Lock Rod Coupling Structure to Prevent Backlash During Release
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Solution Overview
Problem
Existing lock devices attached to stationary bodies face issues with rod movement restriction leading to backlash and reduced operability during unlocking.
Innovation Solution
A lock device with a driving member and a rod that includes a coupling portion and a holding portion, allowing the rod to move in a longitudinal direction, with the holding portion sliding in the lock releasing direction to prevent rattling while maintaining operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the lock device is attached to the stationary body to prevent rod movement restriction, then rod movement freedom is improved, but backlash and rattling occur
Solution Approach 1:
The holding portion is designed to dynamically change its constraint state based on rod movement direction: it restricts movement in the locking direction to prevent backlash, while allowing movement in the lock releasing direction to maintain operability. This dynamic adaptation resolves the contradiction between stability and movement freedom.
Solution Approach 2:
The rod is segmented into functionally distinct portions: the lock portion for engagement, the holding portion for controlled restriction, and the coupling portion for transmission. This segmentation allows each portion to perform its specific function independently, enabling the holding portion to restrict backlash without affecting the overall rod movement freedom needed for locking.
2Stability of the object's composition
If the holding portion restricts rod movement to prevent backlash, then rod stability is improved, but operability during unlocking deteriorates
Solution Approach 1:
The holding portion dynamically adapts its constraint characteristics based on the direction of applied force. During locking operation, it provides rigid support to prevent backlash. During unlocking operation, it allows the rod to move freely in the lock releasing direction, thereby maintaining operability while ensuring stability.
Solution Approach 2:
Instead of uniformly restricting rod movement in both directions, the design inverts the approach by selectively allowing movement in the lock releasing direction while restricting it in the locking direction. This inverted logic resolves the contradiction by making the restriction directional rather than absolute.
3Device complexity
If the coupling portion is fixed to the rod, then structural simplicity is improved, but rattling and backlash occur
Solution Approach 1:
The coupling between the holding portion and coupling portion is designed to be dynamically selective: it provides stable coupling to prevent rattling during normal operation, while allowing relative movement when force is applied in the lock releasing direction. This dynamic coupling behavior prevents rattling without compromising operability.
Solution Approach 2:
The holding portion acts as an intermediary element between the rod and the external environment. It provides the necessary support to prevent rattling and backlash, while simultaneously allowing the rod to move freely when needed for unlocking. This intermediary function resolves the contradiction between simplicity and stability.
Data Source
AI summary
A lock device attached to a stationary body so that an opening and closing body is locked in a closed state with respect to the stationary body includes a driving member that is driven in response to movement of an operation member, and a rod movable in a longitudinal direction. The driving member includes a coupling portion coupled to the rod. The rod includes a lock portion engageable with and disengageable from a lock hole of the opening and closing body, and a holding portion holding the coupling portion so that the coupling portion is slidable in a moving direction of the rod. When the rod is moved in a lock releasing direction in which lock of the lock portion is released by the driving member, the holding portion and the coupling portion move in the lock releasing direction.