Adjustable Tow Hook Assembly With Shear-Pin Collision Retraction
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Solution Overview
Problem
Tow hooks currently mounted on vehicles can cause damage to the vehicle, occupants, or pedestrians during a front-end collision due to their rigid design and fixed positioning, which does not allow for effective absorption of impact forces.
Innovation Solution
A tow hook assembly with a housing and a shear pin that allows the tow hook to move from an extended to a retracted position upon exceeding a predetermined force, minimizing impact with the vehicle or pedestrians by shearing the shear pin and retracting the tow hook into the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tow hook is made rigid and fixed to withstand towing forces, then the towing reliability is improved, but the harm to occupants and pedestrians during collision increases
Solution Approach 1:
The tow hook is designed to be movable rather than fixed, allowing it to dynamically adjust its position based on applied forces. The hook can transition between an extended position (for towing) and a retracted position (for collision safety), resolving the contradiction between needing rigidity for towing and flexibility for safety.
Solution Approach 2:
A shear pin is introduced as an intermediary component between the tow hook and the vehicle frame. The shear pin acts as a force mediator that allows the hook to remain fixed during normal towing forces but shears off when collision forces exceed a threshold, thereby protecting occupants and pedestrians while maintaining towing reliability.
2Ease of operation
If the tow hook is fixed in an extended position to ensure towing functionality, then the ease of operation is improved, but the harmful impact during front-end collision increases
Solution Approach 1:
The tow hook assembly is designed to automatically respond to collision forces without requiring external intervention. When a collision occurs, the shear pin self-actuates by shearing off under excessive force, causing the hook to automatically retract into the housing, thereby eliminating harmful impact forces.
3Stability of the object's composition
If the tow hook is designed to remain secured to the vehicle during towing, then the stability is improved, but the damage to vehicle parts during collision increases
Solution Approach 1:
The connection between the tow hook and vehicle frame is segmented into two functional parts: the shear pin (sacrificial element) and the housing (permanent structure). The shear pin is designed to fail at a predetermined force threshold, allowing the hook to detach from the secured position and retract, thereby protecting vehicle parts from damage while maintaining stability during normal towing.
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 adjustable tow hook assembly reduces the risk of injury to occupants, pedestrians, and vehicle components by moving into a retracted position during a front-end collision, thereby minimizing contact and potential damage.
Implementation Method 1
When the tow hook is in the extended position and a force exceeding a predetermined threshold is applied to the leading portion of the receiving member, the shear pin shears to permit the retaining block of the tow hook to within the arcuate interior of the housing and position the tow hook into the retracted position
Data Source
AI summary
A vehicle including a cross member and a tow hook assembly. The tow hook assembly is coupled to the cross member and includes a housing, a tow hook, and a shear pin. The housing includes an arcuate interior. The tow hook is moveable between an extended position and a retracted position. The tow hook includes a retaining block and a receiving member having a distal portion extending from the retaining block and a leading portion extending from the distal portion. The shear pin is positionable to extend through the housing. When the tow hook is in the extended position and a force exceeding a predetermined threshold is applied to the leading portion of the receiving member, the shear pin shears to permit the retaining block of the tow hook to move along the arcuate interior of the housing and position the tow hook into the retracted position.