Lock Cylinder Eccentric Pin Spring Mechanism

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Solution Overview

Problem

Panic locks require the locking element of the locking cylinder to always be in a neutral, lower position to avoid impeding the lock's panic function, which existing lock cylinders fail to consistently maintain due to dead center positions and torque issues.

Innovation Solution

The lock cylinder design incorporates a restoring spring, either compression or tension, with bearing sleeves that minimize material friction and maintain the locking element in a neutral position, and an additional supplementary spring that forces the cylinder core away from the dead center position, ensuring stable and efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a restoring spring is used to return the cylinder core to neutral position, then the locking element is maintained in neutral position, but dead center positions and torque issues cause instability

Engineering Contradiction:
Improvestability of neutral positionVSAvoiddead center instability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

An intermediary element (such as a cam mechanism or lever arm) is introduced between the restoring spring and the cylinder core. This intermediary converts the linear spring force into a rotational torque that acts on the cylinder core, ensuring that the neutral position is maintained while avoiding dead center positions. The intermediary mechanism transforms the spring's restoring force into a continuous rotational force that prevents the core from settling in unstable dead center positions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring force parameters are optimized to ensure that the restoring torque is sufficient to overcome friction and maintain the neutral position, but not so strong as to create excessive wear or binding. The geometric parameters of the cam mechanism or lever arm are carefully designed to transform the spring force into appropriate torque characteristics that eliminate dead center instability while maintaining reliable neutral position.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If bearing sleeves are used to reduce friction, then material friction is minimized and closing cycles are increased, but device complexity increases

Engineering Contradiction:
Improvenumber of closing cyclesVSAvoidcomplexity of bearing sleeve assembly
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The bearing system is segmented into multiple discrete bearing sleeves positioned at critical friction points within the lock cylinder mechanism. Each bearing sleeve is a simple, standardized component that can be independently manufactured and replaced. This segmentation allows for targeted friction reduction at specific locations without requiring a complete redesign of the entire mechanism, thereby increasing productivity while keeping individual components simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Standardized bearing sleeve designs are copied and replicated at multiple locations where friction reduction is needed. Rather than designing custom friction-reduction solutions for each location, proven bearing sleeve designs are replicated, ensuring consistent performance while simplifying manufacturing and maintenance. This copying approach increases reliability and closing cycle count without proportionally increasing overall device complexity.

Inventive Principle:
Principle #26Copying

3Ease of operation

If the restoring spring is positioned in a chamber of the flange section, then the locking mechanism operates smoothly, but the spring occupies space and increases device dimensions

Engineering Contradiction:
Improvesmooth operationVSAvoidchamber volume for spring
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The restoring spring is nested within an existing chamber in the flange section of the lock cylinder housing. This chamber is designed to accommodate the spring in a compact arrangement, with the spring positioned to work in conjunction with existing mechanical elements. The nested arrangement allows the spring to be housed without significantly increasing the external dimensions of the lock cylinder, maintaining smooth operation while minimizing volume consumption.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The spring arrangement utilizes the axial dimension of the flange section chamber rather than expanding the radial or lateral dimensions. By positioning the spring to operate primarily in the axial direction within the existing chamber volume, the design achieves smooth operation without significantly increasing the overall footprint or external dimensions of the lock cylinder mechanism.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

The design enhances the locking mechanism's reliability by maintaining the locking element in a stable neutral position and preventing dead center instability, allowing for increased closing cycles and smooth operation in panic locks.

Implementation Method 1

The restoring spring, which is in the form of a tension spring, engages around a fastening pin... The helical turns of the tension spring are essentially completely in the chamber... The eccentric pin can be the connecting web between two sections of the cylinder core.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a restoring spring which is in the form of a tension spring engages around a fastening pin, around which the hooked end of the return spring acts, in such a way that twisting the cylinder core from a neutral position leads to a reverse torque which is able to turn the twisted locking cylinder back into the neutral position.

Methodology Applied
Scientific EffectTorque: Torque

Implementation Method 3

To increase the number of closing cycles, the two pivots on which the two hook ends of the spring act have bearing sleeves... As a result of an axial slot, the bearing sleeve can be clipped onto the eccentric pin or the fastening pin... The associated friction is gentle on the material, since the surface pressure is minimized as a result of the large surfaces sliding off one another.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2088263B1Lock cylinder with with automatic return of the lock cam
Publication Date: 2010.06.23 DOM SICHERHEITSTECHN
  • EP2088263B1 patent drawingFigure 1
  • EP2088263B1 patent drawingFigure 2~3
  • EP2088263B1 patent drawingFigure 4~5

AI summary

The cylinder has a flange section (3) comprising a housing (1). A cylinder core (4) is rotatably supported in a bearing section (2) and rotatably connected with a closing member (5). A return spring i.e. pressure spring, is fastened to the housing, and engaged at an eccentric pin, which is arranged eccentric to rotational axis of the cylinder core, to rotate the cylinder core to a neutral position. An end of the return spring is engaged at a fastening pin that is arranged in a chamber of the flange section, where another end is engaged at the eccentric pin of the cylinder core.