초록 ▼

A thermoplastic closure comprises an annular tamper band connected to the skirt of a cap by frangible bridges. In one embodiment of the closure, axially extending ratchet teeth on the bottom of the tamper band cooperate with axially extending lugs on a container shoulder or transfer bead. As the cap

A thermoplastic closure comprises an annular tamper band connected to the skirt of a cap by frangible bridges. In one embodiment of the closure, axially extending ratchet teeth on the bottom of the tamper band cooperate with axially extending lugs on a container shoulder or transfer bead. As the cap is screwed onto the container, the teeth ratchet over the lugs. When an attempt is made to unscrew the cap, the ratchet teeth engage the lugs to prevent rotation of the tamper band so that continued application of an unscrewing force to the cap results in fracturing of the bridges along the intersection of reduced cross-section between the bridges and the skirt. The axial length of the engaging surfaces of the ratchet teeth and lugs is sufficient that they remain axially aligned through any initial axial separation of the cap and transfer bead until the ratchet teeth and lugs engage. In another embodiment of the closure, axially extending projections on the tamper bead are bent circumferentially by the lugs on the container as the closure is screwed onto the container. The bent projections wedge against the lugs as the cap is unscrewed to prevent rotation of the tamper band with the cap resulting in fracturing of the bridges.

대표청구항 ▼

A closure system comprising: a container having a neck portion with external threads thereon, and a generally laterally extending surface axially spaced from said external threads; and a closure comprising: a cap having an end wall and an annular skirt extending axially from said end wall and termin

A closure system comprising: a container having a neck portion with external threads thereon, and a generally laterally extending surface axially spaced from said external threads; and a closure comprising: a cap having an end wall and an annular skirt extending axially from said end wall and terminating in an annular free end, said skirt having internal threads complimentary to the external threads on the container neck for selectively screwing said closure onto said container neck; an annular tamper band having first and second axially displaced ends; and frangible bridge members detachably securing the first end of said tamper band to the free end of said skirt; said closure system further including cooperating ratchet members projecting axially toward one another from attachment points on said second end of the tamper band and on the generally laterally extending surface of the container, said ratchet members defining substantially axially projecting engagement surfaces which when engaged prevent rotation of the tamper band with the skirt as the closure is rotated to unscrew the closure from the container neck thereby fracturing the frangible bridges and separating the tamper band from the skirt, said engagement surfaces being dimensioned to remain axially aligned for engagement throughout any initial axial movement of the tamper band with the skirts as the closure is unscrewed prior to fracture of said bridges.