Patent GB-189909219-A (GB)
Title: Improvements in and relating to Sheet Feeding Mechanism for Printing Machines and the like.
Inventor: BENEDICT LEWIS
Filed: 1899-05-02
Granted: 1899-09-23
Abstract: 9219. Lake, H. H., [Benedict, L.]. May 2. Feeding sheets.-Fig. 2 shows a side elevation, in which 28 is the frame of the feeding-mechanism, secured to the frame 29 of the printing or other machine by bars 30, and 33 is the cylinder having grippers 207 to which the sheets are fed. The pile of sheets 39 is placed on a table 38 raised automatically by any suitable means to keep the top of the pile at the same level. A vacuum is maintained by any suitable means in a chamber 40 connected by a tube 41 to a transverse tube 42 extending transversely across the machine. On a carriage 46 sliding backward and forward on rods 45 are lifter or picker tubes 52 connected by flexible pipes 49 with the vacuum tube 42. The carriage 46 is moved by a lever 51 and cam 50 on a shaft 35 driven by sprocket gearing from the shaft of the cylinder 33. The tubes 52 carry at their lower ends suction cups 54, Fig. 26, for lifting and feeding the sheets. The cups are lowered on to the sheet when the carriage 46 is in its rearward position (to the right in Fig. 2), and valves are then operated by cams on the shaft 35 &c. to open communication, through the pipes 49, from the cups to the vacuum tube 42. The cups are then lifted to raise the sheet, and the carriage then moves forward to deliver the front edge of the sheet to a pair of feed-rollers 87, which feed it on to the tapes 92. Valves are opened to admit air and cause the cups 54 to release the sheet as it is engaged by the rollers 87. The cups 54 are made of compressible material such as rubber or leather, and clamps 55 on each side of the cups operated by a screw 56 are provided to compress the lower end of the cup laterally. When the cups have engaged the top sheet the tubes 52 and cups are positively lifted by springs, and these springs are compressed to permit the cups to fall on to the pile by pistons in cylinders connected, by flexible pipes 65, through cam-operated valves, with the vacuum tube 42. The tapes 92 are driven at a slower speed than the feed-rollers 87. Over the rear of the pile on supports 109 are telescopic lifter tubes 108 having cups at their lower ends similar to the cups 54. The tubes 108 are connected by flexible pipes 98, through cam-operated valves, with the vacuum tube 42. When the top sheet has been moved forward a short distance, the lifters 108 are lowered on to the rest of the pile. They lift the tail end of the sheet temporarily, and then again descend on to the pile ; they then again lift the sheet, and hold it raised until its forward feed movement is about to commence. A blast of air is blown under and separates the top sheet, by a nozzle 115 connected by a flexible pipe 114 with a force-pump 111. In the path of the sheets is a pair of adjustable arms 211 and 214, the ends of which are formed with sharp edges. These ends are so adjusted that they permit only one sheet to pass between them. If two sheets are fed, they are held by the arms 211, 214 and prevented from passing to the machine. The sheets are registered sideways by means of a bar 119 reciprocating transversely in a groove in the table 31. The movement of the sliding bar is adjusted by means of a stop &c. On this bar is adjustably mounted a guide which pushes the sheet sideways in one direction, and then engages it by means of air suction and pulls it in the opposite direction. The guide has air passages, and is connected by a flexible tube 137 with a cam-operated valve 138 connected by pipes 139 and 140 with the vacuum tube 41. The front edge of the sheet, as it is fed to the front stops, engages the lower ends of levers 200, which are thereby moved so as to close the open ends of tubes 186 connected by pipes 196 with the valve 138. In case a sheet is not fed to the side registering-device, or when the front edge of the sheet is not properly fed to the front stop so as to operate the levers 200, air is admitted through the valve 138 and tube 139 into the upper end of a cylinder 147 connected to the tubes 140 and 139 by a tube 149. The piston of this cylinder is thus released, and is then drawn down by a spring 155, and by a connecting-chain 153 opens a valve 150, 151 in a pipe 161 connected to the tube 140 and to a tube 160 and cylinder 157. This causes a vacuum in the cylinder 157, whereby the piston 158 is drawn in and operates through a connecting-rod 159 the arm 118, of a switch so as to stop the machine. If the machine is not driven by electrical power, the piston 158 may operate any belt shipper or stopping arrangement. A brake is applied to a wheel on the driving-shaft, by the piston 163 of a cylinder connected by pipes 174, 177 to the pipe 161. A valve 175 in the connecting-pipe is opened by a connection 178 with the piston 158. The piston 163 is connected with an arm 165 of a shaft 164 which operates the brake mechanism. In a modification, the tubes 186 and levers 200 are replaced by tubes having openings closed by the front part of the sheet itself, such tubes being mounted to swing and move with the sheet as it is moved sideways by the side registering-device. A modified arrangement is also described for operating a belt shipper or stopping mechanism.