Lock Cylinder Coupling with Return Pin for Defined Reset
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Solution Overview
Problem
Current lock cylinder clutches lack secure decoupling mechanisms, leading to potential malfunctions and undefined states during key removal, especially in safety-critical applications like escape route doors, where a free-running cam is required, and existing designs fail to guarantee a defined reset state.
Innovation Solution
A clutch design featuring a longitudinally displaceable coupling element with a return pin and guide, which engages with the key to push the coupling element towards the lock bit during key insertion and forcibly returns to its initial position upon key removal, ensuring a secure uncoupling and defined state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring-return mechanism is used for the clutch, then the clutch can be automatically returned after actuation, but the actual position of the clutch cannot be determined and malfunctions cannot be detected
Solution Approach 1:
The patent introduces a feedback mechanism where the key itself provides positional information about the clutch. When the key is inserted, its geometry directly indicates whether the clutch is in the engaged or disengaged position, allowing the system to know its own state without complex sensors or additional mechanisms.
Solution Approach 2:
The key acts as an intermediary that transfers both the actuating force and the positional information. By designing the key's geometry to interact with specific features of the clutch mechanism, the key simultaneously performs the function of actuating the clutch and indicating its position, eliminating the need for separate detection systems.
2Device complexity
If the clutch is designed as a single integrated component, then the structure is simple, but secure decoupling between core and cam cannot be guaranteed after key removal
Solution Approach 1:
The clutch mechanism is divided into distinct functional components: the clutch body, the return pin with driver/cam, and the nose that engages with the key. This segmentation allows each component to have a specific function - the return pin provides the decoupling action while the nose provides the engagement interface, ensuring reliable separation between the core and cam when the key is removed.
3Ease of operation
If mechanical return forces are used for the clutch, then the reset function is provided, but the system cannot be reset to a defined state in the presence of mechanical defects
Solution Approach 1:
The key's geometry is designed to perform preliminary actions that prepare the system for a defined state. As the key is inserted, its shape guides the return pin and driver/cam into specific positions that pre-establish the conditions for a known, defined state of the locking mechanism, ensuring that regardless of previous mechanical defects, the system reaches a predictable configuration.
Data Source
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AI summary
The invention relates to a coupling for a lock cylinder. The coupling is designed as a multi-part coupling and consists of an integral coupling element, which produces the connection to the locking bit or coupling pressure piece and which can be moved longitudinally in the cylinder core, and of a restoring pin which is mounted in the coupling element. A guide element is provided in or on the coupling element, said guide element being for one end of the restoring pin that is provided with a follower or cam, the other end of said pin having a nose that is guided through the coupling element and can engage in a corresponding recess of the key.