Patent GB-448382-A (GB)
Title: Rotary web undersurface printing machines
IPC: B41F13/04
Filed: 1935-10-30
Abstract: 448,382. Printing-machines. ROWLAND, M. F., 56, Ludgate Hill, London.-(American Bank Note Co. ; 70, Broad Street, Manhattan, New York, U.S.A.) Oct. 30, 1935, No. 29999. [Classes 100 (i) and 100 (ii)] A rotary intaglio printing-machine which is especially applicable for printing stamps, in which a printing-cylinder 10 fitted with one or more printing-plates P coacts with a D-impression roller 11 to print a number of rows of stamps at each passage of a plate P is constructed with a pair of feed rollers 13, 14 which are kept apart while the web is being forwarded when gripped between the surfaces P and 11, the rollers 13, 14 being moved together to engage the web and reverse it so as to cause the successive impressions to register exactly with just sufficient space between the stamps to allow for the cross perforations. The web W is led over guide rolls 15, 16, 17, through the reversing rolls 13, 14, over a tensioning roller 19 coacting with a platen 18, under a guide roll 20 and after passing through the printing- couple moves under a guide bar 24 at a level below that of the printing-line, and is finally wound up. The rolls 13, 14 are normally pressed together by adjustable springs 27, but are moved apart by levers 31 which are formed with forked ends 35 engaging collars 34 loosely mounted on the arbors at each end of the roller 13. Each lever 31 is actuated by a cam 39 on the shaft of the printing-cylinder and an oscillating lever 41 connected to a stirrup plate 45 which engages a roller 32 on the lever 31. The plate 45 is connected by a link 50 to a spring-controlled crank-arm 51, and the movement of the plate 45 is limited by a stop 49 on the lever 41. The rollers 13, 14 are given an oscillating motion from a cam 40 on the shaft of cylinder 10. This cam oscillates a lever 54 connected by a link 56 to a lever 57 connected by a link 62 to a lever 32 mounted on the shaft of the roller 14 and fitted with a segmental gear 35 geared to a similar gear on the shaft of the roller 13. A spring- controlled rod 38 maintains the roller 55 in contact with the cam 40, and the connection between the link 60 and lever 57 consists of a pin 61 on a block which can be adjusted by a screw in a slot in the lever 57 so that the extent of the oscillation of the rollers 13, 14 can be varied to suit stamps of different sizes. If it is desired to separate the stamps into rows of, say 500, a counter mechanism is employed which puts the web-reversing mechanism out of action once for each 25 rotations of the cylinder 10. The counter disc 63 is driven by worm gearing 66, 65, a clutch 70, bevel gears 67, and gears 68 from the cylinder 10, and at each 25th revolution of the shaft 63a of the disc 63 a tappet 64 raises a rod 75 and actuates a stop lever 74 which prevents the lever 31 from depressing the roller 13 into contact with roller 14, so that no reverse movement of the web takes place. The web-reversing mechanism and the counter 63 are arranged to be put out of action when the throw-off mechanism of the press is operated by means of a rod 102. Motion is transmitted from the rod 102 to a lever 95 which is moved clockwise when the printing- couple is tripped. The lever 95 permits a locking-bolt 77 to descend under the action of a weight 85 and a spring 82, and the bolt engages a recess in the link 56 and prevents operation of the mechanism which oscillates the rollers 13, 14. The lever 95 also raises a rod 96 and raises a cam-operated link 89 to such a position that a block 90 on it engages an impact member 94 on a lever 91 which operates a clutch 70 and so declutches the counter 63 from its driving-shaft.