The present disclosure relates to two-piece push-and-turn child-resistant closures, and to packages that include such closures.
U.S. Pat. No. 4,997,096 discloses a child-resistant closure having inner and outer plastic shells. The outer plastic shell has a base wall, a peripheral skirt and a circumferential array of lugs on an undersurface of the base wall. The inner plastic shell has a base wall, a peripheral skirt, at least one internal thread segment on the skirt, and a circumferential array of lugs on an outer surface of the base wall for opposed engagement by the internal lugs on the base wall of the outer shell. To remove the closure when it is threaded onto a container neck finish, the outer shell must be pushed axially against the inner shell and simultaneously rotated so that the lugs on the outer shell engage the lugs on the inner shell and rotate the inner shell with respect to the container neck finish. When the outer shell is rotated without applying an axial force to the outer shell, the lugs on the outer shell simply cam over the lugs on the inner shell and do not rotate the inner shell with respect to the container neck finish. Child-resistant closures of this type have been marketed for many years by applicants' assignee under the trademark ARGUS-LOC. See also GB 1529999. A general object of the present disclosure is to provide improvements in child-resistant closures of this type, and to provide packages that include such improved closures.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A child-resistant closure in accordance with one aspect of the present disclosure includes a plastic inner shell having a base wall with a peripheral skirt, at least one internal thread segment on the peripheral skirt and a plurality of internal lugs on the base wall adjacent to the skirt. A plastic outer shell has a base wall with a peripheral skirt and a plurality of internal L-shaped lugs at a juncture of the base wall and the peripheral skirt. Each of the L-shaped lugs includes a first portion extending radially inwardly along an undersurface of the base wall of the outer shell for engaging the external lugs on the inner shell, and a second portion extending axially along an inner surface of the peripheral skirt of the outer shell for slidably engaging the inner shell and aligning the inner shell within the outer shell. The second portions of the L-shaped lugs preferably have rounded radially inwardly facing surfaces for reduced sliding friction with the skirt of the inner shell.
A child-resistant closure in accordance with another aspect of the present disclosure includes a plastic inner shell having a base wall, a peripheral skirt with at least one internal thread segment and an angularly spaced circumferential array of external lugs on the base wall. A plastic outer shell has a base wall, a peripheral skirt and an angularly spaced circumferential array of internal lugs on the base wall. The inner plastic shell is received within the outer plastic shell such that the internal lugs on the base wall of the outer plastic shell are disposed for engagement with the external lugs on the base wall of the inner plastic shell to apply or remove the closure to or from a container neck finish. The internal lugs on the outer shell and the external lugs on the inner shell have opposed rounded axially facing surfaces such that the internal lugs on the outer shell cannot rest on the external lugs of the inner shell upon application of force to the outer shell.
A child-resistant closure in accordance with a further aspect of the present disclosure includes a plastic outer shell having a base wall with a peripheral skirt and a plurality of internal lugs on the base wall adjacent to the skirt, and a plastic inner shell disposed within the outer shell and having a base wall with a peripheral skirt, at least one internal thread segment on the peripheral skirt and a plurality of external lugs on the base wall adjacent to the skirt. The base wall of the outer shell has a peripheral portion of a first thickness on which the internal lugs are disposed and an imperforate central portion of a second thickness less than the first thickness. The base wall of the inner shell has a peripheral portion of a third thickness on which the external lugs are disposed and an imperforate central portion of a fourth thickness less than the first thickness. The thinner central portions of the inner and outer shell reduce the weight and cost of the closure.
The disclosure, together with additional objects, features, advantages and aspects thereof, will best be understood from the following description, the appended claims and the accompanying drawings, in which:
Child-resistant closure 32 includes a plastic inner shell 42 captured within a plastic outer shell 44. Outer shell 44 is illustrated in
Inner shell 42 is illustrated in
Inner shell 42 preferably is captured within outer shell 44 by bead 64 on the outer shell. To apply the closure to container neck finish 34, outer shell 44 is pushed downwardly and rotated clockwise so that lug portions 56 on the outer shell are brought into engagement with abutment faces 78 of lugs 74 on the inner shell, as shown in
The axially facing surfaces 60,80 of lug portions 56 on the outer shell and lugs 74 on the inner shell preferably are rounded as previously described. In the event that the lugs are in axial alignment as illustrated in
The abutment faces of lug portions 56 on outer shell 44 and lugs 74 on inner shell 42 preferably are as illustrated in
Portions or legs 58 of L-shaped internal lugs 54 on outer shell 44, which extend axially along the inner surface of outer shell skirt 48, function slidably to engage the outer surface of skirt 66 on inner shell 42 and align the inner shell within the outer shell. The radially inwardly facing surfaces 62 of portions or legs 58 preferably are rounded, as best seen in
Provision of shell central portions 52,72 of reduced thickness as compared with respective peripheral portions 50,70 reduces the weight and cost of the respective shells without affecting the strength of the shells because most or all of the forces are applied through the peripheral portions of the respective shells during application and removal of the closure with respect to a container neck finish.
There thus has been disclosed a closure and a package that fully satisfy all of the objects and aims previously set forth. The disclosure has been presented in conjunction with an exemplary embodiment, and a number of modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing discussion. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.