Digital inclinometer

• US 4,942,668 A
• Filed: 05/11/1988
• Issued: 07/24/1990
• Est. Priority Date: 05/11/1988
• Status: Expired due to Fees

• Current Assignee: Zircon Corporation
• Original Assignee: Zircon International Incorporated
• Inventors: Franklin, Robert C.
• Primary Examiner(s): Will, Thomas B.
• Application Number:
  US07/192,809
• Time in Patent Office: 804 Days
• Field of Search: 33/366, 33/1 N, 33/1 PT, 250/231 SE
• US Class Current: 33/366.14
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01C 9/12 by using a single pendulum plumb lines G01C15/10

Abstract

A digital inclinometer for detecting the angular orientation of a structure includes a rotatable encoding disk on which is mounted a horizontal tilt sensor. The inclinometer electronically measures, by angular indices on the encoding disk, the difference between the angular orientation of the device and a horizontal orientation. In another embodiment, the encoding disk is rotated by a stepper motor and the number of steps are electronically counted to determine the angular orientation. The inclinometer has a digital display.

Claims

1. A digital inclinometer comprising:

encoding means for indicating rotation rotated by a direct current motor;

means for sensing a certain orientation fixed to the encoding means; and

means for counting the rotation of the encoding means between a particular position of the orientation sensing means and the certain orientation of the orientation sensing means;

wherein the counting means includes;

an index on the encoding means;

means for sensing the index; and

means for measuring digitally the angular distance that the encoding means rotates between the detection of the index by the index sensing means and the certain orientation of the orientation sensing means;

wherein the measuring means includes;

transparent angular index marks forming a part of the encoding means, light-generating means, and light-responsive means for generating an electronic signal in response to light transmitted by the light-generating means through the portion of said encoding means having the angular index marks;

a first comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to receive the signal generated by the light-responsive means, to produce a first comparator output signal on an output lead;

a first multivibrator having an input terminal electrically connected to the first comparator output lead to produce a first multivibrator output signal on an output lead;

a second comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to an output lead of the index sensing means, so as to produce a second comparator output signal on an output lead;

a second multivibrator having an input terminal electrically connected to an output lead of the orientation sensing means, so as to produce a second multivibrator output signal on an output lead;

motor control means electrically connected to the output lead of the first multivibrator, to control the motor speed;

phase-locked loop means electrically connected to the output lead of the first multivibrator to increase angular resolution and having an output lead;

an up/down counter having three input terminals electrically connected respectively to the output lead of the phase-locked loop means, to the second multivibrator output lead, and to the second comparator output lead, to produce an output signal on an output lead; and

a digital display electrically connected to the counter output lead to visually display the measured angular distance.

2. A digital inclinometer comprising:

encoding means for indicating rotation rotated by a stepper motor;

means for sensing a certain orientation fixed to the encoding means; and

means for counting the rotation of the encoding means between a particular position of the orientation sensing means and the certain orientation of the orientation sensing means;

wherein the counting means includes;

an index on the encoding means;

means for sensing the index; and

means for measuring digitally the angular distance the encoding means rotates between the detection of the index by the index sensing means and the certain orientation of the orientation sensing means;

wherein the measuring means counts the number of steps of the stepper motor needed to rotate the encoding means between detection of the index and the certain orientation of the orientation sensing means; and

a comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to an output lead of the index sensing means, to produce a comparator output signal on an output lead;

stepper motor drive means including a micro-stepping means and having two output leads, the first output lead providing a signal electrically controlling the stepper motor;

a multivibrator having an input terminal electrically connected to an output lead of the orientation sensing means, so as to produce a multivibrator output signal on an output lead;

an up/down counter having three input terminals electrically connected respectively to the comparator output lead, to the multivibrator output lead, and to the drive means second output lead, to produce an output signal on an output lead; and

a digital display electrically connected to the counter output lead to visually display the measured angular distance.

3. A digital inclinometer comprising:

an encoder assembly rotated by a direct current motor in a housing to indicate rotation;

an index mark on the encoder assembly to indicate the angular position of the encoder assembly;

an index sensor fixed to the housing to detect the index mark;

a tilt sensor to detect a horizontal position fixed to the encoder assembly; and

measuring means for measuring digitally and displaying the mount of rotation of the encoder assembly between a horizontal position detected by the tilt sensor and the detection of the index mark by the index sensor;

wherein the measuring means includes;

transparent angular index marks forming a part of the encoder assembly, light-generating means, and light-responsive means for generating an electronic signal in response to light transmitted by the light-generating means through the portion of said encoder assembly having the angular index marks; and

a first comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to receive the signal generated by the light-responsive means, to produce a first comparator output signal on an output lead;

a first multivibrator having an input terminal electrically connected to the first comparator output lead to produce an output signal on an output lead;

a second comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to an output lead of the index sensor, so as to produce a second comparator output signal on an output lead;

a second multivibrator having an input terminal electrically connected to an output lead of the tilt sensor, so as to produce a second multivibrator output signal on an output lead;

motor control means electrically connected to the output lead of the first multivibrator, to control the motor speed;

phase-locked loop means electrically connected to the output lead of the first multivibrator to increase angular resolution and having an output lead;

an up/down counter having three input terminals electrically connected respectively to the output lead of the phase-locked loop means, to the second multivibrator output lead, and to the second comparator output lead, to produce an output signal on an output lead; and

a digital display electrically connected to the counter output lead to visually display the measured angular distance.

4. A digital inclinometer comprising:

an encoder assembly rotated by a stepper motor in a housing to indicate rotation;

an index mark on the encoder assembly to indicate the angular position of the encoder assembly;

an index sensor fixed on the housing to detect the index mark;

a tilt sensor to detect a horizontal position fixed to the encoder assembly; and

measuring means for measuring digitally and displaying the amount of rotation of the encoder assembly between a horizontal position detected by the tilt sensor and the detection of the index mark by the index sensor;

wherein the measuring means counts the number of steps of the stepper motor needed to rotate the encoder assembly between detection of the index mark and the detection of a horizontal position by the tilt sensor; and

wherein the measuring means includes;

a comparator having two input terminals with the first terminal electrically connected to ground and the second terminal electrically connected to an output lead of the index sensor, to produce a comparator output signal on an output lead;

stepper motor drive means including a micro-stepping means and having two output lead, the first output lead providing a signal electrically controlling the stepper motor;

a multivibrator having an input terminal electrically connected to the output lead of the tilt sensor, so as to produce a multivibrator output signal on an output lead;

an up/down counter having three input terminals electrically connected respectively to the comparator output lead, to the multivibrator output lead, and to the drive means second output lead, to produce an output signal on an output lead; and

a digital display electrically connected to the counter output lead to visually display the measured angular distance.