Deformable Slot Seat Belt Buckle for Crash Load Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current seat belt systems lack an effective load limiting mechanism to manage occupant movement during a crash event, which can lead to injuries from excessive force distribution across the chest and shoulders.
Innovation Solution
A seat belt buckle assembly with a deformable slot and rivet system, where the slot plastically deforms in response to impact forces, allowing the buckle housing and plate to translate relative to the bracket, incorporating a retractor pretensioner and locking feature to control movement and absorb energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the seat belt system uses a rigid connection between the buckle housing and bracket, then the structural strength is improved, but the occupant may suffer injuries from excessive force during a crash event
Solution Approach 1:
The slot in the plate is designed to change its mechanical properties under load. During normal operation, the slot maintains a rigid connection. During a crash event, the slot plastically deforms, changing from a rigid state to a deformable state, allowing the buckle housing to translate relative to the bracket and limit the force transmitted to the occupant
Solution Approach 2:
The connection between the buckle housing and bracket transitions from a static rigid connection to a dynamic deformable connection during a crash event. The slot's ability to plastically deform allows the system to adapt its mechanical properties in response to impact forces, enabling controlled movement to protect the occupant
2Ease of manufacture
If the plate and bracket are made from the same material, then the manufacturing process is simplified, but the load limiting performance is reduced
Solution Approach 1:
The plate and bracket are made from different materials with complementary properties. The plate (containing the slot) is made from a material with higher ductility or lower yield strength to enable plastic deformation, while the bracket is made from a stronger, stiffer material to maintain structural integrity. This composite material approach enables effective load limiting while maintaining manufacturing feasibility
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
The assembly effectively limits the forward movement of the occupant during a crash, reducing the risk of injury by absorbing energy and preventing submarining, while maintaining sufficient room to prevent harm to the chest and upper body.
Implementation Method 1
the slot plastically deforms, permitting the buckle housing and plate to translate relative to the bracket
Implementation Method 2
incorporating a retractor pretensioner and locking feature to control movement and absorb energy
Data Source
AI summary
A seat belt buckle assembly includes a buckle housing; a plate extending from the buckle housing and defining a slot; and a bracket including a rivet engaged in the slot. The plate and rivet are configured such that, in response to an impact force that exceeds a threshold acting to pull the buckle housing away from the bracket, the slot plastically deforms, permitting the buckle housing and plate to translate relative to the bracket.