Lathe Tool-Holder Blocking Device with Truncated-Cone Pawl

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Solution Overview

Problem

Existing methods for blocking and replacing tool-holders on CNC lathes are labor-intensive, require significant downtime, and result in increased production costs due to manual intervention and laborious adjustments, especially in multi-spindle setups.

Innovation Solution

A device featuring an anchoring pawl with a truncated-cone mechanism, combined with a nut screw or hydraulic actuator, allows for rapid and precise blocking and centring of tool-holders, enabling quick replacement and orientation without manual adjustments, using a combination of mechanical or hydraulic movements to engage and disengage the tool-holder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual blocking and centring operations are used for tool-holder replacement, then the device structure remains simple, but the replacement time and setup time increase significantly

Engineering Contradiction:
Improvetool-holder replacement speedVSAvoidblocking device structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The blocking device employs dynamic elements including a movable anchoring pawl that can engage and disengage from the tool-holder, and a truncated-cone element that enables automatic centring through rotational movement. These dynamic components allow rapid tool-holder replacement without manual intervention, directly improving productivity while maintaining reasonable device complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The truncated-cone element is pre-configured on the anchoring pawl to automatically perform centring action when the pawl engages with the tool-holder. This preliminary automatic centring eliminates the need for subsequent manual adjustments, reducing both replacement time and setup time

Inventive Principle:
Principle #10Preliminary action

2Reliability

If traditional blocking mechanisms are used, then the device is easy to manufacture, but the reliability and resistance over time decrease

Engineering Contradiction:
Improveblocking device reliabilityVSAvoiddevice manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The blocking device is segmented into distinct functional components: the anchoring pawl with truncated-cone element, the nut screw or hydraulic actuator mechanism, and the tool-holder interface. This segmentation allows each component to be manufactured independently using standard machining processes, maintaining ease of manufacture while improving overall reliability through better-defined functional zones and reduced stress concentrations

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent offers two embodiments: a mechanical embodiment using a nut screw and a hydraulic embodiment using a hydraulic actuator. The hydraulic substitution provides smoother operation and reduced mechanical wear, enhancing reliability over time while the mechanical embodiment remains simpler to manufacture

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

3Ease of operation

If multiple screws are used for blocking and centring positioning, then the blocking strength is sufficient, but the number of manual operations and production costs increase

Engineering Contradiction:
Improvetool-holder replacement operationVSAvoidnumber of blocking components
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The anchoring pawl integrates multiple functions into a single component: blocking (through engagement with the tool-holder flange), centring (through the truncated-cone element), and positioning (through the vertical movement guide). This merging eliminates the need for multiple separate screws and manual adjustment operations, directly improving ease of operation while reducing the quantity of components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The anchoring pawl serves as a universal component that performs blocking, centring, and positioning functions simultaneously for all tool-holder replacements. The truncated-cone element provides universal automatic centring capability regardless of the specific tool-holder being installed, reducing the need for tool-specific adjustment procedures

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

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 solution significantly reduces downtime and production costs by enabling fast and automatic tool-holder replacement and centring, ensuring high reliability and ease of use, with the truncated-cone mechanism facilitating quick locking and unlocking of tool-holders across multiple axes.

Implementation Method 1

The anchoring pawl 16 has a transversal through hole 24 which a screw 26 is inserted in, connecting said pawl to an irregular, prism-shaped element 28 or threaded lead screw with an inner trapezoidal thread

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

the remaining diametrical half-part of the pawl 16, indicated by reference number 16' comprises a vertical wall 20, orthogonal with respect to said plane 18, on which a female truncated-cone shaped recess 22 is made

Methodology Applied
Scientific EffectTruncated-cone mechanical advantage: Mechanical Advantage

Implementation Method 3

The means for moving the anchoring pawl 16 in a vertical direction comprise, in this case, a hydraulic actuator 64

Methodology Applied
Scientific EffectHydraulic actuation: Hydraulic Press

Data Source

PatentEP3357638B1Blocking device of tool-holder on lathes
Publication Date: 2020.10.14 ALGRA SPA
  • EP3357638B1 patent drawingFigure 1~4
  • EP3357638B1 patent drawingFigure 5~6
  • EP3357638B1 patent drawingFigure 7~8

AI summary

A blocking device (10) of tool-holders on lathes, especially for the rapid and precise blocking of tool-holders on CNC (Computer Numerical Control),single spindle or multi-spindle lathes as well as on transfer machines, milling centres of any kind and, in general, on machine tools which perform machining by chip removal, is paired with a tool-holder (12), motorized or non-motorized, connected to the existing support (14) on said lathes and comprises an anchoring pawl (16) provided with a female truncated-cone shaped recess (22). Said pawl is moved vertically with respect to the longitudinal axis of said tool-holder (12) by mechanical or hydraulic means driven to engage said female, truncated-cone shaped recess (22) with an inclined, male truncated-cone appendage (38) made on said tool-holder (12).