Abstract: In order to removably yet reliably assemble the frame parts, endless belt and sprocket of a document tractor, holes are provided in the hub of one of the frame parts which provide a guide platform for the endless belt which has pins engageable with perforations on the document to be metered. Flexible rods in registry with these holes extend from the other frame part. Latches on the outer ends of these rods engage the outsides of the holes when the rods move into latching engagement as the frame parts are brought together. The tractor may be disassembled by manually deflecting the rods to release the latches.

Abstract: In order to clamp a document metering tractor to a support shaft which together with a drive shaft provide a mounting for the tractor and without causing interference, such as binding, with the drive imparted by the drive shaft, a device is provided for clamping the tractor to the support shaft. This device consists of two parts one of which contains a split ring through which the support shaft extends and the other is a member for closing the ring and retaining it in closed condition. The split ring part may be a collet located internally of the tractor or a sleeve extending externally of the tractor and having the split ring as a portion thereof. In either case, a floating connection is provided between the split ring part and the tractor such as may be afforded by an enlarged opening in the tractor which contains the split ring part.