Airbag Tether Release Using Integrated Squib Actuation
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Solution Overview
Problem
Existing airbag tether release systems are often bulky, expensive, and overly complex, making them unsuitable for certain driver airbag package designs due to size and weight constraints.
Innovation Solution
A compact pyrotechnic device, such as a squib, is integrated into an airbag housing with a tab opening and tether opening, allowing the squib to separate and release the tether upon actuation, with a weakened portion facilitating separation and a locking mechanism to retain the squib components within the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pyrotechnic device is used to trigger a piston that cuts a tether, then the tether release function is achieved, but the system becomes bulky and expensive
Solution Approach 1:
The patent extracts the cutting function from a separate piston mechanism and integrates it directly into the pyrotechnic device. The pyrotechnic device itself performs the cutting action through its expanding gases, eliminating the need for a separate piston and cutter assembly. This reduces system size and complexity while maintaining the tether release function.
Solution Approach 2:
The patent merges the pyrotechnic actuation function and the tether cutting function into a single integrated device. The pyrotechnic charge, when activated, directly generates the force needed to cut the tether through the integrated cutting edges, combining multiple functions into one compact unit rather than using separate components.
2Reliability
If existing tether release systems are used, then tether release is achieved, but the system is unnecessarily complicated and heavy
Solution Approach 1:
The patent segments the tether release system into minimal essential components: the pyrotechnic device with integrated cutting edges and the tether itself. By eliminating intermediate components like separate pistons, linkages, and cutter assemblies, the system achieves the required function with minimal complexity while maintaining reliability.
Solution Approach 2:
The pyrotechnic device is designed to be self-contained and self-actuating. Upon ignition, the pyrotechnic charge automatically generates the expanding gases that directly perform the cutting action through integrated edges, without requiring external actuators, linkages, or additional mechanical components to transmit the force.
3Volume of moving object
If a compact pyrotechnic device is used, then system size is reduced, but the squib must be retained within the housing after actuation
Solution Approach 1:
The patent designs the airbag housing with an integrated recess or cavity that receives and retains the pyrotechnic device after actuation. The housing structure itself provides the retention mechanism, with the recess acting as a nested space that accommodates the squib in its post-deployment state, preventing it from becoming a foreign object hazard while maintaining compact overall dimensions.
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 solution provides a lightweight, cost-effective, and simplified tether release system that allows for efficient deployment of airbags while maintaining structural integrity and reducing unnecessary components.
Implementation Method 1
the actuator may comprise a pyrotechnic device. In some such embodiments, the pyrotechnic device may comprise a squib
Implementation Method 2
the actuator/squib may comprise a weakened portion configured to facilitate separation of the actuator/squib into at least two separate portions upon actuation
Data Source
AI summary
Airbag cushion assemblies comprising tether release functionality. Some embodiments may comprise an airbag housing comprising an airbag housing opening configured to receive a squib. An airbag cushion may be coupled with the airbag housing and a tether comprising a tether opening may be coupled with at least a portion of the airbag cushion. A squib may be positioned to extend through the tether opening and positioned within the airbag housing opening. The squib may be configured to, upon actuation, separate to release the tether.