Switching Unit Insulation via Retaining Pin Housing

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Solution Overview

Problem

Existing electrical switches face challenges in achieving good electrical insulation properties while maintaining easy assembly and allowing for torque transmission and connection to a switching mechanism.

Innovation Solution

The use of a non-conductive housing for the switching unit, where a contact lever with pins is pre-assembled with plates and inserted, with a retaining pin extending beyond the plates to secure the subassembly within the housing, and a rotor pin forming the pivot axis for the contact lever, enabling simple assembly and effective electrical insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a non-conductive housing is used for electrical insulation, then electrical insulation properties are improved, but assembly complexity increases

Engineering Contradiction:
Improveelectrical insulation propertiesVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The switching unit is divided into a non-conductive housing and a separate contact lever assembly. The contact lever assembly with plates and pins is pre-assembled as a module that can be independently manufactured and then inserted into the housing, simplifying the overall assembly process while maintaining electrical insulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A retaining pin serves as an intermediary component that bridges the contact lever assembly and the non-conductive housing. The retaining pin extends through holes in the plates and is held in holding recesses of the housing, providing a simple mechanical connection that secures the assembly without requiring complex fastening mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If pins are used to hold the contact lever between plates, then the contact lever is securely positioned, but the assembly becomes difficult to insert into the housing

Engineering Contradiction:
Improvecontact lever positioningVSAvoidassembly insertion ease
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The contact lever, plates, and pins are pre-assembled into a complete module before insertion into the housing. The retaining pin is designed to extend beyond the plates during this pre-assembly stage, creating a protruding feature that facilitates subsequent insertion into the housing by engaging with holding recesses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The retaining pin extends in the dimension perpendicular to the plates (beyond the plate surfaces), creating a three-dimensional engagement structure. This allows the assembly to be inserted into the housing by hanging the protruding pin ends into holding recesses, transforming a potentially difficult planar assembly into an easy vertical insertion operation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the pin length exceeds the distance between plates, then the assembly can be hung in the housing, but the pin becomes longer and more complex

Engineering Contradiction:
Improveassembly insertion easeVSAvoidpin structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The retaining pin serves multiple functions: it positions the contact lever between the plates, secures the assembly to the housing by engaging holding recesses, and provides a hanging feature for insertion. This multi-functionality eliminates the need for separate components, simplifying the overall structure despite the pin's extended length.

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

4Manufacturing precision

If individual housing components are assembled to form the overall housing, then the housing can be precisely manufactured, but the assembly process becomes time-consuming

Engineering Contradiction:
Improvehousing manufacturing precisionVSAvoidassembly speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The housing is designed as a one-piece non-conductive component that integrates all housing functions (electrical insulation, structural support, contact lever mounting, and torque transmission). This eliminates the need to assemble multiple housing components, significantly improving assembly speed while maintaining manufacturing precision through modern one-piece molding techniques.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration provides excellent electrical insulation, facilitates easy assembly, and allows for torque transmission, while ensuring that the switching unit can be rotated for on/off switching, with predetermined contact forces achieved through spring mechanisms.

Implementation Method 1

a contact lever with at least one electrical switching contact (30, 31) is held between two plates (40, 41) by means of pins (51, 52) in a non-conductive housing (105) of the switching unit (100)

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

with the retaining pin (50) extending beyond the plates (40, 41) and thus enabling the subassembly preassembled with the plates, pins and contact levers to be hung in the non-conductive housing (105) of the switching unit (100)

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Implementation Method 3

a rotor pin extends through the housing of the switching unit, the two plates and the pivoting contact lever, the rotor pin forms the virtual pivot axis for the pivoting contact lever

Methodology Applied
Scientific EffectPivoting rotation: Axle

Implementation Method 4

in order to achieve predetermined contact forces, the contact lever can be pivoted relative to the housing of the switching unit, for example by means of springs

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2696359B1Electric switch and method for mounting the switch unit of an electric switch
Publication Date: 2017.08.30 SIEMENS AG
  • EP2696359B1 patent drawingFigure 1
  • EP2696359B1 patent drawingFigure 2
  • EP2696359B1 patent drawingFigure 3

AI summary

The invention relates, inter alia, to an electrical switch with at least one switching unit (100) comprising: a contact lever (20) pivotable about a pivot axis, with at least one electrical switching contact (30, 31), and two parallel plates (40, 41) between which the contact lever is resiliently held by means of pins (50-53). According to the invention, the contact lever with the plates and the pins is inserted into an electrically non-conductive housing (105) of the switching unit (100), wherein at least one of the pins forms a retaining pin (50), the length of the retaining pin exceeding the distance between the parallel plates, and wherein the retaining pin extends through a hole (80) in each of the two plates and is held with one end (110) in a retaining recess (120) of the housing (105) and with its other end (140) in an opposite retaining recess (150) of the housing.