Patent GB-867260-A (GB)
Title: Improvements in or relating to duplicating machines
IPC: B41L11/00
Filed: 1959-04-21
Abstract: 867,260. Copying documents. RITZERFELD, W., and RITZERFELD, G. April 21, 1959 [April 24, 1958], No. 13553/59. Class 100(2) A duplicating machine for printing sections of changeable size from a master sheet, comprises printing and impression elements the co-operation of which is controllable by one or more control members, e.g. cams, the control member, or one of them, having an operative length adjustable in a line-by-line or section-by-section manner relative to one of the elements, a sensing member for the control member, and means for rendering rigid at the beginning of the selected printing section a normally loose connection of the sensing member with one of the elements, the size of the section to be printed being determined by the sensing member's sensing the adjusted operative length of the control member. As shown a printing drum 1 carries a master sheet 2 and co-operates with an impression roller 10 mounted on a shaft 3 carried by two levers 12 which are rigidly mounted on a shaft 13. The shaft 13 is journalled in the machine frame 14 and can be oscillated to bring the roller 10 into and out of contact with the printing drum. The shaft 11 is also rotatably mounted in levers 15 having forked ends which embrace an eccentric 16. The eccentric 16 can be rotated by a hand lever 75 so as to hold the roller 10 continuously in contact with the printing drum against the bias of a spring 17 when it is desired to print from the whole of the master sheet 2. Sensing levers 18, 19 are connected rigidly but adjustably to the shaft 13 and carry rollers 20, 21 for co-operation with cams mounted on the printing drum shaft 3 so that the impression roller 10 is brought into contact with the printing drum when either of the rollers rides on the high part of its corresponding cam. A third sensing lever 22 carrying a roller 23 is rotatably mounted on the shaft 13 and is normally held in contact with an abutment 21 by a spring 72 which is weaker than the spring 17. The printing drum shaft 3 is rotated through gears 4, 5, 6 and a one revolution clutch 8, 9 by an electric motor. A flange 24 is fixed to the printing drum 1 and pawls 26, 27 are pivotally attached thereto by a stud 25. The pawl 26 engages the teeth of a locking wheel 29 under the influence of a spring 28. The locking wheel 29 is keyed to a flange 30 rotatably mounted on the shaft 3 and biased towards rotation in an anti-clockwise direction (Fig. 2) in relation to the shaft by a spiral spring 31. A "line" cam 32 is rigidly but adjustably mounted on the flange 30 and is engaged by the roller 21 on the sensing lever 19. This cam has a raised portion corresponding in length to one line of the master sheet 2 and can be adjusted in relation to the printing drum so as to select any such line for printing. The adjustment is effected in a step-by-step manner by a key 61 which presses the pawl 27 into engagement with the toothed locking wheel 29 and simultaneously raises the pawl 26 out of engagement therewith so that the flange 30 and cam 32 rotate through one step under the influence of the spring 31. A flange 33 rigidly secured to the flange 30 carries an indicating scale 35 visible through a window 77 in the machine casing to indicate the line selected for printing. Alternatively the adjustment of the cam 32 may be effected by moving a lever 63, carrying a roller 64 into the dotted line position shown in Fig. 2 and then rotating the printing cylinder. A flange 37 is rotatably mounted on the flange 30 and carries a "line extension" cam 38 and an indicating scale 39. The cam 38 co-operates with the roller 23 on the sensing lever 22 and has a raised portion which can be adjusted in relation to the raised portion of the "line" cam 32 so as to select the number of lines of the master sheet to be printed after the line selected by the cam 32. A locking pawl 40 secured to one end of a shaft 41 rotatably mounted in the flange 37 is held by a spring 44 in engagement with a toothed wheel 34 secured to the flange 33 so that rotation of the flange 30 and cam 32 is thereby transmitted to flange 37 and cam 38. A release member 42 carrying a roller 43 is fixed to the other end of the shaft 41, the roller 43 engaging a release cam 46 secured to an adjusting wheel 45 rotatably mounted on the flange 37. The adjusting wheel 45 is normally maintained by a spring 47 in such a position relative to the flange 37 that the roller 43 is in engagement with a low portion of the cam 46. The relative positions of the cams 32, 38 may be adjusted by turning the wheel 45 until the cam 46 forces the roller 43 upwards, as shown in Fig. 3, thereby releasing the pawl 40 from the toothed wheel 34. Further movement of the wheel 45 will result in rotation of the flange 37 and cam 38 relative to the flange 30, the number of lines thereby selected for printing being indicated at the window 77 by the scale 39. When the wheel 45 is released the action of the spring 47 will allow the pawl 40 to engage the toothed wheel 34 again. A driving flange 48 is fixed to the shaft 3 and has cams 49, 50, 51 adjustably secured thereto. The pawl 9 of the single revolution clutch is pivoted to the flange 48 and the gear 4 carrying the toothed wheel 8 of the single revolution clutch is rotatably mounted on the flange 48, being kept in continuous rotation during operation of the machine. In use a copy sheet 58 is damped by a device 59 and fed by feed rollers 56, 57 into the nip of the printing cylinder and impression roller. The single revolution clutch is engaged by a lever 55 and the printing drum is rotated once. In the course of this revolution the cam 50 which cooperates with the roller 20 and sensing lever 18 will urge the impression roller 10 into contact with the printing cylinder so as to print the heading of the master sheet on the copy sheet. Thereafter the impression roller 10 moves away from the printing cylinder and the copy sheet is held in position by a clamp 60. The roller 10 is next raised by the cam 32 to print a selected line of the master sheet. As the sensing lever 19 is pushed back by the cam 32 a locking plate 70 attached thereto engages behind a pawl 73 pivoted to the sensing lever 22 so that the levers 19, 22 are coupled together. The cam 38 acting on the roller 23 holds the impression roller in contact with the printing cylinder while the selected number of linesare printed and then allows the impression roller to move away again. At the end of the revolution of the printing drum the cam 51 acts on the roller 20 to raise the impression roller into contact with the drum for ejection of the printed sheet. Simultaneously a roller 53 on the pawl 73 is depressed by the cam 49 so as to disconnect the levers 19, 22. Specification 805,596 is referred to.