GB1156927A - Improvements in and relating to Continuously Moving Shears - Google Patents

Abstract

1,156,927. Flying shears. SECIM. 11 Nov., 1966, No. 50762/66. Heading B3W. A double-crank flying shear includes a misscut mechanism and comprises two connecting rods each carrying a blade, the big-end of each connecting rod being rotatable on an eccentric which in turn rotates on the crank-pin of a motor-driven crank-shaft, the eccentric being driven by a first planetary member which rotates about the crank-pin axis and meshes with a first satellite wheel, the journal of which is carried by an arm of the crank-shaft, a second satellite wheel being mounted on the same journal and meshing with an internally toothed ring gear which is concentric with the crankshaft and there being guide means for the small end of the connecting rod. The crank mechanisms carrying the blades 2 and 3 are symmetrical about the feed path 1 of the material to be cut. The big-end 5 of the rod 6 rotates on an eccentric 8 which runs on the crank-pin 9 of a crank-shaft 10. Both ends of each connecting-rod are similarly supported. The miss-cut action is provided by the eccentrics 8, which vary the relative positions of the connecting rods and their crank-pins so that the cutters 3 and 4 do not reach the cutting position on every cycle of the shear. A planetary gear 17 is secured to the eccentric and meshes with a first satellite gear 18 secured to a shaft 19 which is rotatably mounted in an extension of the crankarm 20. Freely rotatable on the shaft 19 is a second satellite gear 22 which meshes with an internally toothed gear ring 21 which is coaxial with the crank-shaft and is secured to the shear frame. The gear 22 is connected by a slidable pin 24 to a plate 23 which is secured to the shaft 19. As the crank-shaft rotates the gear 22 rolls inside the ring 21 and drives the shaft 19, the gear-wheel 18 and the gear 17, so that the eccentric rotates on the crank-pin at a speed determined by the ratios of the gear train. To make the miss-cut mechanism inoperative the pin 24 is moved axially so that it is withdrawn from the gear-wheel 22 and enters a recess in the crank-arm, thus locking the shaft 19 and the gears 17 and 18 to the crank-shaft. The shear then cuts on each cycle. In a modification, Fig. 9 (not shown), the toothed gear ring 21 is rotatably mounted on the crank-shaft and is driven from the crank-shaft by gearing including a variable-ratio gear-box. The small end 7 of the connecting rod, instead of being mounted on an eccentric carries a roller (30), Fig. 7, which bears on a cam surface (31), designed so that the blade (3) is perpendicular to the material at the time of cutting. Alternatively, the small end is connected to its supporting crankpin by a block which pivots on the crankpin and slides in a slot elongated longitudinally of the connecting rod.