Safety Closure for Containers

This invention relates to the field of safety closures for containers, in which the closure includes a mechanism or structure that makes opening difficult enough that small children in particular cannot normally open containers having materials that would be harmful or dangerous, or that they should otherwise not be able to open.

A variety of such closure caps are known to the prior art which attempt to solve the problem in different ways, and a number of U.S. patents have been issued for such prior art closure caps including the following: U.S. Pat. Nos.

4,625,898, 4,377,247, 4,282,991, 4,220,248, 4,219,138, 4,209,114, 4,172,540, 4,124,151, 4,081,113, 4,047,643, 3,977,557, 3,967,764, 3,957,181, 3,893,593, 3,884,394, 3,881,643, 3,877,598, 3,874,568, 4,209,100, 3,873,005, 3,863,818, 3,860,137, 3,851,805, 3,784,060, 3,777,936, 3,774,808, 3,718,238, 3,655,103, 3,848,780, 3,844,455, 3,765,578, 4,635,823, 4,298,129, 4,281,778, 3,927,805, 4,298,129, 3,826,394, 4,220,262.

The safety closure cap in accordance with this invention provides a novel structure to achieve the safety objective. An outer continuous peripheral wall or skirt of the safety cap is spaced radially outwardly from an inner concentric peripheral wall which seats in the neck of the container to seal it closed. The continuous outer wall is integrally formed with the top closure wall of the cap and depends therefrom giving structural stability and strength to a deflectable barrier strip integrally formed therein which bars access to a hinged closure tab provided on the top closure wall until the barrier strip is deflected inwardly. A thin laterally extending web or nib extends upwardly from the outer portion of the upper edge of the deflectable barrier strip to cover the crack between the free end of the closure tab resting on and abutting against the upper edge of the deflectable barrier strip. Thus, a child for example cannot get his fingernail, or a knife, or other thin item into this crack to pry up the free end of the closure tab. The only way to gain access to an underportion of the closure tab to push it upwardly to the open position is by first pushing in on the deflectable barrier strip to expose an underportion of the closure tab. The closure tab has an elongated cylindrical plug extending downwardly from its inwardly facing surface to frictionally seat in a corresponding cylindrical recess positioned below the closure tab in the top closure wall, thereby closing the apertures in the bottom of the cylindrical recess and sealing against leakage of the contents from the container on which the closure cap is seated.

It is an object of the invention to provide a safety closure cap for a container having a neck on which the safety closure cap is received, wherein the cap is not removable from the container once it has been received thereon and a closure tab on the cap is not openable until a protective barrier is deflected to provide access to the closure tab for opening.

It is an object of the invention to provide a safety closure cap for a container having a neck on which the safety closure cap is received, wherein the cap includes a closure tab connected for pivotal movement between an open and a closed position and a deflectable barrier strip to prevent access to said closure tab until said barrier strip is deflected.

FIG. 1 is a top plan view of a container having a safety closure in accordance with this invention in place thereon.

FIG. 2 is a side elevation of the container with safety closure thereon as showing in FIG. 1.

FIG. 3 is a section view taken on line 3--3 of FIG. 1.

FIG. 4 is a section view as in FIG. 3 but with the deflectable barrier strip portion of this invention shown deflected inwardly to expose an end portion of the lower surface of the closure tab.

FIG. 5 is a top plan view of the container shown in FIG. 1 with the safety closure removed.

FIG. 6 is a top plan view of the container and safety closure shown in FIG. 1 but with the closure tab in the open position.

FIG. 7 is a section view taken on line 7--7 of FIG. 6.

FIG. 8 is a side elevation view of the container with safety closure thereon and closure tab open as shown in FIG. 6.

FIG. 9 is a bottom plan view of the safety closure in accordance with this invention.

FIG. 10 is an enlarged side elevation view of a fragment of the deflectable barrier strip portion of this invention to more clearly show the detail structure of the laterally extending web which conceals the crack between the lower surface of the closure tab and upper edge of the deflectable barrier strip when the closure tab is in the closed position.

FIG. 11 is a section view similar to that of FIG. 4, but showing a metal can having a different kind of neck with which the safety closure in accordance with this invention may also be used, namely a short neck having an annular flange of C-shape cross-section rather than an elongated neck having threads.

A safety closure for containers in accordance with this invention comprises a cap 2 in the form of an inverted cup having an outer peripheral annular wall 4 and an inner peripheral annular wall 6 concentric with the outer annular wall 4 and spaced apart inwardly therefrom a short distance on the order of a sixteenth to an eighth of an inch. The concentric annular walls 4 and 6 terminate at their upper ends at the inwardly facing surface 8 of the top wall 10 which extends across the cap 2 in a direction substantially normal to the concentric annular walls 4 and 6. The annular walls 4 and 6 are relatively rigid but of a material that is pliable enough to permit flexing under pressure.

