Extendable Spirit Level Sliding Structure for Low-Friction Alignment

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Solution Overview

Problem

Existing extendable or telescopic spirit levels face issues with ease of movement due to components being in contact, leading to potential dust or dirt accumulation and hindered sliding motion.

Innovation Solution

Incorporation of sliding elements with spring properties that support and guide the base body and pull-out element, ensuring they remain aligned at the same level by applying force in the direction of the measuring sole, allowing for problem-free relative displacement while maintaining a distance between surfaces for easy movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the base body and extension element are in direct contact to enable relative movement, then the device can be extended and retracted, but dust or dirt accumulates in the contact area and friction increases, hindering smooth movement

Engineering Contradiction:
Improveextendable lengthVSAvoiddust and dirt accumulation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A dust cap is introduced as an intermediary component that covers the contact area between the base body and extension element when retracted. This mediator prevents dust and dirt from entering the sliding interface while allowing the telescopic function to operate normally. The dust cap is positioned to overlap with the extension element's cross-sectional profile, creating a protective barrier without interfering with the sliding mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the base body and extension element are in direct contact, then the structure remains simple, but the measuring surfaces may not remain perfectly aligned at the same level during movement

Engineering Contradiction:
Improvestructural simplicityVSAvoidmeasuring base alignment
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The dust cap is designed to extend the measuring base of the base body in such a way that it creates a common reference plane with the extension element's measuring base. This equipotential design ensures that both measuring surfaces remain aligned at the same level throughout the telescopic movement, maintaining measurement accuracy without requiring complex alignment mechanisms.

Inventive Principle:
Principle #12Equipotentiality

3Ease of operation

If sliding elements with spring properties are added to maintain alignment and reduce friction, then movement smoothness improves, but the device complexity increases

Engineering Contradiction:
Improvemovement smoothnessVSAvoidnumber of components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of adding complex mechanical spring elements, the patent utilizes the inherent flexibility of the dust cap material (such as rubber or elastomer) to provide the necessary compliance and alignment maintenance. The flexible dust cap naturally conforms to the extension element while maintaining contact pressure, reducing friction without requiring separate spring components.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Ensures smooth and secure alignment of measuring soles at the same level, reducing friction and preventing dust or dirt accumulation, thus enhancing the ease of movement and reliability of the spirit level.

Implementation Method 1

the first and the second sliding element each have at least one spring element and/or at least one section having spring properties

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

reducing friction and preventing dust or dirt accumulation, thus enhancing the ease of movement

Methodology Applied
Scientific EffectFriction reduction: Friction

Data Source

PatentEP3255380B1Spirit level
Publication Date: 2023.10.25 STABILA MESSGERATE GUSTAV ULLRICH GMBH & CO KG
  • EP3255380B1 patent drawingFigure 1~5
  • EP3255380B1 patent drawingFigure 6~7
  • EP3255380B1 patent drawingFigure 8~11

AI summary

The invention relates to a spirit level (10) comprising a base body (12) with a first measuring sole (52) and an extension element (14) connected thereto and displaceable relative thereto in its longitudinal direction and having a second measuring sole (54), the the first and the second measuring base run at the same level. In order to enable low-friction displacement, it is provided that a first sliding element (26) extends from the base body (12), which in some areas interacts with the pull-out element (14) in a form-fitting manner and this in or approximately in the normal direction of the measuring soles (52, 54). force is applied to it, and that a second sliding element (28) emanates from the pull-out element, which interacts with the base body in a form-fitting manner in some areas and applies a force to the pull-out element in or approximately in the normal direction of the measuring soles.