Containers and safety closure therefor

Claim 2

In a safety closure made of plastic for a container of the type having a closure member With an integral pull tab mounted within a recess in the top surface of the member and swingable about a hinged connection at one end to an open, grapsing position, the improvement wherein: all edges of the tab are in close fitting abutment to the edges of the recess when the tab is shut; tongue and groove interengagement means between the tab and at least one surface forming said recess are provided to hold the tab shut; at least a portion of the recess is deeper than the thickness of the tab; and a fulcrum means is located adjacent said deeper portion for supporting the tab, the dimensions of said tab, said recess and said fulcrum means being so proportioned in respect of the material from which said closure is made that an inward force on the tab at a point overlying said deeper portion of at least about four pounds is required to cause the tab to deflect inward at that point and thus pivot about the fulcrum means thereby raising an edge of the tab on the other side of the fulcrum means above the top surface of the closure to permit swinging the tab to the open, grasping position.

Claim 3

The safety closure of claim 1 wherin said deeper portion of the recess is located adjacent to the hinged connection, and the fulcrum means is located in spaced relation to the hinged connection.

Claim 4

The safety closure of claim 2 wherein the pull tab has a region of reduced cross section intermediate its hinged end and the location of the fulcrum means for increasing its flexibility in said region.

Claim 5

The safety closure of claim 2 further comprising an opening in the bottom of said recess, between the location of the fulcrum means and the end of the recess opposite the hinged connection, and a means extending from the flap for sealing said opening when the flap is shut.

Claim 6

The safety closure of claim 4 wherein the means for sealing said opening comprises a plug.

Claim 7

The safety closure of claim 2 wherein said required force is in the range from about 4 to 12 pounds.

Claim 8

The safety closure of claim 3 wherein said required force is in the range from about 4 to 12 pounds.

Claim 9

The safety closure of claim 5 wherein said required force is in the range from about 4 to 12 pounds.

Claim 10

The safety closure of claim 1 wherein said interengagement means comprises a protrusion from the tab and a mating indentation in at least one surface forming said recess.

Claim 11

The safety closure of claim 9 wherein said protrusion comprises a bead extending from the end of the tab opposite its hinged end, and the indentation comprises a groove in the corresponding end wall of the recess.

Claim 12

The safety closure of claim 1 in combination with a container having a flat wall with a circular opening, wherein the closure further comprises: a separate insert adapted to be secured in the circular opening of the container, said insert including a tubular body extending within the container when the insert is secured to the container and an inner stop means, the closure member being adapted to sealingly fit within the insert body against the inner stop means such that the surface of the closure member is approximately flush with the outer surface of the container.

Claim 13

The safety closure of claim 1 in combination with a container having a central well in the top with an internally projecting lip at the top of the well, wherein the closure further comprises: a tubular portion depending from the closure member, said tubular portion having a wide outer circumferential groove extending for a portion of its length; a flat-topped cylindrical overcap for the container, said overcap including an integral inner tubular casing extending from the top and adapted to slidingly receive the tubular portion of the tab-carrying member, the casing having: at least one axial slot extending upward from the lower edge for a portion of its length to permit inward flexure of the wall of the casing; an outer circumferential bead adjacent the lower edge of the casing for snap engagement with an internally projecting lip on the top of the container; and an inner circumferential bead spaced from the top of the casing by a distance such that it will engage the wide circumferential groove in the tubular portion near the top of the groove when the top of the tab-carrying member is flush with the top of the overcap.

Claim 14

The safety closure of claim 1 in combination with a container having a flat wall with a circular opening wherein the closure further comprises: a tubular skirt depending from the top surface of the closure member and having an inner circumferential bead adjacent its lower end to form a snap cap; and a separate insert adapted to be secured in the circular opening of the container, said insert including a tubular body extending within the container when the insert is secured to the container and an inner tubular neck, coaxial with and spaced from the inner wall of the insert body, extending from the inner end of the insert body for a portion of its length and terminating in a mouth having a protruding circumferential lip, the bead of said skirt being adapted to snap over said lip to close the mouth, and the length of said skirt being less than the length of said insert body, whereby the surface of the tab-carrying cap is recessed below the surface of the container surrounding said circular opening when the skirt is snapped over the mouth of the insert.

Claim 15

In a safety cap made of plastic and container cobination of the type wherein the container has an open mouth, a protruding circumferential lip surrounding the mouth, and a circumferential ledge spaced from the lip, the portion of the container between the ledge and the lip forming a neck of reduced diameter; and wherein the cap has a top with an integral pull tab flush-mounted within a recess in the top and a tubular skirt with an inner circumferential bead adapted to snap over the container lip, the bottom of the skirt extending in close-fitting abutment with the ledge when the skirt bead is snapped over the lip to prevent insertion of a sharp object between the bottom of the skirt and the ledge so as to pry off the cap from the container the improvement wherein: all edges of the tab are in close-fitting abutment to the edges of the recess when the tab is shut; tongue and groove interengagement means between the tab and at least one surface forming said recess are provided to hold the tab shut; at least a portion of the recess is deeper than the thickness of the tab; and a fulcrum means is located adjacent said deeper portion for supporting the tab flush with the top surface of the cap, the dimensions of said tab, said recess and said fulcrum means being so porportioned in respect of the material from which said cap is made that an inward force on the tab at a point corresponding to said deeper portion of at least about four pounds is required to cause the tab to deflect and thus pivot about the fulcrum means, thereby raising at least one edge of the tab above the top surface of the cap to permit swinging the tab to an open, grasping position.

