Bistable Snap-Action Child-Resistant Closure
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Solution Overview
Problem
Existing child-resistant closures are complex, expensive, and difficult for users to convert between child-resistant and non-child-resistant modes of operation, potentially impeding access for adults with reduced manual dexterity.
Innovation Solution
A child-resistant closure featuring a one-piece plastic shell with a bistable snap-action toggle connection between the base wall and annular skirt, allowing the skirt to move between two stable positions for selecting between child-resistant and non-child-resistant modes, with indicia for mode indication and lug arrangements for engagement with container projections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If child-resistant closures are designed to impede opening by children, then child safety is improved, but opening difficulty for adults with reduced manual dexterity increases
Solution Approach 1:
The closure incorporates a convertible mechanism that dynamically changes its operational mode between child-resistant and adult-accessible configurations. The closure can be inverted or converted between modes, allowing it to adapt its resistance characteristics based on user needs, thus resolving the contradiction between child safety and adult accessibility.
Solution Approach 2:
The closure mechanism changes its operational parameters by inverting or converting between two stable positions. This parameter change allows the closure to switch between providing high resistance to children and providing easy access to adults, effectively resolving the safety versus accessibility contradiction.
2Ease of operation
If child-resistant closures are designed with conversion capability between modes, then accessibility for adults is improved, but device complexity increases
Solution Approach 1:
The closure combines multiple functions (child-resistant mode and adult-accessible mode) into a single integrated structure. The convertible mechanism merges the two operational modes within one closure body, reducing the need for separate closures for different user groups and thereby managing complexity.
Solution Approach 2:
The closure is designed as a universal mechanism that performs multiple functions: it operates as a child-resistant closure in one mode and as an easily accessible closure in another mode. This multi-functionality eliminates the need for different closures for different user groups, managing complexity through design efficiency.
3Adaptability or versatility
If child-resistant closures are made convertible between modes, then user versatility is improved, but manufacturing cost increases
Solution Approach 1:
The closure structure is segmented into distinct functional components that can independently operate in different modes. The convertible mechanism is divided into modular elements (such as the skirt, base wall, and toggle connection) that can be manufactured separately and assembled, facilitating cost-effective production of the versatile closure.
Solution Approach 2:
The closure achieves versatility through parameter changes rather than through completely different structures for each mode. By using a single structure that can change its operational parameters (inverting or converting between positions), the manufacturing cost is reduced compared to producing separate closures for different modes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables easy and user-selectable conversion between child-resistant and non-child-resistant modes, ensuring safe access for both children and adults with reduced dexterity while maintaining the safety features of child-resistant designs.
Implementation Method 1
a bistable snap-action toggle connection between the peripheral edge of the base wall and the skirt such that the skirt is adapted to be moved between two stable positions with respect to the base wall
Data Source
AI summary
A child-resistant closure includes a one-piece plastic shell having a base wall with a peripheral edge, an annular skirt, and a bistable snap-action toggle connection between the peripheral edge of the base wall and the skirt such that the skirt is adapted to be moved between two stable positions with respect to the base wall. At least one lug is disposed on the skirt or the base wall for engagement with cooperating structure in a child-resistant mode of operation in a first position of the skirt with respect to the base wall. The skirt is movable with respect to the base wall between the first position and a second positions for selecting between the child-resistant and the non-child-resistant modes of operation of the closure. The bistable snap-action connection preferably includes a continuous annular wall connecting the peripheral edge of the base wall to the skirt, with the annular wall being outwardly conical in one position of the skirt and inwardly conical in the other position of the skirt with respect to the base wall.