GB1458423A - Containers for liquid materials - Google Patents

Abstract

1458423 Caps with perforatable seals ALLIED CHEMICAL CORP 1 May 1974 [21 May 1973] 19112/74 Heading B8T A closure suitable for containers which hold hazardous liquids comprises an inner cap 11 with a frangible end plate 5, the cap being threaded to the neck of a container and locked in position by ratchet means, plus an outer protective cap 17 also threaded to the neck of the container, which covers the inner cap 11. The ratchet means consists of teeth 9 disposed about the neck of the container which engage a corresponding set of teeth or ribs on the inner surface of cap 11, teeth 9 being fashioned so that they permit rotation of cap 11 whilst it is being screwed on to the container neck subsequent to filling, and yet resist the reverse rotation in order to secure the cap permanently to the neck. End plate 5 obstructs an opening 12 in the end of cap 11 and may be ruptured prior to the dispensing of the contained liquid. The end plate may be impermeable to vapour; if however the contained liquid emits fumes, the end plate is constructed of a vapour permeable material 6 sandwiched between two supporting plates 7 having slit like openings 8. In the latter instance, the outer cap 17 is vented at 22 in order that the fumes may be released. In an alternative embodiment, the end plate may be integral with the inner cap 11, which may be formed with a left-hand screw thread. Also, the ratchet forming teeth may extend completely around the container neck, alternatively they may be arranged in diametrically opposed groups.