Automatic plumb and level tool with acoustic measuring capability

• US 5,182,863 A
• Filed: 06/12/1991
• Issued: 02/02/1993
• Est. Priority Date: 10/22/1990
• Status: Expired due to Fees

• Current Assignee: Spectra-Physics Lasers, Inc. (Perspecta, Inc.)
• Original Assignee: Spectra-Physics Lasers, Inc. (Perspecta, Inc.)
• Inventors: Rando, Joseph F.
• Primary Examiner(s): HAROIAN, HARRY
• Application Number:
  US07/714,240
• Time in Patent Office: 601 Days
• Field of Search: 33/227, 33/228, 33/DIG. 21, 33/290, 33/291, 33/700, 356/138, 356/146, 356/250, 356/147, 356/148, 356/149, 367/99, 367/107, 367/108, 367/127, 367/118
• US Class Current: 33/227
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01B 3/00 Measuring instruments characterised by the use of mechanical techniques
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: Y10S 33/21 with laser

Abstract

An automatic plumb, level, pointing and distance measuring tool uses a visible laser diode to project a beam in any of several different modes through a beam exit window. The tool, approximately the size and shape of a tape measure, can be placed on one edge to project a tilt-compensated vertical beam. Placed on another edge 90°-rotated, the tool projects through the same exit window a tilt-compensated horizontal beam. When laid on either of its larger flat sides, the tilt compensation becomes inoperative and the tool projects a beam which is fixed relative to the housing. Acoustic distance measurement is facilitated using a second component or target side device which is activated to send an acoustic signal across a space to be measured, toward the laser tool. A receiver in the laser tool detects arrival of the acoustic signal and causes the laser to project a characteristically modulated or pulsed beam, received at a photodetector on the target side device. The acoustic transit time is clocked and distance is calculated and displayed. The use of a single acoustic transit time, without reflection increases distance measuring range. Also, the visible laser beam projected between the two components provides a clear visual indication of the distance to be measured.

Claims

1. A laser beam projecting device for plumbing, leveling, alignment and distance measuring, comprising,

a hand-carryable housing having at least two sides capable of resting stably on a flat surface, the two sides being substantially perpendicular to each other, and including two broad sides,

laser source means mounted within the housing, for producing at least one collimated beam of visible laser light,

a laser beam exit window in the housing, positioned in neither of two sides nor on said broad sides,

beam directing means in the housing for directing a beam from the laser source means vertically out of the housing through the exit window when a first side of said two sides is held generally horizontal, and for directing a beam from the laser source means horizontally out of the housing through the exit window when a second side of said two sides is held generally horizontal,

tilt compensation means in the housing and associated with the beam directing means for correcting for relatively small tilt angles of the housing as it rests with one of said two sides against surfaces not truly horizontal or not truly vertical, and for projecting the beam through the exit window in substantially true vertical orientation or substantially true horizontal orientation despite such relatively small tilt angles,

means associated with the laser beam projecting device for distance measuring, including:

means for characterizing at least one collimated beam of visible laser light produced at said laser source means, so that a modulated or pulsed beam is projected from said hand-carryable housing, and

a separate, unconnected component as a target means with photodetector means for receiving and detecting a modulated or pulsed laser beam projected from the hand-carryable housing, and with means for projecting an acoustic signal from the target means toward the hand-carryable housing,

acoustic signal receiver means in the hand-carryable housing for receiving an acoustic signal transmitted directly from the target means, without reflection, and

means coating between the hand-carryable housing and the separate target means, for measuring the time interval between transmission of the acoustic signal at the target means and receipt of the acoustic signal by the receiver means in the hand-carryable housing, with the means for characterizing, which causes a modulated or pulsed laser beam to be projected from the hand-carryable housing toward the photodetector means of the target means, being part of a response loop for measuring said time interval, and with associated means for calculating and displaying the distance between appropriate points on the hand-carryable housing and the target means in response to said measurement of the time interval.

2. The apparatus of claim 1, wherein:

the means for projecting an acoustic signal from the target means comprises an acoustic driver located in the target means, serving as the means for transmitting an acoustic signal,

the means coacting between the hand-carryable housing and the target means for measuring the time interval comprises;

a clock means connected to the acoustic drive for timing the interval between start and stop events in which the acoustic signal is transmitted and received,

manual triggering means in the target means for beginning the distance measuring sequence by initiating the transmission of the acoustic signal from the target means, and

means contained in the hand-carryable housing for triggering a light signal to be emitted therefrom as a modulated or pulsed laser beam when the acoustic signal is received by the acoustic signal receiver means, whereby upon the transmission of the light signal, the photodetector indicates the completion of a loop wherein the acoustic signal has been received, and

the means for calculating distance and displaying uses the measured time interval for calculating and displaying the distance.

