GB1091982A - Improvements in or relating to machines for stamping blanks from strip material - Google Patents

Abstract

1,091,982. Metal sheet feeds. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Feb. 1, 1965 [Feb. 11, 1964], No. 5688/64. Heading B3W. A stagger feed mechanism for a blanking press comprises an inclined table down which a strip 1 moves in the direction of the arrow C by gravity, the inclined table being mounted on rails which can set at any angle to the longitudinal feed direction, and the transverse feed taking place along the rails. The strip is supplied from a coil and passes through straightening rolls to a pair of feed rollers which may assist the movement of the strip down the table. At the side of the table are two fixed guide blocks 20 and 21 against which the strip is clamped by a pressure pad 23, mounted on the piston rod of pneumatic cylinder 25. The force applied by the pressure pad is controlled by a regulator 111. Also mounted on the side of the table are a notch-cutter 27 operated by pneumatic cylinder 31 and a ganging stop 33, spring-loaded to engage a notch 35, and retractable by pneumatic cylinder 37. The cutter 27 remains in engagement with the strip during operation of the blanking press to positively locate the strip. The inclined table can slide along a pair of horizontal rails 19 and is mounted so that the angle between the direction of travel C of the strip and the rails is adjustable. In the embodiment described for blanking circular armature or stator laminations the angle is 60 degrees. Attached to the underside of the table are a driving member 39, a notched spacing bar 41 and a member carrying a pair of abutments 43 and 45. The driving member is engaged by a spring-loaded gripper 47 mounted on the connecting rod 49 of a crank 51 driven by a shaft 53 through bevel gears. The bevel gears are driven by a shaft 75 through a dog clutch 71, 73. The spacing bar 41 has notches which are engaged by a spring-loaded detent 55 which can be withdrawn by a cable operated by a follower 85 actuated by a cam 81 mounted on the driving member 73 of the dog clutch. This clutch is spring loaded to the engaged position and is disengaged by a pneumatic cylinder 79. The shaft 75 is driven by chain gearing from the crank-shaft of the blanking press. Operation.-The table is traversed alternately in the directions AB and BA to cut a row of blanks transversely of the strip, and at the end of each row the table dwells while the strip is fed forward. At the beginning of a traversing step the detent 55 is withdrawn, the crank 51 rotates and the gripper 47 moves the table until the detent drops in the next notch. At the end of a row, one of the abutments 43, 45 operates the valve 65 so that air is supplied to cylinder 75 which disengages the clutch and moves the cam 83 from under its follower, so that the detent 55 is not retracted during the next revolution of the shaft 75 and the crank 51 is not rotated, during the next half-revolution. There is thus a 180-degree phase-change in the relationship between the driving shaft and the crank 51 so that the gripper 47 traverses the table in the opposite direction. The disengaging movement of the driven clutch member 73 brings the cam 83 under a second follower 87 which operates an air valve 101. Cylinders 25 and 31 then withdraw the pressure pad 23 and the cutter 27 and cylinder 37 withdraws the gauging stop 33, which drops into the next notch 35 as the strip moves forward. In a modification for use with heavy strip, Figs. 7 and 8 (not shown) the notching cutter 27 and the gauging stop 33 are omitted and two pawls are provided which engage the leading end of the strip. The pawls are spring-loaded to a position in which they limit forward motion of the strip and are retractable by pneumatic cylinders. The pawls are retracted during transverse movement of the strip, which during this time is held only by the pressure pad 23. If a continuous web of scrap material is produced a scrap cutter may be provided. The Specification states that instead of pneumatic operation, the mechanism may be operated hydraulically or electromagnetically.