Patent GB-1043444-A (GB)
Title: Improvements in or relating to rotary spirit duplicating machines
IPC: B41L11/00
Filed: 1964-02-21
Abstract: 1,043,444. Duplicating machines. W. RITZERFELD, and G. RITZERFELD. Feb. 21, 1964 [March 22, 1963], No. 7294/64. Heading B6C. In a rotary spirit duplicating machine incorporating means for printing selected lines of a master sheet 2, Fig. 3, line selection is accomplished by photo-electric sensing cells F1 to F5 which are actuated in a predetermined cycle through the detection of illuminated marks 9 on the master sheet, these marks being arranged as shown in Fig. 4, in five vertical columns. The sheet 2 shown has twenty-two lines and according to the marks 9 inscribed thereon will print seven copy sheets in sucession, the first bearing lines 1 to 3, the second lines 4 to 8 and so on. The printing of the selected lines is brought about by the swinging of an impression cylinder 33, Fig. 1, against the drum 1 upon which the sheet 2 is mounted, inward movement of the cylinder 33 being effected against a spring 37 by four electromagnets 24 acting on crank levers 31 cradling the cylinder 33. The impulse to the electromagnets 24 derives from an electrical circuit through one of a group of five switches S1 to S5, one or more of contact studs K1 to K5 on a fixed contact bank 14, one or both of studs 35 and 36 on a travelling arm 13, a slip ring 22 on the bank 14, and finally, an amplifier 25. The travelling arm 13 rotates in synchronism with the drum 1 and through a stud 34 and a fixed slip ring 23 on the contact bank 14 energizes in succession a series of electric lamps Z1 to Z22, one for each line on the master sheet 2. The drum 1, and hence the arm 13, is rotated through one revolution at a time, the position of the various parts of the duplicating machine being diagrammatically illustrated in Fig. 3 at the commencement of the first revolution during which a copy sheet 15 is to be printed with lines 1 to 3 of the master sheet. The lamp Z1 is illuminated and therefore denotes the first line of the selected batch of lines to be printed during the ensuing revolution of the drum 1. The machine drive is now energized and the arm moves from the position of lamp Z1, whereupon it goes out. A projection 19 carried by the arm 19 subsequently and momentarily opens a switch 20, which is biased into its " closed " position, whereupon any relays R1 to R5 still energized from a previous revolution of the drum 1 are de-energized. The arm next momentarily closes an " open " biased switch 21 to thereby momentarily energize a lamp 8 which illuminates the area of the master sheet within the field of photo-electric cells F1 to F5. At this moment the mark 9 on line 1 in the third column of the sheet 2 lies opposite the cell F3, whereupon a pulse from amplifier V3 energizes the relay R3 to close the switch contacts S3. A potential is thereupon applied to contact studs K1 to K3 such that when the contact studs carried by the arm 13 are in contact therewith, the electromagnets 24 are energized for a sufficient time to hold the impression cylinder 33 against the copy sheet 15 and the drum 1 in order to print the required three lines. Simultaneous with the closing of the contacts S3 electromagnets M1, M2 and M3 are energized, whereby rollers 42, Fig. 1, are thrust into the path of a pawl 47 of a known pawl-and-ratchet mechanism. Immediately before the end of the printing revolution of the drum 1, the pawl 47 contacts each roller 42 in its path-the pawl is rotating in synchronism with the arm 13 being mounted on the gear-wheel driving the armsuch that a ratchet-wheel 44 is rotated in three successive steps to thereby effect anti-clockwise rotation of the arm 13 to such a position that when the drum 1 comes to rest the arm contact 34 is effecting illumination of the lamp Z4 associated with line 4 of the master sheet 2. The following rotation of the drum 1 is accordingly set to print lines 4 to 8 of the master sheet.