As I read it, the left screw allows the clamp to be fastened to a pipe, 
and the right screw holds the workpiece in place. Alternatively, the 
right screw attaches the clamp to a (thin) table or plank, and the left 
screw holds a pipe or other cylindrical object to be held in place.  
Whichever, the orientation of cylinder and plank are fixed - no pivot.  
Just can't think of anything like that.