Patent GB-566754-A (GB)
Title: Improvements in or relating to cutting machines
IPC: B26D7/22
Filed: 1943-11-17
Abstract: 566,754. Guillotine cutting-machines. HARRIS-SEYBOLD-POTTER CO. Nov. 17, 1943, No. 19197. Convention date, Nov. 2, 1942. [Class 31 (i)] A machine for cutting the edges of a pile of sheet material, such as paper, is constructed with a reciprocating knife 16 for acting upon a pile 20 placed on a board 10 below which are control levers for the knife-carrier 15 which are associated with a locking-bolt to prevent unintentional operation of the machine with consequent injury to the operator. The machine comprises also an improved clamping device 18 for the pile, and means for adjusting a work gauge 22, and a device for preventing reversal of the driving-mechanism. The pile is positioned against a gauge 22, Figs. 1 and 11, which is adjustable to and from the knife for cutting different widths of sheets by means of a chain 140 operated by a wheel 143 and secured in adjusted position by a clamp 147 adjustable by a cam operated by a lever 151. The rear end of the gauge is supported by eccentrics 155 which can be adjusted to vary the tilt of the face 22 of the gauge. The clamp 18 in the inoperative position of the cutter is held in a raised position above the pile, but at a lower level than the edge of the knife 16, by means of rods 50 connected to levers 54 linked together and acted upon by a spring 58 tending to move the levers 54 clockwise. The knife-carrier 15 is adjustably connected to guide blocks 42, 46 adapted to slide in inclined guides 44, 47 which are slightly divergent so as to cause the knife to change its inclination during its descent by pivoting slightly about the block 46 so as to act with a double shearing action due to its inclined movement and pivotal motion. The motion is produced by a connecting-rod 40 connected to a pitman 36 actuated by a crank 35, and also connected to a rock arm 37 which acts to free the clamp 18 from the action of one or more springs 70, 81, which come into action as the knife begins to descend and cause counterclockwise movement of a lever 75 pivoted coaxially with the arm 37. As the arm 37 moves upon descent of the knife, a pad 80 on lever 75 engages one of the levera 54 and the pressure of the springs 70, 81 is sufficient to overcome spring 58, and the clamp is moved on to the pile prior to the cutting action. The springs 70, 81 may be of different strengths and the action of either spring upon lever 75 may be cut off by interposing a.sleeve 87 between the end of the rod 71 or 82, and a collar 73 or 84 which transmits the action of the springs and normally is free to slide on the rod 71 or 82. The clamp may also be controlled by a pedal 62 connected to a lever arm 67 adapted to act on a pin 68 on rod 50. The knife.16 is formed with an inclined cutting-edge 120, Fig. 9, which causes the sheets to form an inclined pile by shifting the pile progressively as it advances downwardly. The knife is secured in a groove 125 in the carrier and thrust blocks 126, 127 are used to take up wear. The knife is secured by a series of bolts 122 engaging threads 123 in the knife. The bolts 122 are secured in apertures arranged at different levels, and are formed with serrated heads 129 to facilitate adjustment. The crank 35 is driven from a motor 25 via a clutch and brake 26, controlled by a lever shaft 28, and a gear 27 transmits motion to a gear 32 on crankshaft 33. To prevent a reverse drive a pawl 91, Fig. 5, is normally held out of contact with gear 32 by a friction member 92 engaging the side of the gear. Should the gear start to reverse, the pawl is moved into contact with the gear and stops it. At the end of the operation, a cam 190, Fig. 17, on gear 32 operates a safety bolt 160 to cause a flanged face 163 thereon to engage a curved surface on the crank 35 and thus stop the drive. As a safety measure, the machine is restarted by the operation of a pair of handles 166, 167, but the use of handle 166 which controls the motion of shaft 28 is optional. The flange 163 is held in the position in which it locks the crank 35 by a spring-pressed yoke 185, and to restart the drive the lever 167 must first be moved in a horizontal plane to relieve it of the action of a spring-bolt 175 which prevents its vertical movement. The lever 167 is then moved in a vertical plane and acts to move the yoke 185 and to move bolt 160 so as to release the flange 163 from the crank 35. The movement of lever 167 operates the clutch shaft 28 also. To allow of adjustment of the crank drive relatively to the clutch shaft, a lever 195 is operated to release the means for restoring the bolt 160 from the lever 167 which can then operate shaft 28 to give a jogging of the mechanism in a limited travel before the actual motion of the knife commences.