Abstract:
A child-resistant container cap has: an internally threaded inner sidewall. An outer sidewall surrounds the inner wall and has a cross-section normal to the central axis characterized by an opposite first pair of ends compressable from a relaxed condition to a compressed condition and an opposite second pair of ends, a direction between the second pair of ends being normal to a direction between the first pair of ends. A pair of engagement features are carried by the outer sidewall and engagable with container body engagement features to prevent an unscrewing rotation with the cap in the installed condition and the outer sidewall relaxed. Compression of the first ends from the relaxed condition to the compressed condition shifts the cap engagement features radially outward to permit the unscrewing rotation. The cross-section of the cap is longer between the first ends than the second ends.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Benefit is claimed of U.S. Patent Application No. 62/145,202, filed Apr. 9, 2015, 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 INVENTION 
     The invention relates to screw-on container closures. More particularly, the invention relates to child-resistant closures. 
     Among numerous examples of child-resistant closures for small over-the-counter (OTC) medications (e.g., pills, capsules, tablets) is U.S. Pat. No. 5,671,853 of Herr, issued Sep. 30, 1997. 
     SUMMARY OF THE INVENTION 
     One aspect of the disclosure involves a child-resistant container system comprising a container body and a cap. The container body has: a sidewall; a mouth; an externally-threaded neck between the mouth and the body; and a pair of engagement features. The cap has: an internally threaded inner sidewall matable to the externally-threaded neck in an installed condition and unscrewable from the externally-threaded neck to a removed condition. An outer sidewall surrounds the inner wall and has a cross-section normal to the axis characterized by an opposite first pair of ends compressable from a relaxed condition to a compressed condition and an opposite second pair of ends, a direction between the second pair of ends being normal to a direction between the first pair of ends. A pair of engagement features are carried by the outer wall and engagable with the container body engagement features to prevent an unscrewing rotation with the cap in the installed condition and the outer sidewall in the relaxed condition. Compression of the first ends from the relaxed condition to the compressed condition shifts the cap engagement features radially outward to permit the unscrewing rotation from the installed condition. The cross-section of the cap is longer in a direction between the first ends than in a direction between the second ends. 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top oblique view of a child-resistant container. 
         FIG. 2  is a top view of the container of  FIG. 1 . 
         FIG. 3  is a transverse sectional view of the container taken along line  3 - 3  of  FIG. 1 . 
         FIG. 4  is a central vertical sectional view of the container taken along line  4 - 4  of  FIG. 2 . 
         FIG. 5  is a top oblique view of a body of the container of  FIG. 1 . 
         FIG. 6  is a front view of the body of  FIG. 5 . 
         FIG. 7  is a side view of the body of  FIG. 5 . 
         FIG. 8  is a top view of the body of  FIG. 5 . 
         FIG. 9  is a bottom view of a closure of the container;  FIG. 9A  is an enlarged view of an engagement feature of the closure of  FIG. 9 . 
         FIG. 10  is a central vertical sectional view of the closure taken along line  10 - 10  of  FIG. 9 . 
         FIG. 11  is a central vertical sectional view of the closure taken alone line  11 - 11  of  FIG. 9 . 
         FIG. 12  is a central vertical sectional view of the closure taken alone line  12 - 12  of  FIG. 9 . 
         FIG. 13  is a top oblique view of a second embodiment of a child-resistant container. 
         FIG. 14  is a top view of the container of  FIG. 13 . 
         FIG. 15  is a transverse sectional view of the container taken along line  15 - 15  of  FIG. 13 . 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
       FIG. 1  shows a container  20  comprising a container body  22  and a cap or closure  24 . The exemplary container body is a molded plastic single-piece member (e.g., roto-molded or blow molded or injection molded). The exemplary body has a base  30 , a sidewall  32  extending upward from the base, a shoulder  34  extending upward from the sidewall, and a neck  36  ( FIG. 5 ) extending upward from the shoulder and extending to a rim  38  to define a body opening or mouth  40  ( FIG. 9 ). The neck bears an external thread  42  for engaging an internal thread of the closure. The neck defines a central longitudinal/vertical axis  500  ( FIG. 2 ). The exemplary thread  42  is a double lead thread providing evenness/straightness of screwing and unscrewing. 
     The exemplary closure  24  is a one-piece closure. An exemplary closure piece is 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, safety seal, or the like. 
