Vehicle Door Closure Latch With Double Pull Override Mechanism
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Solution Overview
Problem
Existing vehicle door closure latches with passive entry systems face regulatory challenges regarding the connection between the inside door handle and the ratchet, particularly for rear doors where children are occupants, as they need to balance electrical release from outside and mechanical release from inside while ensuring safety and convenience.
Innovation Solution
A closure latch with a ratchet and lock mechanism that includes a double pull override feature, allowing the inside door release lever to unlock and open the vehicle door in multiple lock states, including a child-locked state, using a combination of mechanical and electrical actuation, ensuring safe and convenient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the inside door release lever is directly connected to the pawl for mechanical release, then ease of operation from inside is improved, but safety for child occupants deteriorates as they could potentially operate the door release
Solution Approach 1:
The patent introduces an intermediate lock mechanism (including lock lever, lock link, and pawl) that mediates between the inside door release lever and the ratchet. This intermediary system allows adult users to override the lock with a double-pull action while preventing children from operating the door, thus resolving the safety contradiction.
Solution Approach 2:
The lock mechanism transitions between locked and unlocked states dynamically based on the number of pull actions. The system is designed to remain locked during normal conditions but can be overridden by a specific double-pull sequence, providing adaptive safety that responds to user intent while maintaining child protection.
2Ease of operation
If an electrical release actuator is added for passive entry, then convenience for outside access is improved, but device complexity increases
Solution Approach 1:
The lock mechanism is designed to serve multiple functions: it controls both the mechanical inside release and the electrical outside release through the same structural components. The lock lever and lock link serve as universal elements that manage both release methods, reducing overall system complexity despite adding passive entry capability.
Solution Approach 2:
The patent merges the electrical release actuator with the existing mechanical lock structure. The actuator operates the lock lever, which is already part of the mechanical release system, combining both release methods into a unified mechanism rather than creating separate independent systems.
3Object-affected harmful factors
If a double pull override feature is implemented, then safety and control are improved, but ease of operation deteriorates due to requiring multiple actions
Solution Approach 1:
The double-pull override feature uses periodic action by requiring two distinct pull actions separated by a time interval. This periodic operation pattern provides a clear, learnable sequence that enhances safety control while maintaining reasonable ease of operation for authorized users who can remember and execute the simple two-step process.
Data Source
AI summary
A closure latch includes a ratchet movable between an open position and a closed position. A pawl is provided and is movable between a ratchet locking position wherein the pawl holds the ratchet in the closed position and a ratchet release position. An inside door release lever is operatively connectable to the pawl. A lock includes a lock link movable between an unlocked position wherein the lock link operatively connects the inside door release lever to the pawl, and a locked position wherein the inside door release lever operatively disconnects the inside door release lever from the pawl. A lock lever cam rotatable between an unlocking range wherein the lock lever cam permits the lock link to move to the unlocked position, and a locking range wherein the lock lever moves the lock link to the locked position. The lock further includes an override member connected for rotation with the lock lever cam and rotatable between an actuatable range wherein the inside door release lever is engageable with the override member to move the lock lever cam to the unlocking range, and a non-actuatable range wherein the inside door release lever is operatively disconnected from the override member.