Patent GB-707304-A (GB)
Title: Improved rotary duplicating machine
IPC: B41L7/08
Filed: 1951-04-24
Abstract: <PICT:0707304/III/1> In a rotary duplicating machine for copying mirror script originals on moistened copy sheets and comprising a storage container from which liquid is fed to a device for moistening the copy sheets, means are provided for jointly adjusting the length through which each copy sheet is to be moistened by the moistening device and the amount of liquid to be fed to the moistening device, for each cycle of operation of the machine.  Additional means are also provided for varying the amount of liquid to be fed, independently of the length to be moistened, to allow for different qualities of copy sheets.  A cam 2 and a slotted disc 3 fixed to a spindle 1 can by rotation of the spindle be brought into one of a number of positions defined by a flat spring engaging one of a number of notches 17 at the circumference of the disc 3.  The cam 2 bears against a lever 5 pivoting about a screw 6 on a release lever 7 loosely mounted on the spindle 1, movement of the cam adjusting the distance of a roller 4 on the lever 5 from the initial position of a stepped cam 8 rotating with the printing drum 9.  A roller 10 on the lever 7 runs on a cam 11 also rotating with the drum 9 and as the drum rotates in the direction of arrow A, at the commencement of each cycle, the roller 10 runs from a raised portion of cam 11 to rotate lever 7 in the direction of arrow B which disengages a lever 12 secured to the moistening device 14 which is then caused to turn about its pivot 131 by a spring 13 so as to contact a copy sheet 15 on the feed table. Moistening of the copy sheet 15 is stopped when the roller 4 contacts one of the steps of the cam 8 (which step depending on the adjustment) and the levers 5 and 7 are thereby rotated around spindle 1 and the lever 12 re-engaged to pivot the moistening device 14.  Liquid is fed to the moistening device 14 from a storage container 18, through a pipe 39, and the amount fed is controlled by a valve 19 which is opened for the required time by a cranked lever 27.  The lever 27 is rotated about a spindle 28 in the direction of arrow D by a pin 26 on a lever 22 sliding in an p elongated slot therein, the lever 22 being mounted on a pin 25 fixed to bars 23, 24 and rotated in the direction of arrow C by a roller 20 thereon engaging a further cam surface 21 rotating with the drum 9. The time of opening of valve 19 is adjusted by adjustment of the position of roller 20 with respect to the initial position of the cam 21 and this is effected by the same rotation of the spindle 1 as that adjusting the position of roller 4.  A cam slot 29 in the disc 3, engaged by a pin 31 on a lever 30, moves the lever 30 about a spindle 32 fixed to the machine frame, and a bolt 33, eccentrically arranged with respect to the pivotal connection 33a between a lever 34 and the lever 30 and engaging a hole in the bar 23, moves the bar 23 to alter the position of the pin 25 and therefore the roller 20, there being sufficient play between the valve 19 and the lever 27 to allow this without opening the valve.  Fine control of the time of opening of the valve is effected independently by manually rotating the lever 34 to move the eccentric bolt 33 relatively to the lever 30 and thereby move the bar 23, pin 25 and roller 20.  A ball 35 on the lever 34 is urged by a spring 36 into one of a number of slots in the lever 30 to secure the lever 34 in a desired position.  The flow pipe 39 may have a number of pipes at the moistening device 14 so as to distribute more evenly the liquid across the felt pad.