Power tool and method

Patent metadata

Field	Value
Publication number	US-11534902-B2
Application number	US-201716632988-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Jul 24, 2017
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A handheld power tool with a rotatable tool, in which the handheld power tool is a saw blade or milling cutter. The handheld power tool includes a sensor device for detecting a mechanical vector quantity. The mechanical vector quantity includes a force, an acceleration, a velocity, a deflection, a deformation and/or a mechanical stress and the mechanical vector quantity depends on a force emanating from the handheld tool. The handheld power tool also includes a control device which is communicatively coupled to the sensor device and is adapted to recognize an event and/or a state of the power tool according to a direction and/or change of direction of the mechanical vector quantity detected by the sensor device.

First claim

The invention claimed is:

1. A handheld power tool with a rotatable tool, wherein the rotatable tool is a saw blade or a milling cutter, wherein the handheld power tool comprises:
a sensor device for detecting a mechanical vector quantity, wherein the sensor device is adapted to detect the mechanical vector quantity as an at least two-dimensional vector by measuring a mechanical quantity underlying the mechanical vector quantity in at least two different spatial directions,
wherein the mechanical vector quantity comprises a force, an acceleration, a velocity, a deflection, a deformation and/or a mechanical stress, and the mechanical vector quantity depends on a force emanating from the rotatable tool, and
a control device communicatively coupled to the sensor device, which control device is adapted to recognize an event and/or a state of the handheld power tool according to a direction and/or a change of direction of the mechanical vector quantity detected by the sensor device,
wherein the sensor device comprises a first sensor element and a second sensor element, the first sensor element being adapted to measure the mechanical quantity underlying the mechanical vector quantity in a first spatial direction and the second sensor element being adapted to measure the mechanical quantity underlying the mechanical vector quantity in a second spatial direction different from the first spatial direction,
wherein the handheld power tool further comprises a support structure and an output shaft mounted on the support structure, to which output shaft the rotatable tool is coupled, wherein the sensor elements are arranged on the support structure,
wherein the support structure comprises a first subsection and a second subsection, and the first sensor element is a first connecting element between the first subsection and the second subsection, and the second sensor element is a second connecting element between the first subsection and the second subsection, wherein the first sensor element and the second sensor element are spaced apart from each other.

2. The handheld power tool according to claim 1 , wherein the control device is adapted to recognize, as the event and/or the state to be recognized, a kickback, a forward sawing, a backward sawing, and/or a plunging of the tool into a workpiece.

3. The handheld power tool according to claim 2 , wherein the control device is adapted to provide at least one angular range and to recognize the event and/or state based on whether the direction of the mechanical vector quantity is within or outside the angular range.

4. The handheld power tool according to claim 2 , wherein the control device is adapted to provide a plurality of angular ranges and to recognize different events and/or states based on which of the angular ranges the direction of the mechanical vector quantity lies in.

5. The handheld power tool according to claim 3 , wherein the control device is adapted to carry out a calibration of the at least one angular range.

6. The handheld power tool according to claim 2 , wherein the control device is adapted to recognize the event and/or state based on an angular velocity of the mechanical vector quantity and/or an angle of change of the mechanical vector quantity.

7. The handheld power tool according to claim 2 , wherein the handheld power tool comprises an output shaft, to which output shaft the tool is coupled, wherein the sensor device comprises a radial measuring bearing with which the output shaft is mounted, wherein the radial measuring bearing is adapted to measure a force between the output shaft and the radial measuring bearing as the mechanical vector quantity.

8. The handheld power tool according to claim 2 , wherein the control device is adapted to provide a signal in response to the recognized event and/or state.

9. The handheld power tool according to claim 2 , wherein the handheld power tool comprises a drive device for driving the tool and the control device is adapted to control the drive device in response to the recognized event and/or the recognized state in order to change the driving of the tool.

10. The handheld power tool according to claim 1 , wherein the handheld power tool comprises a positioning device which is adapted to position the tool selectively in an operating position or a safety position and the control device is adapted to control the positioning device in response to the recognized event and/or the recognized state so that the tool is positioned in the operating position or the safety position.

11. The handheld power tool according to claim 1 , wherein the control device is adapted to recognize, as the state to be recognized, a state of wear of the tool and/or a state of wear of the handheld power tool.

12. The handheld power tool according to claim 1 , wherein the first subsection is a gearbox housing.

13. The handheld power tool according to claim 2 , wherein the handheld power tool comprises a drive device for driving the tool and the control device is adapted to control the drive device in response to the recognized event and/or the recognized state in order to brake the tool.

14. A method for recognizing an event and/or state of a handheld power tool with a rotatable tool, wherein the rotatable tool is a saw blade or a milling cutter, wherein the handheld power tool comprises a sensor device which comprises a first sensor element and a second sensor element, wherein the handheld power tool further comprises a support structure and an output shaft mounted on the support structure, to which output shaft the rotatable tool is coupled, wherein the sensor elements are arranged on the support structure, wherein the support structure comprises a first subsection and a second subsection, and the first sensor element is a first connecting element between the first subsection and the second subsection, and the second sensor element is a second connecting element between the first subsection and the second subsection, wherein the first sensor element and the second sensor element are spaced apart from each other, the method comprising the steps:
detecting a mechanical vector quantity as an at least two-dimensional vector by measuring a mechanical quantity underlying the mechanical vector quantity in a first spatial direction with the first sensor element and measuring the mechanical quantity in a second spatial direction with the second sensor element, wherein the first and second spatial directions are different from each other, wherein the mechanical vector quantity comprises a force, an acceleration, a velocity, a deflection, a deformation and/or a mechanical stress and the mechanical vector quantity depends on a force emanating from the rotatable tool, and recognizing the event and/or state of the handheld power tool according to a direction and/or change of direction of the detected mechanical vector quantity.

Assignees

• Festool Gmbh

Inventors

• Schmid Markus
• Rusch Marc
• Werner Uwe
• Sommer Remo
• Staubli Tom
• Evertz Jorg
• Lortscher Luca
• Nietlispach Miriam

Classifications

• F16P3/148

  using capacitive technology · CPC title

• B27G19/04

  for manually-operated power-driven circular saws · CPC title

• F16P3/12

  with means, e.g. feelers, which in case of the presence of a body part of a person in or near the danger zone influence the control or operation of the machine (F16P3/08 takes precedence) · CPC title

• B23D59/001

  Measuring or control devices, e.g. for automatic control of work feed pressure on band saw blade (measuring in general G01; controlling in general G05) · CPC title

• B25D2250/221

  Sensors · CPC title