Abstract: Envelope opening machine which is relatively small in size and suitable for use on table tops. The machine has a milling cutter and a pair of belts for feeding envelopes from a hopper past the cutter. The belts extend obliquely with respect to the path of the envelopes and tend to hold the envelopes tightly against a guide on one side of the path for precise alignment with the cutter. A removable chaff tray is located at the front of the machine, with a window for viewing the amount of chaff that has been collected. A removable cover overlies the belts and cutter, with hold-down wheels for maintaining the envelopes in contact with the belts and an interlock switch for deactuating the cutter when the cover is removed.

Abstract: Apparatus and method for checking the contents of envelopes and sorting envelopes and other documents according to thickness. The envelopes or other documents are fed along a predetermined path, the thickness of each envelope or document is checked as it travels along the path, and any envelope or document having a thickness greater than a predetermined thickness is diverted from the path.