Vehicle Armrest Inertia Latch for Collision Locking
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Solution Overview
Problem
Existing vehicle seating assemblies with fold-out armrests do not adequately prevent unintended movement during collisions, posing a safety risk to passengers.
Innovation Solution
An inertia latch system that includes a spin plate, lock plate, and pawl mechanism, which engages to inhibit armrest movement when a predetermined threshold of acceleration is exceeded, ensuring the armrest remains in the up position during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a latch mechanism is added to the armrest to prevent unintended movement, then reliability is improved, but device complexity increases
Solution Approach 1:
The latch mechanism is divided into separate functional components: a latch member with latch surface, a biasing member (spring), and a actuating member. This segmentation allows each component to perform its specific function independently, achieving reliable positioning without requiring a complex integrated mechanism.
Solution Approach 2:
The biasing member automatically returns the latch member to its engaged position after being actuated, providing self-service functionality. The user only needs to initiate the release action, and the spring automatically resets the latch without requiring additional user input or complex control systems.
2Reliability
If a latch mechanism with multiple components is used, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The latch member and actuating member are combined into a single integrated component in many embodiments, reducing the total part count. The actuating member incorporates both the release surface for user interaction and the structural elements that engage with the latch surface, simplifying manufacturing while maintaining reliable positioning.
Solution Approach 2:
The actuating member serves multiple functions: it provides the release surface for user interaction, acts as a lever to disengage the latch, and in some embodiments incorporates the return spring housing. This multi-functionality reduces the number of separate components needed, lowering manufacturing complexity and cost.
3Reliability
If a complex latch mechanism is implemented, then armrest position stability is improved, but ease of operation deteriorates
Solution Approach 1:
The complex internal latch mechanism is extracted and replaced with a simple surface feature on the actuating member that users can easily grasp and press. The complicated spring-latch interaction is hidden inside the armrest housing, exposing only a simple push-button interface to the user, thereby maintaining operational simplicity.
Solution Approach 2:
The actuating member serves as an intermediary between the user's simple pressing action and the complex internal latch mechanism. Users interact with the straightforward surface of the actuating member, while it translates this simple input into the coordinated motion needed to disengage the latch member from the support structure.
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 inertia latch effectively locks the armrest in the up position, preventing unintended rotation and enhancing passenger safety by maintaining the armrest's position during accidents.
Implementation Method 1
a resilient biasing member returning the latch member to the engaged position relative to the support structure
Implementation Method 2
an inertia latch for a vehicle armrest... automatically transitions from an disengaged position to an engaged position
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3A~3B
AI summary
A vehicle seating assembly is provided and includes an armrest configured to rotate about an axis and between an up position and a down position. An inertia latch has a ratchet and is configured to move between a disengaged position and an engaged position to inhibit unintended movement of the armrest in the event of a collision. Certain implementations include one or more gears.