| 摘要 |
A structure for enabling gassing of an aerosol package while its sprayhead is in operative association with the package. The package comprises a canister having a valve assembly and sprayhead combination, the assembly being of the type in which the sprayhead has an integral stem that enters an opening in the cover member of the valve assembly or being of the type known as a stem valve in which there is a permanently connected stem which protrudes through the opening of the cover member. In the latter type, the sprayhead is a button which fits onto the protruding end of the stem. In both cases, the valve is operated by pressing the sprayhead down, which carries the stem inwardly of the cover member and raises a valve seat off a gasket that is crimped into the cover member, beneath the crown of a boss formed in the cover member. The means which enables the gassing with the sprayhead in place comprises making the opening in the crown of the boss formed in the cover member noncircular, but having a plurality of points around the periphery of the opening which supports the stem in its sliding movement, the opening having lateral lobes which are normally blocked by the gasket to enable normal operation of the valve, but which enable propellant to be forced into the valve from the outside thereof while the stem is in place. This action of the entering gas under pressure invaginates the valve, and since the seat is at the same time lifted off the gasket, the gas can and does enter into the body of the canister.
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