Patent GB-891541-A (GB)
Title: Improvements in or relating to rotary duplicating machines
IPC: B41L11/00
Filed: 1959-04-21
Abstract: 891,541. Copying documents; feeding sheets. RITZERFELD, W., and RITZERFELD, G. April 21, 1959 [April 26, 1958], No. 13554/59. Classes 100(1) and 100(2) In a rotary duplicating machine for printing a text or text portion from a master sheet or text portions which alter from one copy sheet to the next, comprising means for feeding copy sheets between printing and impression elements,the feeding means includes a roller which is driven through a lever linkage and a free wheel device from a member rotatable with the printing element. The printing cylinder 1 carries a master sheet 2 and is driven through a single-revolution clutch comprising a toothed wheel 4 and a pawl 5. The impression cylinder 12 has a shaft 13 rotatably mounted in arms 14 which can oscillate about a shaft 15. The impression cylinder is moved into and out of contact with the printing cylinder by means of a toggle joint 16, 17, the lever 17 being pivoted to the shaft 13 and the lever 16 to an eccentrically mounted shaft 19. The toggle joint is actuated by a rod 23 pivoted to a lever 20 carrying a cam follower roller 21. The roller 21 is engaged by any or all of cams 9, 10, 11 mounted on a shaft 84 which is rotated through gearing 6, 7, 8 in synchronism with the printing cylinder 1. The cams 9, 10, 11 are adjustable both circumferentially and longitudinally on the shaft 84; the cam 9 co-operates with the roller 21 so as to hold the impression cylinder in contact with the printing cylinder when the whole of the matter on the master sheet 2 is to be printed on the copy sheet; the cam 10 effects printing of only the heading of the master sheet; the cam 11 effects printing of any one line only of the master sheet. The machine is controlled by a pedal 27 to which rods 28, 47 are pivoted at 48. The rod 28 is pivoted to a lever 29 which, when the pedal 27 is depressed rises and allows the pawl 5 pivoted to the printing cylinder to engage the toothed wheel 4 that is continuously rotated about the printing cylinder shaft 3 whereby the printing cylinder 1 is rotated. If the pedal 27 is released after the printing cylinder has started to rotate the lever 29 will be restored to its original position by a spring 66 and after the cylinder 1 has completed one revolution a part 31 of the pawl 5 will engage the lever and be forced thereby against a stop 32 on the cylinder. The pawl 5 is thus pivoted out of engagement with the toothed wheel 4 and the cylinder 1 ceases to rotate. A copy sheet 24 is damped by a device 45 and fed into the nip of the printing and impression cylinders by feed rollers 25, 26. A cam 33 rotates with the printing cylinder and acts on a cam follower 35 carried by a bell-crank lever 36 and held in engagement therewith by a spring 67. The bell-crank lever is connected by a link 38 to the casing 39 of a one-way coupling so that when the cam follower 35 rides on to the high part of the cam 33 the casing 39 is moved in the direction of the arrow K and a gear 42 connected to the other side of the one-way coupling rotates. The gear 42 meshes with a gear 44 on the shaft of the feed roller 25 so that the latter effects an initial feed of the copy sheet into the nip of the printing and impression cylinders. When it is desired to print on the same copy sheet at successive revolutions of the printing cylinder the pedal 27 is kept depressed so that the rod 47 which is connected to a slide 49 by a pin 50 assumes the dotted line position of Fig. 2; a pawl 52 the underside of which is engaged by the pin 50 also assumes the dotted line position under the influence of a spring 54. In this position the pawl 52 engages behind a stop 55 secured to the casing 39 when the latter has been rotated to its full extent by the action of the cam 33 whereby the bell-crank lever 36 is held in the dotted line position of Fig. 2, closing a switch 56, and further rotation of the feed roller 25 is prevented. The switch 56 is in the circuit of a solenoid 57 which when energized urges a link 58 in the direction of the arrow L and causes a clamping member 46 to pivot about its shaft 59 and grip the sheet at printing position. If the pedal 27 is released after initiating rotation of the printing cylinder the latter will come to rest after one revolution with a small, spring- biased roller 82 mounted therein in engagement with the copy sheet. The pawl 52 does not engage behind the stop 55 and so the switch 56 is open and the clamping member 46 is out of contact with the copy sheet. Shortly before the printing cylinder completes one revolution a cam on its shaft 3 causes engagement of a single revolution clutch one side of which is driven continuously and the other side of which is connected by a chain and sprockets to the feed roller 25. The feed roller 25 is connected to the impression cylinder 12 by a chain and sprocket drive so that when the single revolution clutch is engaged the cylinder 12 and roller 25 are rotated and the printed copy sheet is ejected from between the printing and impression cylinders. When the pedal 27 is kept depressed so as to print on the same copy sheet in a plurality of revolutions of the printing cylinder the lever 29 allows a switch 61 to close. The switch 61 is in the circuit of a solenoid which, when energized, disables the sheet ejecting device and the copy sheet is therefore not ejected until the pedal 27 is released. The single-line-printing cam 11 is secured to a spring casing 87, Fig. 6, rotatably mounted on the shaft 84 and biased in an anti-clockwise direction, as shown, by a spiral spring 89. Pawls 85, 86 pivoted to the driving gear 8 are engageable with a ratchet wheel 88 secured to the spring casing 87. Normally the casing and cam 11 are locked in relation to the gear 8 by the engagement of the pawl 85 with the ratchet 88, but the relative positions are adjustable, for the printing of different lines of the master sheet 2 by means of a hand lever 91 which serves to press the pawl 86 into engagement with the ratchet 88 and disengage the pawl 85 therefrom. When the lever 91 is released the pawl 85 re-engages the ratchet, under the influence of a spring 95, one tooth further on owing to the spring casing's having rotated under the influence of the spring 89. One tooth of the ratchet 88 is equivalent to one line of the master sheet 2. Alternatively the cam 11 can be automatically advanced one line for each revolution of the printing cylinder by moving a lever 102 carrying a roller 104 into the dotted line position of Fig. 6. The cam 11 is wound back against the bias of the spring 89 by means of gears 98, 99, a sprocket 97 and a chain 96.