Child-Resistant Closure
A child-resistant cap for closing an externally threaded neck of a container body, the cap comprising: an inner member having an internal thread for engaging the neck external thread; and an outer member encircling the inner member for gripping by a user, wherein: the outer member comprises a sidewall bearing a first engagement feature; and an upper web having an underside bearing a second engagement feature; and the inner member comprises: an inner sidewall bearing the internal thread; an outer sidewall spaced-apart from the inner sidewall and having an outer surface bearing a third engagement feature, the third engagement feature engagable to the first engagement feature responsive to inward compression of the outer member sidewall so as to allow the outer member to transmit a removal rotation to the inner member; and an upper web joining the inner sidewall and outer sidewall and having an upper surface bearing a fourth engagement feature, the fourth engagement feature engagable to the second engagement feature to transmit an installing rotation to the inner member.
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Benefit is claimed of U.S. Patent Application No. 62/006,792, filed Jun. 2, 2014, and entitled “Child-Resistant Closure”, the disclosure of which is incorporated by reference herein in its entirety as if set forth at length.
BACKGROUND OF THE INVENTIONThe invention relates to screw-on container closures. More particularly, the invention relates to child-resistant closures.
SUMMARY OF THE INVENTIONOne aspect of the disclosure involves a child-resistant cap for closing an externally threaded neck of a container body, the cap comprising: an inner member having an internal thread for engaging the neck external thread; and an outer member encircling the inner member for gripping by a user, wherein: the outer member comprises a sidewall bearing a first engagement feature; and an upper web having an underside bearing a second engagement feature; and the inner member comprises: an inner sidewall bearing the internal thread; an outer sidewall spaced-apart from the inner sidewall and having an outer surface bearing a third engagement feature, the third engagement feature engagable to the first engagement feature responsive to inward compression of the outer member sidewall so as to allow the outer member to transmit a removal rotation to the inner member; and an upper web joining the inner sidewall and outer sidewall and having an upper surface bearing a fourth engagement feature, the fourth engagement feature engagable to the second engagement feature to transmit an installing rotation to the inner member.
One aspect of the disclosure involves a child-resistant cap for closing an externally threaded neck of a container body, the cap comprising: an inner member having an internal thread for engaging the neck external thread; and an outer member encircling the inner member for gripping by a user, wherein: the outer member comprises: a sidewall bearing a first engagement feature and having a lower end formed by partially radially inwardly directed petals; and an upper web having an underside bearing a second engagement feature; and the inner member comprises: a sidewall having an outer surface bearing a third engagement feature, the third engagement feature engagable to the first engagement feature responsive to inward compression of the outer member sidewall so as to allow the outer member to transmit a removal rotation to the inner member; and an upper surface bearing a fourth engagement feature, the fourth engagement feature engagable to the second engagement feature to transmit an installing rotation to the inner member.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTIONThe exemplary closure is a two-piece closure comprising an outer piece or member 50 and an inner piece or member 52. An exemplary outer member and inner member are molded plastic (e.g., injection molded). Exemplary plastics are polyolefins such as polypropylenes and polyethylenes. The closure may comprise an additional member such as an elastomeric or paper seal or gasket 48, safety seal, or the like.
As is discussed further below, the outer member 50 and inner member 52 have two pairs of engagement features cooperating with each other. One pair of engagement features allows the outer member, in certain circumstance(s), to transmit rotation about the axis 500 to the inner member in a direction to install the closure (i.e., screw the closure onto the body). The other pair, in certain circumstance(s) or condition(s), allows the outer member to transmit an opposite unscrewing/removal rotation to the inner member. This unscrewing condition may require application of sufficient force/pressure or manipulation to qualify as a child-resistant action.
The exemplary outer member 50 comprises a sidewall 54 (
As is discussed further below, the removal condition may be entered by squeezing/compressing the sidewall 54 inward. For example, the user may place one finger at one location on the sidewall and another finger approximately diametrically opposite and squeeze the fingers together. This squeezing brings an engagement feature on the ID surface 62 of the sidewall into sufficient engagement with its mating engagement feature (discussed below) on the inner member to allow transmission of the unscrewing/removal rotation.
As is discussed further below, the underside 66 of the outer member upper web bears an engagement feature for engaging with a mating engagement feature of the inner member to transmit sufficient torque to screw the closure on in the installation condition but not, in at least some circumstances, transmit sufficient unscrewing torque.
