GB739280A - Improvements relating to sheet feeding means for duplicating or printing machines - Google Patents

Abstract

739,280. Feeding sheets; copying documents. FORD, Ltd., F. R., and FORD, R. M. March 3, 1954 [March 6, 1953], No. 6211/53. Classes 100 (1) and 100 (2). Sheet separators; duplicating machines.-In a duplicating machine having a rotary printing couple comprising a master cylinder and an impression roller, a sheet feeding mechanism having a sheet feeding roller for engaging and forwarding sheets to the printing couple is characterized in that the roller is driven by an actuating member disposed on the master cylinder or driven in timed relation thereto, a sprocket-wheel having an operative connection with the roller, and a chain lapping the sprocketwheel and having an operative connection with the actuating member so as to be drawn thereby whilst being maintained in a state of tension by a yieldable loading device. As shown, the machine comprises a master cylinder 10 and impression roller 16 supported between side frame members 11 and adjusted to be manually driven by a handle or crank. Fixed on the shaft of the cylinder 10 is a cam 32 which co-operates with cam followers 37, 47 on one end of the bell-crank levers 33, 34. The bellcrank lever 33 is pivoted at 39 and its arm remote from the cam follower 37 carries a component 36 which may be angularly adjusted with respect to the pivot 39 by means of screws 40 and screws 43. The end of the component 36 is connected to a chain 58, the other end of which is attached to a spring 60 and which runs over a sprocket-wheel 53. The lever 34 is similarly provided with an angularly adjustable component 45, and a sprocket chain 62 running over a sprocket-wheel 54. The shaft 55 of the sprocket-wheel 54 carries a gear 56 meshing with a gear 57 fast on the shaft of a forwarding and damping roller 27 which co-operates with another roller 28. The sprocket 53 is fast on a spindle 68 which carries a gear segment 66 marking with a gear 67 which, through a oneway clutch, drives a sheet forwarding and separating roller 20. The arrangement is such that on actuation of the lever 33 by the cam 32 only a slight endwise displacement of the chain 58 will result so that the roller 20 accelerates only slowly so as to prevent slipping of the roller with respect to the top sheet of the pile 19. The acceleration imparted to the forwarding roller 27 is such that its peripheral speed is less than the speed of a sheet at the instant when the leading edge of the sheet is fed between the bite of rollers 27, 28 so that relative slipping between the sheet and rollers is avoided. The sheets are fed over guides 24, 25, 26 and the roller 27 may be dampened by a pad 29. Specifications 678,157 and 719,052 are referred to.