Lock Assembly Cover Member Shear Protection
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Solution Overview
Problem
Conventional cylinder locks are vulnerable to shear at their weakened central region, especially when subjected to sufficient moments, due to design weaknesses and fixing holes, which can compromise security during unauthorized access attempts.
Innovation Solution
A lock assembly with a cover member that impedes access to the protruding end and is fixable relative to the lock, featuring a spine with separately actuatable lock cylinders, a cam for bolt mechanism actuation, and a securing member to prevent forced removal, along with a cover member that encloses the lock and handle sub-assembly to enhance security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional cylinder lock is used with a centrally located cam and fixing hole, then the lock can be actuated and fixed to the door, but the lock becomes vulnerable to shear at the weakened central region when subjected to sufficient moments
Solution Approach 1:
The lock assembly is segmented into distinct functional components: the lock body with cam mechanism, the cover member, and the securing member. This segmentation allows the cam to be positioned away from the central fixing region, eliminating the weakening effect while maintaining actuation functionality.
Solution Approach 2:
The cover member acts as an intermediary element that protects the protruding end of the lock and distributes applied moments away from the weakened central region. The securing member with extending formations serves as a mediator to transfer and distribute mechanical loads across a larger area, preventing concentration of stress at the cam region.
2Adaptability or versatility
If the lock is made accessible from both sides of the door for double cylinder operation, then the lock can be actuatable from either side, but the protruding ends become more accessible to forced removal attempts
Solution Approach 1:
The cover member is positioned in advance to impede access to the protruding end of the lock on the exposed side of the door. This preliminary protective measure prevents attackers from directly applying moments to the lock, countering the vulnerability created by bidirectional accessibility.
Solution Approach 2:
The securing member extends formations outwardly from the lock body in a direction perpendicular to the door surface, adding a spatial dimension to the protection. This three-dimensional extension creates a physical barrier that prevents forced removal while maintaining the bidirectional actuation capability through the cam mechanism.
3Stability of the object's composition
If fixing holes are provided in the central region of the lock for secure attachment, then the lock can be firmly fixed to the door, but the fixing holes create weakened regions that are susceptible to shear
Solution Approach 1:
The fixing function is segmented from the cam actuation function. The cam is positioned away from the central fixing holes, so that the structural integrity required for fixing is maintained without compromising the actuation mechanism. This spatial segmentation allows both functions to coexist without mutual interference.
Solution Approach 2:
The securing member with extending formations creates a redundant fixing system that distributes loads across multiple points rather than relying solely on the central fixing holes. This copied fixing approach provides alternative load paths that bypass the weakened central region.
Data Source
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AI summary
A lock assembly (10) comprising a lock (20) for location within a closure and fixable relative to the closure, such that a first end portion (28) of the lock protrudes from an exposed side of the closure, and a cover member (78) that is adapted to at least impede access to the protruding, first end portion of the lock, wherein the cover member is fixable relative to the lock, by means of cooperating formations of the cover member and the lock.