Spring-Biased Cylinder Plug Return Mechanism for Lock Security

Solution Overview

Problem

Cylinder locks, especially electronic variations, require users to manually return the cylinder plug to the home position for relocking, which can lead to security lapses if forgotten, causing interference with the lockset mechanism and potentially preventing door opening from the opposite side.

Innovation Solution

A spring-biased cylinder plug return mechanism that automatically returns the cylinder plug to the home position using a torque spring or a spring-loaded slider mechanism, ensuring the plug and cam are correctly positioned without user intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a manual return mechanism is used, then the device complexity is reduced, but the reliability deteriorates because users may forget to return the plug to the home position

Engineering Contradiction:

ImprovereliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The spring mechanism automatically returns the cylinder plug to the home position without requiring user intervention. The spring is pre-loaded to provide the necessary force, and the mechanism self-regulates the return motion, eliminating the need for manual operation while ensuring reliable relocking.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The spring is pre-loaded during manufacturing to store the necessary energy for automatic return. This preliminary action ensures that when the plug is rotated to the unlocked position, the spring is already prepared to automatically return it to the home position, guaranteeing reliable operation without user intervention.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the plug is not returned to the home position, then the ease of operation is improved (no need to manually return), but the reliability deteriorates due to security lapses and potential interference with the lockset mechanism

Engineering Contradiction:

Improvesecurity reliabilityVSAvoidease of operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The spring mechanism automatically returns the cylinder plug to the home position without requiring user intervention. The spring is pre-loaded to provide the necessary force, and the mechanism self-regulates the return motion, eliminating the need for manual operation while ensuring reliable relocking.

Inventive Principle:

Principle #25Self-service

3Reliability

If a spring-biased return mechanism is added, then the reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveoperational reliabilityVSAvoidmechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The spring mechanism automatically returns the cylinder plug to the home position without requiring user intervention. The spring is pre-loaded to provide the necessary force, and the mechanism self-regulates the return motion, eliminating the need for manual operation while ensuring reliable relocking.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The spring is pre-loaded during manufacturing to store the necessary energy for automatic return. This preliminary action ensures that when the plug is rotated to the unlocked position, the spring is already prepared to automatically return it to the home position, guaranteeing reliable operation without user intervention.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Ensures the cylinder plug and cam are reliably returned to their home positions, maintaining security and preventing interference with the lockset mechanism, thus enhancing the operational reliability of the lock.

Implementation Method 1

A torque spring is attached to the shell and to a collar that is affixed to the cylinder plug. When the cylinder plug is rotated from the home position, the torque spring is loaded with rotational force-generating elastic potential energy. When the plug is released, the torque spring releases the stored energy and rotates the plug back toward the original home position.

Methodology Applied

Scientific EffectTorque spring: Torsion Spring

Implementation Method 2

the torque spring is loaded with rotational force-generating elastic potential energy

Methodology Applied

Scientific EffectElastic potential energy: Elasticity

Implementation Method 3

A return spring is disposed between the back end of the slider and the spring collar. The axial position of the slider is biased outwardly, away from the housing, by the return spring

Methodology Applied

Scientific EffectSpring: Spring

Data Source

PatentUS8978428B2Apparatus for automatically returning a lock to a desired orientation

Publication Date: 2015.03.17 ASSA ABLOY HIGH SECURITY GROUP INC

AI summary

An electromechanical lock includes a spring-biased cylinder plug return mechanism for automatically rotating the rotatable plug to a home position after the plug has been rotated from the home position and thereafter released. In one embodiment, the cylinder plug return mechanism comprises a torsional spring coupled to the plug, In a second embodiment, the cylinder plug return mechanism comprises a slider that is coupled to the plug so that rotation of the plug moves the slider, thereby increasing the potential energy in a return spring, and when the plug is released, the increase potential energy is released by moving the slider, and the coupling between the slider and the plug causes the plug to rotate back to a home position.