Vehicle Belt Retractor Movable Detent for Rotation Control
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Solution Overview
Problem
Existing belt retractors for vehicle safety belts have limitations in the relative rotation between the belt spool and locking disc, restricting the maximum forward movement of vehicle occupants during deceleration, and require a pin and detent arrangement that geometrically limits the rotation to a specific angle range, which is not sufficient for greater flexibility.
Innovation Solution
A movable detent is integrated into the belt spool, allowing adjustable positioning to increase the permissible angle range for relative rotation between the belt spool and locking disc, enabling more than one revolution without the need for a 360-degree groove on the locking disc, thereby enhancing strength and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pin and detent arrangement is used to limit relative rotation between belt spool and locking disc, then rotation limitation is maintained, but the permissible angle range is restricted to less than 360 degrees
Solution Approach 1:
The detent is made movable relative to the belt spool, allowing its position to change dynamically. This enables the detent to engage with different portions of the locking disc, thereby increasing the permissible angle range beyond the fixed limitation of previous designs while maintaining reliable rotation limitation through the energy absorption element.
2Adaptability or versatility
If the permissible angle range is increased to allow greater relative rotation, then flexibility is improved, but the strength of the locking disc may be compromised
Solution Approach 1:
The movable detent engages with a localized region of the locking disc rather than requiring a 360-degree groove, maintaining the structural integrity and strength of the locking disc while enabling greater permissible angle range through the dynamic positioning capability.
3Adaptability or versatility
If a 360-degree groove is provided on the locking disc for the detent, then maximum angle range is achieved, but manufacturing complexity and reduced strength result
Solution Approach 1:
The movable detent achieves an effective 360-degree or greater angle range without requiring a continuous 360-degree groove on the locking disc. The detent moves to different positions during operation, engaging with different portions of the locking disc, thereby simplifying manufacturing while maintaining maximum angle range capability.
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 allows for a greater relative rotation between the belt spool and locking disc, increasing the permissible angle range and maintaining reliable rotation limitation, resulting in improved safety belt functionality and strength without the constraints of prior art designs.
Implementation Method 1
the energy absorption element makes possible a relative rotation between the belt spool and the locking disc when a particular traction force is exceeded in the safety belt
Implementation Method 2
a detent is provided, which is arranged movably in the belt spool and can prevent a rotation of the locking disc relative to the belt spool as a function of its position
Data Source
AI summary
A belt retractor for a vehicle safety belt has a frame, a belt spool for the safety belt which is rotatably arranged in the frame, a locking disc which is arranged on the belt spool and is connected therewith through an energy absorption element, and a blocking mechanism which allows to block the locking disc against a rotation in the unwinding direction of the safety belt in the frame. A detent is provided which is movably arranged in the belt spool and can prevent a rotation of the locking disc relative to the belt spool as a function of its position.