The inner annular wall 6 terminates at its lower end in an enlarged annular retaining rim 12 to seat within the opening 14 of the neck 16 of a container 18 on which the safety closure cap 2 is to be used. The annular retaining rim 12 includes an outwardly extending annular projection 20 having a triangular cross-section comprising an annular apex 22, a sloping upper annular wall portion 24 sloping inwardly from the annular apex 22 in the direction toward the top wall 10, and a tapering lower annular wall portion 26 tapering inwardly from the annular apex 22 in the opposite direction downwardly terminating at the lower edge 28 of the inner annular wall 6.

When the cap 2 is placed on the neck 16 of a container 18, the tapering lower annular wall portion 26 is received within the neck opening 14 and in contact with its annular edge 30. As the cap 2 is pressed downwardly, the tapering lower annular wall portion 26 in contact with the annular edge 30 of the neck opening 14 deflects the annular retaining rim 12 of the inner annular wall 6 until its annular apex 22 is able to pass the annular edge 30 of the neck opening 14 whereupon it expands back toward its original position thereby preventing withdrawal of the inner annular wall 6 and the cap 2 from the neck 16 of the container 18.

The inner annular wall 6 surrounds a central cavity 32 of the cap 2, opening inwardly to the chamber 34 of the container 18 when the cap 2 is placed thereon.

The outer annular wall 4 extends downwardly from the outer peripheral edge 34 of the top wall 10, and its lower end 36 terminates at a point spaced apart upwardly from the annular apex 22 of the annular retaining rim 12 of the inner annular wall 6.

The top wall 10 of the cap 2 has a substantially annular peripheral edge 38 and a substantially planar upper surface 40 extending in a direction substantially normal to the concentric annular walls 4 and 6. The top wall 10 comprises two spaced apart segments 42 and 44, segment 42 bounded by a straight edge or chord 46 and segment 44 bounded by a straight edge or chord 48 which is spaced apart from and substantially parallel to chord 46, each cord being spaced apart equidistantly in opposite directions from the diameter of the substantially annular top wall 10 which is parallel to chords 46 and 48.

The spaced apart segments 42 and 44 and their respective straight edges or chords 46 and 48 define a substantially rectangular opening 50 to a substantially rectangular recess 52 having a floor 54 spaced apart inwardly of and downwardly from the upper surface 40 of the top wall 10 a short distance substantially equal to the thickness 56 of a closure tab 58 having a substantially rectangular peripheral configuration and dimension corresponding to that of the rectangular opening 50. The closure tab 58 is connected by an integrally formed hinge 60 integrally connected to and extending from the upper end of the outer annular wall 4 in registration with the rectangular opening 50 whereby closure tab 58 is connected for pivotal movement between an open and closed position. In the closed position, the closure tab 58 seats completely within the opening 50 and rectangular recess 52 with its upper surface 62 coplanar with the planar upper surface 40 of top wall 10 of the cap 2, and with its lower surface 64 resting against the floor 54 of the recess 52.

A circular sub-recess or well 66 extends downward from the central portion of the recess 52 opening to the floor 54 thereof and having a circular bottom wall 68 through which three apertures 70 are formed opening to the central cavity 32 of the cap 2 which is bounded by the inner annular wall 6. The sub-recess or well 66 has a frusto-conical wall portion 72 extending downwardly from its relatively large diameter opening 74 to the recess 52, converging inwardly and terminating at an integrally joined cylindrical wall portion 76 having a cylindrical cavity 78 of relatively smaller diameter than the large diameter opening 74. The cylindrical wall portion 76 extends downwardly from its junction with the lower edge of the integrally joined frusto-conical wall portion 72 for a relatively short distance of about a sixteenth of an inch or thereabouts, to terminate at the circular bottom wall 68 which is integrally joined to the lower edge of the cylindrical wall portion 76.

A cylindrical plug 80 extends from the central portion of the lower surface of the closure tab 58, positioned for registration with and seating in the cylindrical cavity 78 of the sub-recess or well 66 when closure tab 58 is pivoted to its closed position. The cylindrical plug 80 has a longitudinal dimension corresponding to the distance between the bottom wall 68 of the sub-recess or well 66 and its large diameter opening 74 to recess 52, whereby when closure tab 58 is in its closed position the free end 82 of cylindrical plug 80 extends to and abuts against the bottom wall 68 to close the three apertures 70. The peripheral configuration and dimension of the cylindrical plug 80 corresponds to that of the cylindrical cavity 78 for a tight sealing fit when received therein.

When the closure tab 58 is in its closed position with cylindrical plug 80 tightly seated in the cylindrical cavity 78 with its free end 82 abutting against the bottom wall 68 of the sub-recess or well 66, the contents of a container 18 on which the closure cap 2 is in place are effectively sealed within the container 18 and prevented from leaking out. When it is desired to pour the contents from the container 18, the closure tab 58 must be pivoted upwardly to the open position, whereupon the contents may be poured out through the apertures 70 in the bottom wall 68 of the sub-recess or well 66.

