GB721875A - Improvements in or relating to machines for performing cutting, creasing, printing and like operations on paper, cardboard and like materials - Google Patents

Abstract

721,875. Cutting-machines. ROWLANDS, T., and THRISSELL ENGINEERING CO., Ltd. July 8, 1952 [May 25, 1951], No. 12358/51. Class 31 (1). [Also in Group XVI] A machine for cutting paper, cardboard or like sheets and, if desired, creasing, embossing or printing them comprises a forme 1, Fig. 1, a member 3 in the form of a segment of a cylinder supported for rocking movement in rolling engagement with the underside of the forme, a plane reaction surface 5 for guiding the axis of the segment along a straight line parallel to the forme, means for reciprocating the segment and causing it to rock about its axis, and a carrier 20 mounted to move forwardly and rearwardly as the axis of the segment moves forwardly and rearwardly for the purpose of feeding sheets between the segment and forme. As shown in Fig. 1, the forme 1 is mounted in a chase 2 and provided with depending cutting rules 11. The segment, which is made of a casting having a steel sheet 27 stretched over its curved surface by clamps 28, 29, is mounted on two rollers 4 rolling on the guides 5, and, at each side, has arcuate guides rolling on fixed guide strips and gear-teeth 9 meshing with fixed racks 10. The segment is driven from a motor-driven pulley 130 through gearing 126, 129, crank discs 15, and connecting-rods 12 pivoted to the segment at the centre of a median radius of the latter. Sheets 16 to be cut are fed one at a time from a magazine 17 into the machine by the grill 20 which is supported by struts 21, 22 from the rollers 4 for horizontal movement with the segment 3, being additionally guided on rollers 36. When the segment and grill move forwardly from the position shown in Fig. 1, a slidable tooth 18 operated by a rod 132 on the grill pulls the lowermost sheet from the magazine so that it drops on to the grill and is then advanced into the machine as the segment advances on the guides 5 and rotates through 180 degrees while rolling on the forme. Cutting occurs during the return of the segment and at the end of this movement the leading end of the cut sheet drops on to a conveyer system which is mounted at the front of the grill and consists of two sets of endless tapes 85, 95, Fig. 18. The outer ends of the two sets of tapes pass over rollers 83, 96 and at their inner ends both sets pass over a common roller 86 driven through a free-wheel device from a rack in the form of a stretched chain 89; the drive is such that during each return movement of the segment and grill the tapes are driven at a linear speed slightly greater than that at which the grill is moved rearwardly. The cut sheet is therefore advanced with the grill clear of the forme on the next forward movement of the segment (with the next sheet to be cut) and moves slightly forward in space during the following return movement of the segment (for the next cutting action) so that it can drop clear of the machine. One or more grippers 103, Fig. 18, carried by a cross-shaft 104 journalled in the grill are so controlled by cams that they grip the forward edge of a cut sheet when the latter is flat on the tapes and release it at the start of the return movement of the grill. In order to hold the sheet in correct position for cutting, one or more grippers operated from cams on a shaft 48, Fig. 15, driven from the pulley 130, Fig. 1, are provided for gripping the forward edge of a sheet when it has been fed forwardly as far as the grill will take it; the upper claw 41 of a gripper is mounted on a cross-bar 42 carried by links 43, 68 and the lower claw 44 is fixed on a shaft 45 journalled in the links 43. A groove 49 in a cam disc 51 acts through a spring-urged roller 52 and rod 47 to operate the lower claw so that it clamps resiliently the sheet against the upper claw which is held at the desired level by a second cam acting on the cross-bar 42. The periphery of the cam disc 51 then co-operates with a spring-pressed roller 61 to cause the linkage 43, 68 to advance the sheet slightly until it abuts a positioning stop 82 on the segment 3; the grip between the two claws is then locked, but the links 43, with the clamp, are free to swing without restraint from the cam disc 31. When operating upon stiff boards, the claws 41, 44 are replaced by spring stops 155, Fig. 21, which are pivoted to the segment 3 and are effective to position the board by pushing it against spring-urged back-stops 152 on bars 153 adjustable on the main frame. Rubber or cork inserts (111, Fig. 19, not shown) are provided in the forme for ejecting the cut sheet which is then stripped from the segment by tapering fingers on a shaft journalled in the grill; these fingers lead the sheet to the endless tapes 95, 85. The machine can be stopped by applying a brake shoe 137, Fig. 1, to the pulley 130 either from a pedal or by energizing a solenoid 147 to break a toggle 138, 139 and thereby act through a cam 141 and lever 143 upon the shoe. To avoid blunting of the cutting knives during the inoperative rolling movement of the segment, pressure may be relieved during this stroke by so mounting the cross-head 39 carrying the chase 2 that it may be moved up and down by cams, screws or toggles; alternatively, the guides 5 co-operating with the rollers 4 may be mounted in this way, or the rollers 4 may be arranged on the inoperative stroke to run on tracks disposed at a lower level than the guides 5. The Provisional Specification describes also the adaptation of the machine for printing, cutting and creasing packet blanks on a web of carton board. Printing occurs while the web is fed continuously, and cutting and creasing during interruptions in the feed, the cutting and creasing segment being then arranged to be effective on both its forward and return strokes and to roll on top of the forme.