LEVEL, PLUMB, AND PERPENDICULARITY INDICATOR FOR POWER TOOL

• US 20140000921A1
• Filed: 02/28/2013
• Published: 01/02/2014
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley 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
• Granted Patent: US 9,464,893 B2
• Time in Patent Office: Days
• US Class Current: 173/11
• CPC Class Codes: B23Q 17/22 for indicating or measuring existing or desired position of tool or work B23Q16/005 takes precedence
• CPC Class Codes: B25F 5/022 with incorporated levels
• CPC Class Codes: G01C 9/00 Measuring inclination, e.g. by clinometers, by levels

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.

Claims

1. A power tool comprising:

a housing;

an output shaft extending from the housing in a direction of a tool axis;

a motion sensor configured to sense motion of the tool housing;

a control circuit configured to receive 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, and 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, 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 motion sensor 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 an X-axis that is substantially parallel to the tool axis, a Y-accelerometer arranged to detect acceleration along a Y-axis that is substantially orthogonal to the X-axis, and a Z-accelerometer arranged to detect acceleration along a Z-axis that is substantially orthogonal to the X-axis and the Y-axis.

4. The power tool of claim 3, wherein the control circuit is configured to compare a mathematical combination of a Y value and a Z value that correspond to signals from the Y-accelerometer and the Z-accelerometer, respectively, to a 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, when the tool is being operated in the horizontal mode, the control circuit is configured to compare a X value that is based on a signal from the X-accelerometer to a second reference value to make the second determination whether the tool axis is substantially level.

6. The power tool of claim 4, wherein the control circuit is configured to compare a X value that is based on a signal from the X-accelerometer to a 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, when the tool is being operated in the vertical mode, the control circuit is configured to compare a mathematical combination of the Y value and the Z value to a fourth reference value to make the second determination whether the tool axis is substantially plumb.

8. The power tool of claim 3, wherein the control circuit is configured to compare a X value that is based on a signal from the X-accelerometer to a 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 control circuit is configured to compare a mathematical combination of a Y value and a Z value that are based on signals from the Y-accelerometer and the Z-accelerometer, respectively, to a 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;

making a first determination, based on the input signal, whether the tool is being operated in a horizontal mode or a vertical mode,

making a second determination, based on the input signal, whether the tool axis is level when the tool is being operated in the horizontal mode, or whether the tool axis is plumb when the tool is being operated in the vertical mode; and

generating an output signal to an indicator to cause the indicator to indicate when 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.

15. The method of claim 14, wherein receiving the input signal comprises receiving input signals from an X-accelerometer arranged to detect acceleration along an X-axis that is substantially parallel to the tool axis, a Y-accelerometer arranged to detect acceleration along a Y-axis that is substantially orthogonal to the X-axis, and a Z-accelerometer arranged to detect acceleration along a Z-axis that is substantially orthogonal to the X-axis and the Y-axis.

16. The method of claim 15, wherein making the first determination that the tool is being operated in the horizontal mode, and making the second determinations that the tool axis is substantially level each comprise comparing a X value based on the input signal from the X-accelerometer to a first reference value.

17. The method of claim 15, wherein making the first determination that the tool is being operated in the vertical mode, and the second determination that the tool axis is substantially plumb comprise comparing a mathematical combination of a Y value and a Z value that are based on signals from the Y-accelerometer and the Z-accelerometer, respectively, to a second reference value.

18. The method of claim 15, further comprising receiving a rotational motion signal from a rotational motion sensor arranged to detect rotational motion of the tool housing, and, based on the rotational motion signal, determining whether any of the accelerometers have given a false indication of the tool axis being substantially level or substantially plumb.

19. The method of claim 14, further comprising receiving a normalization signal for activating an angled mode of operation, and, when the normalization switch is received, storing a reference value corresponding to a desired orientation of the tool axis, and comparing 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 generating an output signal to the indicator that corresponds to the determination of whether the tool axis is substantially aligned with the desired orientation.

20. A method for indicating when a power tool having a housing and an output shaft extending in a direction of a tool axis is substantially aligned with a desired orientation of the tool axis, the method comprising:

receiving a first input signal that indicates a desired orientation of the tool axis,

receiving a second input signal from a linear motion sensor arranged in the housing to sense linear motion of the housing;

determining, based on the second input signal, whether the tool axis is substantially aligned with the desired orientation of the tool axis;

receiving a third input signal from a rotational motion sensor arranged in the housing to sense rotational motion of the housing;

determining, based on the third input signal, whether the second input signal has given a false indication of the tool axis being substantially aligned with the desired orientation of the tool axis; and

,

if the second input signal has not given a false indication, generating an output signal to an indicator to cause the indicator to indicate whether the tool axis is substantially aligned with the desired orientation of the tool axis.