Spring Coupling for Threaded Spindle End-Stop Torsion Relief

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Solution Overview

Problem

Existing power tools, such as pipe presses, face mechanical stress and potential damage when the threaded spindle drive reaches its extreme positions, leading to high force, torque, and current intensity on the motor and other components.

Innovation Solution

Incorporating a coupling device with a spring element, such as a torsion bar spring, to absorb torsional forces and reduce mechanical stress on the threaded spindle drive, thereby mitigating the risk of damage during extreme positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the threaded spindle drive is used in extreme positions (fully extended or retracted), then the power tool can achieve maximum pressing force, but the motor and transmission components are subjected to high torque and blocking current that can cause permanent damage

Engineering Contradiction:

Improvepressing forceVSAvoidcomponent durability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The coupling device incorporates a spring element that acts as a cushioning mechanism before the extreme positions are reached. The spring element absorbs and reduces the torsional forces and blocking currents that occur when the threaded spindle drive reaches its limits, thereby protecting the motor and transmission components from permanent damage while still allowing maximum pressing force to be achieved

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a coupling device with spring element is added to reduce torsional stress, then component protection is improved, but device complexity increases

Engineering Contradiction:

Improvecomponent protectionVSAvoidcoupling device structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The coupling device merges the spring element with the existing transmission components. The spring element is integrated into the coupling device that already connects the transmission device to the threaded spindle drive, combining the protective function with the existing mechanical linkage rather than adding a completely separate protection mechanism

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

The use of a spring element in the coupling device effectively reduces torsional stress, preventing damage to the power tool components and ensuring reliable operation even at extreme positions of the threaded spindle drive.

Implementation Method 1

at least one spring element for reducing torsion acting on the coupling device is comprised

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12343855B2Spring element and coupling device

Publication Date: 2025.07.01 HILTI AG

AI summary

Power tool, in particular a pipe press, including a drive, a transmission device, a threaded spindle drive and a linear actuator, wherein a torque generated by the drive is transmissible via the transmission device and the threaded spindle drive to the linear actuator. The power tool includes a coupling device for converting a rotational movement generated by the transmission device into a linear movement, to be transmitted to the threaded spindle drive, from the transmission device to the threaded spindle drive, wherein at least one spring element for reducing torsion acting on the coupling device is comprised.