Electric Rebar Bending Tool With Sensor-Light Position Control

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Solution Overview

Problem

Hydraulic rebar bending tools are heavy, require high maintenance, and rely on multiple sensors that increase the risk of tool failure due to sensor failure.

Innovation Solution

A portable electric power tool with a DC brushless motor, planetary gear arrangement, and a bias portion mechanism for bending rebar, utilizing a Hall sensor and controller to accurately control the bending process without needing multiple sensors, improving weight distribution and reducing maintenance needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If hydraulic rebar bending tools are used, then bending force is sufficient, but the tool weight increases and maintenance requirements increase

Engineering Contradiction:
Improvebending forceVSAvoidtool weight
Core Design Contradiction:
ForceVSWeight of moving object

Solution Approach 1:

The patent replaces the hydraulic mechanical system with an electric motor system. Specifically, an electric motor (114) coupled to a transmission (116) provides the bending force through a bend mechanism (20), eliminating the need for hydraulic pumps, fluid reservoirs, and associated heavy components while maintaining sufficient bending force for rebar fabrication.

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

Solution Approach 2:

The patent eliminates the hydraulic system entirely in favor of an electric drive system. The hydraulic pump and fluid power transmission are replaced by an electric motor with planetary gear transmission, converting from fluid-based force transmission to direct mechanical force transmission through gear reduction and a ball screw mechanism.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Measurement precision

If multiple sensors are used to monitor internal component position, then measurement precision improves, but the risk of tool failure increases

Engineering Contradiction:
Improvecomponent position measurementVSAvoidtool failure risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts and eliminates unnecessary sensors from the system. Instead of using multiple sensors to monitor the position of movable internal components, the design relies on the controller (112) to track position through motor control parameters and a single Hall sensor (105) for home position detection, reducing the number of potential failure points while maintaining adequate measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The controller (112) performs self-monitoring of the bend mechanism position through feedback from the Hall sensor (105) and motor status information, eliminating the need for additional external sensors. The system uses its own control infrastructure to track position, reducing component count and failure risk.

Inventive Principle:
Principle #25Self-service

3Force

If hydraulic components are used, then bending capability is achieved, but device complexity and maintenance requirements increase

Engineering Contradiction:
Improvebending capabilityVSAvoidsystem complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent substitutes the complex hydraulic system with a simpler electric motor and transmission system. The hydraulic pump, valves, fluid lines, and reservoir are replaced by an electric motor (114) with planetary gear transmission (116) and ball screw mechanism (62), reducing system complexity and maintenance requirements while preserving bending capability.

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

4Weight of moving object

If electric motor with transmission is used, then tool weight decreases, but device complexity increases

Engineering Contradiction:
Improvetool weightVSAvoidmechanism complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the motor, transmission, and bend mechanism into a compact integrated assembly. The electric motor (114), planetary gear transmission (116), and bend mechanism (20) are combined in a space-efficient configuration within the tool housing (12), reducing overall tool weight while managing the complexity of the drive system through integrated design.

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

The tool provides efficient, precise, and reliable bending of rebar with improved weight distribution and reduced maintenance, minimizing the risk of tool failure and enhancing user convenience.

Implementation Method 1

A Hall sensor and controller are used to accurately control the bending process

Methodology Applied
Scientific EffectHall sensor: Hall Effect

Implementation Method 2

A portable electric power tool with a DC brushless motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4635647A1Portable electric power tool for bending elongate objects
Publication Date: 2025.10.22 BLACK & DECKER CORP
  • EP4635647A1 patent drawingFigure 1~2
  • EP4635647A1 patent drawingFigure 3~5
  • EP4635647A1 patent drawingFigure 6

AI summary

A portable electric power tool for bending elongate objects comprising: an electric motor; a bend mechanism having a body portion and a bending portion which is axially moveable relative to the body portion wherein the bend mechanism is operatively coupled to the electric motor for causing axial displacement of the bending portion relative to the body portion between a home position and a retracted position for causing force to be applied by the bend mechanism to an elongate object in use simultaneously at different locations along the length of the elongate object for bending the elongate object; a home position sensor for generating output indicative that the bending portion has reached the home position during a reset stage of operation in which the bending portion is moved towards the home position; and a controller for receiving motor turn information indicative of the number of turns of the electric motor and for monitoring the axial position of the bending portion based on the motor turn information and the output generated by the home position sensor.