Vehicle Seat Pull-Strap Assembly With Pulley Force Reduction
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Solution Overview
Problem
Existing vehicle seat recline mechanisms require significant manual force to release and pivot the seat back, often using cumbersome lever designs that are costly and complex, lacking mechanical advantage and efficiency.
Innovation Solution
A pull-strap assembly with a clevis and pulley system that reduces the force needed to actuate the recline mechanism, utilizing a tension member and pulley to pivot the seat back, providing a mechanical advantage and simplifying the design by eliminating the need for traditional levers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional lever designs are used to actuate the recline mechanism, then the seat back can be released and pivoted, but significant manual force is required and the design becomes cumbersome and complex
Solution Approach 1:
A cable system is introduced as an intermediary between the user's pulling action and the recline mechanism. The cable transmits force from the pull strap through a clevis assembly to the recline mechanism, replacing the need for direct lever manipulation and reducing the effort required by the user.
Solution Approach 2:
The actuation system is divided into separate functional components: a pull strap for user input, a cable for force transmission, a clevis assembly for connection and movement, and the recline mechanism itself. This segmentation allows each component to be optimized independently and simplifies the overall design compared to a monolithic lever system.
2Ease of manufacture
If traditional lever designs are used to actuate the recline mechanism, then the seat back can be released, but the design becomes costly and complex
Solution Approach 1:
The invention uses simple, easily manufactured components such as cables, straps, and basic metal fittings in the clevis assembly. These components can be produced through standard manufacturing processes at low cost, replacing expensive and complex lever mechanisms that require precision machining and assembly.
Solution Approach 2:
The complex lever mechanism is extracted and replaced with a simpler cable-pulley system. The essential function of force transmission is maintained while removing the cumbersome lever components, thereby reducing manufacturing complexity and cost.
3Force
If a pulley system is introduced to reduce manual force, then mechanical advantage is achieved, but the device complexity increases
Solution Approach 1:
The clevis assembly is designed to move dynamically along the cable's path of travel rather than being a fixed pivot point. This dynamic configuration allows the clevis to follow the cable's movement, maintaining mechanical advantage throughout the actuation stroke while keeping the overall system simple and adaptable.
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 pull-strap assembly reduces the manual force required to release the recline mechanism, offering a cost-efficient, compact, and efficient solution that streamlines the actuation process while protecting the pull strap and maintaining mechanical efficiency.
Implementation Method 1
A pulley is rotatably supported on the axle. A tension member has a fixed end connected to an anchor, an intermediate portion trained around the pulley, and a free end disposed outside of the housing and configured to be pulled by a user, wherein the pulley is configured to rotate about the axle, and the clevis is configured to move along the first axis responsive to movement of the free end away from the housing.
Implementation Method 2
A pull-strap assembly with a clevis and pulley system that reduces the force needed to actuate the recline mechanism, utilizing a tension member and pulley to pivot the seat back, providing a mechanical advantage and simplifying the design by eliminating the need for traditional levers.
Data Source
AI summary
A pull-strap assembly for actuating a recline mechanism of a vehicle seat includes a clevis having first and second pieces configured to snap into one another, wherein the pieces cooperate to define a cylindrical body and a cable connector. The assembly further includes a fixed anchor and a tension member having a fixed end connected to the anchor, an intermediate portion looped around the cylindrical body, and a free end. The clevis is configured to move towards the anchor responsive to the free end being pulled by a user to release the recline mechanism.