Bobbin Holder Assembly Rotation Stability

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Solution Overview

Problem

Existing thread winding housing assemblies for vertical hooks in sewing machines face issues with undesired relative rotation and handling inefficiencies, leading to thread waste and increased production costs due to the need for precise dimensional accuracy.

Innovation Solution

A thread winding housing assembly with a separately designed filament winding capsule that can be manufactured with high diameter accuracy, secured against rotation, allowing for easy removal and reinsertion, and featuring a non-rotatably connected web for easy grasping, a separate cover for guiding the looper thread, and a lift lock mechanism to prevent unwanted displacement, along with a brake leaf spring for tension adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the filament winding is fitted with a press fit into the filament winding housing, then rotation stability is improved, but manufacturing complexity increases due to requiring precise dimensional accuracy throughout the entire housing

Engineering Contradiction:
Improverotation stabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The filament winding housing is divided into two separate components: the filament winding capsule (which receives the filament winding) and the filament winding housing (which accommodates the capsule). The capsule can be manufactured with high diameter accuracy to ensure press fit stability, while the housing does not require corresponding dimensional accuracy, thus reducing overall manufacturing complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The critical function of precise dimensional accuracy is extracted from the entire housing and concentrated solely in the filament winding capsule. This allows the capsule to provide the necessary press fit stability while the housing can be manufactured with lower precision requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

2Stability of the object's composition

If the filament winding capsule is secured against rotation in the filament winding housing, then thread winding stability is improved, but insertion difficulty increases due to tighter tolerances

Engineering Contradiction:
Improvethread winding stabilityVSAvoidinsertion ease
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

Multiple anti-rotation mechanisms are combined: the web protrusion engaging with the recess, the bayonet lifting lock providing both lifting and rotational locking, and the spring clips providing additional rotational constraint. This combination ensures stable thread winding while maintaining ease of insertion through the tolerant web engagement.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the web is designed as a flap, then ease of grasping is improved, but structural rigidity decreases

Engineering Contradiction:
Improveease of graspingVSAvoidstructural rigidity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The web is designed with dynamic characteristics - it can be deflectable in certain directions to allow easy grasping and manipulation, while maintaining rigidity in other directions to provide structural support. This allows the web to adapt to user interaction while preserving necessary structural integrity.

Inventive Principle:
Principle #15Dynamics

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

This design reduces thread waste by enabling easy thread color changes without waste, lowers production costs by relaxing dimensional accuracy requirements, and provides consistent thread tension through adjustable clamping force, enhancing handling and operational efficiency.

Implementation Method 1

A brake leaf spring allows a defined gripper thread tension to be specified. A clamping contact force of the brake leaf spring on the jacket wall of the thread winding housing can preferably be adjusted

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The lifting device can be formed by a surmountable latching device, e.g. B. by a resilient locking component, which is fixed to the filament winding housing or to the filament winding capsule and for stroke protection with a fixed counter-locking component

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2589694B1Bobbin holder assembly for insertion into a loop taker housing of a vertical loop taker
Publication Date: 2015.03.04 DURKOPP ADLER GMBH
  • EP2589694B1 patent drawingFigure 1
  • EP2589694B1 patent drawingFigure 2
  • EP2589694B1 patent drawingFigure 3

AI summary

The inner pot module has a winder case which receives a winder in a state which adapted correctly. An inner pot receives the winder case. An upper surface of a fixed knob is non-rotatably connected to the winder case, and formed on an upper position with respect to a remaining portion of the inner pot.