GB721619A - Improvements in guillotines - Google Patents

Abstract

721,619. Guillotine cutting - machines. GOODA, A. R. Aug. 31, 1953 [May 29, 1952], No. 13694/52. Class 31 (1). [Also in Group XXIX] In a guillotine in which a pile of sheets to be cut is clamped against a table 12, Fig. 1, by means of a bar 13 to which clamping force is applied by means of a spring 15, a transmission is interposed between the bar 13 and the spring 15, the transmission including a link 17 the length of which is variable in accordance with the thickness of the pile of sheets to be cut, irrespective of the distance of the bar 13 from the table 12 when the bar 13 is in the clamping position. In the form shown, the link comprises a piston 38 and cylinderball 39, Fig. 2, liquid being supplied to the cylinder through a pipe 48 and spring-influenced ball valve 43 by means of a pump 49 comprising a reservoir 57 and an inner tube 52 housing a piston 53 and provided with ports 58 adapted to be opened and closed by means of a gravity, or spring, operated slide 61, the piston 53 being actuated by a treadle 50, Fig. 3, and the slide 61 by a pedal 63 mounted on the treadle 50. The head 40 of the piston 38 is engaged by rollers 32, Fig. 1, mounted on levers 27 connected to the clamping bar by links 26, and the lower end of a rod 41 connected to the cylinder 39 engages a roller 33 mounted on a pivotallymounted lever 29 which is movable by means of a cam 35 and has its free end connected to the lower end of the spring 15. The blade holder 14, Fig. 1, is reciprocated by means of a crank 21 and connecting-rod 20 coupled to a train of pinions 22 to 24 driven by an electric motor 16. In operation, after a pile of sheets has been placed on the table 12, the pedal 63 is rotated clockwise to lift the slide 61 and open the ports 58. The treadle 50 is now depressed to pump liquid into the link 17 which increases in length causing the clamping bar to move downwardly towards the pile of sheets against the action of springs 31. The pedal 63 is released whereupon the slide 61 drops and closes the ports 58. The motor 16 is then started and the blade holder 14 is moved downward in the first part of the cutting cycle; simultaneously, the cam 35 rotates to permit the spring 15 to apply clamping force through the link to the clamping bar. Immediately the clamping force is applied to the link, a plunger 45, Fig. 2, is caused to close the valve 43. As the blade holder returns to its upper position at the end of the cutting cycle, the cam 35 removes the clamping force from the link permitting the valve 43 to open under the action of its spring. The pedal is again rotated clockwise to open the ports 58 and enable liquid to pass from the inner tube 52 to the reservoir 57. The springs 31 then move the clamping bar upward, the link piston 38 moving downward in the cylinder 39 and the pump piston 53 moving downward and rotating the treadle back to its original position. In a modification, Figs. 4 to 6 (not shown), in which the link is operated mechanically, the link comprises a spring-influenced castellated, or buttress screwthreaded, bar (68) movable in a tube and adapted to be clamped in each of various positions by means of one or more half-nuts movable towards and away from the bar by means of a pedal, or hand mechanism, the bar being raised and lowered by means of a treadle on which the pedal is mounted. According to the Provisional Specification, the spring (15) could be located in the upper part of the guillotine and act directly on the head of the bar (68).