(19)
(11) EP 0 784 242 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.04.1998 Bulletin 1998/16

(43) Date of publication A2:
16.07.1997 Bulletin 1997/29

(21) Application number: 97300142.3

(22) Date of filing: 10.01.1997
(51) International Patent Classification (IPC)6: G03G 15/00
(84) Designated Contracting States:
DE FR GB

(30) Priority: 11.01.1996 US 583829
11.01.1996 US 583830

(71) Applicant: XEROX CORPORATION
Rochester New York 14644 (US)

(72) Inventors:
  • Petocchi, Ermanno C.
    Rochester, NY 14620 (US)
  • Brooks, Janice S.
    Fairport, NY 14450 (US)
  • Bryce, James R.
    Fairport, NY 14450 (US)
  • Direnzo, Bruce J.
    Rochester, NY 14617 (US)

(74) Representative: Johnson, Reginald George et al
Rank Xerox Ltd Patent Department Parkway
Marlow Buckinghamshire SL7 1YL
Marlow Buckinghamshire SL7 1YL (GB)

   


(54) Sheet feeding apparatus


(57) A stack height control assembly that is remote from the feedhead (50). A floating coupler and sensor flag arrangement (150) is mounted so that it is engaged with a paper supply drawer as the drawer is moved into an operative position. The feedhead (50) acts as the stack height sensor and through a mechanical engagement with the sensor, which is removed and remote from the supply drawer, signals as the stack (54) is depleted and the elevator mechanism should raise the stack (54). This control scheme removes complex electrical connectors from the drawer assembly and allows a wide range of substrates to be fed from the paper supply drawer By allowing the sensor/coupler arrangement to float so as to align with the drawer, the need for extremely tight manufacturing and assembly tolerances with respect to the drawer/sensor arrangement is also obviated.
As a result of incorporating the stack height sensor into the feedhead, several advantages are realized. There is no additional drag imparted to the sheets as the result of a sensing arm or other sensing member. This also reduces the possibility of skewing the sheets with an additional sensing member. The feedhead, due to the normal force required to acquire the sheets also provides an accurate measurement of stack height. The normal force of the feedhead also eliminates and inaccurracies that could be caused by curled sheets in a feed tray. The stack height is also measured "on the fly" as the sheets are being acquired and fed, thus providing an efficient stack height sensing scheme.






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