Torque Wrench Handle with Cylindrical Rollers

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Solution Overview

Problem

Existing torque wrench designs are complex, requiring multiple parts and increased manufacturing and assembly efforts due to their multi-part nature, which complicates the process of setting and securing the desired torque.

Innovation Solution

A simplified torque wrench design featuring a one-piece handle with cylindrical rollers that engage with longitudinal grooves and a locking sleeve, allowing for easier adjustment and assembly, using a plastic locking sleeve and rollers for radial deflection to change the release torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multi-part handle design with adjusting tube, balls, helical compression spring, handle tube and pins is used, then the torque wrench can securely lock the handle on the shaft, but the manufacturing effort and assembly complexity increase significantly

Engineering Contradiction:
Improvelocking reliabilityVSAvoidhandle structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate components (adjusting tube, handle tube, balls, spring, pins) into a single integrated handle structure. The locking elements are built directly into the handle as integrated features rather than separate parts, reducing the number of components while maintaining the locking function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The handle is divided into functional zones with integrated locking elements positioned at specific locations. The longitudinal grooves are formed as continuous features within the handle body, allowing multiple locking points without requiring separate discrete components for each locking function.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple individual parts such as adjusting tube, balls, helical compression spring, handle tube and pins are used, then the torque wrench can adjust and secure torque values, but the assembly process becomes more time-consuming and complex

Engineering Contradiction:
Improvetorque adjustment capabilityVSAvoidassembly time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The adjusting tube and handle tube are merged into a single integrated handle structure with built-in locking elements. The torque adjustment mechanism is integrated directly into the handle body, eliminating the need for separate adjusting components and reducing assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking elements and longitudinal grooves are pre-formed as integral features during the handle manufacturing process rather than requiring separate assembly steps. The structure is prepared in advance with built-in adjustment and locking capabilities that are activated during use rather than requiring complex assembly procedures.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If balls are used as locking elements pressed into longitudinal grooves, then the handle can be secured against rotation, but the radial loading and contact stress increase compared to cylindrical rollers

Engineering Contradiction:
Improverotation preventionVSAvoidradial loading
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The locking elements are designed as cylindrical rollers with curved surfaces that engage with rounded longitudinal grooves. The cylindrical shape distributes contact stress over a larger area compared to point-contact balls, reducing peak stresses while maintaining the rotation-prevention function.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The locking element geometry is changed from spherical balls to cylindrical rollers, altering the contact mechanics. This parameter change transforms point-contact loading into line-contact loading, reducing radial stresses and improving load distribution while maintaining the same rotational locking function.

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 design reduces manufacturing complexity, allows for easier assembly, and provides a more intuitive method for setting and securing torque values, enhancing user comfort and handling through a reduced number of parts and improved radial loading characteristics.

Implementation Method 1

A helical compression spring is arranged between the adjusting tube and the handle tube, which permanently loads the handle tube in the direction of the end of the torque wrench facing away from the reversible ratchet

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the cylindrical roller has a radial alternative. As a result, the handle can be twisted and shifted relative to the shaft

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1825959B1Torque wrench
Publication Date: 2010.01.27 HAZET WERK HERMANN ZERVER GMBH & CO KG
  • EP1825959B1 patent drawingFigure 1
  • EP1825959B1 patent drawingFigure 2
  • EP1825959B1 patent drawingFigure 3

AI summary

The tool (1) has a long shaft (5) with a rotating and slightly axially movable handle (3) at its upper end (2) and a head (8) at its opposite end (19). A scale (12) is located at the surface of the shaft (11). The surface of the handle (3) is provided with a multitude of parallel positioned slots (9) for the accommodation of a locking element. The locking element is designed in a cylindrical shape engaging with a recess at a locking sleeve (4) after this has been rotated into the appropriate position.