Plural speed belt document feeder

Claim 1

In a drive system for a document feeder transport for a copier with a drive output normally driven at a high speed for document transport and driven at a lower speed for document registration at a registration position, the improvement wherein said drive system comprises a drive motor and a high speed drive normally driving said document feeder transport through an electrically normally closed clutch in said high speed drive, and a reduction speed system also simultaneously driven by said drive motor, said reduction speed system including a normally over-driven overrunning clutch connected to, but normally disengaged by, said high drive, and means for automatically rapidly and smoothly switching said drive output to said lower speed, as the document approaches the registration position, by electrically opening said normally closed clutch in response thereto, whereby said high speed drive is disengaged and shortly thereafter said reduction speed system automatically begins to drive said drive output at said lower speed by the automatic engagement of said over-running clutch upon the slowing down of said drive output to said lower speed; wherein said means for automatically switching said drive output to said lower speed is actuated only in response to the sensing of a document of larger than a predetermined size and the approach of the lead edge of that document to said registration position; and wherein said normally closed clutch is rapidly opened by shutting off the drive circuit therefor.