| 摘要 |
<p>1,160,745. Shearing. UNITED ENG. & FOUNDRY CO. 8 Nov., 1966 [8 Nov., 1965], No. 47328/65. Heading B3W. A sheet shear comprises a housing, a first knife carried by the housing, a movable knife head to which is secured a second knife, means for supporting the knife head in a position for the knives to co-operate, a first eccentric rotatably carried by the housing and connectable to the knife head for moving the second knife towards and away from the sheet to be cut, a second eccentric discrete from the first eccentric for displacing the second knife out of the cutting position in a direction away from the sheared edge of the sheet and means controlling the movement of the second eccentric in time relationship to the movement of the first eccentric. A mainshaft 13 which has two eccentrics formed thereon is mounted in bearings in the shear frame 11 and worm-driven by a motor 20. The eccentrics are connected by links 22, (23) to a beam 24 which carries a cutter blade 26. A co-operating cutter blade 27 is mounted on the shear frame. The beam 24 is extended rearwards (to the left as seen in Fig. 1) and is connected to a second pair of eccentrics carried on a shaft. Adjacent each eccentric a bell crank 32 is secured to the shaft, one arm of each bell crank being pivotally attached to a respective block 34. Pivotally connected to each of the eccentric links 22 (23) is a strut 36, each strut having a slot 35 to receive one of the blocks 34 and also being connected to an accumulator 38, 39, comprising a piston and cylinder assembly. The piston rods of the accumulators are each connected to one of the blocks 34. The other arms 40 of the bell cranks are engaged by screws 42 (43), the screws being rotatable through screws 48, 49 driven by a motor (50), Fig. 2 (not shown). Operation.-The initial position of the bell cranks 32, is determined by the setting of the screws 42, (43) and the corresponding positions of the eccentrics controls the cutting clearance between the blades 26 and 27. During that part of the revolution of the mainshaft eccentrics which causes downward movement of the cutter 26 the links 36 slide on the blocks 34 so that no rotation occurs of the second pair of eccentrics. During the upward movement of the cutter the links 36 rotate the second pair of eccentrics so that the cutter 26 is withdrawn from the freshly cut edge of the sheet.</p> |