The closure tab 58 has a safety feature to prevent opening by a child or to make it difficult enough to meet a particular standard of difficulty for a child to move the closure tab 58 from the closed position to the open position. This safety feature is described as follows.

The free end 84 of the rectangular closure tab 58, opposite from the integrally hinged end 86, terminates at a point which when in the closed position is substantially in line with that part of the outer surface 88 of the outer annular wall 4 which lies immediately below the free end 84 of closure tab 58. An upper edge cut-away portion 90 is provided across that portion of the upper end 91 of the outer annular wall 4 which faces the rectangular recess 52 and the free end 84 of closure tab 58 when seated therein, the width of such cut-away portion 90 corresponding substantially to the width across free end 84 of tab 58, the depth of the cut-away portion 90 corresponding substantially to the thickness of the closure tab 58.

A pair of spaced apart substantially parallel cuts 92 extend downwardly in the outer annular wall 4 from each opposite side of the cut-away portion 90 to form therebetween an inwardly deflectable barrier strip 94 which prevents access to the lower surface 64 of the closure tab 58 at its free end 84 until deflected inwardly in the direction toward the inner annular wall 6 a sufficient distance to bare a portion of the lower surface 64 of tab 58 at its free end 84. A person can push the deflectable barrier strip 94 inwardly with his thumb, and at the same time use his thumb to then push upwardly on the edge of the closure tab 58 when a portion of its lower surface 64 is bared and in facing relationship to the thumb.

A laterally extending finger nail prevent nib 96 is formed along the upper edge 98 of the deflectable barrier strip 94 to conceal the crack 100 between the free end 84 of tab 58 and the upper edge 98 of barrier strip 94 against which it abuts when tab 58 is in the closed position. This laterally extending nib 96 prevents a child or other person from extending his fingernail or other thin prying device into the crack 100 and prying the free end 84 of closure tab 58 upwardly enough to force it from the closed to open position. The nib 96 is a very thin upward extension of that part of the outer annular wall 4 between the parallel cuts 92 which forms the deflectable barrier strip 94 integrally connected thereto. The nib 96 extends laterally across the entire width of the upper edge 98 of barrier strip 94, which width corresponds to that of the free end 84 of the closure tab 58. The nib 96 extends upwardly from the upper edge 98 of barrier strip 94 a very short distance such as one-sixteenth of an inch or thereabout, just sufficient to cover and conceal the crack 100. The nib 96 extends inwardly from the outer surface 88 of barrier strip 94 along its upper edge 98 a very short distance along its integral connection to the upper edge 98 of barrier strip 94, the inwardly facing surface 102 of the nib 96 then tapering along a diagonal line which converges toward the outer surface 88 as it extends upwardly to terminate at the upper free edge 104 of the laterally extending nib 96. This laterally extending nib 96 is freely deflectable outwardly as it bears and slides against the facing surfaces of the closure tab 58 when the inwardly deflectable barrier strip 94 is pushed upwardly enough to gain access to a free end portion of the lower surface 64 of the closure tab 58 for pushing upwardly to the open position.

The length of the parallel cuts 92 which border the opposite side edges of the inwardly deflectable barrier strip 94 are such that the longitudinal dimension of the side edges 106 and 108 thereof are preferably shorter than the lateral dimension across the barrier strip 94 between the side edges 106 and 108. The lower the ratio of the longitudinal dimension to the lateral dimension of the integrally formed barrier strip 94, the less flexible and less easily deflectable will such barrier strip be. The higher that ratio is, the more flexible and more easily deflectable. These dimensions can be selected to provide whatever ratio and whatever degree of difficulty is desired to deflect the barrier strip 94 inwardly to begin the first step of gaining access to the closure tab 58 for opening.

To open the closure tab 58 for pouring contents from the container 18, a person must first press inwardly on the deflectable barrier strip 94 with sufficient force to bare a portion of the lower surface 64 of the closure tab 58 at its free end 84, then press upwardly on such free end portion of the closure tab 58 with sufficient force to draw the free end 82 of the cylindrical plug 80 out of the cylindrical cavity 78 of the sub-recess or well 66 in the top wall 10, in which it is seated and frictionally held to seal the contents of the container from leaking out.

When pressure is released from the deflectable barrier strip 94 it flexes back to its original position wherein its outer surface is again in arcuate alignment with the outer surface 88 of the outer annular wall 4. Access to the free end 54 of clsour tab 58 for opening it is thereby barred automatically when the closure tab 58 is pivoted back to its closed position with the lower surface 64 of its free end 84 abutting against the upwardly facing free end 98 of the deflectable barrier strip 94 and with the laterally extending nib or web 96 concealing the crack 100 therebetween. The free end 82 of cylindrical plug 80 seats tightly in the cylindrical cavity 78 of sub-recess 66 to securely hold the closure tab 58 in the closed position until the opening procedure described above in again performed.