       FIGS. 9-12  show the exemplary closure as comprising an inner sidewall  50  extending upward from a lower end formed by a rim  52  to an upper end  54  merging with a transverse web  56  closing the upper end. The inner sidewall  50  has an inboard or inner diameter (ID) surface  58  and an outboard or outer diameter (OD) surface  60 . The ID surface  58  bears an internal thread  62  complementary to the external thread of the neck. In the fully installed condition, the underside  64  of the web inboard of the ID surface  58  may seal against the rim  38  or be in close facing proximity thereto ( FIG. 4 ).  FIG. 9  shows an underside  64  of the web and  FIG. 1  shows an upper surface  66  of the web. The upper surface may have, pre-molded thereto, instructional indicia  68 . 
     The closure further comprises an outer sidewall  70  ( FIG. 9 ). As is discussed further below, the outer sidewall  70  has an exemplary four distinct portions with a first pair of opposed portions ( FIG. 2 ) being gripping portions  72 A,  72 B (collectively or individually  72 ) and a second pair of opposed portions  74 A,  74 B (collectively or individually  74 ; orthogonal to the first pair). The portions  72  are gripping/release portions for gripping by the user to release child-resistance features to allow an unscrewing rotation of the closure. 
     The exemplary body  22  and closure  24  have transversely elongate footprints. The exemplary body footprint ( FIG. 3 ) is approximately elliptical with a major axis L B1  and a minor axis L B2 . Exemplary L B1  is about 125% of L B2 , more broadly, at least 110% or at least 115% or at least 120%. Exemplary upper limits pairable with any of those lower limits are 130% or 140% or 150% or 200%. 
     To define frames of reference, for such a generally symmetric container, the neck central longitudinal axis  500  defines central longitudinal axis of the body  22  which is vertical in a normal storage position. With the transverse elongate footprint, a plane  502  ( FIG. 8 ) through the body containing the axis  500  is defined as a lateral or transverse longitudinal side-to-side plane; and a plane  504  containing the axis  500  and normal to the plane  502  is a central longitudinal sagittal (front-to-back) plane. Thus, the major axis of the ellipse falls along the plane  502  and the minor axis of the ellipse falls along the plane  504 . In the exemplary fully screwed on/installed condition, planes of the closure are similar thereto. For ease of reference, the closure  24  central longitudinal axis is shown as  510  ( FIG. 9 ); the closure transverse longitudinal centerplane is shown as  512 ; and the closure sagittal longitudinal centerplane is shown as  514 . In the illustrated installed condition,  510  is coincident with  500 ,  512  coincident with  502 , and  514  coincident with  504 . 
     The exemplary closure  24  footprint is, however, not elliptical. Rather, along what would have been the major axis of the ellipse footprint, end portions of the footprint are concave outward rather than convex outward to form the portions  72 . As is discussed below, this helps gripping. The concavity may mean that actual cross-section/footprint length at the centerplane  512  is about the same as that at the centerplane  514 . Overall footprint or cross-section length L C1  ( FIG. 2 ) in that direction (parallel to plane  512 ) may still be longer than overall length L C2  transverse or normal thereto due to protrusion of transitions  90  (discussed below). Exemplary L C1  is at least 105% of L C2  or at least 110%. Upper limits may be similar to those of the body elongatedness, particularly if the concavities are not present. 
     The closure outer sidewall  70  extends from a lower rim  80  ( FIG. 10 ) to an upper end  82 . The upper end  82  merges with a periphery of the web  56 . The outer sidewall  70  has an inboard or inner diameter (ID) surface  84  and an outboard or outer diameter (OD) surface  86 . Along the gripping portions  72 , the exemplary surface  86  optionally bears a series of lands  88  ( FIG. 13  for modified closure  224  of the container  220 ) and grooves or other contouring to facilitate gripping. 
       FIG. 3  shows the general outward concavity and inward convexity of the gripping portions  72 .  FIG. 3  also shows the portions  74  transverse thereto being, along majority central portions thereof, convex outward and concave inward. Transitions between adjacent edges of the portions  72  and  74  are formed by convex outward/concave inward transitions  90 . In the exemplary embodiment, however, between the transitions  90  and the central portions of the sidewall portions  74 , there are further transitions  92  that are outwardly concave and inwardly convex. 
       FIG. 9  shows the outwardly concave region of gripping portion  72  as extending for an angle θ 1  about the axis  510 . Exemplary θ 1  is at least 20°, more narrowly, at least 30°, or an exemplary 30°-60°. 
