Frangible Detent Pin for High Holding Strength and Easy Release
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Solution Overview
Problem
Conventional spring-loaded detent pins are limited in securely holding parts together due to the force required to retract the pin head into the bore, which can exceed the shear strength of the parts or be hindered by friction, necessitating additional mechanisms for secure positioning and movement.
Innovation Solution
A frangible detent pin with a base, pin head, and elastic member, transitioning from a rigid to a spring-loaded stage when a compression load exceeds a predetermined threshold, allowing secure holding and movement without additional mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the outward bias of the pin head is increased to hold parts more securely, then the holding strength is improved, but the lateral force required to depress the pin head increases and may exceed the shear strength of the parts
Solution Approach 1:
The detent pin transitions from a static spring-loaded design to a dynamic frangible design where the connection between pin head and base can change state. The pin operates in two distinct modes: rigid stage for strong holding, and spring-loaded stage for easy release, allowing optimal performance in both states without compromise.
Solution Approach 2:
The invention changes the structural parameter of the pin connection from permanently rigid to conditionally frangible. The frangible connection allows the pin to transition between rigid and flexible states based on applied load, fundamentally altering the force-displacement characteristics to resolve the contradiction between holding strength and release force.
2Force
If the angle of the inclined plane is decreased to reduce the lateral force required to depress the pin head, then the lateral force is reduced, but the axial force required to hold the parts increases
Solution Approach 1:
The frangible connection enables the pin to dynamically adjust its mechanical characteristics. In the rigid stage, the full axial force is transmitted for secure holding. In the spring-loaded stage, the spring absorbs axial force while allowing lateral movement, eliminating the need to compromise the inclined plane angle.
Solution Approach 2:
The frangible connection acts as an intermediary mechanism between the pin head and base. It transmits forces differently depending on its state: rigidly transmitting both axial and lateral forces during holding, and allowing independent spring-loaded response during release, thereby decoupling the conflicting force requirements.
3Force
If a conventional spring-loaded detent pin is used, then the pin can be easily depressed with low lateral force, but the holding strength is insufficient and may require additional mechanisms
Solution Approach 1:
The detent pin transitions from a static spring-loaded design to a dynamic frangible design where the connection between pin head and base can change state. The pin operates in two distinct modes: rigid stage for strong holding, and spring-loaded stage for easy release, allowing optimal performance in both states without compromise.
Solution Approach 2:
The invention changes the structural parameter of the pin connection from permanently rigid to conditionally frangible. The frangible connection allows the pin to transition between rigid and flexible states based on applied load, fundamentally altering the force-displacement characteristics to resolve the contradiction between holding strength and release force.
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 secure positioning and transition between configurations without secondary restraints, maintaining structural integrity and facilitating movement by altering the spring constant based on the frangible connection's status, thus overcoming the limitations of conventional detent pins.
Implementation Method 1
an elastic member configured to bias the pin head away from the base
Data Source
AI summary
A frangible detent pin comprising a base a pin head and an elastic member. The base is configured to be secured within a bore. The pin head and the base are interconnected through a frangible connection. The elastic member is configured to bias the pin head away from the base. The frangible detent pin has a rigid stage in which the pin head is rigidly positioned relative to the base and a spring-loaded stage in which the pin head is moveable relative to the base under a compression load between pin head and the base. The frangible detent pin is configured to transition from the rigid stage to the spring-loaded stage in response to the compression load exceeding a predetermined threshold sufficient to cause the frangible connection to fail.