NZ194475A - Container cap: retains liquid while venting gas - Google Patents

Description

194475 wt *. J. P. & s.

..... No.: Date: NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION WITH VEHTINC, CLOtWRB CAT ABLATING TO CONTAINERG FOR LIQUIB6 J. P. & s. 4-^-9if ML.......

X/ We, ICI AUSTRALIA LIMITED of 1 Nicholson Street, Melbourne, Victoria, 3000, Australia, a Company organised and existing under the laws of the State w*0 w e<*. 1+k of Victoria, Gommonweafclh of Australia . hereby declare the invention for which X / we pray that a patent may be granted to iS8/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - -2- 1 94 4 75 Difficulty is experienced in satisfactorily sealing containers for liquids which release gas on decomposition. A particularly difficult material is hydrogen peroxide in aqueous solution. It is found with conventional gasketed caps on containers of hydrogen peroxide solution that oxygen produced on decomposition passes the gasket, carrying some of the liquid with itr As a result, the outside of the container becomes wet with the hydrogen peroxide liquid, thereby creating a fire hazard.

It is the principal object of the present invention to provide a container for liquids whereby gases produced on decomposition may be safely vented.

In order to achieve this principal object, the present invention provides a container for liquids comprising an internally threaded cylindrical cap engaging a complementary external thread on the container, a first circular resilient flexible gasket within the cap adjacent to the closed end of the cap extending over the entire cross section of the cap, a pressure pad within the cap between the closed end of the cap and the first gasket to press a peripheral sealing annular portion of the gasket between the end of the container and the cap, a peripheral recess in the pressure pad extending past the peripheral sealing annular portion of the gasket and of width along the inner edge of the peripheral annular portion greater than three times the thickness of the first gasket, and a flat circular second gasket fitting neatly across the interior of the container at a location spaced from the first gasket, said second gasket being formed of flexible, resilient material and having there through an aperture of such dimensions that a liquid in the container is prevented by surface tension from passing through.

The recesses are preferably segments of cylinders with axes 9k> .... #; 1 - G-a-s-e T O 6 6 / IU 61 3 ' - rs-g—ttT6b/ I U fa'/ 1944/5 parallel to the axis of the cap.

Practical arrangements of containers according to the present invention will now be described with reference to the accompanying drawings. In these drawings : 5 Fig. 1 is a longitudinal cross section of the neck of the container with one form of associated cap; Fig. 2 is a detail; Fig. 3 is a perspective view of one optional component of the cap; yaske-t Fig. 4 is a perspective view of the second ■wad; and x. J. P. & S. Fig. 5 is a detail of an alternative form of cap.

- - Referring now to Figs. 1 to A, there is provided a bottle having a relatively narrow externally threaded neck 11 which is closed by a cap 12 having an internal thread matching and engaging with the thread on the neck. A stiff polythene disc 13 approximately 1 mm thick rests inside the cap against the closed end thereof. The disc has cut from its edge region diametrically opposed circular scollops 14 each in the shape of a segment of a cylinder of approximately the same radius as the disc with its axis parallel to that of the disc and of the cap 12, and of a size such that the minimum diametrical distance between the scollops is approximately 4 mm less than the internal diameter of the neck 11 of the bottle. The scollops 14 constitute the recesses above referred to. gasket P. & S. A circular wa-4 15, herein designated the first wad, approximately 1 mm thick and formed from stiff, flexible polythene, extends across the interior of the cap 12 in contact with the face of the disc 13 remote from the end of the cap.

QAtket A i P & S. A second 16 formed from flexible polythene approximately Ga3e—1066/10 6-?- _ — -g ^ - n vw<3 ^ n M k ?c 1066/106-74=- 19447 0.5 mm thick fits neatly across the interior of the neck 11 of ga*fcet the bottle. The 16 is produced as a single moulding, and A. J. P. & $ has a flat disc portion 17 extending across the neck of the bottle, a cylindrical portion 18, and a flat annular flange 19 5 to rest against the open end of the neck 11. The cylindrical portion 18 is attached at one end to the circumference of the portion 17 and at the other end to the inner circumference of P & S flanee ^9. The disc portion 17 is accordingly spaced inward- $44 feebly of the bottle from the -wa4 15. An aperture 20 of diameter % 0.5 mm extends through the portion 17 at any location therein.

