GB190525262A - Improvements in Pressure Controlling Devices for the Air Springs of Printing Presses. - Google Patents

Abstract

25,262. Lake, H. H., [Cottrell & Sons Co., C. B.]. Dec. 5. Cylinder machines with plane printing surfaces. - Relates to pneumatic cushioning - mechanism for the reciprocating beds of cylinder printing - machines, provided with means for controlling the air pressure in the cylinders. The bed 12 is reciprocated in the usual manner by means of a pinion 16 on a shaft 15 and a rack 17, Fig. 1, the rack being provided at each end with a roller 18 and a semicircular shoe 19, with which engage rollers 20 on the pinion 16, to direct the pinion from one side of the rack to the other. On the bed 12 are two cylinders 22, provided with air-inlet valves 23, which are adapted to receive pistons 24, screwed adjustably on to rods 25 which slide in bearings 26 in the frame 11. The piston-rod 25 carries a collar 25*, which receives a roller 27 on the end of an arm 28 on a rock-shaft 29, mounted in bearings 30 secured to framing 11. This shaft carries a second arm 32, between which and a stop 40 on the frame is a spring 41 in compression, and which also carries a roller 33, bearing on the underside of a cam plate 34, pivoted on the rack hanger 36, Fig. 4. The cam plate 34 is normally held stationary by a spring-controlled gabhook 38 engaging a pin 39 on the cam. The operation of the arrangement is as follows :-As the piston 24 is about to enter the cylinder 22, the roller 33 is in engagement with the end of the cam 34 and the piston-rod 25 is in its extreme outward position with the collar 42 in contact with the frame 11. During the continued motion of the bed, the roller 33 is depressed by the cam 34, and the piston 24, driven into the cylinder 22 independently of the motion of the bed, to produce the maximum pressure when the driving-gear is in the position shown in Fig. 1. The reverse portion of the cam 34 then causes the piston to be withdrawn to reduce, keep constant, or otherwise adjust the air pressure. The further motion of the bed causes the gab-hook 38 to be disengaged from the pin 39 by a stud 43, and the piston to be withdrawn to the position shown in Fig. 4.