bore in said second barrel;   said second barrel slidingly engaging a second cylindrical bore in said housing;   said second cylindrical bore extending along a second axis; and,   wherein said second axis is substantially perpendicular to said spindle axis.   
     
     
         8 . The structure of  claim 7 , which further comprises:
 said first axis and said second axis being substantially parallel.   
     
     
         9 . The structure of  claim 1 , which further comprises:
 a second brake comprising a second concavity contacting said spindle to discourage rotation of said spindle when said second brake is in a second locked position; and,   a second mechanism for releasably driving the second concavity against the spindle.   
     
     
         10 . The combination of a ceiling track and an adjustable framework:
 wherein said ceiling track comprises a pair of inwardly extending substantially parallel rails separated by a slot having a given slot width;   wherein said adjustable framework comprises:
 a beam including a first end and a second end; 
 a first hanger located proximate said first end for suspending said beam from said track; 
 a second hanger located proximate said second end for suspending said beam from said track; 
 wherein at least one of said first and second hangers is adjustable along a vertical direction; 
 a pivot secured to a medial part of said beam, said pivot comprises:
 a housing; 
 a spindle rotatively mounted to said housing, and having a first axis of rotation substantially parallel to said vertical direction; 
 a clamp releasably locking the angular position of said spindle in said housing; 
 
 a boom secured to said housing; 
 a first cradle secured to said boom; and, 
 a second cradle secured to said boom. 
   
     
     
         11 . The combination of  claim 10 , wherein each of said cradles comprises a hook for engaging an oblong member perpendicular to said axis of rotation. 
     
     
         12 . The combination of  claim 11 , wherein each of said cradles further comprise a cradle lock for releasably securing said member within said hook. 
     
     
         13 . The combination of  claim 10 , wherein said clamp comprises:
 said spindle intimately and rotatively engaging a bearing in said housing;   said bearing having a substantially cylindrical sidewall;   a pair of brakes bearing against said spindle;   wherein a first one of said brakes comprises:
 a first concavity contacting said spindle to discourage rotation of said spindle when said first one of said brakes is in a first locked position; and, 
 a first mechanism for releasably driving the first concavity against the spindle. 
   
     
     
         14 . The combination of  claim 10 , wherein said boom comprises at least one level secured thereon. 
     
     
         15 . The combination of  claim 10 , wherein said boom comprises a second pair of inwardly extending substantially parallel rails separated by a second slot having a given second slot width. 
     
     
         16 . The combination of  claim 15 , wherein said given second slot width is commensurate with said slot width. 
     
     
         17 . A method for suspending a screen from a ceiling track, said method comprises:
 selecting a framework which comprises an oblong beam having opposite ends, a pivot secured to a middle part of said beam, a boom secured to said pivot, and a pair of cradles secured to said boom;   engaging said opposite ends to said ceiling track;   adjusting a distance between at least one of said opposite ends and said track, thereby leveling said beam;   hanging a screen from said pair of cradles;   rotating said boom with respect to said beam about said pivot, thereby adjusting an angle of said screen with respect to said track; and,   locking said pivot, thereby releasably preventing further angular movement of said screen with respect to said ceiling track.   
     
     
         18 . The method of  claim 17 , wherein said leveling comprises:
 repeatedly observing a level affixed to said boom while said adjusting is undertaken.