Spring-Loaded Spindle Liner Coupling for Rapid Lathe Changeover

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Solution Overview

Problem

The exchange of traditional spindle liners in machine tools is time-consuming and cumbersome, requiring the loosening and tightening of multiple bolts, leading to unwanted downtime in workshops that machine rod-shaped workpieces of varying diameters.

Innovation Solution

A spindle liner arrangement featuring a spring-loaded bayonet coupling with a mounting disc, clamping disc, and flange member, allowing for quick and tool-free manual exchange by utilizing a spring element and elongate fixation members with varying cross-sectional areas for secure fixation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional spindle liners are used with multiple fixation bolts, then secure fixation of the liner is achieved, but the exchange process becomes time-consuming and complex

Engineering Contradiction:
Improvesecure fixationVSAvoidexchange time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The fixation system is segmented into a mounting disc fixed to the spindle and a clamping disc attached to the liner, connected by multiple spring-loaded fixation members. This segmentation allows the liner to be quickly released by simply pulling it axially, as each fixation member independently engages and disengages, eliminating the need to manually loosen multiple bolts while maintaining secure fixation during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fixation members incorporate spring elements that provide dynamic engagement and disengagement capability. The springs allow the fixation members to flex during insertion and removal, enabling quick exchange by simple axial movement while maintaining reliable locked positioning during machining operations. This dynamic mechanism transforms static bolt fixation into a movable, tool-free release system.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple fixation bolts are used to secure the liner, then reliable fixation is achieved, but the operation complexity and tool requirements increase

Engineering Contradiction:
Improvefixation reliabilityVSAvoidexchange ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The fixation members are designed to be self-actuating through axial movement of the liner. When the liner is pulled axially, the fixation members automatically disengage from their locked positions without requiring external tools or manual manipulation of bolts. The spring elements provide the necessary force for engagement and disengagement, making the exchange process tool-free and simple while maintaining secure fixation during operation.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If a simple mounting structure is used, then ease of manufacture is improved, but fixation security may be compromised

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfixation security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The mounting disc and clamping disc are merged into a single integrated assembly that combines multiple functions: the mounting disc provides the fixation interface with the spindle, the clamping disc attaches to the liner, and spring-loaded fixation members provide secure locking. This merged structure achieves reliable fixation through a relatively simple manufacturing process, as the components can be produced separately and assembled together without complex machining operations.

Inventive Principle:
Principle #5Merging (Combining)

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 effortless, ergonomic, and rapid spindle liner exchange with secure fixation, reducing downtime and manufacturing costs while maintaining reliability and simplicity.

Implementation Method 1

at least one spring element arranged between the mounting disc and the clamping disc for urging the clamping disc longitudinally away from the mounting disc

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4450193B1Spindle liner arrangement for a machine tool
Publication Date: 2026.02.04 RAPID LINERS AB
  • EP4450193B1 patent drawingFigure 1
  • EP4450193B1 patent drawingFigure 2a
  • EP4450193B1 patent drawingFigure 2b

AI summary

A spindle liner arrangement for a lathe for feeding a rod-shaped workpieces comprises; a mounting disc (20); a clamping disc (30); a tubular liner (12) with a flange member (14) with penetrating third fixation holes (18) being elongate in the circumferential direction and exhibiting a wide portion (18a) and narrow portion (18b); at least one spring element (42) arranged between the mounting disc (20) and the clamping disc (30) for urging the clamping disc (30) longitudinally away from the mounting disc (20); and a plurality of fixation members (44) fixed to the mounting disc (20), extending through the clamping disc (30) and, when mounted, through third fixation holes (18) of the flange (14).