Patent GB-912099-A (GB)
Title: Improvements in or relating to roll feeds
IPC: B21D43/09
Filed: 1961-01-12
Abstract: 912,099. Metal strip feeds. BLISS CO., E. W. Jan. 12, 1961 [Jan. 13, 1960], No. 1339/61. Class 83 (4). An intermittent roll feed for sheet metal comprises a pair of ingoing feed rolls, one of which is mounted on a drive shaft, fluidoperable clutch means mounted on said shaft, means to sequentially rotate said shaft and thereafter provide a dwell in the rotation of said shaft and means to engage and disengage said clutch means during said dwell. The apparatus also comprises outgoing feed rolls which are driven from the ingoing feed rolls, and a selfpowered scrap cutter. The feed rolls are driven by a motor 16 (Fig. 3) through a speed adapter unit 18 which has an output shaft 22 connected to a flywheel 24 mounted on a shaft 26 which carries a combination clutch and brake unit 28 and a pinion 30. The pinion 30 engages a gear 32 which carries a crank-shaft 34 connected by a crank-arm 40 to a sector gear 36 which in turn drives a pinion 42 secured to a throw block shaft 44. Pivotally mounted on a throw block 46 is a rack 48 which engages a pinion 52 mounted on a shaft 54 which drives the ingoing feed roll 58 through a pneumatic clutch and brake unit 56. In each of the clutch and brake units air pressure is used to engage the clutch and mechanical means engage the brake upon release of the air pressure in the clutch. The upper ingoing feed roll 60 is freely mounted on its shaft and is driven from the roll 58 through a square gear arrangement, Fig. 6 (not shown). At the start of a cycle both clutches 28 and 56 are engaged and after the crank-shaft 34 has rotated 180 degrees the clutch 56 is disengaged and the brake applied to the roll 58 while the main clutch 28 remains engaged and returns the crank to its starting position. The linkage system provides a dwell at the roll clutch pinion 52 equivalent to 20 degrees on either side of centre every 180 degrees of crank rotation, during which the roll clutch is engaged and disengaged. The main clutch is disengaged at the end of every cycle and engaged at the beginning of the next cycle. Fluid motors 111 are provided to release the pressure on the upper roll 60 as required. The ingoing and outgoing feed rolls are connected by a shaft 6 which is driven through a gear-box 62 which has two gear ratios and a neutral position. The neutral position is used when the work produces no scrap webbing, a first gear position causes the ingoing and outgoing rolls to rotate at the same speed and is used when stock stretch is negligible, and a second gear position causes the outgoing feed rolls to rotate more than the ingoing feed rolls. In the embodiment described, the excess rotation equals # inch of stock travel. If the stock stretch is less than this the difference is accommodated by a lost motion coupling between the outgoing feed roll shafts and the rolls which are freely mounted thereon. The upper and lower rolls 84 and 82 are connected by a square gear arrangement similar to that shown in Fig. 6. Each lost motion coupling comprises a spider 90 (Fig. 10) keyed to a roll shaft 88 and connected by a rod 98 and nut 102 to a sleeve 100 on the roll. Between the arm 94 of the spider and the sleeve is a spring 104 which compresses to accommodate over-travel of the roll relative to the stock. The return action of the spring is controlled by an air dash-pot 105. The upper roll 84 may be lifted by fluid cylinders 110 during counter rotation of the rolls. The scrap cutter (Fig. 12) comprises a motor 122, flywheel 124, eccentric 130, sliding cutter blade 132 and a stationary blade 134.