Child-Resistant Cap for Liquid Medicaments

Abstract

An improved child-resistant closure for dispensers of liquid medicaments, the closure being of a two-part construction. The closure has an outer cap with a quantity of shoulder lugs and skirt lugs and an inner cap with a quantity of shoulder lugs and flexible beams. The closure has equal quantities of shoulder lugs on the inner and outer caps, equal quantities of skirt lugs and flexible beams, flexible beams having an arcuate underside, shoulder lugs having a depth to prevent hyper-flexion of the flexible beams, and an ideal overlap when the faces of the shoulder lugs are aligned. Additionally, provided are methods for attaching and removing the cap from a pre-existing bottle.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application 61 / 671,194 filed on Jul. 13, 2012, which is incorporated herein in its entirety.FIELD OF THE INVENTION[0002]The invention relates to improvements to child-resistant closures for dispensers of liquid medicaments, in particular dispensers of liquid ophthalmic and nasal medicaments, and thereby provides enhanced safety of the dispensers by making the contents of the containers less susceptible to access by children.BACKGROUND OF THE INVENTION[0003]Child-resistant caps for medicaments have been known in the art for nearly fifty years. These caps generally require two opposed movements acting at the same time to overcome the locking mechanism. For example, one type of cap requires a user to squeeze the cap at specific points, causing a deformation, and then to rotate the cap. If either the squeezing or rotating step is not performed, the cap cannot be opened. Another common metho...

AI Technical Summary

Benefits of technology

[0010]The present invention provides an improved child-resistant closure for liquid ophthalmic and nasal medicaments, as well as a system for providing child-resistant closure of an existing bottle, and a method of application and removal, providing ease of application during the bottling phase and enhanced child-resistant properties once the apparatus and system have been distributed to an end user.

[0011]One embodiment of the closure provides for a cap with matching numbers of complementary lugs and beams, with the flexible beams having an angled ridge with an arcuate underside. Additional embodiments of the closure include the requirement that an underside of an upper lug overlap a lower flexible beam by a predetermined distance or range of distances when the lug faces of upper lugs are properly aligned. These embodiments improve upon the reliability of a child-resistant closure by ensuring that it is only engaged when properly aligned, providing ideal frictional contact, and preventing undue stress upon the flexible beams when a downward force has been applied to them. Additional embodiments include modifications to a top portion of the cap, wherein one embodiment provides for a flat top and an alternative embodiment provides for a shaped top, complementary to the shape of a dispenser of liquid medicaments, to minimize the internal volume available for unintentional pooling of excess medicament.

[0012]An additional embodiment of the invention is a system in which flexion of the flexible beams is limited such that the beam head does not extend below the beam base of an adjacent flexible beam. By limiting such flexion, the beams are not damaged by hyper-flexion. The prior art does not address this issue, and by permitting beams to be unnecessarily hyper-flexed, the resiliency of the beam is decreased, often to the point where no downward force is necessary to engage the lugs of the cap, and the child-resistant nature of the cap has been eliminated.

[0013]The final embodiments of the invention relate to methods for attaching and removing the closure from a bottle containing liquid medicaments. In one embodiment, the steps of applying a downward force and rotating the outer cap are sequential. In another embodiment, the steps are simultaneous. However, the present invention advantageously eliminates the requirement of a constant downward force, such elimination being beneficial for elderly populations or those with arthritis. The final embodiment of the invention relates to the manner in which the invention is affixed to a bottle containing liquid medicaments. In this embodiment, no downward force is necessary. As a result, the present method is advantageous in that it does not require a re-tooling of present cap-applying machinery which lack the ability to exert a downward force. By providing for a method in which no downward force is needed, not only are more machines capable of affixing the cap to the bottle, but there is also a reduction in the likelihood of damage to the flexible beams due to miscalibrations in the amount of downward force required.

Problems solved by technology

If either the squeezing or rotating step is not performed, the cap cannot be opened.

However, several issues arose with implementation of prior art caps.

This lack of engagement allowed for slippage during the rotational process, which can lead to damage to the lugs, beams, and fingers of both the outer and inner caps.

Such damage often manifested itself in the form of stripping of the lugs, beams, and fingers.

However, the application of this downward force would often result in additional damage to the lugs, beams, or fingers.

This angled underside presented problems in that it would concentrate flexion at a very specific point which would often weaken the lug, beam, or finger.

When excess force is applied to flexible lugs, beams, or fingers, they are often forced to flex beyond their capabilities.

This hyper-flexion can result in a permanent deformation and even complete breakage of the lugs, beams, or fingers.

In lugs, beams, or fingers having an angled underside, breakage often occurred immediately above the angle.

Therefore, the cap is no longer child-resistant.

However, a major complaint of child-resistant caps has been that they are difficult for the elderly and infirm to remove.

With free-floating caps, the elderly often have a difficult time applying the appropriate amount of downward force necessary to get the appropriate lugs, beams, or fingers to engage.

Similarly, the elderly often have a difficult time maintaining the appropriate downward force throughout the rotational movement.

When applied to prior art caps, this lack of coordination and partial engagement would result in frustration on the part of the user.

Redoubled efforts often resulted in damage to the elements of the cap, through the combination of improper alignment and application of excess force, albeit briefly applied.

Additionally, when excess force is applied to a misaligned cap, portions of the cap may jam, requiring additional unconventional movements to clear the jam.

These unconventional movements may damage the cap, again leading to decreased, if not eliminated, child-resistance.

Similarly, an additional problem of prior art caps is that they require a downward force to apply them to a pre-existing bottle.

This is especially important to manufacturers, as machines capable of applying a downward force are more expensive than those which only apply a rotational force.

Work-arounds have been designed, however they are expensive and can often involve re-tooling of a machine, at a cost which eats into the profit margin of the manufacturer.

If the machine ventures too far beyond these tolerances, excess downward force may be applied to the cap as it is being affixed to the pre-existing bottle, and damage to the lugs, beams, and fingers may result.

The prior art caps are prone to damage resulting in loss of child-resistant qualities, and further, may unintentionally provide access to significant amounts of residual liquid medicament stored in the removed cap.

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