GB566808A - Improvements in paper cutters - Google Patents

Abstract

566,808. Guillotine cutting-machines. BELLAR, O. July 10, 1943, No. 11216. [Class 31 (i)] In a guillotine paper-cutting machine in which the stock is mounted on a bed supported on a frame 28, 30, 32, which is designed to be of narrow width to permit the passage of the machine through a workshop door, the cutting is effected by a reciprocating knife blade 23 mounted in a carrier 180, the stock being held during cutting by a vertically reciprocating clamp 25 which is reciprocated by the same cranks 166 and connecting rods 168 as actuate the knife carrier. The clamps are driven by a friction drive which yields at a given pressure and permits the blade to move relatively to the clamps which grip the stock with increased pressure as the cutter comes into action. As shown in Fig. 16 in the raised position of the cutter block 180, the low left edge of the knife 23 is below the level of the right edge, but in the descent of the block 180 the right end is caused to travel faster so that at the completion of the stroke the edge 23 is level, and the cutter is given a movement to the left as it descends, as well as a slight pivotal movement. These effects are produced by transmitting the reciprocating movement by blocks engaging level slots 176 and inclined slots 178, and by a fixed guide 186 engaging a pivoted block 184 on the knife block 180. The machine is driven by a fly-wheel 40, Fig. 1, driven by a belt 22, and the drive is transmitted to the crank-shaft 42 by mechanism involving a one-revolution clutch and also an overload device which yields and throws out the drive if the power is not adequate to complete the cutting operation. As a safety measure the clutch can only be thrown in by both hands of the operator, who operates a shaft 104 to cause a sliding cam 118 to expand arms 96, 98 which force into engagement with a drum 64, Fig. 5, on a gear 50 geared to the fly-wheel, spring arms 66 on a ring 68 connected to the shaft 58 of a pinion 60 which drives an internal gear 62 on the crank-shaft 42. Between the ring 68 and shaft 58 is a. connection comprising a cam member 76 which acts as an overload device and yields under great pressure, and so disconnects the drive of the shaft 58, which normally takes place by engagement of the cam 76 with a recess 74 in a disc 72 on shaft 58, as shown in Fig. 5. Before the shaft 104 can be operated to throw in the clutch, a lever 122 must be moved to permit movement of a rod 126 which is moved to the left by operation of the shaft 104. The clutch is thrown out automatically by a cam 138, Fig. 6 (not shown), which operates a roller on a rod 134 connected to the shaft 104. A brake band 142 is also applied and is controlled by spring pressure when the safety rod 126 returns. The rod 126 may also actuate a safety stop 162 which checks the wheel 62 positively by engaging a projection on the wheel if the brake fails.