Synchronized Claw Puller for Long-Stroke Annular Removal

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Solution Overview

Problem

Conventional pullers for removing annular elements from axles are inefficient, hazardous, and require multiple phases of operation due to independent claw engagement and limited stroke, posing safety risks and inefficiencies.

Innovation Solution

A puller design featuring a collar with synchronized claws, a synchronizer, and an abutting assembly, allowing for a long stroke operation by pivotally connecting claws to the collar and using a synchronizer to control their opening and closing, integrated with a hydraulic or pneumatic system for efficient detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pullers use independent claws without interconnection, then the structure is simple, but the claws may disengage accidentally from the annular element causing safety hazards

Engineering Contradiction:
Improveclaw engagement reliabilityVSAvoidclaw interconnection structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple claws into a unified structure where they are interconnected through a common collar assembly. The claws share common pivotal connectors and a synchronizing mechanism ensures they move together as a coordinated unit, preventing accidental disengagement while maintaining structural integration.

Inventive Principle:
Principle #5Merging (Combining)

2Length of moving object

If a threaded rod is used to move the annular element, then a long stroke is achieved, but the rotation operation is inefficient

Engineering Contradiction:
Improvestroke lengthVSAvoidextension operation efficiency
Core Design Contradiction:
Length of moving objectVSProductivity

Solution Approach 1:

The patent replaces the threaded rod's rotational mechanical system with a direct linear extension mechanism. The abutting assembly extends linearly along the axial direction without requiring rotation, converting the operational mode from rotational-to-linear conversion to direct linear motion, thereby improving efficiency while maintaining long stroke capability.

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

3Speed

If a hydraulic device is used to extend the piston rod, then the extension is fast, but the stroke is short requiring multiple phases

Engineering Contradiction:
Improveextension speedVSAvoidstroke length
Core Design Contradiction:
SpeedVSLength of moving object

Solution Approach 1:

The patent merges the advantages of both threaded rod and hydraulic device by combining a fast-extension mechanism with a long-stroke abutting assembly. The abutting assembly is designed to provide both rapid extension speed and sufficient stroke length in a single continuous operation, eliminating the need for multiple phases while maintaining high speed.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If the synchronizer closes the claws by protuberances, then the claws are synchronized, but the synchronizer structure becomes complex

Engineering Contradiction:
Improveclaw synchronizationVSAvoidsynchronizer structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses protuberances on the synchronizer as intermediary elements that engage with corresponding recesses on the claws. These protuberances act as simple mechanical mediators that transmit motion from the synchronizer to the claws, ensuring synchronized movement without requiring complex linkage mechanisms or additional actuating systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design ensures safe, efficient, and convenient detachment of annular elements with a single-phase operation, reducing user hazards and operational inefficiencies by synchronizing claw movement and extending the stroke length.

Implementation Method 1

The synchronizer includes a receiving portion for receiving the protuberances. The synchronizer is movable in the collar between an opening position and a closing position. In the opening position, the synchronizer opens the claws by the protuberances. In the closing position, the synchronizer closes the claws by the protuberances.

Methodology Applied
Scientific EffectMechanical coupling: Mechanical Force

Implementation Method 2

The abutting assembly is extensible from the collar. The abutting assembly is inserted in the screw hole of the collar.

Methodology Applied
Scientific EffectLinear extension: Displacement

Data Source

PatentEP3984701B1puller
Publication Date: 2026.04.29 CHEN YI FANG
  • EP3984701B1 patent drawingFigure 1
  • EP3984701B1 patent drawingFigure 2
  • EP3984701B1 patent drawingFigure 3

AI summary

A puller includes a collar, claws, a synchronizer and an abutting assembly. The collar includes slots and pivotal connectors located corresponding to the slots. The claws are pivotally connected to the pivotal connectors. Each of the claws includes a protuberance movable in a corresponding one of the slots. The synchronizer includes a receiving portion for receiving the protuberances. The synchronizer is movable in the collar between an opening position and a closing position. In the opening position, the synchronizer opens the claws by the protuberances. In the closing position, the synchronizer closes the claws by the protuberances. The synchronizer is extensible from the collar.