Programmable Cylinder Lock Stop Bar Key Recess
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Solution Overview
Problem
Existing programmable cylinder locks face challenges in securely modifying codification without increasing size, complexity, and cost, while also preventing unauthorized key copying and ensuring a high number of compatible keys.
Innovation Solution
Incorporating a stop bar with protrusions and corresponding recesses on the use and change keys, which allows secure operation and modification while hindering unauthorized key copying by requiring specific key features, and optionally providing multiple projections and recesses to increase key compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stop bar with protrusions and corresponding recesses is added to the key, then secure codification modification and prevention of unauthorized copying is improved, but key complexity increases
Solution Approach 1:
The key is divided into functional segments: the coding portion (teeth) for lock interaction and the side surface features (recesses or grooves) for stop bar engagement. This segmentation allows each part to perform its specific function independently, making the security enhancement achievable without redesigning the entire key structure.
Solution Approach 2:
The invention adds features to the side surface dimension of the key, perpendicular to the traditional tooth profile. By engaging the stop bar protrusions with recesses on the side surface rather than modifying the tooth geometry, the patent enhances security without complicating the primary key coding function.
2Adaptability or versatility
If multiple projections and recesses are added to increase key compatibility, then the number of compatible keys increases, but key design complexity increases
Solution Approach 1:
The side surface recesses serve multiple purposes: they engage with stop bar protrusions to prevent unauthorized copying, and their positioning enables compatibility with different key codes. The same structural feature (recess) supports both security and versatility requirements simultaneously.
Solution Approach 2:
Different regions of the key side surface are designed with specific qualities: recesses are positioned at locations corresponding to stop bar protrusions for security engagement, while the tooth profiles maintain traditional coding patterns for compatibility. This local differentiation allows one key structure to satisfy multiple requirements.
3Reliability
If the stop bar projection engages with the key recess to prevent key extraction, then security against unauthorized copying is improved, but ease of operation for legitimate users may be affected
Solution Approach 1:
The engagement between the stop bar projection and key recess is dynamic rather than static. During normal operation, the key rotates and the stop bar remains engaged with the recess, preventing extraction. During change operation, the change bar mechanism temporarily releases the engagement, allowing controlled key exchange. This dynamic behavior adapts to different operational contexts.
Solution Approach 2:
The change bar acts as an intermediary mechanism that mediates between the stop bar security function and the need for key exchange during change operations. The change bar temporarily overrides the stop bar's engagement, allowing legitimate key changes while maintaining security against unauthorized copying during normal operation.
Data Source
Figure 1~4
Figure 5~7
AI summary
A programmable cylinder lock comprising a stator (1) and a cylindrical rotor (2), mounted inside stator (1) for rotation around its own axis and having a keyhole for insertion of a key (3), and comprising inside rotor (1) a number of key followers (5) movable along the longitudinal and transversal directions, intended to cooperate with a key inserted into the keyhole of rotor (2), and locking pins (6) movable along the longitudinal direction, the key followers (5) and locking pins (6) forming together a number of pairs and having toothings intended to mutually cooperate in order to define the lock codification, rotor (2) including a stop bar (9) cooperating with a longitudinal groove (10) of stator (1) and susceptible of cooperating with the locking pins (6) in order to immobilize them, and comprising a change bar (11) which is slidingly coupled with the key followers (5) in order to normally keeping the key followers (5) engaged with the locking pins (6) and to disengage them from the locking pins (6) when said change bar (11) provides a lock programming position, wherein the stop bar (9) has projections (12) facing the keyhole of rotor (2) intended to receive the key (13, 15), and the use key (13) has in its side surface some recesses (14) so located as to place themselves facing the projections (12) of the stop bar (9) when the key (13) is correctly inserted in the lock, whereas the corresponding change key (15) has a longitudinal groove (16) extending in a position corresponding to the recesses (14) of the use key (13).