Level, plumb, and perpendicularity indicator for power tool

Patent metadata

Field	Value
Publication number	US-9464893-B2
Application number	US-201313779919-A
Country	US
Kind code	B2
Filing date	Feb 28, 2013
Priority date	Jun 28, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A power tool includes a housing, an output shaft having a tool axis, and a motion sensor that senses motion of the tool housing. A control circuit receives an input signal from the motion sensor, to make a first determination, based on the input signal, whether the tool is being operated in a horizontal mode or a vertical mode. The control circuit makes a second determination, based on the input signal, whether the tool axis is substantially level when the tool is being operated in the horizontal mode or the tool axis is substantially plumb when the tool is being operated in the vertical mode. An indicator receives an output signal from the control circuit that causes the indicator to indicate whether the tool axis is level when being operated in the horizontal mode or plumb when being operated in the vertical mode.

First claim

What is claimed is:

1. A power tool comprising:
a housing;
an output shaft extending from the housing in a direction of a tool axis;
a motion sensor including at least one accelerometer configured to sense motion of the tool housing by detecting acceleration of the tool housing along an X-axis that is substantially parallel to the tool axis, a Y-axis that is substantially orthogonal to the X-axis, and a Z-axis that is substantially orthogonal to the X-axis and the Y-axis, the motion sensor further configured to generate at least one input signal that comprises an X input value corresponding to acceleration of the tool housing along the X-axis, a Y input value corresponding to acceleration of the tool housing along the Y-axis, and a Z input value corresponding to acceleration of the tool housing along the Z-axis;
a control circuit configured (a) to receive the at least one input signal from the motion sensor, (b) to make a first determination, based on the at least one input signal, automatically, whether the tool is being operated in a horizontal mode or a vertical mode wherein in the vertical mode the tool axis is substantially perpendicular to ground and in the horizontal mode the tool axis substantially parallel to ground, and (c) to make a second determination, based on the input signal, whether the tool axis is substantially level when the tool is being operated in the horizontal mode or the tool axis is substantially plumb when the tool is being operated in the vertical mode, wherein the control circuit is configured to make the first determination by comparing one of the input values or a result of a calculation of two of the input values to an at least one reference value that has been pre-stored independently of a user input, in order to distinguish whether the tool is being operated in the horizontal mode or the vertical mode, and
an indicator coupled to the control circuit, the indicator configured to receive an output signal from the control circuit that causes the indicator to indicate whether the tool axis is level when being operated in the horizontal mode or plumb when being operated in the vertical mode.

2. The power tool of claim 1 , wherein the at least one accelerometer comprises at least three accelerometers arranged to detect acceleration of the tool housing along at least three different axes.

3. The power tool of claim 2 , wherein the at least three accelerometers comprises an X-accelerometer arranged to detect acceleration along the X-axis, a Y-accelerometer arranged to detect acceleration along the Y-axis, and a Z-accelerometer arranged to detect acceleration along the Z-axis.

4. The power tool of claim 1 , wherein the at least one reference value includes a first reference value, and the control circuit is configured to compare a mathematical combination of the Y input value and the Z input value to the first reference value, to make the first determination whether the tool is being operated in the horizontal mode.

5. The power tool of claim 4 , wherein the at least one reference value includes a second reference value, and when the tool is being operated in the horizontal mode, the control circuit is configured to compare the X input value to the second reference value to make the second determination whether the tool axis is substantially level.

6. The power tool of claim 4 , wherein the at least one reference value includes a third reference value, and the control circuit is configured to compare the X input value to the third reference value to make the first determination whether the tool is being operated in the vertical mode.

7. The power tool of claim 6 , wherein the at least one reference value includes a fourth reference value, and when the tool is being operated in the vertical mode, the control circuit is configured to compare a mathematical combination of the Y input value and the Z input value to the fourth reference value to make the second determination whether the tool axis is substantially plumb.

8. The power tool of claim 1 , wherein the at least one reference value includes a first reference value, and the control circuit is configured to compare the X input value to the first reference value to make the first determination whether the tool is being operated in the horizontal mode, and the second determination whether the tool axis is substantially level.

9. The power tool of claim 8 , wherein the at least one reference value includes a second reference value, and the control circuit is configured to compare a mathematical combination of the Y input value and the Z input value to the second reference value to make the first determination whether the tool is being operated in the vertical mode, and the second determination whether the tool axis is substantially plumb.

10. The power tool of claim 1 , wherein the control circuit comprises a microprocessor programmed to make the first and second determinations.

11. The power tool of claim 1 , wherein the control circuit comprises at least one operational amplifier coupled the motion sensor, the operational amplifier configured to compare the input signals from the motion sensor to at least one reference signal make the second determination.

12. The power tool of claim 2 , wherein the motion sensor further comprises a rotational motion sensor arranged to detect rotational motion of the tool housing, and the control circuit is configured to determine, based on the detected rotational motion of the tool housing, whether any of the accelerometers have given a false indication that the tool axis is substantially level or substantially plumb.

13. The power tool of claim 1 , further comprising a memory unit and a normalization switch for activating an angled mode of operation, wherein when the normalization switch is actuated, a reference value corresponding to a desired orientation of the tool axis is stored in the memory unit, and the control circuit is configured to compare further input signals from the motion sensor to the reference value to determine whether the tool axis is substantially aligned with the desired orientation of the tool axis, and to generate an output signal that corresponds to whether the tool axis is substantially aligned with the desired orientation of the tool axis.

14. A method for indicating when a power tool having a housing and an output shaft extending in a direction of a tool axis is level when being operated in a horizontal mode, or plumb when being operated in a vertical mode, the method comprising:
receiving an input signal from a motion sensor that is configured to sense motion of the tool housing, the motion sensor including at least one accelerometer configured to detect acceleration of the tool housing along an X-axis that is substantially parallel to the tool axis, a Y-axis that is substantially orthogonal to the X-axis, and a Z-axis that is substantially orthogonal to the X-axis and the Y-axis, the input signal including an X input value that corresponds to the detected acceleration along the X-axis, a Y input value that corresponds to the detected acceleration along the Y-axis and a Z input value that corresponds to the detected acceleration along the Z-axis;
making a first determination, based on the input signal, automatically, whether the tool is being operated in a horizontal mode or a vertical mode, wherein in the vertical mode the tool axis is substantially perpendicular to ground and in the horizontal mode the tool axis substantially parallel to ground, wherein making the first determination includes comparing one of the input values or a result of a calculation of two of the input values to an at least one reference va

Assignees

• Black & Decker Inc

Inventors

• Vanko John C
• Schell Craig A
• Gehret Robert S
• Forster Michael K
• Gottesman Tal
• Murthy Sankarshan
• Puzio Daniel
• Zellerhoff Joerg
• Usselman Robert A
• Eshleman Scott J
• Norona Joao

Classifications

• B25F5/022 Primary

  with incorporated levels · CPC title

• G01C9/00 Primary

  Measuring inclination, e.g. by clinometers, by levels · CPC title

• B23Q17/22

  for indicating or measuring existing or desired position of tool or work {(B23Q16/005 takes precedence)} · CPC title