Semi-automatic loading paper feed tractor

摘要

A tractor is provided with an endless belt which travels in a triangular path and a drive shaft located well below the level of the paper path. The tractor body has both an inner and outer body portion, each of which contains a journal bearing for support on the support shaft. An adjustable torsion spring lock is provided on the outer body portion and surrounds the support shaft to allow for easy locking adjustment of the axial location of the tractor on the support shaft. A front and rear closeable panel are provided along the document feed path. Only the front panel need be opened during feeding while both front and rear panels may be opened to clear the feed path during advancement jam. Two mirror image features are provided at the entrance of the feed path on either body portion such as to cover document pins located on the belt path and thereby decrease likelihood of injury to an operator during feeding operations. A unique configuration of belt teeth pitch, pin pitch, and number of drive sprocket teeth is provided to allow for easy adjustment of belts in each tractor located at opposite sides of a document.