Abstract: Drinks cans are provided with a gas reservoir containing a gas to bubble into beer to initiate the production of further bubbles from gas dissolved in the beer, when the can top (4) is opened by pulling the ring-pull device (5). In the construction of FIG. 1, a plastics cap (8) is a tight snap fit on an annular rib (9) formed on the can base (3), the cap (8) being provided with a fine hole (10) through which nitrogen bubbles on opening of the can. In the construction of FIGS. 2 and 3, an unapertured blow-off cap (8) is fitted on an annular rib (15) formed on a partition wall (12) of the can, the cap normally covering fine holes (13) in the partition wall, air under super-atmospheric pressure in gas reservoir (13) bubbling into beer in the main chamber (6) when the cap blows off the rib (15) on opening of the can top.

Abstract: A foot pump comprises a base member and an operating member pivotally connected to the base member. A piston-and-cylinder assembly is connected between the members. In use the user depresses the operating member with his or her foot, thereby causing air to be compressed in and expelled from said assembly. A return spring returns the operating member to its raised position. The base and operating members have complementary pivot pin and hook means which are hooked together to form the pivotal connection between the members. The members are preferably made as unitary plastics mouldings, the pivot pin and hook means being resiliently clipped together.

Abstract: A foot pump comprises a base member and an operating member pivotally connected to the base member. A piston-and-cylinder assembly is connected between the members. In use the user depresses the operating member with his or her foot, thereby causing air to be compressed in and expelled from said assembly. A return spring incorporated in said assembly returns the operating member to its raised position. The assembly can be disconnected from the base member and connected to the base member again, at will, and the whole is so arranged that when the assembly is disconnected from the base member the pump can assume a storage position in which the operating member is in a depressed position and the return spring is not loaded, or at least not significantly loaded.

Abstract: The casing for a filter comprises at least two body portions defining a chamber for the filter means. The body portions are relatively movable between a closed position in which fluid cannot escape between them, and an open position in which fluid can escape between them. An increase in pressure in the chamber tends to urge the body portions to their open position, but there is resilient means which resists that and only permits the portions to part when the pressure in the chamber reaches a predetermined value.