Tension Spring Handle Vibration Decoupling

Solution Overview

Problem

Compression springs in hand-held power tools, such as demolition hammers, tend to buckle under compressive loading, leading to friction with spring guides and impaired vibration decoupling, which reduces the effectiveness of vibration isolation.

Innovation Solution

The use of tension springs instead of compression springs, which remain under tensile stress and are designed with specific mounting and fastening configurations to prevent buckling and minimize friction, ensuring reliable decoupling of handles from tool body vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compression springs are used for vibration decoupling, then the handles can be mounted on the tool body, but the springs buckle under compressive loading causing friction with spring guides and impairing vibration decoupling

Engineering Contradiction:

Improvevibration decoupling reliabilityVSAvoidspring buckling and friction

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional compression spring approach by using tension springs instead. The tension springs are arranged to be pulled rather than compressed, fundamentally changing the loading mode from compressive to tensile, which eliminates buckling and friction issues associated with compression springs.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the mechanical parameter of spring loading from compression to tension. By modifying the loading state parameter, the tension springs operate in a regime where they maintain consistent contact with mounting surfaces without buckling, thereby eliminating friction and improving vibration decoupling reliability.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If compression springs are used, then the handles are mounted on the tool body, but friction occurs between the spring and spring guide reducing decoupling effectiveness

Engineering Contradiction:

Improvehandle mountingVSAvoidvibration decoupling effectiveness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent inverts the conventional compression spring approach by using tension springs instead. The tension springs are arranged to be pulled rather than compressed, fundamentally changing the loading mode from compressive to tensile, which eliminates buckling and friction issues associated with compression springs.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the mechanical parameter of spring loading from compression to tension. By modifying the loading state parameter, the tension springs operate in a regime where they maintain consistent contact with mounting surfaces without buckling, thereby eliminating friction and improving vibration decoupling reliability.

Inventive Principle:

Principle #35Parameter changes

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

The tension springs effectively prevent buckling and friction, ensuring that vibrations are significantly reduced or not transmitted to the handles, enhancing vibration decoupling and maintaining operational comfort and efficiency.

Implementation Method 1

a tension spring, by means of which the handle is hooked on the tool body in such a way that the handle is decoupled from vibrations acting on the tool body

Methodology Applied

Scientific EffectVibration: Vibration

Implementation Method 2

a tension spring, by means of which the handle is hooked on the tool body

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12048993B2Hand-held power tool

Publication Date: 2024.07.30 HILTI AG

AI summary

A hand-held power tool includes a handle which is grippable by a user, a tool body, a pivot pin, where the handle is pivotably mounted on the tool body by the pivot pin, and a tension spring, where the handle is hooked on the tool body by the tension spring and the handle is decoupled from vibrations acting on the tool body by the tension spring.