Servo Controlled Wire Pulling for Paper Stitching

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Solution Overview

Problem

Conventional wire stitching machines face issues with uneven wire feeding, leading to improper stapling due to unrestrained wire pulling, which results in tangling, kinking, and inconsistent staple lengths, affecting product quality and the lifespan of the stitching head.

Innovation Solution

A servo-controlled stitching apparatus with a programmable servo motor and gearbox system that uses wire pulling rollers with grooves and pressure rollers to pull a predefined length of wire, maintaining uniform tension and avoiding direct pulling from the spool, ensuring consistent wire length and reducing load on the stitching head.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the stitching head directly pulls wire from the spool, then the stitching operation can be performed, but the wire feeding becomes uneven and inconsistent staple lengths occur

Engineering Contradiction:
Improvestitching operationVSAvoidwire feeding consistency
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

A wire pulling mechanism with controlled rollers is introduced as an intermediary between the spool and stitching head. This mechanism includes a pulling roller that engages the wire and a control roller that regulates wire feed, preventing direct pulling by the stitching head and ensuring uniform wire delivery

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The wire feeding parameters are controlled by adjusting the rotation speed and position of the pulling and control rollers. The system changes the wire feed rate dynamically to maintain consistent tension and length, resolving the precision issue while maintaining operational ease

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the stitching head pulls wire directly from the spool, then the stitching process continues, but the wire becomes tangled and kinked

Engineering Contradiction:
Improvestitching process continuityVSAvoidwire feed reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The wire pulling mechanism with guided rollers acts as a mediator that controls wire extraction from the spool. The rollers guide the wire smoothly and prevent tangling by maintaining proper tension and alignment during the stitching process

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The wire is pre-pulled and positioned by the pulling mechanism before reaching the stitching head. This preliminary action ensures the wire is properly aligned and tensioned, preventing kinking and tangling during the actual stitching operation

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If the spool weight is high, then wire storage capacity is sufficient, but the stitching head experiences overload and reduced lifespan

Engineering Contradiction:
Improvewire storage capacityVSAvoidstitching head durability
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The wire pulling mechanism serves as an intermediary that bears the load of pulling wire from the heavy spool. This protects the stitching head from direct exposure to high pulling forces, extending its lifespan while maintaining adequate wire storage capacity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The wire is pre-pulled by the controlled mechanism before reaching the stitching head. This preliminary pulling action reduces the instantaneous load on the stitching head, protecting it from overload even when the spool is fully loaded

Inventive Principle:
Principle #10Preliminary action

4Strength

If the spool weight is reduced, then the stitching head load is reduced, but excessive wire length is pulled out

Engineering Contradiction:
Improvestitching head load reductionVSAvoidwire length control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The wire feed length is precisely controlled by adjusting the rotation parameters of the pulling and control rollers. This allows accurate control of wire length even with lighter spools, preventing excessive wire extraction while maintaining reduced load on the stitching head

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3538375B1Servo controlled stitching apparatus and method thereof
Publication Date: 2020.10.28 PATEL UDAYKUMAR CHHABILDAS
  • EP3538375B1 patent drawingFigure 1
  • EP3538375B1 patent drawingFigure 2
  • EP3538375B1 patent drawingFigure 3a~3c

AI summary

The present invention relates to a servo controlled stitching apparatus that comprises a servo controlled wire pulling means (4) for pulling the required length of wire for stitching bunch of paper sheets. Said pulling means (4) comprises pulling roller (11) having wire retaining groove (11a) for guiding wire extending from the spool (2) towards the stitching head (1). It also comprises pressure roller (13) that rotates against pulling roller (11) for pulling the wire (16) from the spool (2). The length of wire to be pulled is predefined in the controller means which is communicated with the servo motor (7) that rotates said rollers (11, 13) until the predetermined length of wire is pulled. The stitching head (1) utilize the wire (16) of pulled length without rotating the spool itself to avoid pulling load and to apply even stapling on the bunch of paper sheets.