Pivoting Tool Cartridge Arms With Rigid Pin Support Against Sagging

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Solution Overview

Problem

Heavy machining punches cause cartridge arms to sag due to loose fits in the bearing point, leading to issues with stamp sensor systems and fretting corrosion, especially during ultrasonic cleaning.

Innovation Solution

A tool cartridge design with cartridge arms having pins that form a firm connection with the cartridge body, providing a large support length to distribute radial forces and prevent sagging and fretting, achieved through a press fit or similar permanent connection, using pins that protrude on both sides of the cassette arm and made of steel, with a plastic cassette body for ease of manufacturing and cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a loose fit bearing point is used between the cartridge arm and pin to allow rotation, then the cartridge arm can pivot freely, but the cartridge arm sags under heavy loads and experiences fretting corrosion

Engineering Contradiction:
Improvepivot movementVSAvoidsagging prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connection between the cartridge arm and pin is segmented into two functional zones: a fixed connection zone that prevents sagging and fretting, and a rotation zone that enables pivot movement. This segmentation allows each zone to optimize its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different local qualities are applied to different parts of the pin-cartridge arm connection. The fixed connection zone has high rigidity to prevent sagging, while the rotation zone maintains appropriate clearance for pivot movement. This local differentiation resolves the contradiction between stability and mobility.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If a loose fit bearing point is used between the cartridge arm and pin, then rotation is enabled, but fretting corrosion occurs during ultrasonic cleaning

Engineering Contradiction:
Improverotation capabilityVSAvoidfretting corrosion
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The connection is segmented into a fixed zone that eliminates fretting corrosion through rigid connection, and a rotation zone that maintains necessary movement capability. This segmentation prevents harmful fretting while preserving functional rotation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pin acts as an intermediary element with a dual-function design: one portion is firmly connected to the cartridge arm body to prevent fretting, while another portion allows rotation. This intermediary structure mediates between the conflicting requirements of stability and mobility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the pin is firmly connected to the cartridge arm body, then sagging is prevented, but the structure becomes more complex

Engineering Contradiction:
Improvesagging preventionVSAvoidconnection structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pin is merged with the cartridge arm body through a firm connection that integrates the two components into a single rigid unit. This merging eliminates sagging while the integrated design keeps the overall structure simple rather than adding complex separate mechanisms.

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

Prevents sagging of cartridge arms under heavy loads, reduces wear and fretting corrosion, allowing for effective use in ultrasonic cleaning and weight savings, while maintaining rigidity and ease of assembly.

Implementation Method 1

a cartridge body (2) each having an associated opening (8) for rotatably receiving the pins (7)

Methodology Applied
Scientific EffectRotation:

Implementation Method 2

elastic deformation of the material in this area is greatly reduced

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

there is a problem that fretting occurs in the opening between the cassette arm and the pin. This happens in particular when the cassette is cleaned in ultrasonic baths with aqueous cleaning baths

Methodology Applied
Scientific EffectFretting corrosion: Tribocorrosion

Data Source

PatentEP3576893B1Tool cartridge
Publication Date: 2021.03.31 TRUMPF SCHWEIZ AG
  • EP3576893B1 patent drawingFigure 1
  • EP3576893B1 patent drawingFigure 2

AI summary

A tool cartridge (1) is provided, for receiving tool parts of a multipart machine tool, consisting of a male die and a female die, for machining workpieces in sheet form. The tool cartridge (1) has a main cartridge body (2), a male die mount (3), for releasably holding a tool part formed as a machining male die, and a female die mount (4), for releasably holding a tool part formed as a machining female die. The male die mount (3) has two cartridge arms (6), which are pivotable in relation to one another and respectively have a pin (7) for the pivotable bearing of the respective cartridge arm (6). The main cartridge body (2) has two openings (8) assigned to the pins (7) for rotatably receiving the pins (7).