Lockable Rotary Handle for Electrical Switching Devices

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Solution Overview

Problem

Existing lockable locking handle systems for electrical switching devices are inadequate in securing the OFF position with multiple padlocks, often requiring precise fitting, limited to fewer than four locks, and complicating the locking mechanism, which can lead to unauthorized switching on.

Innovation Solution

A lockable locking handle system comprising a rotary handle and a locking collar that can be displaced vertically into a LOCKED position, featuring guide grooves and rails to prevent rotation and allow secure engagement of multiple padlocks, ensuring the device remains in a safe OFF state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking device is separate from the rotary handle, then the locking function can be achieved, but the size becomes unsatisfactory and the number of components increases

Engineering Contradiction:
Improvelocking functionVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the locking device directly into the rotary handle by forming a locking protrusion on the handle itself that engages with a corresponding locking recess in the switching device housing. This merging eliminates separate locking components and reduces overall device complexity while maintaining reliable locking functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotary handle serves multiple functions: it acts as both the operating mechanism for switching and as the locking mechanism itself. The locking protrusion is formed as an integral part of the handle, allowing the same component to perform both rotation control and security locking functions simultaneously.

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

2Reliability

If the end of the switching shaft is matched very precisely to the nose of the pivoting lever, then the locking connection is achieved, but this cannot be achieved if the switch is at different distances from the front panel or if the front panel is of different thicknesses

Engineering Contradiction:
Improvelocking connectionVSAvoidadaptability to different installations
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The locking mechanism uses a spring-loaded locking protrusion that can dynamically adjust its position. The spring allows the locking protrusion to move axially, enabling it to engage with the locking recess regardless of variations in panel thickness or switch positioning, thus providing adaptability while maintaining reliable locking connection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking mechanism incorporates a spring that allows the locking protrusion to change its axial position based on the engagement requirements. This parameter change capability enables the same locking structure to adapt to different installation conditions without requiring precise pre-matching of components.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a locking lever is used with a slot for accommodating padlocks, then the locking function is achieved, but the attachment of the twist grip on the selector shaft becomes cumbersome and precisely measured

Engineering Contradiction:
Improvelocking functionVSAvoidattachment process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The locking function is segmented from the rotary handle operation. The locking protrusion is designed as a separate functional element on the handle that independently engages with the housing, allowing the handle to be manufactured and assembled without complex precise measurements, while still achieving reliable locking.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If the locking positions are fixed unchanged, then the structure is simple, but additional locking positions cannot be added

Engineering Contradiction:
ImprovestructureVSAvoidadditional locking positions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The spring-loaded locking protrusion can be dynamically positioned at different angular locations on the rotary handle. This allows the system to provide fixed locking positions for standard configurations while also enabling additional or customized locking positions to be added by repositioning the protrusion, thus balancing structural simplicity with versatility.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2410550B1Lockable rotary handle
Publication Date: 2016.08.17 EATON ELECTRICAL IP
  • EP2410550B1 patent drawingFigure 1~2
  • EP2410550B1 patent drawingFigure 3~4
  • EP2410550B1 patent drawingFigure 5

AI summary

The invention relates to a locking handle system for an electrical switching device. A locking ring (130) is slid over the switching shaft of the electrical switching device and is attached to the switch housing or a front panel. A locking handle (100) is fixed to the switching shaft in a rotationally fixed manner and consists of a rotary handle (110) and a locking collar (120). The locking collar (120) is vertically displaceable relative to the rotary handle (110) in the direction of the longitudinal axis of the switching shaft into at least one CLOSE position and one OPEN position, and the locking collar (120) engages with the locking ring (130) such that it is not rotatable relative to the locking ring (130) in the CLOSE position.