GB1152538A - Sheet Sensing Device - Google Patents

Abstract

1,152,538. Sheet feeding apparatus. RANK XEROX Ltd. 5 Oct., 1967 [11 Oct., 1966], No. 45381/67. Heading B8R. A device for sensing the feed of superposed sheets comprises gauge means positioned adjacent a reference member, and supported on a rotatable frame mounted on a base member whereby means are provided to adjust the spacing between the gauge means and the reference member; and a limit switch which is operated whenever the gauge means is disturbed by a superposed sheet to divert the superposed sheet from the normal feed path. Sheet-forming means (Fig. 4).-The apparatus is particularly suited to a xerographic copier (Fig. 1, not shown), in which sheets from a pile are fed to conveyer belts 414 entrained about a drive roller 417 and an idler roller (420) which is provided with a larger diameter index portion 422 along a part of its length. Sheets are fed through the gap between the index portion 422 and a sensor shoe 510, and are maintained on the belts by vacuum means, the belts 414 and vacuum shoe 408 having co-operating apertures connected to a vacuum source. Sheet-diverting means.-When superposed sheets are detected (see below), the sensor shoe 510 actuates limit switch LS-9 (Fig. 6) which, in turn, de-actuates solenoid SOL-3 and rotates shaft 427 against a spring (429) (Fig. 3, not shown) thus rotating reject fingers 426 through the spaces between belts 414 and breaking the vacuum, to allow the superposed sheets to drop into a receiver tray. Sheet-sensing means (Fig. 6).-The sensor shoe 510 is fixed to a shaft 513 which rotates in bifurcated portions of a frame member 520 which is itself rotatable on shaft 521 mounted in the base 530 of the sensing means; the frame 520 is biased into contact with an adjusting cam 540 which is mounted on shaft 541 also mounted in the base 530. An eccentric 550 is rotatably supported on shaft 551 mounted in the frame 520, rotation being supplied by worm-gear 553 and spur-gear 522; a lever 542 also serves to rotate the cam 540 relative to the eccentric 550 to alter the spacing between the sensor shoe 510 and index portion 422. If a superposed sheet is fed sensor shoe 510 is rotated anticlockwise (as seen in Fig. 6) by the sheet and arm 512 actuates limit switch LS-9, thus operating the reject fingers 426 through solenoid SOL-3.