Wire Curl Guide Geometry for Large Rebar Binding Reliability

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Solution Overview

Problem

Existing binding machines face challenges in guiding wires around reinforcing bars with increased diameters due to increased friction and resistance when the wire tip contacts the curl guide's bottom surface, preventing reliable feeding to the binding portion.

Innovation Solution

The binding machine incorporates a curl guide part with a bottom surface portion featuring a guiding portion that includes an inclined surface to guide the wire tip towards the base end, reducing friction and ensuring smooth wire feeding by maintaining an entering angle of 50° or less, allowing the wire to move along the surface and reach the binding portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the diameter of the feeding path of the wire is increased to accommodate larger reinforcing bars, then the binding machine can handle larger reinforcing bars, but the wire tip comes into contact with the bottom surface portion of the curl guide, increasing friction and potentially preventing wire feeding

Engineering Contradiction:
Improvecapability to bind larger reinforcing barsVSAvoidwire feeding reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The bottom surface portion of the curl guide is given a specific inclined shape (guiding portion) that creates a gentle slope (50 degrees or less) to reduce friction. This local modification of the surface geometry allows the wire tip to slide smoothly without getting stuck, resolving the contradiction between handling larger bars and maintaining reliable wire feeding.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameters of the curl guide's bottom surface, specifically setting the inclination angle to 50 degrees or less. This parameter optimization reduces the friction coefficient between the wire and the guide surface, enabling reliable wire feeding even when the wire tip contacts the bottom surface during annular winding around larger reinforcing bars.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the wire is guided to pass through a path spaced from the bottom surface portion of the curl guide, then friction is reduced for small reinforcing bars, but the binding machine cannot reliably guide wires with increased diameters

Engineering Contradiction:
Improvewire feeding smoothnessVSAvoidcapability to bind larger reinforcing bars
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The guiding portion's inclined surface allows the wire feeding path to dynamically adapt to different reinforcing bar sizes. For small bars, the wire naturally follows a path spaced from the bottom surface. For larger bars, the wire tip contacts the inclined surface which guides it smoothly, providing dynamic adaptability across different binding scenarios.

Inventive Principle:
Principle #15Dynamics

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

This design enables reliable guidance of wires with increased diameters, ensuring they are properly fed and twisted around reinforcing bars, enhancing the binding process efficiency and effectiveness.

Implementation Method 1

the resistance caused by friction when the wire slides along the bottom surface portion increases, potentially making it impossible to feed the wire to the binding portion

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4644641A1Binding machine
Publication Date: 2025.11.05 MAX CO LTD
  • EP4644641A1 patent drawingFigure 1A
  • EP4644641A1 patent drawingFigure 1B
  • EP4644641A1 patent drawingFigure 2

AI summary

A binding machine includes: a curl forming portion configured to form an annular feeding path for winding the wire fed by a wire feeding portion around a to-be-bound object; and a binding portion configured to twist the wire wound on the to-be-bound object. The curl forming portion includes an arm part configured to curl the wire fed by the wire feeding portion, and a curl guide part configured to guide the wire curled by the arm part to the binding portion. The curl guide part includes a bottom surface portion on a radially outer side of the annular feeding path. The bottom surface portion includes a guiding portion forming at least a part of a tip portion side of the curl guide part and configured to guide a tip of the wire toward a base end portion side of the curl guide part.