Patent GB-537075-A (GB)
Title: Improvements in duplicating machines
IPC: B41L3/00
Filed: 1939-12-04
Abstract: 537,075. Copying documents. MOSS, E. W. (Copeland, R. J.). Dec. 4, 1939, No. 31407. [Class 100 (ii)] [Also in Group III] A manually operated rotary machine for printing on dampened copy sheets from a master sheet clamped on a printing cylinder, is provided with an electric motor drive and a switch mechanism for starting the motor and automatically stopping it after a predetermined number of revolutions of the cylinder. Improved means for clamping the master sheet on the cylinder, for damping the copy sheets, and for tripping the impression cylinder are also described. The printing cylinder 2, Figs. 4 and 8 is secured to a sleeve 27 which may be driven manually by a hand lever 22, a ratchet connection on a shaft 23 and gearing 24, 25, 26, or may be driven from an electric motor through worm and chain gearing and a sprocket wheel secured to a ratchet clutch member 34, Fig. 10. The ratchet connections allow of independent operation of the cylinder by hand or power. The motor is controlled by a mercury switch 56, Fig. 4, operated by a lever 55 and vertical slidable rod 49 carrying a pin 51 co-operating with a notched cam 46 and pressed into contact therewith by a spring 54 on the rod 49. The shaft 43 of the cam is rotated step by step by a ratchet and pawl mechanism 44, 45, Fig. 10, from a cam 37 on the clutch member 34. Upon manually depressing the rod 49, the motor is started and remains in operation until, after a number of revolutions of the cylinder 2 determined by the ratchet mechanism 44, 45, the pin 51 rises into a notch in the cam 46 thereby tilting the switch 56 to break the motor circuit. Instead of using the mercury switch and its controlling mechanism, the motor circuit may be closed manually and opened automatically by a circuit closed by contact of a switch finger resting on the strip of connected copy sheets when that finger passes through a hole provided at a predetermined position in the strip or makes contact with a piece of conducting material placed on the strip. The copy sheet or the strip of connected copy sheets pass over a feed support 21, Fig. 4, beneath a weighted guide member 81, over a damping pad 15 on which it is pressed by a bar 20, and between the printing cylinder 2 and an impression cylinder 6 pressed towards the cylinder 2 by springs. The support 21 is provided with an adjustable register indicator 57 co-operating with marks or notches on the copy sheet. The damping device comprises a liquid container 12 containing a wick 14 extending over a shelf 13 and pressed against the side of the container to control the flow of liquid by a presser member 18 fixed to a shaft 17 to which is secured an arm 78 which can be held in one of several positions to vary the pressure of the member 18. The pad 15, which rests upon the wick 14 on the shelf 13 comprises a body of felt in an envelope of chamois skin. The bar 20 is carried by a bell crank lever 19 fully mounted on the shaft 17 and normally held in pressing position by a spring 76 connected to the lever 19 and to an arm fixed to the shaft 17. The impression cylinder 6 is raised from the copy sheet at the end of the printing position of the rotation of the cylinder 1 by a cam 75 Fig. 8, on the cylinder 2, this cam consisting of two arcuate portions having a tongue and groove connection so that the length of the cam can be varied. When the roller 6 is lifted by the cam, a projection on the bearing of the roller engages under and lifts the bar 20 from the copy sheet which is then held by the member 81. The master sheet is held on the cylinder 2 by a radially slidable clamp 4 held in clamping position by springs and moved radially to release the sheet by a cam member 67 pivoted to the end of the cylinder at 68 and to a lug 65 on an operating member 64 loose on the sleeve 27. The unlocking of the clamp is effected by moving a member 63 laterally on a support C', Fig. 4, to bring it in the path of the member 64 which is thereby arrested, the further movement of the cylinder causing the cam 67, which engages beneath the inner end of the clamp, to move the clamp radially outward as shown in Fig. 8. During this operation the cylinder 2 is actuated manually by the crank 22 and a pin 69 is projected into the path of the crank to arrest the cylinder at the moment the clamp is opened. This pin 69, which is slidable in the frame of the machine, is actuated by a lever 71 and a bar 73 secured to the member 63. The member 63 is actuated by an arm on a shaft carrying a finger piece 62 projecting through an opening in the machine frame.