Reciprocating Saw Current Sensing for Adaptive Cutting Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Power tools lack advanced communication systems to efficiently monitor and control their operations, leading to suboptimal performance and maintenance challenges.

Innovation Solution

A power tool system that includes a motor with a rotor and stator, a transmission for converting rotational motion to reciprocating motion, a blade holder, a sensor to monitor motor current, and an electronic processor that determines when cutting is occurring and adjusts the motor's operation accordingly, while also enabling wireless communication with an external device for data exchange and configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sensor and electronic processor are added to monitor motor current and automatically adjust performance, then operational efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveoperational efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements feedback control by using a sensor to monitor motor current and an electronic processor to analyze the feedback signal. The processor determines cutting conditions based on current patterns and automatically adjusts motor performance, creating a closed-loop control system that optimizes operational efficiency through real-time feedback.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The power tool system performs self-adjustment by automatically detecting cutting conditions through motor current monitoring and self-regulating motor performance without external intervention. The electronic processor autonomously determines when cutting is occurring and adjusts operational parameters, enabling the system to service itself during operation.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If wireless communication capability is added for remote monitoring and data exchange, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improveease of operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces wireless communication as an intermediary layer between the power tool and external devices. This mediator enables remote monitoring and data exchange without requiring direct physical connection or user intervention, allowing users to access tool performance data and receive notifications through external devices while isolating the tool's core functionality from communication complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If motor current monitoring is implemented to detect cutting conditions, then measurement precision is improved, but loss of energy increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidloss of energy
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent replaces complex mechanical sensing systems with electrical current monitoring to detect cutting conditions. By measuring motor current, which naturally varies with cutting conditions, the system achieves precise detection without adding mechanical sensors or complex measurement apparatus, thereby minimizing additional energy consumption.

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

Data Source

PatentEP3411204B1System and methods for configuring a reciprocating saw
Publication Date: 2021.07.28 MILWAUKEE ELECTRIC TOOL CORP
  • EP3411204B1 patent drawingFigure 1
  • EP3411204B1 patent drawingFigure 2
  • EP3411204B1 patent drawingFigure 3A

AI summary

Systems and methods for configuring a power tool. One system includes a power tool communication system that includes an external device and a power tool. The external device includes a user interface configured to receive a first selection to enable a feature of a power tool, and receive a second selection of a threshold of a motor characteristic of the power tool. The power tool includes a motor within a housing. The power tool receives the selected feature and the selected threshold from the external device. The power tool includes a sensor configured to monitor the motor characteristic of the motor. The power tool further includes an electronic processor that controls the motor to operate according to the selected feature and adjusts an operating parameter of the motor when the motor characteristic is determined to cross the selected threshold.