Safety closure cap with retaining feet

Claim 1

A safety closure cap for connection with a filler spout of an automobile tank or the like comprising a top, said spout having an open filling end surrounded by a rim, a spring pressed sealing disc structure secured to the underside of the top to seal against said rim, the spout having adjacent said rim opposite cam surfaces which are separated by opposite entry notches, opposite latching lugs on the cap secured to a downwardly extending cylindrical centering hub secured to the underside of the cap top and being insertable through the notches, turning of the cap in one direction latching the cap against said rim of the spout by the lugs riding over the cam surfaces, blocking prongs secured to said centering hub and extending downwardly from and in alinement with the respective latching lugs to insure proper seating of the cap on the spout, and an arcuately shaped slightly downwardly inclined retaining foot extending circumferentially about the axis of said hub from the lower end of each prong and having its lower end spaced from the prong and forming a generally L-shaped rigid structure with said blockinG prong, such feet extending in the same circumferential direction about said hub to form a screw and being insertable with the associated prongs through the entry notches upon turning of the cap in said one direction to latch the same; and upon turning of the cap in an opposite direction to unlatch the same, said feet being engageable with said cam surfaces upon axial displacement of the cap to retain the cap loosely on the spout until said lower ends of the feet are removed manually through the entry notches to thus allow venting of gas pressure which may have built up in the tank and thus prevent the gas pressure from blowing the cap away from the spout as it is being unlatched.