Child-resistant cap and container assembly

Abstract

A child-resistant container assembly for selectively storing materials is provided. The child-resistant container assembly includes a cap and a container. The cap has a top wall and a sidewall. First and second levers are positioned in respective gaps in the sidewall and are pivotably connected thereto via hinges. The container includes a neck positioned at an upper end thereof, having a radially outwardly extending, circumferentially tapering locking rib. The locking rib defines at least one locking edge, at a largest diameter of the locking rib, and at least one base edge, at a smallest diameter of the locking rib. To remove the cap from the container, the first and second levers are manually pivoted to clear the at least one locking edge, in order to permit sufficient rotation of the cap relative to the container to remove the cap from the container.

We claim: 
     
         1 . A child-resistant container assembly for selectively storing materials, the child-resistant container assembly comprising:
 a cap having a top wall and a sidewall extending from the top wall to a terminal end and having internal threads defined on an internal surface thereof, a first gap defined in the sidewall and a second opposing gap defined in the sidewall, a first lever positioned substantially in the first gap and connected to the sidewall by a first hinge, a second lever positioned substantially in the second gap and connected to the sidewall by a second hinge, the first and second levers including respective first and second proximal ends, respective first and second distal ends, and each of the first and second levers having a generally smooth interior surface extending between the proximal and distal ends thereof, the respective distal ends of the first and second levers extending downwardly past the terminal end of the sidewall; and   a container including a cylindrical body, an upper end and a lower end, a shoulder and a neck positioned at the upper end, the neck having external threads formed on an external surface thereof for mating with the internal threads of the cap, a circumferentially tapering locking rib extending radially outwardly from the external surface of the neck between the external threads and the shoulder, the locking rib defining at least one locking edge at a largest diameter of the locking rib, and at least one base edge at a smallest diameter of the locking rib, wherein the first and second levers are configured such that the at least one locking edge of the locking rib impacts at least one of the first and second levers in a locked position of the cap, thereby resisting rotation of the cap relative to the container to remove the cap from the container, the first and second levers being manually pivotable about the first and second hinges, respectively, such that the first and second proximal ends pivot radially inwardly toward one another and the first and second distal ends pivot radially outwardly away from one another, thereby clearing the at least one locking edge and permitting sufficient rotation of the cap relative to the container to remove the cap from the container.   
     
     
         2 . The child-resistant container assembly of  claim 1 , wherein the first and second hinges of the cap are torsional stress members. 
     
     
         3 . The child-resistant container assembly of  claim 1 , wherein the cap further comprises a plurality of vertical ribs located circumferentially around the sidewall and spanning between an upper end and the terminal end of the cap, the plurality of vertical ribs having a substantially consistent external diameter. 
     
     
         4 . The child-resistant container assembly of  claim 1 , wherein the first and second levers, the locking rib and the neck are configured such that an audible sound confirms that the cap has reached the locked position when the cap is rotated onto the container. 
     
     
         5 . The child-resistant container assembly of  claim 4 , wherein the audible sound is created by tension of the first and second levers on the locking rib of the container after respective trailing edges of the first and second levers pass over the at least one locking edge of the locking rib, thereby causing the first and second levers to snap inwardly onto the neck of the container. 
     
     
         6 . The child-resistant container assembly of  claim 1 , wherein the locking rib includes a first circumferentially tapering rib portion and a second circumferentially tapering rib portion, the first and second rib portions being configured to slidably engage the respective smooth interior surfaces of the first and second levers as the cap is rotated relative to the container. 
     
     
         7 . The child-resistant container assembly of  claim 6 , wherein a first of the at least one locking edge is defined at a largest diameter of the first rib portion and a second of the at least one locking edge is defined at a largest diameter of the second rib portion. 
     
     
         8 . The child-resistant container assembly of  claim 7 , wherein a first of the at least one base edge is defined at a smallest diameter of the first rib portion and a second of the at least one base edge is defined at a smallest diameter of the second rib portion. 
     
     
         9 . The child-resistant container assembly of  claim 1 , wherein the at least one locking edge includes a first locking edge and a second locking edge. 
     
     
         10 . The child-resistant container assembly of  claim 9 , wherein the first locking edge is positioned on an opposite side of the neck relative to the second locking edge. 
     
     
         11 . The child-resistant container assembly of  claim 9 , wherein the at least one base edge includes a first base edge and a second base edge. 
     
     
         12 . The child-resistant container assembly of  claim 11 , wherein a first locking surface is defined between the first base edge and the first locking edge, the first locking surface extending substantially perpendicularly outwardly from an outside surface of the neck. 
     
     
         13 . A child-resistant container assembly for selectively storing materials, the child-resistant container assembly comprising:
 a cap having a top wall and a sidewall extending from the top wall to a terminal end and having internal threads defined on an internal surface thereof, a first gap defined in the sidewall and a second opposing gap defined in the sidewall, a first lever positioned substantially in the first gap and connected to the sidewall by a first torsional stress member extending from sides of the first lever, a second lever positioned substantially in the second gap and connected to the sidewall by a second torsional stress member extending from sides of the second lever, the first torsional stress member defining a first pivot axis and the second torsional stress member defining a second pivot axis, the first and second levers including respective first and second proximal ends, respective first and second distal ends, and each of the first and second levers having a generally smooth interior surface extending between the proximal and distal ends thereof, the respective distal ends of the first and second levers extending downwardly past the terminal end of the sidewall; and   a container including a cylindrical body, an upper end and a lower end, a shoulder and a neck positioned at the upper end, the neck having external threads formed on an external surface thereof for mating with the internal threads of the cap, a circumferentially tapering locking rib extending radially outwardly from the external surface of the neck between the external threads and the shoulder, the locking rib defining at least one locking edge at a largest diameter of the locking rib, and at least one base edge at a smallest diameter of the locking rib, wherein the first and second levers are configured such that the at least one locking edge of the locking rib impacts at least one of the first and second levers in a locked position of the cap, thereby resisting rotation of the cap relative to the container to remove the cap from the container, the first and second levers being pivotable about the first and second pivot axes, respectively, from a biased configuration wherein the interior surfaces of the first and second levers define a biased diameter, the biased diameter being less than the largest diameter of the locking rib.   
     
     
         14 . The child-resistant container assembly of  claim 13 , wherein the first torsional stress member is comprised of a pair of members extending from side surfaces of the first lever, the pair of members having substantially oval cross-sections. 
     
     
         15 . The child-resistant container assembly of  claim 14 , wherein the first pivot axis extends through the pair of members. 
     
     
         16 . The child-resistant container assembly of  claim 13 , wherein the cap and the container are constructed of a polymeric material. 
     
     
         17 . The child-resistant container assembly of  claim 16 , wherein the container is constructed of a high density polyethylene material. 
     
     
         18 . The child-resistant container assembly of  claim 16 , wherein the cap is constructed of a material exhibiting elastic and shape memory characteristics. 
     
     
         19 . The child-resistant container assembly of  claim 16 , wherein the cap is constructed of a polypropylene material. 
     
     
         20 . The child-resistant container assembly of  claim 13 , wherein the first and second levers, the locking rib and the neck are configured such that an audible sound confirms that the cap has reached the locked position when the cap is rotated onto the container