Apparatus for a carriage traveling along a roof structure

Abstract

An apparatus is movable along a roof structure having a plurality of elongated purlins defining longitudinal axes. The apparatus includes a carriage movable along the length of the purlins. The carriage extends across the purlins. A plurality of support members are mounted on the carriage and engage with the purlins. Each of the support members includes a flange which abuts a purlin to prevent the purlin from twisting about its longitudinal axis.

What is claimed is:  
     
         1 . An apparatus movable along a roof structure having a plurality of elongated purlins defining longitudinal axes, said apparatus comprising: 
 a carriage movable along the purlins, said carriage extending across the purlins; and    a plurality of support members mounted on said carriage and engaged with the purlins, wherein each of said support members includes a flange which abuts one of the purlins to prevent the purlin from twisting about the longitudinal axis of the corresponding purlin.    
     
     
         2 . The apparatus of  claim 1 , wherein there is at least one support member for substantially every one of the plurality of purlins of the roof structure.  
     
     
         3 . The apparatus of  claim 1 , wherein one of said support members is mounted within a puller assembly attached to said carriage, said puller assembly engageable to move said carriage along the purlin.  
     
     
         4 . The apparatus of  claim 1 , wherein said carriage includes a plurality of carriage sections joined together to form said carriage.  
     
     
         5 . The apparatus of  claim 1 , wherein said support members are removably mounted on said carriage.  
     
     
         6 . The apparatus of  claim 1 , wherein said plurality of support members each include a roller rotatably engageable with a purlin as the carriage moves along the length of the purlin.  
     
     
         7 . The apparatus of  claim 6 , wherein said flange is a disc fixed to said roller.  
     
     
         8 . In combination: 
 1) a roof structure having a plurality of elongated purlins defining longitudinal axes, said plurality of purlins having a generally Z-shaped cross-section including a generally horizontally extending upper portion, a generally horizontally extending lower portion, and a vertically extending web disposed between said upper portion and said lower portion; and    2) an apparatus including: 
 a carriage movable along the purlins, said carriage extending across the plurality of purlins; and  
 a plurality of support members mounted on said carriage and engaged with the purlins, wherein each of said support members includes a flange which abuts said upper portion of a purlin to prevent the corresponding purlin from twisting about its longitudinal axis.  
   
     
     
         9 . The combination of  claim 8 , wherein there is at least one support member for substantially every one of the plurality of purlins.  
     
     
         10 . The combination of  claim 8 , wherein said support members include a roller rotatably engaged with the corresponding purlin as the carriage moves along the length of the purlin.  
     
     
         11 . The combination of  claim 10 , wherein said flange is a disc fixed to said roller.  
     
     
         12 . The combination of  claim 10 , wherein said plurality of purlins define a plane, and wherein said roller rotates about an axis at an angle with respect to the plane.  
     
     
         13 . The combination of  claim 12 , wherein said roller includes a frustoconical surface to rotatably roll along the upper portion of the corresponding purlin.  
     
     
         14 . The combination of  claim 13 , wherein said upper portions of said plurality of purlins include an upper flange extending at an angle from an edge of said upper portions, and wherein said roller includes a cylindrical surface adjacent said frustoconical surface to rotatably roll along said upper flange of the corresponding purlin.  
     
     
         15 . The combination of  claim 14 , wherein said flange of said support member has a surface which defines a plane which abuts an edge of said upper flange of a purlin at a perpendicular orientation.  
     
     
         16 . A support member for guiding a carriage movable along a roof structure having a plurality of elongated purlins defining longitudinal axes which are spaced apart from one another in a parallel arrangement, said support member comprising: 
 a mounting member adapted to be attached to the carriage;    a roller rotatably attached to said mounting member and adapted to rotatably engage the purlin; and    a flange attached to said mounting member and positioned for abutment against the purlin to prevent the purlin from twisting about the longitudinal axis.    
     
     
         17 . The support member of  claim 16 , wherein said flange is attached to said roller.  
     
     
         18 . The support member of  claim 17 , wherein said flange is a disc.  
     
     
         19 . The support member of  claim 16 , wherein said roller includes a frustoconical surface to rotatably engage an upper portion of the purlin.  
     
     
         20 . The support member of  claim 19 , wherein said roller includes a cylindrical surface adjacent said frustoconical surface to rotatably engage an upper flange of the purlin.