Lock Cam Mechanism for Back-Security and Bolt Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional locks with oblique control cams require two turns of the key to achieve sufficient bolt ejection, leading to inadequate back-security after a single lock engagement due to the pin's position on the sloping section.
Innovation Solution
A lock design featuring two obliquely running cam sections separated by a perpendicular section, where the first turn secures the bolt against back-pushing and the second turn further extends the bolt, utilizing two pins to ensure reliable interaction with the control cam for enhanced security and space efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single oblique cam section is used, then the bolt ejection path is sufficient with one turn, but the bolt cannot be secured against being pushed back
Solution Approach 1:
The single cam section is divided into two separate cam sections (first cam section and second cam section) that are adjoined to each other. The first cam section provides the initial ejection path while the second cam section provides the perpendicular section for back-security. This segmentation allows each section to perform its specific function independently, resolving the contradiction between ejection path sufficiency and back-security.
Solution Approach 2:
The solution transitions from a single-dimensional oblique cam section to a two-dimensional cam configuration by adjoining two cam sections with different orientations. The first cam section has an oblique section for ejection, while the second cam section has a perpendicular section for preventing back-pushing. This dimensional change enables both functions to coexist within the same locking mechanism.
2Reliability
If two cam sections are adjoined to provide back-security after one turn, then the bolt is secured against back-pushing, but the height of the bolt increases
Solution Approach 1:
The two cam sections are merged into a single integrated cam structure that is adjoined to itself. The first cam section and second cam section share a common interface, allowing them to function as a unified mechanism. This merging approach enables the bolt to achieve both ejection path and back-security within a compact height, as the two sections work together in sequence rather than requiring separate independent mechanisms.
3Ease of operation
If the pin is positioned in the middle of the sloping section after one turn, then the bolt ejection is achieved, but the bolt is not secured against being pushed back
Solution Approach 1:
The cam mechanism is designed so that the perpendicular section of the second cam section is engaged before the pin can move to a position where it would allow back-pushing. The sequence of events is predetermined: the pin first engages the oblique section for ejection, then automatically transitions to engaging the perpendicular section which prevents back-pushing. This preliminary action ensures that the locking security is established before any potential vulnerability can occur.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The lock has a latch (8) with a cam (6) engaged with a spigot (4) of a push rod (3), where the cam has a section provided adjacent to an end that is turned away from a section of the spigot. The sections of the cam and the spigot pass perpendicular and diagonal to pushing direction. The latch has another cam (7) running parallel to the former cam such that the latter cam has a section provided adjacent to another end that is turned away from another section of the spigot, where the section of the latter cam and the latter section of the spigot pass perpendicular and diagonal to the direction.