Cam Mechanism Housing Assembly for Tamper-Resistant Battery Access

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing motion detection devices lack a secure and easy-to-use housing design that allows for battery replacement while preventing tampering, as they often require complex mechanisms or external features that compromise their appearance and security.

Innovation Solution

A housing assembly with a cam mechanism that automatically locks and ejects the front assembly, using a torsion spring to bias the cam towards the locked position, requiring a tool for unlocking and allowing manual separation for maintenance, with a clean and unobtrusive design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a secure locking mechanism is implemented to prevent tampering, then security is improved, but device complexity increases

Engineering Contradiction:
ImprovesecurityVSAvoidhousing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking and ejection functions are merged into a single cam mechanism. The cam's rotational movement simultaneously performs locking by engaging the latch and ejection by disengaging retention features, reducing the number of separate mechanisms while maintaining security.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cam mechanism serves multiple functions: it locks the housing by engaging the latch, ejects the front assembly by disengaging retention features, and provides a clean exterior when retracted. This multi-functionality reduces overall device complexity while maintaining security.

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

2Reliability

If a locking mechanism is designed to be secure and tamper-resistant, then security is improved, but ease of operation for maintenance deteriorates

Engineering Contradiction:
Improvetamper resistanceVSAvoidbattery replacement ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A tool interface acts as an intermediary between the user and the cam mechanism. The tool enables precise rotational control of the cam to perform locking and ejection functions, while the clean exterior design ensures no external features compromise security or aesthetics.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cam mechanism automatically performs both locking and ejection functions through its rotational movement. Once the tool initiates the rotation, the mechanism self-completes the locking or ejection action without requiring additional user intervention or complex操作步骤.

Inventive Principle:
Principle #25Self-service

3Reliability

If external locking features are added to the housing, then security is improved, but aesthetic appearance deteriorates

Engineering Contradiction:
ImprovesecurityVSAvoidaesthetic appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The locking and ejection functions are extracted from the external housing features and relocated to internal mechanisms. The cam and latch are positioned inside the housing, allowing the exterior surface to remain clean and unobtrusive while maintaining secure locking functionality through internal engagement features.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of operation

If a manual ejection mechanism is implemented, then ease of maintenance is improved, but device complexity increases

Engineering Contradiction:
Improvemaintenance accessVSAvoidmechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The ejection function is merged with the existing locking cam mechanism. The same cam that performs locking also performs ejection by continuing its rotational movement to disengage retention features, eliminating the need for a separate ejection mechanism.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cam mechanism is designed to perform multiple functions: locking by engaging the latch, ejection by disengaging retention features, and providing a clean exterior when retracted. This multi-functionality achieves ease of maintenance without adding separate ejection mechanisms.

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

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 solution provides secure locking and easy maintenance access, ensuring the device is tamper-resistant and aesthetically pleasing, with automatic relocking upon assembly, enhancing user convenience and security.

Implementation Method 1

using a torsion spring to bias the cam towards the locked position

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP3369079B1Detector housing assembly
Publication Date: 2019.08.14 ROBERT BOSCH GMBH
  • EP3369079B1 patent drawingFigure 1
  • EP3369079B1 patent drawingFigure 2
  • EP3369079B1 patent drawingFigure 3

AI summary

A housing assembly includes a base and a front assembly assembled with the base. The base includes a bottom and a sidewall that surrounds a peripheral edge of the bottom, and the front assembly is configured to engage with the sidewalls and close an open end of the base. The front assembly includes a latch that protrudes inward from an inner surface, and a spring-biased cam is rotatably supported on the base. The cam includes a cam surface that is engaged with the latch in such a way that rotation of the cam about the rotational axis results in a translation of the front assembly relative to the base in a direction parallel to the cam rotational axis. The cam is manually actuated using a tool.