Device for supplying a power tool with electrical energy, as well as the use of a load resistor for absorbing and/or converting electrical energy, system and operating method

Patent metadata

Field	Value
Publication number	US-12304050-B2
Application number	US-202118277088-A
Country	US
Kind code	B2
Filing date	Nov 24, 2021
Priority date	Feb 26, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A device for supplying a power tool with electrical energy is provided. The device has a load resistor for absorbing electrical energy, which may be in particular electrical energy that is produced or released when a power tool or its tool is braked. In addition, the released braking energy can be converted into heat by the load resistor. A system which includes a device and a power tool, a load resistor of the device being set up to absorb electrical energy that is released during a braking process of the power tool. The released braking energy can be converted into heat by the load resistor. The use of a load resistor for absorbing such electrical energy released during a braking process of a power tool or for converting the braking energy into thermal energy, as well as an operating method for a system which includes a energy supply device and a power tool.

First claim

The invention claimed is:

1. A device for supplying a power tool with electrical energy, the device comprising:
a load resistor, the load resistor being set up to absorb braking energy released during a braking process of the power tool
wherein voltage limits are implemented as hysteresis.

2. The device as recited in claim 1 wherein the load resistor is arranged at an electrical connection in the device.

3. The device as recited in claim 1 wherein the load resistor is designed as a pulse width modulating module or as a binary load resistor.

4. The device as recited in claim 1 wherein the load resistor is designed as a chopper.

5. The device as recited in claim 1 wherein the load resistor is controllable in dependence on an output voltage of the device.

6. The device as recited in claim 1 further comprising a disconnector as overload protection.

7. A system comprising the device as recited in claim 1 and a power tool, electrical energy released during a braking process of the power tool being absorbable by the load resistor.

8. A method for operating the system as recited in claim 7 , the method comprising the steps of:
a) operating the power tool;
b) braking the power tool, whereby electrical energy is released;
c) absorbing the released electrical energy via the load resistor or conversion of the released electrical energy into thermal energy via the load resistor.

9. A device for supplying a power tool with electrical energy, the device comprising:
a first AC/DC converter to convert an alternating current to direct current with a direct current voltage;
a DC/DC converter to convert the direct current voltage to a device direct voltage of the power tool; and
a load resistor, the load resistor being set up to absorb braking energy released during a braking process of the power tool.

Assignees

• Hilti Ag

Inventors

• Lacher Michael
• Ringler Stefan

Classifications

• H02J7/64 Primary

  against overvoltage · CPC title

• H02P3/20

  by reversal of phase sequence of connections to the motor · CPC title

• H02P3/14

  by regenerative braking · CPC title

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• H02J7/00308

  Electricity · mapped topic