Document tractor

In a document tractor having an endless belt carrying drive elements engageable with perforations in the document, a sprocket also engageable with the belt, a frame made of molded plastic having a pair of plates disposed in side-by-side relationship and having aligned holes in which said sprocket is journaled, a first of said pair of plates having a hub extending from the side thereof facing a second of said pair of plates and adjacent to said sprocket to define a guide platform for said belt, said belt being entrained around said hub and said sprocket, a mechanism for removably fastening said plates to each other to assemble said tractor, which comprises openings through said hub extending between said plates and from the inside of said hub which abuts the inside of said second plate to the outside of said hub, flexible rods integrally molded as part of said second plate in registry with said holes at the inside of said hubs and in interfering relationship with said holes along one side thereof near the outside of said holes, latches formed on the outer ends of said rods facing the sides of said holes which are in interfering relationship with said rods when said hub is brought into abutment with said second plate to deflect said rod to engage said latches with the outside of said holes to attach said plates whereby said plates are removable upon manual deflection of said rods at the outsides of said holes.