Spring-Loaded Actuating Part for Microswitch Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing control safety blocks for high-pressure cleaning devices with microswitches face reliability issues due to unpredictable actuation paths and sensitivity to vibrations, requiring critical adjustment and direct actuation by an adjusting screw.

Innovation Solution

A spring-loaded actuating part is introduced at the free end of the switching arm, which is displaced under the load of a compression spring, indirectly actuating the microswitch, ensuring a consistent and repeatable actuation path regardless of system oscillations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a microswitch is directly actuated by an adjusting screw at the free end of the switching arm, then the switching mechanism can be compact, but the actuation becomes unreliable under vibrations and requires critical adjustment

Engineering Contradiction:
Improvemicroswitch actuation reliabilityVSAvoidadjustment complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A spring-loaded actuating part is introduced as an intermediary between the switching arm and the microswitch. This actuating part includes a spring element that provides consistent actuating force and a cam surface that reliably engages the microswitch, eliminating the need for critical adjustment of the microswitch position while ensuring reliable actuation even under vibrations

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring constant and pre-load of the spring element are optimized to provide sufficient actuating force for reliable microswitch activation. The spring-loaded mechanism transforms the variable displacement of the switching arm into a consistent actuating force on the microswitch, changing the parameter from direct mechanical coupling to spring-mediated force transmission

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If an adjusting screw is used to set the actuation path of the microswitch, then the switching point can be precisely controlled, but the adjustment is tedious and expensive requiring counter nuts

Engineering Contradiction:
Improveswitching point precisionVSAvoidadjustment process simplicity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The spring-loaded actuating part serves as a mediator that provides consistent actuation geometry through its cam surface. This eliminates the need for precise adjustment of the microswitch position, as the spring mechanism inherently provides the correct actuation path and force, simplifying manufacturing while maintaining switching precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring-loaded actuating part automatically compensates for variations in switching arm displacement through its elastic properties. The spring element self-adjusts to provide consistent actuating force and cam surface engagement, eliminating the need for manual adjustment procedures and counter nuts

Inventive Principle:
Principle #25Self-service

3Reliability

If the control piston vibrates undesirably in the system, then the microswitch can be actuated undesirably, but increasing the actuation path stability reduces system responsiveness

Engineering Contradiction:
Improveswitching stabilityVSAvoidswitching response speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The spring element acts as a cushioning element that absorbs vibrations and irregularities in the switching arm movement before they reach the microswitch. This beforehand cushioning ensures stable actuation while the spring's elastic properties allow rapid response to legitimate pressure changes, maintaining both reliability and speed

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 provides reliable and consistent actuation of the microswitch, eliminating the need for precise adjustment and reducing the impact of vibrations, ensuring consistent operation of the high-pressure pump.

Implementation Method 1

a compression spring (14) arranged on the actuating part (10, 30) which ensures reliable displacement of the actuating part (10, 30) in the direction of the switching cam (18) of the microswitch (17) and away from it

Methodology Applied
Scientific EffectCompression spring force: Spring

Data Source

PatentEP2518320B1Control safety block for high pressure cleaning devices with switching device
Publication Date: 2015.07.01 NILFISK-ADVANCE AS
  • EP2518320B1 patent drawingFigure 1~3
  • EP2518320B1 patent drawingFigure 4~5

AI summary

The regulating safety block comprises a switching device (1) for a high pressure pump, a micro-switch (17), and a switching cam (18) which is actuated by a switching arm (2) by the displacement of a spring (3). The high pressure of the high pressure pump is acted upon the control piston (4). The actuation of the micro-switch is carried out through the free end of the switching arm, under the load of a compression spring (14) which is slidably mounted on an actuator (10).