Patent GB-115472-A (GB)
Title: Improvements in Machines for Printing Linoleum, Floor-cloth, and the like.
Inventor: SCOTT CHARLES HERBERT
IPC: B41F1/10
Filed: 1917-05-07
Abstract: 115,472. Scott, C. H. May 7, 1917. Platen or block machines. - Relates to machines for printing linoleum and the like, of the kind in which the linoleum &c. is fed intermittently under a series of printing blocks which are reciprocated vertically by suitable mechanism from a pair of bars or members reciprocated longitudinally of the machine, the colour being supplied to the blocks by tiering devices which are traversed under the blocks by means of a second pair of longitudinally reciprocated bars or members, and consists in the employment of fluid pressure driving mechanism for effecting the movements of the blocks and tiering devices and the feed of the material. Figs. 1 and 2 show diagrammatically a machine in which two fluid pressure cylinders b, a are employed to operate the printing blocks c and tiering devices c<1> respectively, the feed of the material being effected by connexions from the cylinder a. The piston of the cylinder b is attached directly by a cross-head l<1> to a pair of longitudinal bars c connected by links d and sliding arms d' to the printing blocks c so that the blocks receive a complete up and down movement at every stroke of the piston. The piston of cylinder a is connected by a cross-head l to the pair of longitudinal bars e<2> carrying the tiering devices e<1>. To ensure correct timing of the movements of the tiering devices and printing blocks, the valve of each cylinder a, b is controlled by the piston rod of the other cylinder. This may be effected in any known manner such as by the provision of tappet rods connected to the valves and adapted to be actuated by contact with the crossheads l, l<1>. The valves are preferably actuated by a differential gear to permit of variation in the speed of the press. Fig. 4 shows a suitable form of such differential gear for controlling the valve f of the cylinder a. The valve spindle is connected to a lever n, one end of which is connected to a rod m provided with yielding tappets m<1>, m<2> adapted to be engaged by the crosshead of the cylinder b. The other end of the lever n is connected to a rod o adjustable connected at o' to a rod q pivoted at r<1> and connected by a link s to the crosshead l. If the pivot o<1> is adjusted to coincide with the pivot r<1>, the valve f is controlled wholly by the tappet rod m, but if the pivot o<1> is adjusted along the rod q, the swing of the rod q by the movement of the crosshead l will also act in conjunction with the tappet rod in in governing the valve f. A similar differential gear is employed in connexion with the valve g of cylinder b. In another method of operating the valves in proper timed relationship, the valves are actuated by cams on a shaft which is turned by ratchet mechanism operated by connexions from the cylinder piston rods. To obtain a good printing impression, a throttle valve is preferably arranged in the admission or exhaust pipe of the cylinder b so as to cause a dwell in the movement when the printing block is in contact with the material. The mechanism for operating the throttle may comprise a lever operatively connected to the throttle valve and carrying an adjustable wedge cam arranged in the path of a roller carried by a bar moving in unison with the piston rod of the cylinder b. The material to be printed is fed through the machine by endless bands v operated intermittently by a ratchet t<1> and pawl t which is connected to a crank shaft a<7> which receives a complete revolution at each stroke of the piston of the cylinder a by means of a rack a<4> on the piston rod and a spur gear a<5>.