Vacuum Switch Stroke Adjustment With Stable Contact Force

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Solution Overview

Problem

Existing methods for adjusting the stroke and preload of vacuum switching tubes in switching devices result in impermissible deviations in mechanical parameters, leading to inconsistent contact forces, which are inefficient and costly to correct.

Innovation Solution

An adjusting device using an eccentric or movable stop element to adjust the stroke and preload of vacuum switching tubes, allowing for simultaneous adjustment of the stroke without altering the contact force, with optional stepless or stepped adjustments and locking mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the stroke is adjusted by changing the stop position or using variable-length links, then the stroke deviation is corrected, but the contact force changes and becomes inconsistent

Engineering Contradiction:
Improvestroke precisionVSAvoidcontact force consistency
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The adjusting device is segmented into independent functional components: an adjusting mechanism for stroke adjustment and a contact force adjustment mechanism. This allows separate adjustment of stroke and contact force, enabling precise stroke control without affecting contact force consistency. The segmented design lets each component optimize its function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary adjusting device positioned between the fixed stop and the movable contact system. This intermediary component enables independent adjustment of the movable contact's stroke without directly affecting the contact force, as it mediates the relationship between stroke position and contact pressure through a decoupled adjustment mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If variable-length links are used to adjust stroke independently for each pole, then stroke precision is improved, but the device complexity increases

Engineering Contradiction:
Improvestroke adjustment precisionVSAvoidadjusting mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple adjustment functions into a single integrated adjusting device. Instead of using separate variable-length links for each pole, the invention combines stroke adjustment and contact force adjustment into one unified mechanism that can service multiple poles, thereby reducing overall device complexity while maintaining precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The adjusting device is designed with multi-functionality, capable of adjusting both stroke and contact force through a single mechanism. This universal adjusting device can be applied to multiple poles and performs multiple adjustment functions, eliminating the need for separate adjusting mechanisms for each function and reducing overall system complexity.

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

3Force

If simultaneous adjustment of stroke and preload is made, then the contact force consistency is maintained, but the adjustment mechanism becomes more complex

Engineering Contradiction:
Improvecontact force consistencyVSAvoidadjusting device complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The adjusting device incorporates dynamic adjustment capabilities where the stop position can be modified during operation or maintenance. The mechanism allows for dynamic repositioning of the adjustable stop along the movement path, enabling real-time adjustment of stroke and preload while maintaining contact force consistency without requiring complex static pre-adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

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

Enables precise and cost-effective adjustment of the stroke and preload, maintaining consistent contact force throughout the switching process, thereby improving the efficiency and reliability of vacuum switching devices.

Implementation Method 1

a contact pressure spring (250) associated with the vacuum switching tube (2)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the adjustable stop is formed by an eccentric or a movable, elongated stop element

Methodology Applied
Scientific EffectEccentric: Eccentric

Data Source

PatentEP3756205B1Adjusting device and method for adjusting switching device mechanisms
Publication Date: 2026.03.04 SIEMENS AG
  • EP3756205B1 patent drawingFigure 1~2
  • EP3756205B1 patent drawingFigure 3
  • EP3756205B1 patent drawingFigure 4

AI summary

The invention relates to an adjusting device (10) for adjusting the stroke (Hv) of a vacuum switching tube (2) and the bias of a contact compression spring (250) of a switching device mechanism (5), said spring being paired with the vacuum switching tube (2), for a medium-voltage switch and/or high-voltage switch, wherein the adjusting device (10) can be driven by a switch shaft (100), the switch shaft (100) is connected to a transmission element (300) via a connection element (200), and the transmission element (300) can be connected to a movable switch contact (400) of a medium-voltage switch and/or a high-voltage switch. The transmission element (300) is arranged in a rotatable manner and in a laterally movable manner in the connection element (200) along a recess (205).