Traversing Unit Cam Synchronization to Prevent Blade Interference

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Solution Overview

Problem

Existing traversing devices face challenges in achieving accurate traverse control and preventing interference between rotating blades due to backlash issues in worm gear configurations, while toothed transmission belts are prone to damage, leading to device failure.

Innovation Solution

A traversing device with a toothed transmission belt system that includes interference avoidance cams to regulate deviations in rotation speeds between adjacent drive force transmission shafts, ensuring synchronized operation and preventing blade interference, and a control unit to maintain uniform rotation speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a worm gear is used to transmit drive force to the plurality of traversing units, then the rotating blades can be prevented from interfering with each other, but accurate traverse control is difficult due to backlash between the worm and worm wheel

Engineering Contradiction:
Improveprevention of blade interferenceVSAvoidtraverse control accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary mechanism (the cam profile on the drive shaft) that mediates between the drive force transmission and the blade rotation control. This cam profile acts as a mediator that converts the rotational motion into precise blade traversal while eliminating the need for direct worm-gear engagement, thus resolving the backlash issue while maintaining blade interference prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional worm gear mechanical transmission system with a direct drive shaft system equipped with a cam profile. This substitution eliminates the worm-gear backlash problem while maintaining the ability to prevent blade interference through the cam's geometric design, thereby achieving both accurate traverse control and reliable blade separation.

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

2Measurement precision

If a toothed transmission belt is used to transmit drive force to the plurality of traversing units, then accurate traverse control can be performed without backlash, but the transmission belt may become damaged leading to device failure

Engineering Contradiction:
Improvetraverse control accuracyVSAvoiddevice failure risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by designing the cam profile with sufficient clearance and robust geometry that can withstand belt damage or slippage conditions. The cam's design incorporates safety margins that prevent blade interference even when the transmission belt deteriorates, thus cushioning against the harmful effects of belt failure while maintaining accurate traverse control during normal operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The cam profile serves as a protective intermediary between the transmission belt and the blade system. Even when the belt is damaged, the cam's geometric design ensures that the blades remain properly separated and controlled, thus protecting the blade system from interference while allowing the belt to be replaced without causing device failure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of moving object

If the rotating blades are arranged closer to each other to reduce device size, then the device becomes more compact, but the rotating blades may interfere with each other during rotation

Engineering Contradiction:
Improvedevice compactnessVSAvoidblade interference
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent employs asymmetry through the cam profile design, where the cam's eccentricity and asymmetric geometry create controlled clearance zones between adjacent blades during rotation. This asymmetric cam profile allows the blades to be positioned closer together for compactness while the asymmetric motion pattern ensures they never interfere with each other, resolving the contradiction between device size and blade separation.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The cam profile performs preliminary action by pre-positioning the blades in specific angular orientations before they enter the potential interference zone. The cam's geometric design ensures that blades are always separated by sufficient clearance in the critical angular regions, allowing compact arrangement while preventing interference through advance positioning control.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4410725B1Traversing device
Publication Date: 2025.12.03 TMT MACHINERY INC
  • EP4410725B1 patent drawingFigure 1
  • EP4410725B1 patent drawingFigure 2
  • EP4410725B1 patent drawingFigure 3

AI summary

[Problem to be Solved] To provide a traversing device capable of performing an accurate traverse control, preventing rotating blades adjacent in an alignment direction of a plurality of traversing units from interfering with each other, and avoiding device failure. [Solution to Problem] A traversing device (1) includes a drive motor (1), a toothed transmission belt (12), and a plurality of traversing units (13). Each of the plurality of traversing units (13) includes a traverse guide (17), rotating blades (18, 19) configured to rotate in directions opposite to each other so as to traverse a thread (101), a drive force transmission shaft (22) for transmitting drive force to the rotating blades (18, 19), and an interference avoidance cam (21). The interference avoidance cams (21) adjacent in an alignment direction (Y) of the plurality of traversing units (13) rotate without abutting each other in a state where rotation speeds of the drive force transmission shafts (22) adjacent in the alignment direction (Y) are the same, and, when a deviation occurs in rotation speeds of the drive force transmission shafts (22), the interference avoidance cams (21) abut each other so as to regulate the deviation in rotation speeds between the drive force transmission shafts (22) and to avoid interference between the rotating blades (18, 19) adjacent in the alignment direction (Y).