Abstract: A pressurized cylinder has a cap mounted thereto. The cap has a skirt wall of corrugated configuration to form a plurality of radially inwardly opening channels which alternate circumferentially with radially outwardly opening channels. A plurality of coplanar, circumferentially extending grooves or slits are formed in the outwardly open channels so as to extend radially completely therethrough. The cap is inserted longitudinally onto the cylinder such that a plurality of tabs carried by the cylinder travel longitudinally within the radially inwardly open channels. Thereafter, the cap is rotated such that the tabs enter the grooves to prevent longitudinal removal of the cap. A yieldable latch locks the cap in its secured position.

Abstract: A pressurized cylinder has a cap mounted thereto by a coupling comprising tabs in the cap which are rotatable within an annular groove carried by the cylinder. Stops are provided which limit rotation of the cap in both directions once the cap is installed. One of the stops comprises a movable latch which can be released to permit the cap to be removed by rearward rotation. The tabs are loosely disposed within the groove to minimize chances of the tabs becoming rusted thereto. The tabs are of elongate dimension in the circumferential direction to maximize the resistance to inadvertent dislodgement of the cap. The tabs are formed separately of the cap and are mounted within slits formed in a ductile wall of the cap to render the arrangement more shock resistant.