Snap-Fit Electrical Device with Retractable Claw for Rail Mounting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrical devices fixed to horizontal support rails with upper and lower wings face challenges in being easily removed without disassembling the rigid electrical energy distribution comb, due to the narrow slots and fixed claw positions, which hinder forward movement and release from the rail.

Innovation Solution

The electrical device features a retractable claw with a one-piece carriage and pawl mechanism, allowing precise locking and unlocking, enabling the device to be raised and released from the rail without disassembling the comb, using a slider and spring system for independent operation and enhanced reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the claw is fixed in the service position with narrow slots, then the device is securely locked to the rail, but the device cannot be moved forward to free it from the lower flange of the rail

Engineering Contradiction:
Improvelocking reliabilityVSAvoidease of removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The claw is designed to be movable between a service position (locked) and a retracted position (unlocked). The carriage assembly allows the claw to slide vertically along the rail, transitioning from engaging the lower flange in the service position to disengaging it in the retracted position, enabling easy removal while maintaining secure locking during operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The fixing mechanism is divided into separate functional components: the claw for engagement, the carriage for movement, and the pawl for locking. This segmentation allows independent optimization of each component - the claw provides reliable locking when engaged, while the carriage enables smooth transitions between positions for easy removal

Inventive Principle:
Principle #1Segmentation

2Strength

If the comb is rigid with teeth engaged in narrow slots, then the comb maintains structural integrity, but the device cannot be moved forward without disassembling the comb

Engineering Contradiction:
Improvecomb structural integrityVSAvoidease of device removal
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The movable claw on the device body allows the device to be raised and lowered independently of the rigid comb structure. When the claw is in the retracted position, the device can be lifted clear of the comb teeth without requiring disassembly of the comb itself, maintaining comb integrity while enabling easy device removal

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The carriage assembly acts as an intermediary mechanism between the device body and the rail/comb system. It provides the necessary movement capability to raise the device clear of the rigid comb teeth, allowing removal without forcing or disassembling the comb structure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the claw is made movable between service and retracted positions, then the device can be easily removed from the rail, but the mechanism becomes more complex

Engineering Contradiction:
Improveease of removalVSAvoidclaw mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The movable claw mechanism is segmented into distinct functional modules: the claw itself for engagement, the carriage for vertical movement along the rail, and the pawl for locking/unlocking. This modular segmentation allows each component to be simple in its own right while collectively providing the full range of motion and locking functionality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pawl and ratchet mechanism provides automatic locking when the carriage is in the service position, eliminating the need for additional actuators or complex control systems. The mechanism self-locks through the inherent geometry of the pawl engaging the ratchet teeth, reducing overall system complexity while maintaining reliable positioning

Inventive Principle:
Principle #25Self-service

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

This solution allows for easy removal and repositioning of electrical devices from the rail without disassembling the comb, improving operational convenience and reliability by enabling the claw to transition between service and retracted positions, facilitating efficient installation and maintenance.

Implementation Method 1

a spring disposed between said slider and said pawl of the carriage

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

said pawl and the body of the device being configured so that the carriage is blocked vis-à-vis the body of the device in the high position when the pawl is in the rest position

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP2498353B1Electrical device to be attached by snap fitting to a horizontal support rail
Publication Date: 2015.02.18 LEGRAND FRANCE SA
  • EP2498353B1 patent drawingFigure 1~2
  • EP2498353B1 patent drawingFigure 3
  • EP2498353B1 patent drawingFigure 4~5

AI summary

The appliance has a fixation clamp (35) including a carriage (36) slidably mounted on a body of the appliance by a chassis, between raised and lowered positions. A latch of the carriage and the body are configured such that the carriage is locked against the body in raised position when the latch is in a rest position, and released from the body when the carriage is in raised position and the latch is in bent position. A slide (37) is separated from the carriage and slidably mounted in the carriage, where an upper end of the slide forms a lower jaw maintained on a horizontal support rail. The carriage is made of molded plastic material.