The inner member 52 (
At their upper ends, the inner sidewall 80 and outer sidewall 82 are joined by a web 100 which extends further radially inward and has an underside 102 and an upper surface 104. In this example, a lateral portion of the upper surface bears engagement features 122 complementary to the engagement features 120 (
The exemplary installation engagement features 120, 122 of respective members 50, 52 are shaped and dimensioned so that no force or torque other than the turning torque applied to the outer member is required to screw the closure on to the body. For example, the features 120, 122 may be barbs having first surfaces 124, 126 (
For unscrewing, as noted above, one may radially inwardly press opposite portions of the outer member sidewall 54 to render the outer member sidewall slightly eccentric (e.g., elliptical). This elastic deformation brings the unscrewing engagement features 140, 142 (
In this example, surfaces 144 and 146 (
For axially retaining the outer member to the inner member, a lower portion of the outer member sidewall 54 adjacent the rim 56 is formed by an array of partially inwardly directed petals 160 (
The petals 160 capture the inner member outer sidewall rim 92 to resist axial separation of the outer member form the inner member and leave enough axial play to allow the ratchet action (discussed above) of the installation engagement features 120, 122 responsive to an attempted uninstallation rotation. Exemplary petals extend inward by 20° to 70°, more narrowly, 30° to 60°, or about 45°. Thus, the inner diameter (ID) at the outer member lower rim may be slightly smaller than the outer diameter (OD) at the inner member outer sidewall lower rim to retain the two members to each other. A slight inward taper (if any) from bottom to top of the inner member outer sidewall OD surface and/or rounding or beveling/chamfering 170 (
The double sidewall of the inner member facilitates one or more advantages relative to a hypothetical single wall variant. First, it allows convenient location of the bevel/chamfer 170 or other such feature. Second, the radial deformation of the inner member outer sidewall by the contact force of squeezing allows a greater circumferential engagement than a more rigid single sidewall would. This allows more teeth to be effectively engaged and reduces chances of slippage, allowing relatively shallower teeth than might otherwise be necessary. Finally, it gives a softer, more ergonomic feel than a hard stop feel associated with a rigid single sidewall. Nevertheless, single sidewall variants are not precluded.
In this example, the span of θ is measured between corresponding portions first and last features in a group rather than the overall span of features in such group which may extend beyond by the circumferential length of one feature. Exemplary θ is 10° to 60°, more narrowly, 30° to 50°. This leaves associated gaps in regions or sectors 304 (outer member) and 306 (inner member). Accordingly, the indicia now further include specific indicia 112-1 on the outer member upper web indicating where the user should squeeze (e.g., that the user should squeeze along the regions 300 rather than the regions 304). If the user squeezes on the regions 304, the features 140 will be brought further radially away from the complementary features 142 and no unscrewing will be possible.
If the user grasps the regions 300 and squeezes when the features 140 are not aligned with the features 142 (e.g., when the features in the sector 300 of the outer member are aligned with the sector 304 of the inner member) initial rotation will have no effect but, eventually, the two sets of features will come into engagement and allow unscrewing. Nevertheless, to avoid any initial confusion of the user grasping in this condition and finding no resistance, the inner member may have indicia 112-2 indicating the proper alignment for engagement. Thus, a user will not give up rotating a properly squeezed outer member before it comes into engagement with the inner member. Accordingly, it is seen that a yet alternative embodiment may have a full array of features 142 on the inner member but only the two opposite sectors of features 140 on the outer member.
One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, desirability of reusing existing molding and/or capping equipment may influence particular implementations. Accordingly, other embodiments are within the scope of the following claims.
Claims
1. A child-resistant cap for closing an externally threaded neck of a container body, the cap comprising:
- an inner member having an internal thread for engaging the neck external thread; and
- an outer member encircling the inner member for gripping by a user, wherein:
- the outer member comprises: a sidewall bearing a first engagement feature; and an upper web having an underside bearing a second engagement feature; and
- the inner member comprises: an inner sidewall bearing the internal thread; an outer sidewall spaced-apart from the inner sidewall and having an outer surface bearing a third engagement feature, the third engagement feature engagable to the first engagement feature responsive to inward compression of the outer member sidewall so as to allow the outer member to transmit a removal rotation to the inner member; and an upper web joining the inner sidewall and outer sidewall and having an upper surface bearing a fourth engagement feature, the fourth engagement feature engagable to the second engagement feature to transmit an installing rotation to the inner member.
2. The child-resistant closure of claim 1 wherein:
- the outer member upper web has a central aperture exposing the inner member upper web.
3. The apparatus of claim 1 wherein:
- a lower end of the outer member sidewall is formed by partially radially-inwardly directed petals.
4. A container comprising:
- the child-resistant cap of claims 1; and
- a container body having an externally threaded neck engaged to the inner member internal thread.
5. The container of claim 4 further comprising:
6. A method for using the container of claim 4, the method comprising:
- inwardly compressing the outer member sidewall; and
- rotating the outer member sidewall in a direction to unscrew the internal thread from the external thread.
7. The method of claim 6 wherein:
- the inwardly compressing causes the third engagement feature to engage the first engagement feature.
8. A method for manufacturing the container of claim 4, the method comprising:
- downwardly installing the outer member over the inner member, the downward installation outwardly flexing a lower rim portion of the outer member and then relaxing to capture the inner member.
9. A child-resistant cap for closing an externally threaded neck of a container body, the cap comprising:
- an inner member having an internal thread for engaging the neck external thread; and
- an outer member encircling the inner member for gripping by a user, wherein:
- the outer member comprises: a sidewall bearing a first engagement feature and having a lower end formed by partially radially-inwardly directed petals; and an upper web having an underside bearing a second engagement feature; and
- the inner member comprises: a sidewall having an outer surface bearing a third engagement feature, the third engagement feature engagable to the first engagement feature responsive to inward compression of the outer member sidewall so as to allow the outer member to transmit a removal rotation to the inner member; and an upper surface bearing a fourth engagement feature, the fourth engagement feature engagable to the second engagement feature to transmit an installing rotation to the inner member.
10. A method for manufacturing the closure of claim 9, the method comprising:
- downwardly installing the outer member over the inner member, the downward installation outwardly flexing the petals of the outer member and then relaxing to capture the inner member.
Type: Application
Filed: Jun 2, 2015
Publication Date: Dec 3, 2015
Applicant: Plastek Industries, Inc. (Erie, PA)
Inventor: Peter A. Piscopo (Medford, NJ)
Application Number: 14/728,276