Enclosed Switch Lockout Tab Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing switch designs require a separate handle guard to lock the operating handle in the OFF position, increasing part numbers, cost, and assembly time, which is inefficient.

Innovation Solution

A formed handle lockout design where a tab on the cover flange with a hole aligns with the operating handle's hole to lock the switch in the OFF position, eliminating the need for a handle guard.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a handle guard is used to lock the operating handle in the OFF position, then the switch can be securely locked, but the number of parts, cost, and assembly time increase

Engineering Contradiction:

Improvelocking reliabilityVSAvoidnumber of parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the handle guard function into the operating handle itself by forming a lockout tab directly on the handle. This integration eliminates the need for a separate handle guard component while maintaining the locking function, as the tab aligns with a hole in the enclosure to prevent handle movement when in the OFF position

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The operating handle is designed to serve multiple functions: it operates the switch and simultaneously provides the locking mechanism through its integrated tab. This multi-functionality reduces the overall component count while ensuring the switch can be securely locked in the OFF position

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a handle guard is used to lock the operating handle, then the switch can be locked in the OFF position, but the manufacturing cost increases

Engineering Contradiction:

Improvelocking reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

By combining the locking function into the operating handle itself, the patent eliminates the need to manufacture and inventory separate handle guard components. This reduces manufacturing complexity and cost while maintaining UL 98 compliance for lockable switches

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the essential locking function from the separate handle guard component and integrates it directly into the operating handle. This extraction eliminates unnecessary components and reduces overall manufacturing cost while preserving the required safety function

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If a handle guard is used to lock the operating handle, then the switch can be locked in the OFF position, but the assembly time increases

Engineering Contradiction:

Improvelocking reliabilityVSAvoidassembly time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The integration of the lockout tab into the operating handle means that the locking mechanism is already built into the component being installed. This eliminates the separate step of installing a handle guard, reducing assembly time while ensuring proper locking functionality

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS10950405B1Locking an enclosed switch, a bus plug or a panelboard switch

Publication Date: 2021.03.16 SIEMENS INDUSTRY INC

AI summary

An enclosed switch, a bus plug or a panelboard switch with means to lock them in an OFF position are provided. An enclosed switch comprises an operating handle with a first hole situated at a distal end and an enclosure including a cover. The operating handle is disposed external to the enclosure. The cover having a flange including a tab formed with a second hole that is configured to be aligned with the first hole of the operating handle in order to lock the enclosed switch in an OFF position without the use of a handle guard.