Pin Tumbler Lock Anti-Bumping Mechanism

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Solution Overview

Problem

Conventional pin tumbler cylinder locks are susceptible to unauthorized access through techniques like lock picking and bumping, where the separation of driver and tumbler pins allows rotation of the plug, enabling unauthorized opening.

Innovation Solution

The lock is configured to maintain at least one driver pin extended across the shear line during a bumping operation by creating a gap between the tumbler and driver pins, reducing the impact force on the driver pin, thereby blocking rotation of the plug. This is achieved through specific pin and channel configurations, such as smaller plug channels and contoured driver pins, and using reduced mass tumbler pins to dissipate kinetic energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pin tumbler cylinder locks are used, then ease of manufacture and operation are maintained, but susceptibility to bumping and lock picking increases

Engineering Contradiction:

Improveresistance to bumping and lock pickingVSAvoidpin and channel configuration complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a gap between the driver pin and tumbler pin at a specific location (the interface between plug and shell) while maintaining normal pin configuration elsewhere. This localized modification at the critical shear line interface prevents bumping without requiring changes to the entire lock mechanism, thus improving reliability while limiting complexity increase to only the necessary local area.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the driver pin into two distinct portions: a first portion extending into the plug channel and a second portion extending into the shell channel. This segmentation allows the driver pin to function differently in each zone, with the gap between pins occurring at the segmentation point, thereby preventing the simultaneous alignment needed for bumping while maintaining individual pin functionality.

Inventive Principle:

Principle #1Segmentation

2Reliability

If driver and tumbler pins are allowed to separate during bumping, then ease of operation with proper key is maintained, but unauthorized access through bumping becomes possible

Engineering Contradiction:

Improveprevention of unauthorized accessVSAvoidimpact force on driver pin

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent implements beforehand cushioning by positioning the gap between the driver pin and tumbler pin upstream of the impact path. When a bump key is inserted and struck, the gap prevents the full transmission of impact force to the driver pin, as the pins are already separated at the critical interface. This pre-positioned gap acts as a cushion that dissipates impact energy before it can move the driver pin across the shear line, thereby preventing unauthorized access while allowing normal operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the lock is made more resistant to bumping through pin configuration changes, then security is enhanced, but manufacturing precision requirements increase

Engineering Contradiction:

Improvebumping resistanceVSAvoidpin gap positioning accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-configuring the driver pin and tumbler pin with a designed gap between them during the manufacturing assembly process. This gap is established beforehand at the correct position at the interface between plug and shell, eliminating the need for high-precision field adjustments. The pins are manufactured and assembled with the gap already in place, ensuring consistent bumping resistance without requiring extreme manufacturing precision during installation or operation.

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

The configuration effectively impedes unauthorized access by reducing the impact force on driver pins, making it difficult for bumping or lock picking to rotate the plug, thereby enhancing security against such attacks.

Implementation Method 1

using reduced mass tumbler pins to dissipate kinetic energy

Methodology Applied

Scientific EffectKinetic energy dissipation: Damping

Data Source

PatentUS8739588B2Anti-tampering arrangements for pin tumbler cylinder locks

Publication Date: 2014.06.03 MASTER LOCK CO INC

AI summary

A pin tumbler cylinder lock includes a shell, a plug, and at least first and second tumbler pins and first and second driver pins. At least the first driver pin extends into a corresponding plug channel when the plug is in a locked condition, such that rotation of the plug with respect to the shell is blocked. The lock is configured such that at least the first driver pin is separated from the first tumbler pin by a gap when the plug is in the locked condition. When the first and second tumbler pins are raised without the proper key and the gap between the first tumbler pin and the first driver pin is eliminated, the second tumbler pin extends across the shear line and into the corresponding shell channel.