Patent GB-1305034-A (GB)
IPC: B65H31/10
Filed: 1969-12-16
Abstract: 1305034 Folding paper; detector devices INTERNATIONAL COMPUTERS Ltd 20 Oct 1970 [16 Dec 1969] 61153/69 Heading B8R A sensing device for detecting when a surface reaches a predetermined position includes at least one member on a rotatable shaft and arranged to contact said surface, drive means supported on a mounting rotatable about the shaft, means for applying a predetermined force to resist movement of the mounting about the shaft in the opposite sense to shaft rotation, and means for detecting rotary movement of said mounting about said shaft against the applied force, whereby as the distance between the surface and the shaft decreases, frictional engagement of said member with the surface increases such that when the surface is at said predetermined position the frictional engagement is sufficient to overcome said force and produce said rotary movement of the mounting. The arrangement shown is for handling a continuous paper web issuing from the printing mechanism of data-processing equipment to which the web has been fed from a zig-zag stack. A vertically-movable frame 6 has sliders 7 engaging fixed frame members 5 and attached to chains 38 carried by shafts 42, 43 mounted on the members 5, the shaft 43 being driven by a motor through an electrically energized clutch to raise the frame 6. Rollers 12 receive the web 1 and feed it on to the stack 2, the roller shafts 11 being driven from a splined shaft 44 driven from a separate motor situated in a base 3. As the web 1 leaves the rollers 12, its prefolded creases cause it to assume the original zig-zag formation as it falls on to the supporting surface 4 of the base 3. At the ends of arms 8 of the frame 6 extending outwardly from the frame members 5 are identical devices for aligning and smoothing out the folds, and for sensing the stack height, the sensing devices controlling the clutch in the drive to the frameraising motor. The left-hand device, Fig. 1, includes flexible guide strips 51 fixed to a bar 49, side stops 50, and a shaft 14 driven from a motor unit 24. On the shaft 14 are rollers 15 with resilient fingers (17, Fig. 2) rotated clockwise. At the right-hand side are a shaft 22, rollers 23, and guides 54, 55 corresponding to those on the left, the shaft 22 being driven anticlockwise. These parts are mounted on arms 19 adjustably secured to the frame 6. The drive unit comprises a motor 29, coupled through an idler gear 28 to a gear 26 on the shaft 22. Plates 25 pivotally mounted on the shaft 22 carry the motor 29 and gear 28. A block 47 fixed to the arms 19 has a thumbscrew 33 connected to the plates 25 by a tension spring 33 which resists clockwise movement of the plate. A lug 34 on the plate 25 carries an adjusting screw 35 which bears against an actuating lever 37 of a micro-switch 36 carried by another block 48 fixed to the arms 19. The fingers press the web downwards and towards the stop 54. As the stack 2 increases in height, the fingers are flexed increasingly resulting in a progressive increase in resistance to the rotation of the roller 23. When this reaches a certain value, the gear 28 moves in a clockwise direction taking the plate 25 with it, so that the switch 36 is closed causing energizing of the clutch in the drive to shaft 43 so that the shaft is driven to raise the frame 6 until the switch 36 is again opened. The drive unit 24 for the left-hand shaft 14 is similar to that for the shaft 22, although it is only essential for one unit to have a movable plate 25 and microswitch 36. According to a modified arrangement, the frame 6 may be pivotally mounted and have a lifting chain such as 38 at each end, the drive for each chain being controlled by a mechanism as described above. The rollers 12 may be replaced by finger rollers similar to rollers 15, 17, and a clutch may be provided in the drive to the splined shaft 44 and controlled so that the shaft 44 and therefore the rollers 12 are only driven when web is being supplied to the stacking arrangement.