GB932343A - Improvements in or relating to guillotines - Google Patents

Abstract

932,343. Guillotine cutting-machines. J. E. THOMPSON. Dec. 13, 1961 [Dec. 19, 1960], No. 43635/60. Class 31 (1). A guillotine machine comprises a clamp 5 and a blade 4, operated by respective linkage systems for moving them towards and away from the base 1 of the machine, each linkage system including two arms pivotally connected with bell-cranks, which are interconnected for simultaneous movement, and the linkage system for the blade having a further link 21 for the purpose of imparting a horizontal component of movement to the blade. Arms 9, 10, Fig. 2, connect the blade 4 to a pair of bell-cranks 14, 18 which are interconnected by a link 19 and operated by an hydraulic piston-and-cylinder 23, 24 acting on a lever 22 which extends from one of the bell-cranks. The cylinder 24 is adjustable in height to set the height of the blade and the link 21 is also adjustable to set the horizontal movement of the blade. The clamp 5 which is disposed adjacent the blade has similar depending arms 27, 28, Fig. 3, which are connected to a pair of bell-cranks 31, 34 operable through an hydraulic cylinder 42. In the clamping arrangement, however, the lever 38 has an extension for a foot pedal 39 and the hydraulic piston 41 is arranged to engage within a cup 40 provided on the lever 38; the piston 41 is cushioned at the bottom of its stroke by a rubber pad 43 and by the trapped air in the cup. In operation, the foot pedal 39 is depressed to lower the clamp so that it rests on the work. The sequence of operations is then initiated by pulling a guard into position whereupon it actuates a solenoid valve 66 to cause the cylinder 42 to force the clamp into clamping position. As the piston 41 reaches the end of its travel, it actuates a switch 45 to set the valve 66 to cause the cylinder 24 to lower the guillotine blade. After a cut, the guard is raised to cause the sequence of operations to be reversed. In the modification shown in Fig. 4, the linkages of both the clamp 5 and the blade 4 are operated by a motor-driven cam 54 which acts through a crank 53 to drive the blade and, through followers 57, 64, to control a spring-pressed ratchet rod 61 and pawl 63 for operation of the clamp. In operation, the foot pedal 59 is depressed while the pawl is out of engagement so that the clamp rests on the work. Applying the safety guard actuates a switch for starting the motor which drives the cam 54. As the cam turns, the follower 64 causes the pawl 63 to engage its ratchet rod 61 while the follower 57 allows the spring 58 to press down the clamp 5 through the ratchet linkage mechanism. The blade is arranged to make its cut just after the full clamping pressure has been applied to the work. After 180 degrees rotation of the cam, the cut is complete and the blade and clamp start their return. The machine may incorporate the mechanism described in Specification 932,344 for programming the operation of the guillotine and/or indicating the position of the material to be cut.