Patent GB-765440-A (GB)
Title: Hectographic duplicating machine
IPC: B41L11/00
Filed: 1955-03-28
Abstract: 765,440. Duplicating machines. DELPLANQUE. M. L. A. March 28, 1955 '[April 7, 1954; April 30, 1954], No. 8952/55. Class 100(2) In a hectographic duplicating machine of the kind in which the copy sheet is moistened before being pressed against the master sheet by an impression cylinder control means are provided for moving the moistening means and the impression cylinder to and from their operative positions so that selected parts only of the master sheet may be copied on the copy sheet. In the form of Figs. 1 and 2 the printing cylinder C is driven at a constant rate, and the impression cylinder P is driven from it by rubber friction discs D1. D2 of somewhat larger diameter than the cylinders C, P so that the discs engage each other even when the cylinders are separated as shown. The impression cylinder is mounted on a limb 52 of an arm 53 pivoted at 54 and normally resting on a stop 55 at the other end. A link 56 connects the free end of the arm with the armature 57 of a solenoid E2. The moistening device F is pivotally mounted and normally kept by spring 50 in an inoperative position out of contact with the impression cylinder. The armature of a solenoid E1 is connected to the moistening device so that when the solenoid is energized it moves the moistening device to the operative position. The copy sheet I is fed over a table 48 and between the impression cylinder and a co-operating cylinder 44. On passing out on the other side it is constrained by a guide 46 to move round the impression cylinder and pass between this cylinder and the printing. cylinder C on which is fixed the hectographic master sheet. The solenoids E1 and E2 are energized through pairs of contacts 34, 36 and 40, 42 respectively and these contacts are closed'by pins 32, 38 on lever arms 5, 5a pivotally mounted at 6 above a control disc 15. This disc is mounted on the shaft 11 of the printing cylinder and has a number of bores arranged in a circle around the periphery each containing a slidable key 2 movable into operative or inoperative positions. In the operative position (shown at the top in Fig. 2) pins 2a, 2b on the key are aligned with striking faces 3, 4 on the arms 5, 5a so that as. the disc rotates the arms are raised by the pins 2a, 2b to close the contacts and energize the solenoids E1, E2 which Cause moistening of the copy sheet and application of the impression cylinder. In the inoperative position (at the bottom in Fig. 2) the pins 2a, 2b are out of alignment with the faces 3, 4 and so are ineffective to close the contacts. The faces 3, 4 are approximately as long as the peripheral distance between the ends of pins 2a, 2b of adjacent keys so that when all keys are in operative position the contacts remain closed. A disc 21 slidably mounted on shaft 11 is adapted to be pulled out against spring 24 by handle 26 to move all the keys to the inoperative position. To avoid having to reset the keys constantly in use for each printing operation, the pins may be replaced by arcuate elements 9, 10 which are screwed to the disc in a position aligned with the faces 3, 4. Key positions on drum 15 may correspond with line positions on the master sheet so according to which lines it is desired to print, those keys are pressed into operative position. In the form shown in Fig. 1 the heading part of the copy sheet, which is constant, is printed by the elements 9, 10 and subsequent lines or items are printed by corresponding pins 2a, 2b. The face 3 is somewhat in advance of the face 4 in the direction of rotation of the printing cylinder so that the moistening device comes into operation to moisten the copy sheet as it is passing into printing position and the impression is applied when the copy sheet is in printing position. In a modification, Fig. 7, the machine is adapted to print lines or sections spaced apart on the master sheet, adjacent each other on the copy sheet if desired, or with the same spacing. For this purpose the rubber driving discs D1, D2 are smaller so that they separate when the arm 53 rests on its stop 55. and a brake may be applied to the impression cylinder. By this means the impression cylinder is arranged to stop rotating, when it moves into the lowermost position, causing movement of the copy sheet to stop also. A further solenoid E3 is provided connected to the arm 53 by a pin and slot, which when energized lifts the impression cylinder into an intermediate position so that the rubber discs engage each other and the impression cylinder is rotated to advance the copy sheet but the impression is not applied until solenoid E2 is energized. The contacts 71, 72 energizing the solenoid E3 are closed when the moistening device is moved to operative position. In operation the impression cylinder and the copy sheet remain stationary until a pin 2a closes the contacts controlling the moistening device which comes into operation and simultaneously the solenoid E3 is energized to cause the impression cylinder and copy sheet to advance and at the appropriate moment the solenoid E2 is energized by pin 2b to apply the impression and print the desired line or section of the master sheet. The contacts 71, 72 may be short-circuited by a switch 81 so that the copy sheet is continuously advanced and in this case the lines are printed with the same spacing as on the master sheet.