Claim 16

In a safety cap made of plastic and container cobination of the type wherein the container has an open mouth, a protruding circumferential lip surrounding the mouth, and a circumferential ledge spaced from the lip, the portion of the container between the ledge and the lip forming a neck of reduced diameter; and wherein the cap has a top with an integral pull tab flush-mounted within a recess in the top and a tubular skirt with an inner circumferential bead adapted to snap over the container lip, the bottom of the skirt extending in close-fitting abutment with the ledge when the skirt bead is snapped over the lip to prevent insertion of a sharp object between the bottom of the skirt and the ledge so as to pry off the cap from the container the improvement wherein: all edges of the tab are in close-fitting abutment to the edges of the recess when the tab is shut; tongue and groove interengagement means between the tab and at least one surface forming said recess are provided to hold the tab shut; at least a portion of the recess is deeper than the thickness of the tab; and a fulcrum means is located adjacent said deeper portion for supporting the tab flush with the top surface of the cap, the dimensions of said tab, said recess and said fulcrum means being so porportioned in respect of the material from which said cap is made that an inward force on the tab at a point corresponding to said deeper portion of at least about four pounds is required to cause the tab to deflect and thus pivot about the fulcrum means, thereby raising at least one edge of the tab above the top surface of the cap to permit swinging the tab to an open, grasping position.

Claim 17

The safety cap and container of claim 14 wherein the upper surface of the inner skirt bead is bevelled, and the junction between the skirt and the tab-carrying member also has a bevelled surface, the angles of each of said bevelled surfaces being approximately equal, thereby rendering the cap more difficult to remove from the container except by use of the pull tab.

Claim 18

A safety closure made of plastic and a container combination wherein the container includes a round mouth, a first tubular portion extending axially inward from the mouth, and a stop means within the first tubular portion spaced from the mouth; and the safety closure comprises a round body with a flat top surface, the body fitting within the first tubular portion of the container against the stop means and having an integral pull tab mounted within a recess in its top surface and swingable about a hinged connection at one end to an open, grasping position, all edges of the tab being in close-fitting abutment to the edges of the recess when the tab is shut with tongue and groove interengagement means provided between the tab and at least one surface of the recess to hold the tab shut, at least a portion of the recess being deeper than the thickness of the tab, and a fulcrum means being located adjacent said deeper portion for supporting the tab, the dimensions of said tab, said recess, and said fulcrum means being so proportioned in respect of the material from which said closure is made that an inward force on the tab at a point overlying the deeper portion of at least about four pounds is required to cause the tab to deflect inward at that point and thus to pivot about the fulcrum means thereby raising an edge of the tab on the other side of the fulcrum means above the top surface of the closure body to permit swinging the tab to the open, grasping position.

Claim 19

A safety closure made of plastic and a container combination wherein the container includes a round mouth, a first tubular portion extending axially inward from the mouth, and a stop means within the first tubular portion spaced from the mouth; and the safety closure comprises a round body with a flat top surface, the body fitting within the first tubular portion of the container against the stop means and having an integral pull tab mounted within a recess in its top surface and swingable about a hinged connection at one end to an open, grasping position, all edges of the tab being in close-fitting abutment to the edges of the recess when the tab is shut with tongue and groove interengagement means provided between the tab and at least one surface of the recess to hold the tab shut, at least a portion of the recess being deeper than the thickness of the tab, and a fulcrum means being located adjacent said deeper portion for supporting the tab, the dimensions of said tab, said recess, and said fulcrum means being so proportioned in respect of the material from which said closure is made that an inward force on the tab at a point overlying the deeper portion of at least about four pounds is required to cause the tab to deflect inward at that point and thus to pivot about the fulcrum means thereby raising an edge of the tab on the other side of the fulcrum means above the top surface of the closure body to permit swinging the tab to the open, grasping position.

Claim 20

The safety closure and container combination of claim 17 wherein said required force is in the range from about 4 to 12 pounds.

Claim 21

The combination of claim 16 wherein the stop means in the container comprises an annular ledge, a second tubular portion of reduced diameter, coaxial with the first tubular portion, extending from the inside circumference of the ledge away from the mouth; and the safety closure further comprises a cylindrical portion of reduced diameter depending from the body for fitting in removable sealing engagement within the second tubular portion of the container.

Claim 22

The combination of claim 18 additionally including means for bleeding air from said container when said safety closure is fitted thereon.