Adjustable height scaffold

Abstract

An adjustable height scaffold includes an upright and a cage for mounting a work platform on the upright. The cage has two spaced side plates on opposite sides of the upright. Two crossbars are connected to the side plates for relative movement of the crossbars between a captured position with the crossbars spaced by a distance greater than the cross section of the upright and a release position spaced by a distance less than the cross section of the upright. The couplings joining the crossbars to the side plates prevent disconnection of the crossbars from the side plates in the captured position but allow disconnection of at least one of the crossbars from the side plates in the release position. With the upright in the cage between the crossbars, the crossbars cannot move to the release position. To allow the cage to be conveniently assembled on and disassembled from the upright, while the upright remains in a vertical orientation, the upright has at least a section of reduced cross section, allowing the crossbars to move to the release position for assembly or disassembly. The reduced cross section may be provided by a notch in the upright.

Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A cage for use in an adjustable height scaffold having an upright with opposite inner and outer sides and a predetermined cross sectional dimension therebetween, the cage comprising: 
 two spaced apart side members for receiving the upright therebetween;    an inner crossbar and an outer crossbar;    crossbar couplings for connecting each of the crossbars to the two side members for relative movement of the crossbars between a captured position with the crossbars spaced by a distance greater than the predetermined cross sectional dimension between the inner and outer sides of the upright and a release position spaced by a distance less than the predetermined cross sectional dimension between the inner and outer sides of the upright, the couplings preventing disconnection of the crossbars from the side plates in the captured position and allowing disconnection of at least one of the crossbars from the side members in the release position.    
     
     
         2 . A cage according to  claim 1  wherein the crossbar couplings include keyhole openings in the side members, accommodating at least one of the crossbars.  
     
     
         3 . A cage according to  claim 2 , said at least one of the crossbars having a transverse cross section smaller than larger ends of the keyhole openings whereby said at least one of the crossbars may be removed endwise from the key hole openings.  
     
     
         4 . A cage according to  claim 2  wherein said at least one of the crossbars comprises grooves for engaging the side plates at the narrow ends of the keyholes so as to retain the crossbar in engagement with the side members.  
     
     
         5 . A cage according to  claim 2  wherein said at least one of the crossbars comprises flanges for engaging the side plates at the narrow ends of the keyholes so as to retain the crossbar in engagement with the side members.  
     
     
         6 . A cage according to  claim 1  wherein one of the crossbars is secured to the side members of the cage.  
     
     
         7 . A cage according to  claim 1  including rouinded jaws mounted on respective ones of the crossbars to contact the upright.  
     
     
         8 . A cage according to  claim 7  including at least one notch in each crossbar for receiving the respective jaw to limit motion of the respective jaw along the crossbar.  
     
     
         9 . A cage according to claims  7  including bosses at the ends of each rounded jaw for engaging the respective side members.  
     
     
         10 . A cage according to  claim 1  including rounded jaws mounted on respective ones of the crossbars to contact the upright and wherein the crossbar couplings include openings in the side members, the openings having a cross sectional configuration larger than at least one of the crossbars and smaller than a combined cross sectional configuration of the crossbar and jaw.  
     
     
         11 . An adjustable height scaffold comprising: 
 an upright with opposite inner and outer sides with a predetermined cross sectional dimension therebetween, and at least a section of said upright having a reduced cross sectional dimension smaller than said predetermined cross sectional dimension; and    a cage for mounting on the upright, the cage comprising: 
 two spaced apart side members for receiving the upright therebetween;  
 an inner crossbar and an outer crossbar for engaging the inner and outer sides respectively of the upright;  
 crossbar couplings for connecting each of the crossbars to the two side members for relative movement of the crossbars between a captured position with the crossbars spaced by a distance greater than the predetermined cross sectional dimension between the inner and outer sides of the upright and a release position spaced by a distance between said reduced cross sectional dimension and said predetermined cross sectional dimension, the couplings preventing disconnection of the crossbars from the side members in the captured position and allowing disconnection of at least one of the crossbars from the side members in the release position.  
   
     
     
         12 . A scaffold according to  claim 11  wherein the section of the upright comprises a notch in the upright.  
     
     
         13 . A cage according to  claim 11  wherein the crossbar couplings include keyhole openings in the side members, accommodating at least one of the crossbars.  
     
     
         14 . A cage according to  claim 13 , said at least one of the crossbars having a transverse cross section smaller than larger ends of the keyhole openings whereby said at least one of the crossbars may be removed endwise from the key hole openings.  
     
     
         15 . A cage according to  claim 13  wherein said at least one of the crossbars comprises grooves for engaging the side plates at the narrow ends of the keyholes so as to retain the crossbar in engagement with the side members.  
     
     
         16 . A cage according to  claim 13  wherein said at least one of the crossbars comprises flanges for engaging the side members at the narrow ends of the keyholes so as to retain the crossbar in engagement with the side members.  
     
     
         17 . A cage according to  claim 11  wherein one of the crossbars is secured to the side members of the cage.  
     
     
         18 . A cage according to  claim 11  including planar jaws mounted on respective ones of the crossbars to contact the upright.  
     
     
         19 . A cage according to  claim 18  including at least one notch in each crossbar for receiving the respective jaw to limit motion of the respective jaw along the crossbar.  
     
     
         20 . A cage according to claims  18  including bosses at the ends of each planar jaw for engaging the respective side members.  
     
     
         21 . A cage according to  claim 11  including planar jaws mounted on respective ones of the crossbars to contact the upright and wherein the crossbar couplings include openings in the side members, the openings having a cross sectional configuration larger than at least one of the cross bars and smaller than a combined cross sectional configuration of the crossbar and jaw.