Portable Rescue Tool Motor Control for Faster Piston Rod Motion

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Solution Overview

Problem

Existing portable electromechanical or electrohydraulic tools, such as rescue tools, face challenges in operational reliability, mechanical stress, and prolonged opening and closing times, which can lead to inefficiencies and safety concerns during rescue operations.

Innovation Solution

The introduction of an electronic control and regulation unit that allows the electric motor to switch between two operating frequencies, enabling faster piston rod extension and retraction, and incorporating a display device with temperature monitoring and load indicators to enhance operational control and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the electric motor operates at a single frequency, then the device structure is simple, but the opening and closing times are prolonged

Engineering Contradiction:
Improvepiston rod extension and retraction speedVSAvoidmotor control system complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent applies dynamics by enabling the electric motor to switch between two operating frequencies (F1 and F2) based on operational requirements. The control unit allows manual switching between a first frequency for normal operation and a second, higher frequency for rapid extension/retraction, making the system adaptable to different speed requirements without permanent structural changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the operating frequency of the electric motor. The control unit modifies the frequency parameter from F1 to F2 (where F2 > F1) to achieve different piston rod speeds, directly addressing the need for faster operation when required while maintaining simplicity during normal use.

Inventive Principle:
Principle #35Parameter changes

2Stress or pressure

If hydraulic proportional valves are used, then the pressure control is improved, but the opening and closing times remain long

Engineering Contradiction:
Improvehydraulic pressure controlVSAvoidopening and closing time
Core Design Contradiction:
Stress or pressureVSLoss of time

Solution Approach 1:

The patent applies preliminary action by using the higher frequency F2 to quickly position the piston rod near its target position before switching to the lower frequency F1 for precise pressure-controlled positioning. This preliminary rapid movement reduces the overall time loss while maintaining the benefits of proportional valve pressure control for the final positioning.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the piston rod extends to full length, then the rescue capability is maximized, but the opening time increases significantly

Engineering Contradiction:
Improverescue operation capabilityVSAvoidpiston rod extension time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements periodic action by using two distinct frequency phases: a first phase at frequency F1 for normal operation, and a second phase at higher frequency F2 for rapid extension. This periodic switching between frequencies allows the system to achieve full extension capability when needed while minimizing the time required to reach that state.

Inventive Principle:
Principle #19Periodic action

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 solution significantly reduces the opening and closing times of the tools, enhances operational reliability, and allows operators to manage mechanical stress more effectively, thereby improving the overall efficiency and safety of rescue operations.

Implementation Method 1

electric motor (3) which drives a hydraulic pump (2)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

hydraulic pump (2)...hydraulic cylinder (4) with a movable piston rod (5)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP4424473B1Portable working device for portable use
Publication Date: 2025.06.18 LUKAS HYDRAULIK
  • EP4424473B1 patent drawingFigure 1
  • EP4424473B1 patent drawingFigure 2
  • EP4424473B1 patent drawingFigure 3

AI summary

The present invention relates to a portable work device (1), such as a spreader, cutter, or combination device with cutting and spreading functions, for portable use, comprising an electric motor (3), a battery (18) housed on the work device (1), a mechanically or hydraulically driven, movable piston rod (5) for performing work, in particular spreading and/or cutting and/or lifting or pushing work, and an electronic control unit (7) for controlling and/or regulating the electric motor (3), particularly according to claim 1, wherein the electric motor (3) is a brushless DC motor, wherein the electronic control unit (7) defines a first operating state in which the electric motor (3) is operated at a first frequency F1, and the electronic control unit (7) defines a second operating state in which the electric motor (3) is operated at a second frequency F2.wherein the operating state of the work device (1) can be switched between the first and second operating states by means of manually operated switching means, wherein the speed of the three-phase electric motor (3) is higher at the second frequency F2 than at the first frequency F1, and wherein a display device (10) is provided which includes a temperature display (10c) which shows the range in which the current operating temperature of the semiconductor components is located.