Locking Mechanism with Segmented Keyhole and One-Piece Actuator

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing locking mechanisms are vulnerable to drill attacks, allowing unauthorized disassembly despite security features like key-operated locks and cammed actuators, due to weak points in assembly joints and large drill sizes that can fit through keyholes.

Innovation Solution

A locking mechanism with an oblong keyhole and a one-piece actuator design, where the actuator can be inserted after locking members, and a snap ring for secure retention, reducing the size of tools that can be used for disassembly and eliminating weak assembly joints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a key-operated lock is mounted into the first part through its distal end with a keyhole, then the lock can be operated, but a sufficiently large drill can be used to destroy internal components through the keyhole

Engineering Contradiction:
Improvekey operationVSAvoiddrill attack vulnerability
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The keyhole is segmented into two functional zones: an oblong insertion portion that accepts the key, and a circular keyway portion that transmits rotational movement. This segmentation allows the keyhole to fulfill both operational access and security protection functions, as the oblong shape restricts drill bit insertion while still permitting key insertion and rotation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The keyhole employs an asymmetric oblong shape with a major axis and minor axis, where the maximum dimension of the minor axis is less than 5mm. This asymmetric geometry selectively permits key insertion (which engages with the oblong shape) while preventing drill bits of sufficient size from passing through, thereby asymmetrically enabling legitimate operation while blocking harmful attacks.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If support plates are used to restrict the actuator to rotary movement, then the actuator is constrained properly, but the support plates cannot pass the locking members during assembly

Engineering Contradiction:
Improveactuator rotation restrictionVSAvoidassembly difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The support plate transitions from a static constraint component to a dynamic assembly aid through the addition of acircular portions. During assembly, these acircular portions temporarily alter the plate's effective shape, allowing it to pass through locking members. Once assembled, the plate returns to its circular form, restoring its function of restricting actuator rotation. This dynamic adaptation resolves the conflict between assembly ease and operational reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The support plate incorporates acircular portions that extend in a different dimensional orientation compared to the circular portions. This dimensional differentiation allows the plate to navigate through the locking members during assembly by utilizing the extra spatial dimension provided by the acircular geometry, while maintaining its rotational constraint function in the operational dimension.

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

3Adaptability or versatility

If the locking mechanism uses multiple components (lock, actuator, support plates, locking members), then the functionality is comprehensive, but there are weak points in assembly joints that can be exploited

Engineering Contradiction:
Improvelocking functionalityVSAvoidnumber of assembly joints
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The support plate merges multiple functions into a single component: it restricts actuator rotation, facilitates assembly by passing through locking members, and provides structural support. This merging reduces the number of separate parts and assembly joints, thereby eliminating potential weak points while maintaining comprehensive locking functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support plate is designed as a universal component that performs multiple functions: constraining actuator movement, aiding assembly operations, and providing structural integrity. This multi-functionality reduces overall device complexity by consolidating several components into one, thereby reducing the number of assembly joints and potential security vulnerabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2436861B1Locking mechanism, locking bolt, actuator and method of assembly
Publication Date: 2018.05.30 MAYPOLE
  • EP2436861B1 patent drawingFigure 1~2
  • EP2436861B1 patent drawingFigure 3~5
  • EP2436861B1 patent drawingFigure 6~7

AI summary

This invention relates to a locking mechanism, to a locking bolt (sometimes referred to as a locking pin), to an actuator for the lock mechanism and to a method of assembly. The locking mechanism comprises a first part (10) and a second part (12), the first part and second part being securable together by way of at least one locking member (26) carried by the first part. The locking member(s) is driven into its locking position by an actuator (24) which is in turn driven by a key-operated lock carried by the first part. The first part has a first end portion (16). The first part has a second end (32) opposed to its first end portion (16), and has a recess (18) in its second end (32) which is adapted to accommodate the key-operated lock and the actuator (24). The actuator has a cam section (42) whereby rotation of the actuator causes radial movement of the locking member(s) (26). The actuator has a first support plate (72) located between the cam section (42) and the key-operated lock and a second support plate (74) located to the opposed side of the cam section (42), the support plates (72, 74) being adapted for sliding engagement with the substantially circular internal surface of the recess (18). The first support plate (72) has an acircular periphery (76, 80) whereby the first support plate can pass the locking member(s) (26) during assembly of the first part, so that the actuator can be made as a one-piece construction. There is also provided a first part of a locking bolt, and a method of assembling the first part of a locking bolt.