Vehicle Seat Trigger Mechanism for Lap Belt Anti-Submarining
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Solution Overview
Problem
Existing vehicle seats do not effectively prevent submarining during collisions, which increases the likelihood of serious injury due to the occupant sliding under the lap belt.
Innovation Solution
A seat frame with a flexible mat and trigger mechanism that responds to forward force by rotating a cross tube upward and rearward, preventing the occupant from slipping under the lap belt by altering the position of the seat structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional rigid seat structure is used, then structural strength is maintained, but the ability to adapt to collision forces and prevent submarining is reduced
Solution Approach 1:
The patent applies the dynamics principle by making the seat structure adaptable during collision. The flexible mat and trigger mechanism allow the cross tube to rotate from a horizontal to an elevated position in response to forward collision forces, creating a dynamic response that adapts to the collision scenario to prevent submarining while maintaining structural integrity.
2Reliability
If the cross tube is elevated to prevent submarining, then occupant security is improved, but the device complexity increases due to trigger mechanism
Solution Approach 1:
The trigger mechanism is designed to be self-activating through the flexible mat that detects forward forces and automatically triggers the cross tube rotation. This self-service approach eliminates the need for external sensors, control systems, or power sources, achieving occupant security enhancement while minimizing device complexity.
3Measurement precision
If a flexible mat is used to detect forward force, then response accuracy to collision is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent utilizes a flexible mat constructed from flexible material that detects forward forces through its deformation characteristics. This approach provides adequate collision detection capability through the mat's inherent flexibility and force transmission properties, avoiding the need for high-precision manufacturing tolerances while maintaining effective collision response activation.
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
Reduces the risk of submarining by maintaining the occupant securely in the seat during a collision, enhancing safety by preventing sliding under the lap belt.
Implementation Method 1
A forward force exerted on the flexible mat deforms the bar away from the cam
Implementation Method 2
A forward force exerted on the flexible mat deforms the bar away from the cam allowing rotation of the arms
Data Source
AI summary
A vehicle seat includes an anti-submarining feature which enhances the effectiveness of the lap belt. The seat includes a seat frame with two side rails joined by front and rear tubes. A trigger mechanism includes two arms pivotably supported by the front tube. The two arms support a cross tube. A flexible mat is supported by the cross tube and the rear tube. In normal operation, the arms are prevented from rotating about the front tube by cam lobes which contact a trigger rod. In a front collision, the occupant's inertia, acting through the flexible mat, deforms the trigger rod releasing the trigger mechanism. The cross tube pivots upward and rearward. A missile portion of the flexible mat moves downward.