Gripper Head Pneumatic Thread Clamp for Weaving Machines

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Solution Overview

Problem

Existing rapier weaving machines face challenges in achieving high speeds due to the inability to adapt the clamping force of thread clamps to different yarn properties and the lack of contactless, reliable control of thread clamps, especially in the middle of the machine.

Innovation Solution

A rapier head with a thread clamp system that utilizes a first hollow body under internal pressure to exert a clamping force, combined with a restoring spring and a valve system for contactless control, allowing for adjustable clamping force and reliable thread transfer without mechanical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spring-loaded thread clamps are used in prior art, then the structure is simple, but the clamping force cannot be adapted to different yarn properties while the machine is running

Engineering Contradiction:
Improveadaptability of clamping force to different yarn propertiesVSAvoidcomplexity of thread clamp control system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the clamping force adjustable during machine operation. The thread clamp system transitions from a fixed spring-loaded mechanism to a dynamically controllable system where the clamping force can be adapted to different yarn properties while the machine is running, through pneumatic or electromagnetic actuators that modify the clamping force in real-time

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs pneumatics by introducing a bellows attached to the gripper head that can be put under internal pressure. This pneumatic system allows for contactless control of the thread clamp, enabling the clamping force to be adjusted dynamically during operation without mechanical contact, thus resolving the contradiction between adaptability and complexity

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Speed

If contactless actuators are used to control thread clamps, then higher speeds can be achieved, but reliable control of thread clamps in the middle of the machine is not possible with existing designs

Engineering Contradiction:
Improvespeed of rapier weaving machineVSAvoidreliability of thread transfer in the middle of the machine
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies universality by designing a control system that can reliably operate at high speeds across all positions of the rapier head, including the middle of the machine. The bellows-based pneumatic system or electromagnetic actuator provides universal contactless control capability that works consistently regardless of the rapier head's position, enabling both high speed and reliable thread transfer in the middle of the machine

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces mechanical contact-based control systems with contactless pneumatic or electromagnetic actuation. This substitution eliminates mechanical wear and allows for reliable high-speed operation, as the contactless actuators can precisely control the thread clamps without the limitations of mechanical linkages that plagued previous middle-machine transfer reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If mechanical control systems are used for thread clamps, then the structure is straightforward, but mechanical wear reduces reliability over time

Engineering Contradiction:
Improvelong-term reliability of thread clamp controlVSAvoidcomplexity of control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical control systems with contactless pneumatic or electromagnetic actuation mechanisms. The bellows-based pneumatic system or electromagnetic actuator eliminates mechanical contact between control components and the thread clamp, thereby eliminating mechanical wear and improving long-term reliability while maintaining manageable system complexity through standardized actuator designs

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables high-speed operation with adaptable clamping force and reliable thread transfer, reducing mechanical wear and improving transfer reliability, especially in the middle of the machine.

Implementation Method 1

the volume of which is increased under the internal pressure of a gaseous and therefore also compressible medium

Methodology Applied
Scientific EffectInternal pressure of gaseous medium: Pressure Increase

Implementation Method 2

internal pressure of a gaseous and therefore also compressible medium

Methodology Applied
Scientific EffectCompressible medium: Gas Compressor

Implementation Method 3

The restoring means is preferably designed as a spring

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 4

the pressure can be equalized between the two hollow bodies by opening the valve. The gaseous medium is passed from one hollow body to the other

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 5

a closing means designed as a valve spring. The valve body is thereby pressed against a valve seat

Methodology Applied
Scientific EffectValve spring force: Spring

Data Source

PatentEP2640880B1Gripper head for the insertion of weft threads on a gripper weaving machine
Publication Date: 2015.08.19 LINDAUER DORNIER GMBH
  • EP2640880B1 patent drawingFigure 1
  • EP2640880B1 patent drawingFigure 2
  • EP2640880B1 patent drawingFigure 3

AI summary

A thread clamp (3, 103, 203) is attached to a gripper head (1, 101, 201) for the insertion of weft threads (2) on a gripper weaving machine, which thread clamp (3, 103, 203) has a stationary clamping part (4, 104, 204) and a movable clamping part (5, 105, 205). In order to open or close the thread clamp (3, 103, 203), it is connected to a hollow body (6, 106, 206) which can be expanded by compressed air. A second expandable hollow body (8, 108, 208) is compressed by means of a control device which is attached on the gripper weaving machine, in such a way that an internal pressure is built up therein. Moreover, there is a valve (9, 109, 209) on the gripper head, which valve (9, 109, 209) is configured as an automatically closing non-return valve. The valve (9, 109, 209) is opened by an increase in the internal pressure in the second expandable hollow body (8, 108, 208) or by contactless transmission of signals or forces of an actuator (13, 113, 213) which is attached on the gripper weaving machine. The inlet and outlet of the valve are connected to in each case one of the two expandable hollow bodies (6, 8, 106, 108, 206, 208) in such a way that, when the valve (9, 109, 209) opens, a pressure equalization takes place between the two hollow bodies (6, 8, 106, 108, 206, 208). As a result of this pressure compensation, the thread clamp (3, 103, 203) is opened or closed, with the result that a weft thread (2) can be received or released by the gripper head (1, 101, 201).