Patent GB-739087-A (GB)
Title: Improvements in or relating to a machine for cutting or creasing sheets of paper, card or the like
Inventor: FAWDRY CHARLES FREDERICK
IPC: B26D1/30
Filed: 1953-01-16
Abstract: 739,087. Cutting-machines. BACKHOUSE, H. T. Jan. 15, 1954 [Jan. 16, 1953], No. 1405/53. Class 31 (1). [Also in Group XVI] Relates to a machine for cutting or creasing a paper sheet comprising a flat bed 20, Fig. 1, with projecting cutting or creasing blades 21, a presser 24 having an arcuate surface and arranged so that, by reciprocation of its centre of curvature in a direction parallel to the bed, its arcuate surface rolls over the bed and presses the sheet against the blades, and a sheet-feeding carriage 41 which is arranged to reciprocate with the presser in such manner that in its forward movement it feeds a sheet into position on the bed while the presser makes an idle stroke in advance of the carriage, and in its rearward movement returns empty while the sheet is held and pressed against the blades by the returning presser. According to the invention, the presser 24 is provided with means operable during the initial part of the return stroke of the carriage until the sheet is first pressed against the blades by the presser to grip the sheet and hold it against return movement with the carriage. The machine is generally similar to those described in Specifications 721,875 and 739,074, the presser being shaped as a sector of a cylinder and having a roller 25 running on a guide 23; the presser is connected to means for giving it and the associated carriage 41 the desired reciprocating movement. A sheet is fed on to the bed on each forward movement of the carriage and, near the end of this movement, suction grippers holding the sheet are released and the front edge of the sheet is then registered by lays 92 and gripped by jaws 93 carried by the presser as shown in Figs. 1 and 4. Both the lays and jaws are mounted on a cross-shaft 101 which is carried in bearings 100 on the sector. The lays consist of the headed ends of rods 103 screw-threaded in brackets 102 which are pivoted on the shaft and urged by torsion springs so that the lays engage the arcuate surface of the presser. Oscillation of the shaft 101 to control the gripping jaws 93 is effected by a pivoted air-operated cylinder 109, Fig. 1, which has its piston rod 108 pivoted to an arm 106 on the shaft and is connected through a valve in a block 112, Figs. 4 and 5, with a source of suction. The block 112 is mounted at the side of the presser in position for cooperation with two cams 128, 129 on the carriage 41, the cam 128 being arranged to coact with the valve plunger 115 and the cam 129 with a second plunger 120 in the block. As the carriage nears the end of its forward stroke, the cam 129 first moves the plunger 120 inwardly against its spring 126 and the cam 128 then depresses the valve plunger 115 so as to open the valve to suction and cause the jaws 93 to grip the sheet against the arcuate surface of the presser. On the return stroke of the carriage, the cam 128 first releases the valve plunger 115 which, however, remains in its suction position by reason of a ball catch 118 until the sector 24 grips the sheet against the first blade 21; at that stage the second cam 129 releases the plunger 120 for outward movement by its spring 126 so that by the interengagement of flanges 121, 122 on the two plungers the valve plunger is moved to cut off suction and allow release of the jaws 93 by a spring 113. Alternatively, the grippers may be spring-closed and opened by the application of suction to the cylinder 109, or hydraulic, mechanical or electrical operating means may be provided.