Resettable Harness Web Tensioning for Adaptive Seat Restraints
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Solution Overview
Problem
Current motor vehicle seat restraint systems lack an efficient mechanism for dynamically adjusting the tension of restraint harnesses in response to varying operating conditions, which can impact occupant safety and comfort.
Innovation Solution
A device comprising an elongated housing with a piston assembly and a biasing member, actuated by a gas reservoir and electronically controlled valve, allows for controlled tensioning and release of the restraint harness through precise movement within the housing, enabling adaptive tension adjustment based on control signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a restraint system includes a tensioning device with piston assembly and gas reservoir, then the ability to dynamically adjust harness tension is improved, but the device complexity increases
Solution Approach 1:
The restraint system employs a piston assembly that can dynamically change position between retracted and extended states, enabling the harness tension to be adjusted in real-time based on vehicle operating conditions. The piston's movable configuration within the housing allows the system to transition between different tensioning states rather than maintaining a fixed tension level.
Solution Approach 2:
The system uses a gas reservoir connected to the piston assembly through a control valve to provide pneumatic actuation. Pressurized gas from the reservoir drives the piston to extend and tension the harness when needed, while the valve controls the timing and duration of gas discharge. This pneumatic mechanism enables dynamic tension adjustment without complex mechanical linkages or electrical motors.
2Adaptability or versatility
If the piston assembly is made resettable with control valve and gas reservoir, then the adaptability to varying operating conditions is improved, but the ease of operation deteriorates
Solution Approach 1:
The system incorporates sensors that detect vehicle operating conditions such as collisions, rapid deceleration, or seatbelt misuse events. These sensors provide feedback signals to the control circuit, which automatically activates the control valve to discharge gas and tension the harness when predefined conditions are met. This closed-loop feedback mechanism eliminates the need for manual operation while enabling responsive adaptation to varying conditions.
Solution Approach 2:
The restraint system is designed to automatically monitor its own operating conditions through integrated sensors and control electronics. When the system detects a tensioning event, it self-actuates by controlling the valve to release gas from the reservoir, thereby tensioning the harness without requiring external manual intervention. The system also automatically resets when conditions return to normal.
3Productivity
If the piston assembly uses biasing member for automatic reset, then the productivity of tensioning operation is improved, but the device complexity increases
Solution Approach 1:
The biasing member (spring) is pre-loaded in a compressed state within the piston assembly, storing elastic potential energy. When the control valve discharges the gas and pressure equalizes, the pre-loaded spring automatically expands, rapidly pushing the piston back to its retracted position and resetting the tensioning mechanism. This preliminary energizing of the biasing member enables quick reset action without requiring additional power sources or complex control mechanisms.
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
This solution enables the restraint system to dynamically adjust tension in response to detected conditions, enhancing occupant safety and comfort by ensuring optimal harness tightness during different vehicle operations.
Implementation Method 1
a biasing member coupled to and between an opposite end of the piston and a respective end of the elongated chamber, the biasing member configured to bias the piston assembly axially along the elongated chamber
Implementation Method 2
an actuator responsive to a first control signal to cause the piston assembly to move from the unactuated position to the actuated position to tension the occupant restraint harness
Data Source
AI summary
An apparatus for tensioning an occupant restraint harness coupled to an occupant seat mountable in a motor vehicle, wherein the occupant restraint harness includes first and second lap webs securable about an occupant of the seat, may include a web tensioning device configured to be attached to a rear side of the occupant seat, the web tensioning device having an actuated state and an unactuated state, and a mechanical movement converter configured to be attached to the rear side of the occupant seat and having an input operatively coupled to the web tensioning device, a first output coupled to the first lap web and a second output coupled to the second lap web, the mechanical movement converter responsive to a transition of the web tensioning device from the unactuated state to the actuated state to simultaneously apply tension to the first and second lap webs.