Eccentric Key Rotation in Lock Cylinder for Controlled Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical lock cylinders with electronic key coding lack a direct mechanism to ensure key removal only in defined positions, leading to potential comfort, functionality, and security issues if the key can be removed outside these positions.
Innovation Solution
A lock cylinder design featuring a ring-shaped disc with axial grooves and a key shank with corresponding grooves, allowing the key to be rotated eccentrically relative to the cylinder core, ensuring axial fixation and removal only in specific positions, with the key's axis of symmetry offset from the cylinder core's axis, creating an undercut for secure key retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic key coding is used without mechanical locking elements, then the key coding precision is improved, but the key removal control capability deteriorates
Solution Approach 1:
The patent introduces an intermediary mechanical key removal lock mechanism that works in conjunction with electronic key coding. This intermediary device consists of a disc with grooves that interact with corresponding grooves on the key shank, providing the necessary mechanical control for key removal while preserving electronic coding precision.
Solution Approach 2:
The patent merges electronic key coding with a mechanical key removal lock mechanism into a unified system. The electronic coding provides authentication and positioning information, while the mechanical disc and groove system provides physical key removal control, creating a hybrid system that achieves both precision and reliability.
2Ease of operation
If the key can be removed in any position, then the ease of operation is improved, but the security deteriorates
Solution Approach 1:
The patent employs asymmetric groove positioning on the disc and key shank that only aligns at specific rotational positions. This asymmetric design allows the key to be removed only when the grooves match, providing security control while maintaining ease of operation at the correct position.
Solution Approach 2:
The key removal capability is enabled only at specific local positions (defined groove alignments) rather than uniformly across all positions. This local quality approach allows convenient removal at authorized positions while preventing removal at other positions, balancing ease of operation with security.
3Reliability
If a mechanical key removal lock is added to electronic key coding, then the key removal control capability is improved, but the device complexity increases
Solution Approach 1:
The key removal lock is segmented into distinct functional components: a disc with grooves, a key shank with corresponding grooves, and a key channel. This segmentation allows each component to perform its specific function independently while working together as a unified system, reducing overall complexity.
Solution Approach 2:
The key removal control function is extracted as a separate mechanical subsystem (disc and groove mechanism) that operates independently from the electronic key coding system. This extraction allows the mechanical lock to be designed and analyzed separately, simplifying the overall system architecture.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a key-withdrawal block for a reversible key which can be introduced into the key channel of a cylinder core mounted in a rotatable manner in a lock-cylinder casing. Said key-withdrawal block is characterized in that the cylinder-core head has arranged behind it an annular disc (1) which is retained at a fixed location, such that it cannot be rotated, in the lock-cylinder casing and has at least one axial, groove-like cutout (3) on the inner circumference, in that the key, on its shank (2), has mutually opposite grooves (6) which extend in the axial longitudinal direction and of which the dimensioning corresponds with the groove-like cutout (3) in the annular disc (1), and in that the key is arranged in the key channel such that the rotary path of its axis of symmetry (5) running in the key shank (2) is spaced apart from the axis of rotation of the cylinder core, wherein the distance which gives rise to eccentricity of the rotation of the key in relation to the axis of rotation (4) of the cylinder core is smaller than the depth of the groove-like recess (3) on the disc (1).