Browse Prior Art Database

Original Publication Date: 1978-Feb-28
Included in the Prior Art Database: 2004-Mar-31

Publishing Venue

Xerox Disclosure Journal


A mechanical differential motion sensor/timer is disclosed for detecting the differential motion between a sheet of paper and the roll driving it with the sensor being used as a means of starting and stopping the drive roll. As shown in the Figure, paper that is forwarded into tray 10 in the direction of the arrow engages motion sensor roll 22, and drives it, causing the actuator pulley 23 to undergo lateral movement over threaded collar 18 to close switch 30 to actuate drive roll 13. The drive roll tends to move the actuator pulley in the reverse lateral direction to open the switch and deenergize the drive roll. However, as long as the paper is moving under the motion sensor roll 22 and driving it, the effect of the two rolls on the threaded collar cancel each other, and the actua-tor pulley does not move laterally. When the paper is stopped, as by registration fingers, the motion sensor roll stops. The drive roll 13 continues, and this action now reverses the lateral movement of the actuator pulley until the switch is opened to deenergize the drive roll.