Sleeve-Driven Tool Holder Clamping Wedge for Compact Turrets

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing clamping mechanisms for driven tool holders in machine tools require significant axial space and are not suitable for tool turrets with limited space, often necessitating manual operation and separate force-amplifying components like gas springs.

Innovation Solution

A compact clamping device with a housing, drawbar, wedge engagement member, and sleeve arrangement that uses a wedge mechanism to achieve locking without separate force-amplifying means, allowing for automatic operation and integration in tool turrets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a traditional clamping mechanism with separate force-amplifying components (gas spring) is used, then the clamping force is sufficient, but the axial space requirement increases significantly

Engineering Contradiction:
Improveclamping forceVSAvoidaxial space
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The patent combines the force amplification function directly into the wedge engagement member itself, eliminating the need for separate gas spring components. The wedge member integrates both the clamping action and force amplification in a single compact element, resolving the contradiction between sufficient clamping force and reduced axial space requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention transitions from linear force application (gas spring) to angular/wedge-based force amplification. By using the wedge geometry with inclined surfaces, the mechanism amplifies force in a different dimensional approach, achieving sufficient clamping force within a compact axial footprint suitable for tool turret integration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If a manual cam shaft operation is used, then the structure is simple, but the automation capability is lost

Engineering Contradiction:
Improvestructure simplicityVSAvoidautomatic operation capability
Core Design Contradiction:
Device complexityVSExtent of automation

Solution Approach 1:

The clamping mechanism is designed to be self-actuating through the wedge-sleeve interaction. When the sleeve moves axially, the wedge geometry automatically generates the clamping force without requiring external manual operation or complex control systems, enabling integration with automatic tool changing while maintaining structural simplicity.

Inventive Principle:
Principle #25Self-service

3Length of moving object

If a compact design without separate force-amplifying means is used, then the space utilization improves, but the self-locking capability must be achieved through the wedge geometry alone

Engineering Contradiction:
Improveaxial spaceVSAvoidself-locking capability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The wedge engagement member is pre-configured with specific angular geometry that inherently provides self-locking capability. The inclined surfaces are designed at angles that ensure the clamping force is maintained without requiring additional locking mechanisms, achieving reliable self-locking through the preliminary geometric design of the wedge itself.

Inventive Principle:
Principle #10Preliminary action

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 provides a compact, self-locking clamping mechanism suitable for tool turrets, eliminating the need for gas springs and enabling automatic operation, thus enhancing the efficiency and space utilization in machine tools.

Implementation Method 1

a wedge comprising a first pressure receiving surface, a first wedge surface facing towards the rear end, and a second wedge surface facing towards the forward end, wherein the first and second wedge surfaces approach each other in a radial direction towards the longitudinal axis

Methodology Applied
Scientific EffectWedge mechanism: Wedge

Implementation Method 2

The sleeve, the wedge, the wedge engagement member and the drawbar are such arranged that, when the sleeve is moved in the first direction, the first pressure applying surface presses the wedge radially inwards in the aperture by sliding and pressing against the first pressure receiving surface of the wedge, resulting in the first and second wedge surfaces sliding and pressing against the wedge engagement slide surface and the aperture slide surface, respectively, to force the drawbar to displace inside the bore towards the rear end

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Implementation Method 3

The clamping device can be designed for keeping the device in a clamped state without requiring separate means (such as a gas spring), and the device can be made very compact in the longitudinal direction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3750653B1Clamping decvice for tool holder
Publication Date: 2022.06.01 SANDVIK COROMANT
  • EP3750653B1 patent drawingFigure 1~2
  • EP3750653B1 patent drawingFigure 3~4
  • EP3750653B1 patent drawingFigure 5~8

AI summary

The invention relates to a clamping device (1) for releasably holding a tool holder shank (33). The device comprises a housing (2), a drawbar (6) being mounted reciprocally movable inside a bore (5) in the housing, a wedge engagement member (8) securely arranged to the drawbar (6), and a wedge (10) comprising a first pressure receiving surface (13), a first wedge surface (11), and a second wedge surface (12). An aperture (14) extends radially through a peripheral wall of the housing (2) and the wedge engagement member (8) extends radially outwards from the bore (5) into the aperture (14), whereas the wedge (10) extends radially inwards from the outside of the housing (2) into the aperture (14). The first wedge surface (11) acts upon a wedge engagement slide surface (9) on the wedge engagement member and the second wedge surface (12) acts upon an aperture slide surface (15) in the aperture. Thus, the wedge (10) is arranged between a surface of the housing (2) and a surface of a member securely arranged to the drawbar (6) to effectuate a displacement of the drawbar when the wedge is moved inwards, resulting in clamping of the tool holder shank (33). A sleeve (16) is arranged around the peripheral surface of the housing, over the aperture, for causing the wedge to move inwards when the sleeve is moved in a first direction (D) such that a first pressure applying surface (17) of the sleeve slides and presses upon the first pressure receiving surface (13) of the wedge.