3. The apparatus of claim 1, wherein the distance display means comprises liquid crystal display means on the target means, for displaying a numerical distance scale which is movable relative to the target means as the distance between the hand-carryable housing and the target means varies, such that the LCD distance scale appears to the user as a tape measure with particular distance indications fixed relative to the hand-carryable housing and movable relative to the target means.

4. An acoustic distance measuring device, comprising,

a first component including a characteristic light signal transmitting means, for being located at a first position,

a second component which is separate from the first component and which may be placed at a second position, the distance of which from the first position is to be measured,

the second component including:

a target means with photodetector means for receiving and detecting a characteristic light signal projected from the first component, and

acoustic means for projecting an acoustic signal from the target means toward the first component;

acoustic signal receiver means in the first component for receiving the transmitted acoustic signal from the target means, and

means coacting between the first component and the second component, for measuring the time interval between transmission of the acoustic signal at the target means and receipt of the acoustic signal by the receiver means in the first component, with the characteristic light signal transmitting means, which projects the characteristic light signal from the first component toward the photodetector means of the target means, being part of a response loop for measuring said time interval, and with associated means for calculating and displaying the distance between the first component and the second component in response to said measurement of the time interval.

5. An acoustic distance measuring device, comprising,

a first component including a characteristic light signal transmitting means, for being located at a first position,

a second component which is separate from the first component and which may be placed at a second position, the distance of which from the first position is to be measured,

the second component including:

a target means with photodetector means for receiving and detecting a characteristic light signal projected from the first component, and

acoustic means for projecting an acoustic signal from the target means toward the first component;

acoustic signal receiver means in the first component for receiving the transmitted acoustic signal from the target means, and

means coacting between the first component and the second component, for initiating and carrying out a timing event which is clocked by on acoustic transit time and one optical transit time, without reflection, with associated means for calculating and displaying the distance between the first component and the second component in response to said timing event.

6. The apparatus of claim 5, wherein the associated means for calculating and displaying the distance includes liquid crystal display means on the target means, for displaying a numerical distance scale which is movable relative to the second component as the distance between the hand-carryable housing and the second component varies, such that the LCD distance scale appears to the user as a tape measure with particular distance indications fixed relative to the hand-carryable housing and movable relative to the target means.

7. An acoustic distance measuring device, comprising,

a first component for being located at a first position, and

a second component which is separate from the first component and which may be placed at a second position, the distance of which from the first position is to be measured,

one way acoustic transmission means including:

acoustic means for projecting an acoustic signal from one of said first and second components to the other, and

acoustic signal receiver means for receiving the acoustic signal at the other of said first and second components;

light signal means for aligning the one way acoustic transmission means, including;

a characteristic light signal transmitting means for transmitting a characteristic light signal from one of said first and second components to the other, and

a target means with photodetector means for receiving and detecting the characteristic light signal at the other of said first and second components;

means coacting in said first and second components for initiating and carrying out a timing event which is clocked by one acoustic transit time and one optical transit time, without reflection, with associated means for calculating and displaying the distance between the first component and the second component in response to said timing event.

8. The apparatus of claim 7 wherein:

the first component includes the acoustic signal receiver means for receiving an acoustic signal, and the characteristic light signal transmitting means for transmitting a characteristic light signal, and

the second component includes the acoustic means for projecting an acoustic signal from the second component to the first component, and the target means with photodetector means for receiving and detecting the characteristic light signal from the first component.

9. The apparatus of claim 7, wherein the means coacting in said first and second components for initiating and carrying out a timing event comprises:

a clock means in one of said first and second components for timing the interval between start and stop events in which one acoustic signal is transmitted and received,

triggering means in one of said first and second components for beginning the timing even by initiating the start event which includes transmitting one acoustic signal from one of said first and second components to the other, and

means contained in the other of said first and second components for indicating the stop even which includes receiving one acoustic signal at the other of said first and second components, whereby the means for calculating distance and displaying uses the timed interval between start and stop events for calculating and displaying the distance.

10. The apparatus of claim 7 wherein the means for initiating and carrying out a timing event includes a clock means for timing the interval between start and stop events in which the acoustic signal is transmitted and received, wherein the start event is communicated by said characteristic light signal and said stop event is communicated by said acoustic signal.

11. The apparatus of claim 7 wherein the acoustic signal receiver means and the associated means for calculating and displaying the distance between the first component and the second component are at the same one of said first and second components.

12. The apparatus of claim 7, wherein the associated means for calculating and displaying the distance includes liquid crystal display means on one of said first and second components, for displaying a numerical distance scale which is movable relative to the component which includes the liquid crystal display means, as the distance between the components varies, such that the LCD distance scale appears to the user as a tape measure with particular distance indications fixed relative to the other of said first and second components and movable relative to the component which includes the liquid crystal display means.