GB1122999A - Improvements in or relating to containers and closures therefor - Google Patents

Abstract

1,122,999. Caps for bottles. METAL BOX CO. Ltd. 11 Aug., 1966 [19 Nov., 1965], No. 49339/65. Heading B8T. A venting cap and bottle neck construction which permits the ingress of air into a plastics bottle 1 but prevents the egress of the bottle contents comprises a two-part plastics closure 23, 6 of which the inner part 6 has inner and outer co-axial tubular walls 11, 10 pushed on to the plastics bottle neck 2. Two diametricallyopposite flats 18 on the outside of the inner wall 11 leave gaps between the wall and the inner surface 15 of the bottle neck 2. A peripheral bead 3 around the bottle neck 2 engages the inner surface 12 of the outer wall 10. Axial ribs 25 are formed around the outer surface of the outer wall 10; during the process of moulding, these ribs contract to form recesses (26), Fig. 3 (not shown), around the inner surface 12, Fig. 1, of the outer wall 10. These recesses (26) thus form small gaps between the inner surface 12 of the outer wall 10 and the peripheral bead 3 around the outer surface of a bottle neck 2. The lower surface 20 of the outer wall 10 is an interference fit on a shoulder 5 around the base of the bottle neck 2. The arrangement is such that, should the pressure within the plastics bottle 1 fall, due to absorption of air into its contents, &c,. air will be drawn in from the ambient atmosphere through the gap between the lower surface 20 and the shoulder 5, through a tubular space 21 between the outer wall 10 and bottle neck 2, through the gaps (26) and the bead 3 into a tubular space 4 between the outer wall 10 and the bottle neck, and thence through the gap 16 formed by the diametrically-opposite flaps 18 on the outside of the inner wall 11 into the bottle. However, should the contents of the bottle 1 attempt to escape through the gaps 16, &c., the gaps (26) and the engagement between the lower edge of the skirt 20 with the shoulder 5 will both act as traps. The crown 9 of the inner closure member 6 is formed with a discharge hole 22. A lid 23 is moulded integrally with the inner member 6, and is hinged to the inner member. A spigot 24 inside the crown of the lid 23 is snapped into the hole 22 to closure the bottle.