Patent GB-540726-A (GB)
Title: Improvements in or relating to machines for copying documents
IPC: B41L7/08
Filed: 1940-01-17
Abstract: 540,726. Coating surfaces. KORESKA, W. Jan. 17, 1940, No. 1056. [A Specification was laid open to inspection under Sect. 91 of the Acts, July 18, 1940.] [Class 95] [Also in Group XVI] In a rotary duplicating machine printing on moistened copy sheets from a minor script original, a pair of feeding and damping rollers for the copy sheets are carried by levers, so controlled by mechanism including an adjustable pointer on the printing drum, that the period of contact of the rollers and thus the length of the dampened portion of the copy sheet may be adjusted to correspond with the length of the matter on the original. Means are also provided to adjust the position on the copy sheets at which the matter is printed, and improved means for gripping the original on the printing drum is also provided. The printing drum 11, Fig. 2, is free upon its shaft 24 which is driven by a gear 23 from a gear 18 on a shaft 17 on which is a hollow shaft 15 to which are secured three cams 30, 37 45 and a hand lever 16, Fig. 4. The shaft 17 is operatively locked to the lever 16 by a worm 22 on the lever engaging a quadrant 20 formed on a pointer 19 fixed to the end of the shaft 17 and co-operating with a scale marked on the rounded end of the lever 16. The gear 18 also drives an upper feeding and damping roller 8 carried by levers 27 actuated to raise the roller 8 by a cam 30 engaging a roller 29. and to lower the roller by a spring 28. A co-operating feed roller 10 is carried by bell crank levers 34 actuated to raise the roller by a spring 36 and to lower the roller by the cam 37 acting on the end of one of the levers 34 through a roller 38 on an arm pivoted to the frame of the machine. The roller 10 is also slightly lowered out of feeding contact with the roller 8 at certain periods by the engagement with an arm 42 fixed to the shaft 35 of the levers 34 of a roller 41 carried by a pointer 40 secured to but regularly adjustable on the gear wheel 23. When the roller 10 is thus lowered, a pawl 43 engages a stop 44 on one of the levers 34 to hold the roller lower until the pawl is raised by the cam 45. A front stop 7 for the copy sheets placed on the feed take 6 is carried by a pair of arms 46 pivoted on the shaft of the roller 10 and carrying pins 47 held by springs 48 in contact with flanges 47 on the machine frame. Thus, as the roller 10 is raised the stop 7 is turned down clear of the edge of the sheet. The distance along the circumference of the drum 11 from the position at which the arm 42 is actuated to the line of contact of the drum 11 with the impression roller 12 is equal to the distance between this line of contact and the line of contact of the rollers 8, 10. In operation, the pointer 40 is adjusted to a position a little to the rear of the end of the matter on the original. The parts of the machine are shown in Figs. 2 and 4, at the beginning of a printing operation. The hand lever 16 is turned in a clockwise direction and shortly afterwards the cams 30, 37 leave the rollers 29, 38 to allow the rollers 8, 10 to contact and feed the sheet forward to the roller 12 and drum 11, When the roller 41 engages the arm 42, the roller 10 is slightly lowered so that further damping of the sheet ceases. Towards the end of the rotation of the drum the parts are reset by the cams 30, 37, 45. By adjustment of the worm 22 on the lever 16 by a thumb wheel 21, the timing of the contact of the rollers 8, 10 relatively to the angular position of the drum 11 may be varied to adjust the position at which the matter is printed on the copy sheets. The pressure of the roller 12 on the drum 11 is adjustable by a hand lever 88, shaft 92 and linkage 89, 90, 91. Securing original on printing drum. A clamping jaw 57, Fig. 5, for the original is secured to radially slidable rods 59 having recesses 62 engaged by bell crank levers 63 pivoted at 64 on the drum 11 and having pins 66 engaging slots in arms 68 fixed to the drum shaft 24. To open the jaw 57 to release or receive an original sheet, the drum 11 is turned by the lever 16 in a clockwise direction. When the clamp reaches a position adjacent the feed table 101 for the original, a pawl 69 pivoted on one end of the drum 11 engages in a notch 73 in a fixed bracket 72 and the drum is arrested. On further movement of the shaft 24, the bell crank levers 63 are turned against the action of springs 65 and the jaw 57 is opened. Moistening copy sheets. The damping roller 8 is provided with moisture from an absorber bar 9 projecting from a liquid container 33 through which excess liquid is circulated from a supply tank 77. The liquid is raised from the tank 77 by buckets 78, Fig. 4, on an endless chain 79 driven by gearing from the shaft 24 of the drum 11, the liquid flowing from the buckets into a gutter 83 leading by a pipe 84 to one end of the container 33 the opposite end of which has an outlet pipe leading to the tank 77. The bar 9 is clamped against the bottom of the container 33 by a front wall 33<SP>1</SP> adjustable by a screw to vary the flow of liquid through the bar. Specification 540,725 is referred to.