GB449861A - Improvements in closure caps and method and apparatus for making same - Google Patents

Abstract

449,861. Making closure caps. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.- (National Seal Co., Inc. ; 14th Avenue, Brooklyn, New York, U.S.A.) Jan. 29, 1936, No. 2656. [Classes 83 (ii) and 83 (iv)] [See also Group XVII] Stamping.-A closure cap Fig. 19 is formed by curling inwards the edge of a metal cup to form an inner wall R, in a series of dies and then stamping the inner wall with locking lugs or screw threads to engage on the container. The cup is carried on a rotary work table in turn to a series of dies, as in Fig. 8 in which the die ring 54 performs the initial curling over of the edge as in Fig. 10, while the next curling die bends it round, through the stages shown in Figs. 13, 14, 15. The threading or like is then produced as in Fig. 16 by radially expanding segmental dies 91 forced outwards by the cone 94, and retracted again by the shoulder on the cone engaging shoulders 95 on the segments and pivoting them inwards about their top corners 96. The unformed threads at the spaces between the die segments are completed by a second set of dies operating in a similar way on these spacings. The cap may contain a loose sealing disc held by the inturned bead against dropping out. Die - holders.-In Fig. 8 a hollowed out portion 39 in the bed plate receives an annular anvil 40 containing a spring-pressed pad 44 within it, and is itself surrounded by a spring- pressed dial bushing 51. The curling ring 54 is fastened to the die holder 56 bv set screws 55 and surrounds a spring pressed ejector 61 and a spring-pressed pin 70 to break the vacuum on ascent by the die ring. A nut 59 adjusts the height of the die holder. The die holder shown in Fig. 16 contains the ring 87 to hold the cap firmly on the anvil 78 while the cone 94 descends to force the threading die segments 91 out, and ascends to withdraw them inwards, the cone stem being screwed into the shank 84. The segments 91 are held in position by an annular holder 98 held in position by a key pin 99 sliding in a slot 100 in the shank 84, the coil spring 101 in the slot 102 and the registering slot 103 in the segment holder enabling the segments to be yieldingly held in the shank 84. 113 is the spring of the ejector pad 108.