GB547891A - Improvements in curling and like machines for use in the manufacture of sheet metal articles such as containers - Google Patents

Abstract

547,891. Making cans. CROWN CORK & SEAL CO. March 13, 1941, No. 3457. Convention date, Jan. 24, 1940. [Classes 83 (ii) and 83 (iv)] The formation of the curls, to receive crown corks, on the necks of containers of the type made by the machine described in Specification 546,489, is effected by a machine having a combined rotary work and die carrier. Pedestals 17, 18, Fig. 1, support a non-rotatable shaft 21 on which is hinged a cam 50. Bearings 37, 38 support a gear 36 provided with pairs of bosses 58 in which are mounted rods 62 that pass also through bosses 60 in a second rotary member 55 tying the members together for simultaneous rotation by a pinion 35 on a shaft 28 driven through a clutch 31 and reduction gearing 25 from a motor 22. On each pair of bars a carriage 65 supporting a mandrel 71 is mounted to slide as controlled by a follower 68 engaging the cam 50. Also mounted on the member 55 is a circular work carrier with pockets. Each pocket receives a cam body from a supply shoot, the body seating at 77, clearance being provided at 78 for the seaming flange 79. A front plate 82 is shaped to suit the neck 84 and a plate 81 acts to strip the body from the mandrel 71 just prior to discharge down a delivery shoot. Journalled at 95 in the member 55 are a series of die carriers 100 having projections 99 received in arcuate slots in 55. Arms 101 carry rollers 102 engaging a fixed external cam track 103 mounted at 104 on the base so that either the preliminary curling die 110 or the closing die 111 may be swung into position in axial alignment with the cam. Further cams 105 carry blocks 106 sliding on pivoted rods 107 so that confined springs 109 keep the roller in engagement with the cam track. The dies are mounted in holders 112 having shanks screwed at 114 into flanged screwed bushes 115 clamped in the projections 99 by nuts and washers 118. In operation after a can body is seated in the pocket the mandrel advances rapidly into the blank then more slowly toward the neck against the curling die after which there is a brief dwell followed by a retraction of blank and mandrel sufficient to permit the die carrier 100 to be rocked to swing the closing die into position. After another advance and dwell a rapid and complete withdrawal follows during which the can is stripped from the mandrel. The next dwell provides for the discharge of the can and the reception of a fresh blank. The front plate 82 is mounted on spring controlled rods to permit the can to move forward with the mandrel during the actual curling and flattening operations and to ensure the return of the can with the mandrel during the short retraction between the two operations. If the preliminary leading of the edge, to prevent splitting, is also then carried out in the machine then the die carriers 100 have three positions and carry three dies, the cam tracks being modified accordingly. Specification 544,040 also is referred to.