Gripper Shaft Toggle Fastening for Quick Sewing Pattern Changes

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Solution Overview

Problem

Existing multi-needle sewing machines face challenges in quickly and securely attaching grippers to gripper shafts, requiring complex adjustments and tools, leading to surface wear and potential errors during pattern changes.

Innovation Solution

A device utilizing a toggle screw or latching mechanism for attaching grippers to gripper shafts, allowing for easy detachment and precise adjustment, with features like a T-shaped hammer head and disc spring for secure fastening and adjustable components for precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking bracket with high clamping force is used to secure the looper holder on the looper shaft, then the secure fit is improved, but surface wear on the looper shaft increases

Engineering Contradiction:
Improvesecure fit of looper holderVSAvoidsurface wear on looper shaft
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a toggle screw mechanism as an intermediary between the looper holder and the looper shaft. The toggle screw engages with a recess in the looper shaft through a locking action that distributes the clamping force over a larger area and involves additional contact surfaces, thereby reducing direct surface wear on the looper shaft while maintaining secure fixation of the looper holder

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If complicated screw connections are used to attach needles to the needle bar, then the secure attachment is improved, but the ease of operation deteriorates due to difficulty in access and requirement for special tools

Engineering Contradiction:
Improvesecure attachment of needlesVSAvoidease of needle removal and reattachment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the attachment system into modular components: needle, needle holder, and needle bar with integrated locking mechanisms. Each needle can be independently attached or removed from the needle bar through simple manual operations, eliminating the need for special tools while maintaining secure attachment through the segmented design with dedicated locking elements for each needle position

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If manual adjustment of hook holders on the hook shaft is performed to align hooks with needles, then the adjustment precision can be improved, but the time required and complexity of the process increases

Engineering Contradiction:
Improvealignment precision of hook to needleVSAvoidtime for pattern conversion
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent incorporates preliminary alignment features in the design of hook holders and needle bars, such as pre-positioned mounting locations and guide elements that automatically align hooks with needles during assembly. This preliminary configuration eliminates the need for time-consuming manual adjustments while maintaining the required alignment precision through built-in mechanical guides and standardized positioning systems

Inventive Principle:
Principle #10Preliminary action

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 quick, secure, and precise attachment of grippers, reducing the need for complex tools and minimizing surface wear, facilitating efficient pattern changes and adjustments without requiring additional components.

Implementation Method 1

a disc spring (38) which is arranged between the toggle screw (11) and the support element (3) and which is prestressed in the released state

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The connecting element (11) is designed as a toggle screw

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3739097B1Device for fixing a gripper on a gripper shaft of a textile machine
Publication Date: 2024.06.05 NAHMASCHINENFABRIK EMIL STUTZNACKER GMBH & CO KG
  • EP3739097B1 patent drawingFigure 1
  • EP3739097B1 patent drawingFigure 2
  • EP3739097B1 patent drawingFigure 3~4

AI summary

The invention relates to a device for attaching a gripper (1; 101) to a gripper shaft of a textile machine, in particular a sewing machine, preferably a multi-needle sewing machine, with a support element (3; 103) for the gripper (1; 101), wherein the support element (3; 103) for the gripper (1; 101) is connected to a holder (2; 102) or the gripper shaft via a connecting element such that the support element (3; 103) for the gripper (1; 101) is detachable from the holder (2; 102) or the gripper shaft, wherein the connecting element is designed as a toggle screw (11) or as a locking device (152), wherein the toggle screw (11) rotatably engages a bore in the support element (3) in a corresponding opening in the holder (2) or the gripper shaft, engaging a counter-bearing, or wherein the locking device (152) is designed as a positive-locking connection is formed between the support element (103) and the holder (102).