Control method for an electric power tool

• US 10,644,502 B2
• Filed: 06/14/2016
• Issued: 05/05/2020
• Est. Priority Date: 06/17/2015
• Status: Active Grant

• Current Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Original Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Inventors: Moessnang, Franz, Kock, Laurent-Sebastian, Neuper, Karl
• Primary Examiner(s): Kaplan, Hal
• Assistant Examiner(s): Chowdhuri, Swarna N
• Application Number:
  US15/737,237
• Publication Number:
  US 20180175617A1
• Time in Patent Office: 1,421 Days
• Field of Search: 307326
• CPC Class Codes: B23Q 11/0078 Safety devices protecting the operator, e.g. against accident or noise protecting the machine tool B23Q5/58; protecting people, in general F16P1/00, F16P3/00
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: H02H 11/00 Emergency protective circuit arrangements for preventing the switching-on in case an undesired electric working condition might result

Abstract

A power tool has a tool holder, an electric motor, a handle, and a main switch for switching on the electric motor. The power tool executes the following control method. The main switch is scanned to see whether it has been actuated. A start inhibitor transmits a blocking signal to a motor controller if the main switch is actuated before the power tool has been connected to the power supply. An activator receives signals from a control unit separate from the electric power tool, compares the received signals with a predefined signature and transmits a release signal to the motor controller if the received signal corresponds to the predefined signature. The motor controller switches on the electric motor in response to actuation of the main switch if the start inhibitor is not transmitting a blocking signal or the activator is transmitting a release signal.

Claims

1. A control method for an electric power tool, comprising the steps of:

scanning whether a main switch is actuated;

transmitting a blocking signal to a motor controller by a start inhibitor if the main switch is actuated before the electric power tool is connected to a power supply;

receiving a signal by an activator from a control unit separate from the electric power tool;

comparing the received signal with an activation code;

transmitting a release signal to the motor controller by the activator if the received signal matches the activation code; and

switching on an electric motor of the electric power tool by the motor controller when the main switch is actuated if the start inhibitor is not transmitting the blocking signal or if the activator is transmitting the release signal.

2. The control method according to claim 1, further comprising the step of transmitting the signal by the control unit with the activation code wirelessly.

3. The control method according to claim 2, wherein the signal with the activation code is received wirelessly.

4. The control method according to claim 1, further comprising the step of transmitting the signal by the control unit with the activation code, wherein a control code is transmitted with the activation code, and wherein the motor controller sets a speed, an acceleration, and/or a torque based on the control code.

5. An electric power tool, comprising:

a machine housing;

a handle disposed on the machine housing;

a tool holder for holding a tool on a working axis;

an electric motor, wherein the tool holder is drivable in rotation around the working axis by the electric motor;

a motor controller for controlling the electric motor;

a main switch for actuation by a user;

a connection for connecting the electric power tool to a power supply;

a start inhibitor, wherein the start inhibitor transmits a blocking signal to the motor controller if the main switch is actuated before the electric power tool is connected to the power supply; and

an activator, wherein the activator has a receiver for receiving a signal from a control unit separate from the electric power tool and has a decoder for comparing a received signal to an activation code, wherein the activator transmits a release signal to the motor controller if the received signal matches the activation code;

wherein the motor controller switches on the electric motor when the main switch is actuated if the start inhibitor is not transmitting the blocking signal or if the activator is transmitting the release signal.

6. The electric power tool according to claim 5, wherein the receiver has a radio receiver and a demodulator for extraction of signals embedded in the power supply or a plug connection on an outside of the machine housing.

7. The electric power tool according to claim 5, wherein the control unit has a memory with stored control codes and wherein the motor controller sets a speed, an acceleration, and/or a torque according to a control code transmitted by the control unit.