     As is discussed further below, the body and closure have two pairs of engagement features  120 ,  122  ( FIG. 3 ) cooperating with each other. The engagement features allow the closure to be rotated about the axis  500  in a direction to install the closure (i.e., screw the closure onto the body) but normally block the opposite unscrewing/removal rotation. The engagement features may be manipulated to allow the closure to be rotated in an opposite unscrewing/removal rotation. The manipulation involves inwardly compressing the gripping portions  72 . This manipulation may require application of sufficient force/pressure or manipulation to qualify as a child-resistant action. Absent the manipulation, unscrewing rotation is blocked by the engagement features. 
     The exemplary engagement features  120  ( FIG. 3 ) are formed by a pair of ramps extending radially outward from the neck  36  along the shoulder  34  diametrically opposite each other. The ramps have a first circumferential surface or face  123  and opposite second circumferential surface or face  124 . The surfaces  123  and  124  may also meet at an apex region  130 . 
     As is discussed further below, the surfaces  123  are ramp surfaces and the surfaces  124  are stop surfaces. The surfaces  124  are relatively radial or over-radial so as to cooperate with complementary surfaces of the closure engagement features  122  to resist unscrewing motion absent the aforementioned manipulation. The surfaces  123  allow the closure engagement features to override in a screwing/installing rotation as is discussed further below. 
       FIG. 3  shows further details of the features  122 . The exemplary features  122  are formed by a pair of barbs or ramps extending radially inward from the outer sidewall inboard surface along the respective portions  74  diametrically opposite each other. As is discussed below, the features have circumferential surfaces  143  and  144  (which may meet at or be joined by an apex or junction region  146 ). The surfaces  143  may be angled in complementary fashion to the surfaces  123  so that they override each other (discussed below) during an installing rotation. 
     The surfaces  144  and  124  are sufficiently complementary to provide an opposite cooperation. During an attempt at unscrewing engagement without proper actuation, the surfaces  124  and  144  of adjacent projections abut and do not override 
       FIG. 3  shows an installed or screwed-on condition wherein the ends or surfaces  144  are in abutting engagement with the surfaces  124  to prevent/block an unscrewing rotation of the closure about the axis  500 . It is seen that the surfaces  144  are sufficiently radial or over-radial to provide the aforementioned interlocking action. Specifically, by being over-radial they are angled off-radial so that an unscrewing rotation causing contact between the surfaces  144  and  124  will drive the projections  122  radially inward into securer engagement perhaps ultimately abutting the apex regions  130  against the inner surface of the outer sidewall. 
     However, for unscrewing, the portions  72  may be squeezed inward (i.e., compressed inwardly toward each other and toward the plane  514 ). This compressing and inward shift causes a corresponding flexing of the portions  74  radially outward and shifting the closure projections  122  radially outboard of the body projections  120 . In this condition, while maintaining compression between the portions  72 , the closure may be unscrewed via an unscrewing rotation about the axis  500  with the each of the features  122  passing radially outboard and circumferentially past the features  120 . 
     The heights (parallel to axis  500 ) of the projections  120  may be merely sufficient to provide sufficient strength for a desired resistance to opening. In the exemplary embodiment, they only have potential engagement with the projections  122  for a small portion of a single turn. With the exemplary thread, full removal can occur in one full turn. 
     In an installing rotation, one need not squeeze the portions  72 . Instead, the junction regions  146  will engage the ramping surface  123  (and/or a curving transition to the apex region  130 ). The angling of the meeting surfaces is sufficient to flex the closure (e.g., radially outwardly flex the portions  74 ) to permit an overriding return to the installed condition. 
     The elongate cross-section may provide one or more of several advantages in use. First, compressing the long direction may be counterintuitive for a child. Particularly, a small child with small hands would tend to grasp across the portions  74  and compress them toward each other preventing unscrewing. Larger adult hands may be more amenable to compressing the portions  72 . This is particularly the case when there are written instructions on the closure or where the optional gripping features such as lands  88  are located along the end portions  72 . Also, the concavity of the portions  72 , however, assists in gripping by a user with sufficiently large hands. Accordingly, this may be regarded as particularly useful for users with arthritis or other grip-related disability. However, the elongate nature of the body footprint allows easy intuitive gripping with the off hand. Thus less grip strength is required of the off hand on the body than with a round footprint body. Also, the elongate nature of the footprint of the closure allows for a greater amount of compression between the portions  72  than what may be found with corresponding portions of a circular outer sidewall close to the inner sidewall. This greater possible stroke may allow for lower compression forces. 
     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.