Eccentric-Lock Cutter Holder Structure for Wider Cutter Size Range

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Solution Overview

Problem

Conventional cutter holders with collets have a limited application range due to their clamping mechanism, requiring multiple collets of different sizes for diverse machining environments, which increases machining costs and restricts the size range of cutters that can be used.

Innovation Solution

A cutter holder structure featuring a cutter arbor with an external thread, a connecting shaft with a tapered section and positioning holes, and a nut with an eccentric screw arrangement, allowing for increased locking rigidity and accommodating cutters up to 30mm in diameter, thereby expanding the application range by 3 times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a collet clamping mechanism is used in conventional cutter holders, then quick mounting and dismounting of cutters is achieved, but the application range is limited to specific cutter sizes requiring multiple collets

Engineering Contradiction:
Improvequick mounting and dismountingVSAvoidapplication range
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The cutter holder structure uses a universal clamping mechanism with a clamping plate and set screws that can accommodate cutters of various sizes (from small to 30mm diameter) through the same holder body, eliminating the need for multiple specialized collets of different sizes

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

2Adaptability or versatility

If multiple collets of different sizes are purchased to cover diverse machining environments, then the application range is expanded, but the machining cost increases

Engineering Contradiction:
Improveapplication rangeVSAvoidnumber of collets
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention merges the function of multiple collets into a single cutter holder structure that can accommodate various cutter sizes using the same clamping mechanism, thereby reducing the total number of components needed and lowering machining costs

Inventive Principle:
Principle #5Merging (Combining)

3Force

If a collet is retracted in a limited range for clamping, then the clamping force is sufficient for small cutters, but the size of the shank of the cutter is restricted

Engineering Contradiction:
Improveclamping forceVSAvoidcutter size range
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The clamping mechanism allows dynamic adjustment of the clamping position and force through movable clamping plates and adjustable set screws, enabling the same mechanism to effectively clamp cutters ranging from small diameters up to 30mm by adjusting the clamping point rather than relying on fixed-range collet retraction

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3702076B1Cutter holder structure
Publication Date: 2024.02.21 CHANG
  • EP3702076B1 patent drawingFigure 1
  • EP3702076B1 patent drawingFigure 2
  • EP3702076B1 patent drawingFigure 3

AI summary

A cutter holder structure comprises a cutter arbor (10) and a connecting shaft (20) having a tapered section (21) at one end thereof. One end of the tapered section (21) is formed with a first inner screw hole (211), and another end of the tapered section (21) is formed with a second inner screw hole (211). The connecting shaft (20) further has a horizontal positioning hole (23) that penetrates through the connecting shaft (20). Two ends of the positioning hole (23) are formed with cylindrical holes (231). A reduced hole (232) is defined between the cylindrical holes (231). A nut (30) has a third inner screw hole (31) at one end and an axial hole (32) at another end. The nut further has a horizontal countersink hole (33) and a horizontal fourth inner screw hole (34). An eccentric distance (e) is defined between a center of the countersink hole (33) and a center of the fourth inner screw hole (34). A screw (40) is inserted through the countersink hole (33) and locked into the fourth inner screw hole (34).