Clamping Device with Tensile-Force Limiting for Sheet-Metal Parts

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Solution Overview

Problem

Existing clamping devices for securing workpieces, particularly in the automotive industry, often apply excessive clamping force due to imprecise adjustments, risking damage to the workpiece or the device, especially when clamping sheet metal parts with varying thicknesses.

Innovation Solution

A clamping device with an integrated tensile force limiting mechanism, featuring a spring element that absorbs excess force, preventing damage by maintaining a maximum clamping force, and ensuring secure fixation without deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clamping force is increased to securely fix the workpiece, then the workpiece stability is improved, but the risk of damaging the workpiece or clamping device increases

Engineering Contradiction:
Improveworkpiece stabilityVSAvoiddamage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a tensile force limiting mechanism that acts as a cushion against excessive force. The mechanism includes a maximum force determiner and a limiter that prevents the actuator from applying force beyond a predetermined threshold, thereby cushioning against potential damage before it occurs.

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

Solution Approach 2:

The patent implements a feedback mechanism where the actual clamping force is monitored and compared against a predetermined maximum force. When the force approaches or exceeds the limit, the system provides feedback to prevent further force application, ensuring the workpiece is securely clamped without exceeding safe force levels.

Inventive Principle:
Principle #23Feedback

2Reliability

If the clamping force is increased to prevent workpiece shifting, then the clamping security is improved, but the clamping device itself may suffer damage or deformation

Engineering Contradiction:
Improveclamping securityVSAvoidclamping device integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The tensile force limiting mechanism serves as a protective cushion for the clamping device. By predetermined maximum force levels before excessive force can be applied, the mechanism prevents damage to the clamping device components while maintaining sufficient clamping security.

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

Solution Approach 2:

The feedback mechanism continuously monitors the applied force and provides real-time information to control the actuator. When the force approaches the maximum threshold, the feedback system adjusts the actuator to maintain force within safe limits, protecting the clamping device from damage.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If the adjustment precision is improved to adapt to workpiece thickness, then the clamping adaptability is improved, but the complexity of the adjustment mechanism increases

Engineering Contradiction:
Improveworkpiece thickness adaptationVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a feedback-based force control system that automatically adapts to workpiece thickness variations. Instead of complex mechanical adjustments, the system uses force sensing and control to maintain optimal clamping force across different workpiece geometries, simplifying the adjustment mechanism while improving adaptability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the control parameter from mechanical position adjustment to force magnitude control. By controlling the clamping force rather than the physical position of clamping elements, the system achieves better adaptability to varying workpiece thicknesses with a simpler mechanism.

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 device prevents excessive clamping force, safeguarding the workpiece and the clamping device from damage while maintaining secure clamping, even with varying workpiece thicknesses.

Implementation Method 1

a spring element (34) arranged between the first and second rod sections (29, 32). The spring element (34) is designed to deform elastically when the tensile force exceeds a maximum force

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4640374A1Clamping device
Publication Date: 2025.10.29 WITTE BARSKAMP GMBH & CO KG
  • EP4640374A1 patent drawingFigure 1~2
  • EP4640374A1 patent drawingFigure 3~4
  • EP4640374A1 patent drawingFigure 5~7

AI summary

A clamping device (10) for securing workpieces has a body (11) on which a contact surface (16) for a section of a workpiece is arranged, a centering mandrel (17) projecting outwards from the body (11) beyond the contact surface (16, 116), a pair of clamping elements (20) each having a pressure end (19), a tension element (24) coupled to the clamping elements (20) and an actuator (22) for applying a tension force to the tension element (24).The clamping elements (20) are movably arranged in the body (11) and coupled to the tensioning element (24) such that, in a released position of the tensioning element (24), their contact ends (19) are inserted into slots (18) formed on opposite sides of the centering mandrel (17) and into the centering mandrel (17). In a clamped position of the tensioning element (24), obtained from the released position by applying a tensile force to the tensioning element (24), their contact ends (19) extend radially out of the slots (18) towards the contact surface (16), with their end faces (21) of the contact ends (19) pointing towards the contact surface (16). The tensioning element (24) has an integrated tensile force limiting mechanism.