Vehicle Latch Single Switch Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle door latch systems face issues where external forces can prevent doors from opening freely, and the detent lever may return to the engaged position even after an electric release command, leading to confusion about the latch status due to the need for multiple switches to determine the fork bolt and detent lever positions.
Innovation Solution
A latch assembly with a single switch that is activated by the movement of a hold open lever, which maintains the detent lever in a disengaged position until the fork bolt is rotated to the unlatched position, allowing the latch to be opened without additional components or complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple switches are used to determine fork bolt and detent lever positions, then the latch status can be accurately determined, but the device complexity and component quantity increase
Solution Approach 1:
The patent combines the functions of multiple switches into a single switch by using a linkage mechanism. The single switch is actuated by both the fork bolt and detent lever through mechanical linkages, allowing one switch to detect the status of multiple components. This merging approach reduces component quantity while maintaining the ability to determine latch status accurately through the combined switch signal.
Solution Approach 2:
The single switch serves multiple functions by detecting both fork bolt position and detent lever position. Through the linkage mechanism, the same switch component responds to movements of different latch elements, making it a multi-functional sensing element that replaces what would traditionally require separate switches for each component.
2Reliability
If the detent lever is spring biased into the engaged position, then the latch remains secure, but external forces cannot easily open the door and the detent may return to engaged position after power release
Solution Approach 1:
The patent introduces a power actuator that dynamically overrides the spring bias when opening commands are given. The actuator can force the detent lever from the engaged to disengaged position against the spring force, enabling easy door opening when needed. The system transitions from a purely passive spring-biased mechanism to an active controlled system that can adapt its behavior based on operational requirements.
Solution Approach 2:
The power actuator serves as an intermediary between the control system and the detent lever-spring system. It mediates the conflict between spring bias (security) and opening ease by providing controlled force to move the detent lever when opening is required, then allowing the spring to return it to the engaged position when closed.
3Ease of operation
If a hold open lever is added to maintain detent in disengaged position, then the door can open freely under external force, but the device complexity increases
Solution Approach 1:
The hold open lever is integrated with the existing single switch mechanism rather than being a completely separate component. The lever's movement is mechanically linked to the switch actuation, combining the holding function with the sensing function in a unified mechanical arrangement that minimizes additional complexity.
Data Source
AI summary
A latch is provided, the latch having: a fork bolt that moves between an unlatched position and a latched position; a first detent lever that that cooperates with the fork bolt and moves between an engaged position and a disengaged position; a hold open lever for biasing against the first detent lever when the first detent lever is in the released position; and a single switch that is activated only when the first detent lever is moved from the engaged position towards the disengaged position and when the fork bolt moves from the unlatched position towards the latched position, wherein the latch does not have any other switches.