Reusable container closure cap

A closure cap for sealing the neck portion of a container such as a milk bottle, the neck portion having an upstanding annular rim, a first outer wall portion depending therefrom and having threads thereon and further having a recess thereon, the closure cap being formed of a material having limited flexibility and comprising:

• (a) a disc-like top wall engageable with the rim to effect a substantially fluid-tight seal;
• (b) an annular skirt depending from the top wall, the skirt having on its inner periphery:
• (i) helical threads configured to mate with the threads on the first outer wall portion of the container neck to secure the closure cap to the bottle, the threads cooperating to form a second substantially fluid-tight seal;
• (ii) a radially inwardly projecting tooth for cooperative reception within the recess of the outer wall portion when the closure cap is fully threaded onto the container, the tooth having a configuration precluding axial vertical movement thereof in response to relative unthreading movement of the cap;
• and,
• (iii) a pair of spaced generally vertically extending rupture zones on either side of the tooth, the rupture zones extending from the lowermost extremity of the skirt to points generally adjacent the closure disc;
• (c) a tab projecting laterally outwardly of the skirt from a location near the lower edge thereof, the tab being disposed between the vertically extending rupture zones whereby, upon forward flexure of the tab, the rupture zones will fail and permit the lower skirt area therebetween to be hinged radially outwardly to withdraw the tooth from the recess and permit unthreading removal of the closure cap from the neck of the container, the limited flexibility of the cap material permitting substantial cooperation of the threads notwithstanding rupture of the skirt wall along the rupture lines, where the cap may thereupon be releasably resecured to the container by the threads with the closure disc effecting the first seal to preclude leakage;
• (d) the recess on the outer wall portion of the container neck including an upper wall surface which extends substantially normal to the axis of the container neck;
• and,
• (e) the closure cap tooth including a flat upper surface for reception in said recess against the upper wall surface thereof, the tooth further having a camming surface thereon to permit minimal deflection of said skirt thereon outwardly as said closure cap is threaded onto the container neck portion prior to the reception of the tooth in the recess;
• (f) the container neck portion further including a second outer wall portion beneath the first outer wall portion and having a generally upwardly facing annular surface;
• (g) the closure cap further including an annular rim at the lower extremity of said skirt for cooperative engagement with said second outer wall portion of said container neck thereby to form a third fluid-tight seal when said cap is assembled upon said container to preclude contamination attack of the first and second seals;
• (h) the disc-like top wall including an annular inwardly extending flexible lip for cooperation with said annular rim of the bottle neck portion in forming said first seal;
• (i) the outer wall portion recess being disposed axially below the outer wall portion threads;
• and,
• (j) the tooth being located on the skirt adjacent the lowermost extremity thereof and below said threads thereon.