GB738718A - Improvements in or relating to closures for containers - Google Patents

Abstract

738,718. Assembling gaskets in closure caps. TICKNER, A. (Gore-Lee Corporation). Oct. 28, 1953, No. 29833/53. Class 125 (3). [Also in Group V] Mouldable gasket material, e.g. rubber, is warmed in a mill, removed from the mill as a narrow continuous strip and passed between a circular series of pairs of continuously travelling dies which cut annular or circular slugs from the strip. Each slug is applied to the inner surface of a (metal) cap and moulded in the cap to form a gasket that adheres to the cap. The waste of the strip is returned to the mill. Figs. 1, 2, 6, 8 to 11 and 14 show a machine comprising a roller mill M on one roll 22 of which the gasket material 20 builds up, cutters 46 that cut a strip 44 from roll 22, a clockwise continuously rotating heated drum A to which the strip is fed and in which annular slugs are cut from the strip and deposited in caps C, and a counterclockwise continuously rotating heated drum B to which the caps and slugs are transferred from drum A and in which the slugs are moulded to shape in the caps. The strip 44 is guided by rollers 47, 47a, 47b into the space between upper and lower dies 51, 52 in drum A, where annular slugs 111 and waste circular discs 110 are cut out. The waste strip then returns to the mill, having the discs 110 stuck thereon, via rollers 47d, 47e; the rollers 47 and 47e are positively driven by a chain (not shown). At 49 a spray or wick lubricates the strip. Each upper die 51 is vertically stationary and has an annular cutter 78 fixed therein, the cutting being performed by ascent of an anvil 92 as shown in Fig. 8. The anvil is raised by toggle mechanism 102 operated by a roller 103 co-acting with an' adjustable cam 104. The cutting occurs at the 12 o'clock position on drum A. After cutting, the anvil descends (Fig. 9) and the perforated strip 44 falls onto a plate 120. As the strip diverges from the circular track of the dies the waste disc 101 is ejected from the cutter by a cam-operated ejector 130 and pressed on to the strip, to which it sticks. Closure caps C are fed along a shoot 136 into compartmented plates 141 rotating with the drum, and each cap is directed onto an anvil 92 by a guide plate 146. The anvil is then raised (Fig. 10) and the slug is ejected from the cutter into the cap by a cam-operated sleeve 137; this occurs at 6 o'clock on A. The caps with their slugs are deflected from drum A to drum B by a stationary inclined fence 153, each cap coming to rest on a die 168, Fig. 11. This die is then raised by cam-operated toggle mechanism 102, whereby the slug is pressed against an upper die 160 and moulded to the shape shown in Fig. 14. The pressure may be released and then re-applied, once or twice. A central member 163 prevents the material spreading inward, but this member may be modified to permit flow of the slug over the whole of the inner surface of the cap. During the moulding the die 160 curls the upper edge of the cap to the Fig. 14 position. After the moulding the die 168 descends and an ejector 171 is raised by cam means 175, 173 to raise the cap, which is then swept by an arm 185 into a shoot 186 whence it falls on a belt 187 running through a curing oven 0. The machine is driven by an electric motor, and a clutch may be moved to disengage the drive to the drums A, B without disturbing the drive to the mill M; and whilst the drums are thus disengaged they may be rotated manually by means of a handle (Fig. 7, not shown) the use of which opens a switch to cut the circuit to the motor and thus prevent accidental starting of the drums. The cam 104 may be withdrawn outwardly to such a degree that the dies, merely grip the strip and feed it back to the mill. The dies 160 may be backed by resilient plates to absorb overload (Figs. 15 and 17, not shown). If the waste disc 110 tends to fall away prematurely from the ejector 130 it may be temporarily retained by pins (Fig. 24, not shown). Fig. 30 shows part of a modified machine for cutting a circular slug 111<SP>1</SP>, inserting it in a cap and moulding it onto the flat surface of the cap (Fig. 28). In this machine, after the slug has been punched out by ascent of a die 52 operated by a spring-loaded toggle 102<SP>1</SP>, 106<SP>1</SP>, the waste strip 44<SP>1</SP> is pushed down by a spring-operated stripper 307 under the control of a cam roller 309, then an ejector 128<SP>1</SP> pushes the slug into a cap, then (in drum B, not shown) a similar stripper 307 pushes the cap down against the lower die when the moulding dies are being separated.