Cam Lock Reset Mechanism Combining Key and Combination
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Solution Overview
Problem
Existing combination and key operated locks lack an effective mechanism for resetting the manual combination without requiring knowledge of the current combination or possession of a physical key, leading to security vulnerabilities and inconvenience in changing combinations.
Innovation Solution
A combination cam lock design that requires both knowledge of the current combination and possession of a physical key to reset the combination, with additional features to prevent unauthorized access, such as a detent actuator and cut out region in the inner cylinder, ensuring secure operation and combination change.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lock allows combination reset with only key possession, then ease of operation is improved, but security is worsened
Solution Approach 1:
The patent combines two authentication methods (combination entry and key insertion) into a single reset mechanism. The key insertion activates a cam mechanism that enables the combination wheels to be repositioned, while the combination entry provides the final authorization. This merging ensures both convenience (key holders can reset) and security (current combination knowledge is required).
Solution Approach 2:
The key insertion performs a preliminary action by rotating the cam to an unlocked position, which prepares the mechanism for combination change by releasing the combination wheels from their fixed positions. This preliminary step enables subsequent combination wheel repositioning without requiring force or specialized tools.
2Ease of operation
If the lock allows combination reset with only combination knowledge, then ease of operation is improved, but security is worsened
Solution Approach 1:
The patent merges physical key authentication with combination code authentication. The combination wheels must be positioned correctly AND the key must be inserted and rotated to activate the cam mechanism. Both authentication factors are required simultaneously, preventing unauthorized resets by anyone who only knows the combination or only has access to the key.
3Reliability
If the lock uses complex reset mechanism, then security is improved, but device complexity is worsened
Solution Approach 1:
The cam mechanism serves multiple functions: it controls the locking/unlocking of the shackle, enables/disables the combination wheels for repositioning, and provides the mechanical linkage between key insertion and combination wheel release. This multi-functionality reduces the need for separate components for each function, simplifying the overall structure while maintaining security.
Solution Approach 2:
The combination wheels are nested within the lock body, with the cam mechanism positioned to interact with them. When the cam rotates to the unlocked position, it simultaneously releases all combination wheels, allowing them to be repositioned. This nested arrangement allows compact integration of multiple functional elements without increasing external dimensions significantly.
4Reliability
If the lock prevents unauthorized access, then security is improved, but ease of operation is worsened
Solution Approach 1:
The patent combines the authorized user's existing authentication methods (combination or key) with the combination change function. The same key that unlocks the lock also activates the combination change mode when inserted and rotated. This merging means authorized users face no additional operational burden while unauthorized users are effectively blocked.
Data Source
AI summary
Disclosed are apparatus and methodology for providing a resettable manual entry combination and key operated cam lock. Methodologies are provided for enabling changing of the manual entry resettable combination given knowledge of the previous combination and possession of an operable key. In alternative embodiments, provisions are made to prohibit forced opening of the lock by way of the use of foreign objects.