The aperture 20 may be replaced by a knife cut through the portion 17- The size and shape of the aperture 20 is not critical, provided that it permits gas to pass through the portion 17 ». J. P. & S. qasktA' qi'VLf of the wad- when the gas pressure within the bottle is appreciably gasket "' greater than the pressure outside the wa#, and that it is sufficiently narrow so that the liquid within the bottle is prevented by its surface tension from passing through the aperture. It is kefs therefore possible to use -wado having differing apertures to accord with different liquids in the bottle.

In use, the bottle 10 was charged with a solution of hydro- gasket I D 0 _ gen peroxide in water, the -wa4 16 was placed across the mouth of - J- r. ik 5, . j 4-1 $a$ket the bottle and the cap 12 with the disc 13 and -w&4 15 in place was screwed on to the neck 11 of the bottle to effect closure thereof. Engagement of the internal screw thread on the cap 12 25 with the external thread on the neck 11 was sufficiently imperf ect to allow communication between the spaces within the cap 12 at the scollops 14' and the external atmosphere, so that the pressure within the scollops remained at atmospheric. As the hydr^ ogen peroxide decomposed, the oxygen so released increased the gas pressure within the bottle so that gas passed through the '>/ -Saac 1066tH-W- • _ V) ^ ^ " 44 7 5 ICLfk&t t^a.<ike-t aperture 20 into the space between the wa^b 15 and the -wa4- port- gasket ion 17 to equalize the pressure within the -wa4 15.

A. J. P. & 5. gasket f-zify When the gas pressure within the bottle and the -wad- 15 inc- • M( ^kef " reased sufficiently, the 15 was flexed where it overlies the A. J. p | s scollops 14 to thereby allow gas to pass into the scollops 14, along the thread and thence to atmopshere. The build up of pressure within the bottle was therefore avoided, and, as the liquid did not pass through the aperture 20, the presence of liquid on the outside of the bottle was obviated.

In Fig. 5, a modified cap 21 is illustrated, in which the disc 13 is dispensed with. Recesses 22 corresponding in shape J. P. & . yukefc with the scollops 14 are moulded into the cap. The wads- 15 and * JML 16 are used with this cap in the manner described with reference to Figs. 1 to 4, and the operation is identical. 15 The shape of the scollops 14 above described is considered to be the most effective and convenient to produce, however it will be appreciated that any shape which permits the ■wa4 15 to flex and allow gas to pass into the recess and thence to atmos-phere would be suitable, provided the sealing by the .wad- 15 is J. P. & S j-i mL in general maintained. 184475

Claims (3)

WHAT WE CLAIM IS:

1. A container for liquids comprising an internally threaded cylindrical cap engaging a complementary external thread on the container, a first circular resilient flexible gasket within the cap adjacent to the closed end of the cap extending over the entire cross section of the cap, a pressure pad within the cap between the closed end of the cap and the first gasket to press a peripheral sealing annular portion of the gasket between the end of the container and the cap, a peripheral recess in the pressurie pad extending internally past th£ peripheral sealing J : annular! portion of the gasket and of width along the inner edge ' ) of the peripheral sealing annular portion greater than three times the thickness of the first gasket, and a flat circular second gasket fitting neatly across the interior of the container at a location spaced from the first gasket, said second gasket being formed of flexible, resilient material and having therethrough an aperture of such dimensions that a liquid in the container is prevented by surface tension from passing through.

2. A container according to claim 1, wherein the recesses are segements of cylinders with axes parallel to the axis of the cap.

3. A container for liquids substantially as herein described with reference to and as illustrated by Figs. 1 to 4 or Fig 5 of the accompanying drawings. > i fcD THIS ^ DAT Of A. J. PARK a SON ■ .ENTS FOM THf APPLICANTS. U.2. Fa, -. • ■ - -3FEB 1984 j