Vehicle Seat Hinge Mechanism with Nested Biasing Spring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seat hinge mechanisms are not compact enough for integration within vehicle seats and lack adequate safety features, with external springs complicating the design.
Innovation Solution
A hinge mechanism with a second spring housed between the hinge plates, independently biasing the drive shaft and control member, allowing for compact design and secure locking without external springs, featuring a drive shaft with an internal hub and connecting rod for manual assembly and robust operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the second spring is housed externally to the hinge mechanism, then the spring can bias the drive shaft against an abutment, but the axial dimensions of the hinge mechanism increase and integration within the seat becomes difficult
Solution Approach 1:
The second spring is nested within the hinge mechanism by housing it between the first and second hinge plates. The spring is received in a recess formed in the first hinge plate, allowing it to be contained within the internal space of the mechanism rather than extending externally, thus reducing axial dimensions and facilitating integration.
Solution Approach 2:
The spring arrangement transitions from an external axial extension to an internal configuration utilizing the radial and thickness dimensions of the hinge plates. The recess in the first hinge plate accommodates the spring in a direction perpendicular to the main biasing direction, effectively using three-dimensional space optimization.
2Reliability
If the drive shaft and control member are coupled together, then the control member can be actuated directly, but the mechanism cannot maintain secure locking when no stresses are applied on the handle
Solution Approach 1:
The drive shaft is decoupled from the control member, creating two independent but coordinated components. The drive shaft is biased to a rest position by the second spring, while the control member is biased to a locking position by the first spring. This segmentation allows each component to maintain its own biasing and locking characteristics independently.
Solution Approach 2:
The cam profile acts as an intermediary that translates the rotation of the drive shaft into the movement of the control member. The cam converts rotational motion into the linear or angular motion required to actuate the locking elements, mediating between the decoupled drive shaft and control member.
3Ease of operation
If the locking elements are held in locking position by spring bias alone, then secure locking is achieved, but the mechanism cannot be actuated by manual input
Solution Approach 1:
The control member transitions from a static spring-biased locking position to a dynamic state during actuation. When the user rotates the drive shaft, the cam profile dynamically moves the control member against the spring bias, allowing temporary override of the locking position for adjustment purposes.
Solution Approach 2:
The locking mechanism operates in periodic cycles: the spring maintains the locking position during normal use, and the cam temporarily overrides this position during manual actuation. The periodic engagement and disengagement of the locking elements provides stepwise angular adjustment while maintaining security between adjustments.
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 results in a more compact and safely integrated hinge mechanism that maintains secure locking even without applied stress, enhancing user perception of quality and ease of assembly.
Implementation Method 1
a control member, able to move locking elements which are adapted to immobilize the first hinge plate rotationally relative to the second hinge plate, and biased to a locking position by at least one first spring
Implementation Method 2
a drive shaft, biased to a rest position by at least one second spring
Data Source
AI summary
A hinge mechanism for a motor vehicle seat allowing angular adjustment of a backrest relative to a seating portion. The hinge mechanism includes first and second hinge plates, a control member moving locking elements and biased to a locking position by first springs, and a drive shaft biased to a first rest position by second springs. The second springs are housed between the first and second hinge plates and are supported on the first plate.