Child resistant closure

Abstract: A child resistant closure comprising outer (11) and inner (12) nested closure members each of which has a base wall (19,21) on a peripheral skirt with sets of lugs (18,17) on the inner surface of the outer closure member and on the outer surface of the inner closure member which are adapted to be engaged when the members are moved axially toward one another. The outer surface of the base wall of the inner closure member is provided with a plurality of ramps (20) and depressions (23) and the inner surface of the base wall of the outer closure member is formed with a plurality of integral spring fingers (22). When the closure is applied, the springs fingers (22) engage the depressions (23) and orient the outer closure member and inner closure member preventing inadvertent engagement of the lugs (17,18) by any top load. When the outer closure member (11) is rotated relative to the inner closure member (12) without bringing the lugs thereof into engagement, the spring fingers slip over the ramps allowing the outer closure member to rotate with respect to the inner closure member.

Description: This invention relates to child resistant closures. Background and Summary of the Invention Child resistant safety closures comprising two nested closure members are well known in the art. Typically, the outer and inner closure members are provided with cooperating sets of lugs which engage each other when the outer closure is rotated in the direction to remove the closure. A plurality of spring fingers on the inner surface of the base wall of the outer closure member yieldingly urge the outer closure member away from the inner closure member. In United States Patent 3,857,505, the outer surface of the base wall of the inner closure member is formed with a plurality of ramps and associated tear drop shaped detent projections which are associated with the plurality of spring fingers on the inner surface of the base wall of the outer closure member such that when the outer closure member is rotated relative to the inner closure member in a direction to apply the closure, the spring fingers drivingly engage the ramps, and by virtue of their position between the ramps and the detent projections orient the outer closure member circumferentially relative to the inner closure member to prevent inadvertent engagement of the lugs by any top load. When the outer closure member is rotated in the opposite or unthreading direction, the spring fingers ride over or slip over the detent projections. When the closure is rotated in the unthreading direction and an axial force is applied to the outer closure member the lugs are interengaged to unthread the inner closure member from the container. It has been found that the use of lugs and detent projections on the inner closure member together with the spring fingers limits the number of lugs on the closure members because of the limited vertical space between the closure members. As a result, it is necessary to rotate the outer closure member through a larger arc, sometimes as much as 90° to engage the lugs, necessitating grasping, releasing and regrasping the outer closure member. Among the objectives of the present invention are to provide a child resistant closure which effectively holds the inner and outer closure members out of engagement thereby preventing top load from being applied during shipment of the containers to which the closures have been applied; which provides for a greater number of cooperating lugs; which has a lesser height; and which can be readily manufactured. In accordance with the invention there is provided a child resistant closure as set forth in Claim 1. This comprises outer and inner nested closure members each of which has a base wall on a peripheral skirt with sets of lugs on the inner surface of the outer closure member and on the outer surface of the inner closure member which are adapted to be engaged when the members are moved axially toward one another, the peripheral skirt of the inner closure member having means for threaded attachment to a container. The outer surface of the base wall of the inner closure member is provided with a plurality of ramps and recesses and the inner surface of the base wall of the outer closure member is formed with a plurality of integral spring fingers. When the closure is applied to a container, the spring fingers engage in the recesses and orient the outer closure member and inner closure member preventing inadvertent engagement of the lugs by any top load. When the outer closure member is rotated relative to the inner closure member without bringing the lugs thereof into engagement, the spring fingers slip over the ramps allowing the outer closure member to rotate with respect to the inner closure member. Removal of the closure is achieved by axially moving the outer closure member relative to the inner closure member so that the lugs interengage, and rotating the closure. Description of the Drawings FIG. 1 is a fragmentary part sectional view of a package embodying the invention. FIG. 2 is a part sectional elevational view of the outer closure member. FIG. 3 is a part sectional elevational view of the inner closure member. FIG. 4 is a plan view of the inner closure member. FIG. 5 is a fragmentary sectional view on a large scale taken along the line 5-5 of FIG. 4. FIG. 6 is a fragmentary sectional view on a large scale taken along the line 6-6 of FIG. 4. FIG. 7 is a view similar to FIG. 1 showing the closure members in a different operative position. Description Referring to the drawings, the child resistant closure 10 comprises an outer closure member 11 and an inner closure member 12 which are telescoped in assembled relationship with the inner closure member extending into the outer closure member and retained therein by retaining bead 13. The closure is adapted to be applied to the neck of the container C which has threads 14 that are engaged by threads 15 on the inner surface of the peripheral wall 16 of the inner closure member. The inner closure member 12 is formed with a plurality of circumferentially spaced lugs 17 that are adapted to be engaged by lugs 18 on the inner surface of the base wall 19 of the outer closure member. A plurality of ramps 20 are provided in circumferentially spaced relationship on the upper surface of the base wall 21 of the inner closure member 12 and are generally V-shaped. Integral spring fingers 22 extend in circumferentially spaced relation from the inner surface of the base wall 19 of the closure. The aforementioned construction is like that previously described in United States Patent 3,857,505, incorporated herein by reference, and functions such that when the closure is applied to a container, rotation of the outer closure member will cause the spring fingers 22 to engage the ramps 20 (FIG. 1) and rotation in the opposite or unthreading direction will cause the spring fingers 22 to slip over or ride over the ramps 20. When the outer closure member 11 is moved axially toward the inner closure member against the action of the spring fingers 22, the lugs 17, 18 become engaged so that the closure can be unthreaded from the container. In accordance with the invention, a depression or recess 23 that is generally radial is associated with each ramp 20 adjacent its abutting surface 24 so that when the spring fingers 22 are in engagement with the ramps 20, the tips of the fingers 22 extend into the recesses 23 and hold the outer closure member 11 away from the inner closure member 12 and, at the same time orient the outer closure member 11 relative to the inner closure member 12 such that the lugs 18 on the outer closure member 11 are aligned with the lugs 17 on the inner closure member 12 and prevent any top load on the package from being applied to spring fingers 22. When the outer closure member 11 is rotated in unthreading direction and at the same time forced axially toward the inner closure member 12, the lugs 18, 17 become engaged so that the closure can be removed from the container. By providing depressions 23 instead of tear drop shaped projections of the type set forth in the aforementioned United States Patent 3,857,505, the height of the ramps 20 is reduced and the reverse ratchet torque is reduced. In addition by omitting tear drop shaped projections, the number of lugs 18, 17 on the outer closure member 11 and inner closure member 12 may be increased, herein shown as eight in number, because there is sufficient room provided for the fingers 22 to be depressed without the vertical height restriction that is normally formed by the tear drops projecting upward. The height of the ramps 20 is approximately equal to the thickness of the tip of the spring fingers 22. Because of the depression 23, the height of the ramps 20, with respect to the base wall 21, may be reduced without reducing the contact areas between the spring fingers 22 and the ramps 20. It can thus be seen that there has been provided a child resistant closure which effectively holds the inner and outer closure members out of engagement thereby preventing top load from being applied during shipment of the containers to which the closures have been applied; which provides for a greater number of cooperating lugs; which has a lesser height; and which can be readily manufactured.

