Safety cap assembly for pressurized vessels

Claim 1

A safety cap assembly comprising: a filler member having a lower portion for attachment to a pressurizable vessel and an upper portion, a complementary closure cap received on said filler member upper portion, said cap having an elongated skirt portion and a transverse planar portion, thread means on said filler member and said closure cap skirt for non-releasably interacting such that said cap cannot be normally unscrewed from said filler member when said vessel is pressurized; gasket means mounted between said filler member upon portion and said cap planar portion for establishing sealing engagement between said filler member and said cap; means for achieving the release of vessel pressure when said cap is unscrewd including a plurality of bleed holes spaced within said cap adjacent said cap planar portion and extending through said skirt of said cap; at least one circumferentially located venting channel positioned at the externally threaded upper portion of said filler member which has a greater depth than the root depth of the threads of said filler member; a cage-type safety means operatively attached to said filler member lower portion and extending about said cap with said cap in place such that said cap is disposed within the region circumscribed by said safety means, said cage-type safety means including ring members and connecting bar members forming a grid having open areas smaller than the cap in order to restrain the cap if it should be expelled from the filler member; and a chain operatively attached to and extending between said closure cap and safety means.