Patent GB-928062-A (GB)
Title: Improvements in or relating to apparatus for conveying and stacking documents
IPC: B65H29/40
Filed: 1961-02-03
Abstract: 928,062. Stacking sheets. BULL NEDERLAND ADMINISTRATIE-EN STATISKIEKMACHINE MIJ. N.V. Feb. 3, 1961 [Feb. 9, 1960], No. 4210/61. Class 100 (1). Documents S successively advanced along a track 7 are stacked at 27 by grippers 17 carried by a rotatable arm 4, locking means holding a gripper stationary in a position where it receives the leading edge of a document to be stacked and releasing the gripper after the introduction of the leading edge into the gripper. The arm 4 is rotatably mounted on a driven shaft 1 between a pair of discs 2 which are secured to the shaft. On their inner faces near the shaft 1 the discs 2 carry bronze friction plates which contact a nylon central portion of the arm 4 whereby the rotation of the shaft is imparted to the arm 4. The discs 2 have rubber friction rings 3 on their peripheries which near the end of the track 7 engage spring biased rollers 11. The arm 4 rotates in the direction of the arrow F until one of the grippers encounters a spring-biased detent 19 comprising a U-shaped piece of wire pivoted at 20, Fig. 3, in a recess in a fixed member 10. The detent engages a shoulder 17A on the gripper 17 and pi events rotation of the arm 4 with the shaft 1 and discs 2 while the latter continue to rotate, the frictional coupling between the discs and the arm slipping. The gripper 17 which is a resilient finger rigidly secured to the arm 4 is prevented from rebounding upon engagement with the detent 19 by a fixed bar 24 in the member 10. A document S is advanced along the track 7 into the nip of the discs 2 and the rollers 11 which feed the document until its leading edge is engaged beneath the resilient finger of the gripper, a guide 9 pivoted at 8 being in the full-line position of Fig. 1 to direct the document towards the gripper. As the leading edge of the document passes beneath the gripper finger it pushes the detent 19 upwards and disengages it from the shoulder 17A so that the arm 4 is free to rotate with the discs 2 and the document is carried round therewith, the leading edge being gripped between the resilient gripper finger and the disc friction rings 3. The document is deposited on the stack 27 after the leading edge has been disengaged from the gripper by a pair of vertical stops 29 on a stop plate 28, and is held down by a pair of lugs 30 the stack 27 being formed on a plate 25 which is urged upwards by a spring. In order to prevent slipping of the friction coupling between the plates 2 and the arm 4 at this point, resilient, laterally protruding plates 18 secured to the end of the arm 4 opposite to that which is passing the stack 27 are gripped between the rings 3 and the rollers 11 and thereby provide a supplementary drive for the arm 4 which continues to rotate until the other gripper 17 i.e. that which has just passed the rollers 11 is arrested by the detent 19. Only selected documents need be stacked by the device, the guide 9 being raised to its dotted line position to allow documents not selected for stacking to pass over the top of the member 10. In a modification the guide 9 is replaced by a resilient strip secured to the member 10 at one end and resting on top of the track 7 at the other end, the free end of the strip being raised by solenoids to direct selected documents leaving the track 7 underneath the strip to the stacking device. In another form the detent 19 is replaced by a detent pivoted to each of the grippers which detent engages an abutment on the member 10; this detent is also disengaged by the leading edge of a document. In another modification, Fig. 10, each gripper finger 17b is pivoted to the arm 4 at 42 and is spring-biased in a clockwise direction. Each linger has a forward projecting part 45 which carries at its end lateral projections 46 overlying the friction rings 3. As a gripper passes the stack 27 the projections 46 are pressed into the rings 3 by a pair of rollers 48 or stationary blades 50 mounted on the stop plate 28 so that a supplementary drive for the arm 4 is provided and the gripper pivots slightly in an anticlockwise direction to facilitate release of the document held thereby, and to depress the top of the pile 27 slightly as shown. As a gripper travels from documentreceiving to document-stacking position the projections 46 are pressed lightly into engagement with the rings 3 by reason of the document engaged beneath the finger 17B. This embodiment is particularly suitable for very thin documents.