Claims: A child resistant closure comprising outer (11) and inner (12) nested closure members, each of which has a base wall (19, 21) on a peripheral skirt with sets of lugs (18, 17) on the inner surface of the outer closure member (11) and on the outer surface of the inner closure member (12) which are adapted to be engaged when the members (11, 12) are moved axially toward one another, the peripheral skirt of the inner closure member (12) having means (15) for threaded attachment to a container (C), the inner surface of the base wall (19) of the outer closure member (11) being formed with a plurality of integral spring fingers (22) yieldingly urging said outer closure member (11) away from said inner closure member (12), and said outer surface of the base wall (21) of the inner closure member (12) being provided with a plurality of ramps (20), characterised in that said outer surface of the base wall (21) of the inner closure member (12) is also provided with a plurality of recesses (23), each said ramp (20) including a ramp surface extending axially outwardly from the outer surface of the base wall (21) of said inner closure member (12) and having an abutting surface (24) extending axially inwardly below the outer surface of the inner closure member (12) and being adapted to be engaged by the ends of the spring fingers (22), each said recess (23) being associated with an adjacent ramp (20) and including an inclined surface extending axially inwardly from said outer surface (21) of said inner closure member (12) to said abutting surface (24) of said ramp (20) to form said recess (23), said ramps (20) and recesses (23) being constructed and arranged such that (i) when the closure (10) is rotated to apply the closure, the spring fingers (22) engage the abutting surface (24) and engage the recesses (23) to orient the outer closure member (11) and inner closure member (12) such that the lugs (18) on the outer closure member (11) are aligned with the lugs (17) on the inner closure member (12) to prevent inadvertent engagement of the lugs (17, 18) by any top load, (ii) when the outer closure member (11) is rotated relative to the inner closure member (12) in the closure removing direction without bringing the lugs (17, 18) thereof into engagement, the spring fingers (22) slip over the ramps (20) and the recesses (23) and allow the outer closure member (11) to rotate with respect to the inner closure member (12), and (iii) when the outer closure member (11) is rotated relative to the inner closure member (12) in the closure removing direction and moved axially relative to the inner closure member (12), the lugs (17, 18) are brought into engagement so that the closure (10) can be removed from the container (C). A child resistant closure as claimed in claim wherein the height of said abutting surfaces (24) is approximately equal to the thickness of the tip of the spring fingers (22). A child resistant closure as claimed in claim 1 or 2 wherein said recesses (23) extend generally radially. A child resistant closure as claimed in any one of claims 1-3 wherein each said lug (17, 18) is located at less than 90° relative to an adjacent lug. A child resistant closure as claimed in any one of claims 1-3 wherein each said closure member (11, 12) has a greater number of lugs (17, 18) than ramps (20) or spring fingers (22).

Inventors: KUSZ MAXIMILLIAN, KUSZ, MAXIMILLIAN
Applicants: OWENS ILLINOIS CLOSURE INC, OWENS-ILLINOIS CLOSURE INC.,
Application year: 1991
Main classification: B65D55
IPC codes: B65D41, B65D50