Retractable Vehicle Seat Cam Release Mechanism
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Solution Overview
Problem
Conventional retractable vehicle seats face issues with inconsistent cable stroke lengths due to variations in component sizes and assembled positions, leading to unreliable unlocking of the reclining device when the seat is moved to its retracted position.
Innovation Solution
A retractable vehicle seat design where a release device is positioned at the proximal end of the first leg, using a cam to pull a cable and unlock the reclining device based on the rotation of the first leg, independent of the interlocking member and second leg, thereby ensuring reliable unlocking and reducing cable length requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cable is coupled to the upper end of the front leg and pulled through rotation of the front leg, then the reclining device can be unlocked, but the cable stroke amount becomes insufficient due to variations in component sizes and assembled positions
Solution Approach 1:
A release device is introduced as an intermediary mechanism between the first leg rotation and the cable pulling action. This release device includes a cam that converts the rotational movement of the first leg into linear cable pull, ensuring sufficient and consistent cable stroke regardless of variations in the interlocking member or second leg dimensions.
Solution Approach 2:
The cam mechanism changes the movement parameter from rotational displacement to linear displacement, amplifying the effective cable stroke. By designing the cam with appropriate curvature radius and lift, the system ensures that the cable is pulled by a sufficient amount even when the first leg rotates through a limited angle.
2Length of moving object
If the release device is provided at the distal end of the first leg, then the cable stroke may be increased, but the cable length becomes excessive and the system becomes more complex
Solution Approach 1:
The cam mechanism utilizes a curved surface (spheroidal geometry) to convert rotational motion into linear motion. This curvature allows the release device to be positioned at the proximal end of the first leg while still achieving sufficient cable stroke, as the cam's rotational lift accumulates along its curved surface.
3Reliability
If the cable stroke is increased to ensure reliable unlocking, then the reclining device can be consistently unlocked, but the risk of excessive cable pull and potential damage increases
Solution Approach 1:
The cam mechanism provides inherent feedback control: as the first leg rotates and the cam pushes the cable, the cable tension increases progressively. Once the reclining device is unlocked, the cable becomes taut and prevents further pull, automatically limiting the stroke to the exact amount needed for unlocking without excessive force.
Solution Approach 2:
The cam is designed with a controlled lift profile that delivers the cable pull in a predetermined sequence. The curvature of the cam surface ensures that the cable is pulled by the exact amount needed to unlock the reclining device, no more and no less, preventing excessive force application.
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 reliably releases the reclining device by decoupling it from variations in component sizes and positions, ensuring consistent operation and reducing the risk of damage by limiting excessive cable pull through a restriction device.
Implementation Method 1
The release device may include a cam that is secured to the proximal end of the first leg. The cam is formed with a curved surface that curves the cable when the first leg is rotated with respect to the seat cushion.
Data Source
AI summary
A retractable seat for a vehicle includes: a first leg with a proximal end that is rotatably attached to a seat cushion and a distal end that is rotatably attached to a floor; a second leg that is rotatably attached to the seat cushion; and an interlocking member that couples the first leg to the second leg so that the second leg is move in accordance with movement of the first leg. Rotating the first leg with respect to the floor moves the seat cushion from a use position to a retracted position. The rotation of the second leg through the interlocking member, from a position at which a second leg stands upright with respect to the seat cushion to a position which the second leg extends along the seat cushion.