Steady Rest Scissor Mechanism for Workpiece Alignment

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Solution Overview

Problem

Existing steady rests for machine tools require manual dexterity and time to align rotationally symmetrical workpieces correctly with the machine tool's axis of rotation, risking incorrect machining due to potential misalignment.

Innovation Solution

A steady rest design featuring a base body with linear drives, scissor levers, and support levers that allow for adjustable guidance of workpieces, ensuring central alignment with minimal operator effort through motorized adjustments and a controller for automated setup, accommodating a wide range of workpiece diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual alignment of support bodies on workpiece is used, then operator control over workpiece positioning is achieved, but time expenditure and risk of misalignment increase

Engineering Contradiction:
Improvealignment precisionVSAvoidsetup time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The steady rest device performs self-alignment through the scissor mechanism that automatically positions the support bodies according to the workpiece diameter. The operator only needs to input the diameter value, and the system automatically calculates and executes the correct positioning, eliminating the need for manual alignment operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical alignment operations with an automated control system that uses electrical drives and computational algorithms to position the support bodies. The control unit processes the diameter input and automatically actuates the linear drives to achieve precise alignment.

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

2Adaptability or versatility

If fixed geometry steady rest is used, then structural simplicity is maintained, but adaptability to different workpiece diameters is reduced

Engineering Contradiction:
Improveworkpiece diameter rangeVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The steady rest employs a dynamic scissor mechanism that can continuously adjust its geometry to accommodate different workpiece diameters. The support bodies are positioned along the generatrix of the workpiece, and the scissor mechanism's variable configuration allows adaptation to any diameter within the specified range while maintaining structural integrity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device integrates multiple functions into a single system: diameter measurement, calculation, mechanical adjustment, and alignment all occur within the unified steady rest structure. The control unit serves multiple purposes by processing diameter input and generating positioning commands for both support bodies.

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

3Reliability

If multiple separate support bodies are used, then comprehensive workpiece support is achieved, but alignment complexity and time expenditure increase

Engineering Contradiction:
Improveworkpiece support stabilityVSAvoidsetup complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent combines the positioning and alignment functions for multiple support bodies into a single integrated control process. The control unit simultaneously manages both support bodies, coordinating their positions based on the workpiece diameter to ensure they are correctly aligned with the workpiece axis and the machine tool's rotation axis.

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

Facilitates quick, accurate, and stable centric guidance of workpieces with reduced risk of misalignment and deflection, suitable for various diameters, enhancing machining precision and efficiency.

Implementation Method 1

at least one linear drive transverse to the machine bed, with which two drive bodies can be moved in opposite directions on the base body

Methodology Applied
Scientific EffectLinear motion mechanism:

Implementation Method 2

two scissor levers, which are arranged transversely to the machine bed in a V-shape... the distance between the supports can be changed by scissor-like pivoting of the scissor levers

Methodology Applied
Scientific EffectScissor mechanism:

Implementation Method 3

The support levers thus laterally support the scissor levers when a workpiece is placed on them. In this way, the advantageous effect is achieved that deflection of the scissors-type lever due to the weight of the workpiece placed on it is reduced

Methodology Applied
Scientific EffectMechanical support and force transmission:

Implementation Method 4

Vibrations occurring in the workpiece are to be dampened

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 5

particularly in the case of long or thin workpieces, deflection of the workpiece due to its own weight and the passive forces exerted by the tool are to be reduced

Methodology Applied
Scientific EffectMechanical support and force distribution:

Data Source

PatentEP3501728B1Steady rest for a machine tool
Publication Date: 2020.04.15 WEILER WERKZEUGMASCH
  • EP3501728B1 patent drawingFigure 1
  • EP3501728B1 patent drawingFigure 2
  • EP3501728B1 patent drawingFigure 3

AI summary

The steady rest (L) according to the invention for a machine tool with a machine bed for guiding a rotationally symmetrical workpiece (W) comprises a base body (G) for support on the machine bed, at least one linear drive (S) transverse to the machine bed, whereby two drive bodies (S13, S14) are movable in opposite directions on the base body, two scissor levers (L1, L2) which are arranged in a V-shape transverse to the machine bed, wherein one end of each is rotatably held on the base body and the other end of each has a support (L13, L23) for the workpiece, and two support levers (L3, L4) which are rotatably held at one end on a drive body and at the other end on a scissor lever in the area of ​​a support, so that the distance between the supports can be changed by pivoting the scissor levers in a scissor-like manner by moving the drive bodies.A steady rest according to the invention offers the advantage that a workpiece is already horizontally centered in the steady rest when placed on it, and this remains almost unchanged when the linear drive is actuated.