Position and orientation locator/monitor

• US 5,155,442 A
• Filed: 03/01/1991
• Issued: 10/13/1992
• Est. Priority Date: 03/01/1991
• Status: Expired due to Term

• Current Assignee: Merlin Technologies Incorporated
• Original Assignee: John Mercer
• Inventors: Mercer, John
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): DO, DIEP N
• Application Number:
  US07/662,939
• Time in Patent Office: 592 Days
• Field of Search: 324/676, 324/660, 324/687, 324/686, 324/672, 324/704, 324/724, 33/377, 33/379, 33/365, 33/366, 73/500, 73/501, 73/516 LM, 73/515 R, 73/515, 340/620
• US Class Current: 324/690
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17

Abstract

The present invention provides a locator/monitor capable of locating a boring tool and monitoring the progress of the tool for control purposes. The locator/monitor may be used in expedited locating methodology and straightforward calibration techniques of the present invention. A durable and cost effective pitch sensor is also provided by the present invention. In addition, the present invention provides a slotted transmitter housing formed of an electrically conductive material, where the magnetic field generated by the transmitter is capable of penetrating to the surface.

Claims

1. A pitch sensor capable of generating an output voltage indicative of fluid displacement within the pitch sensor, comprising:

a first outer electrically conductive portion;

a second outer electrically conductive portion electrically insulated from the first outer conductive portion;

an inner electrically conductive portion exhibiting equal electrical properties with respect to the outer conductive portions when in a baseline, zero pitch orientation and exhibiting unequal electrical properties with respect to the outer conductive portions when in a non-baseline orientation; and

a flowable material through which electrical connections between the outer portions and the inner portion are made, such that a ratio between an electrical property of the first outer portion and the inner portion to the electrical property of the second outer portion and the inner portion is indicative of fluid displacement, wherein the pitch sensor is capable of generating an output voltage indicative of fluid displacement regardless of the circumferential rotation of the pitch sensor about it baseline.

2. A pitch sensor according to claim 1 wherein the flowable material is an electrically conductive fluid and the electrical property is conductivity.

3. A pitch sensor according to claim 2 wherein the flowable material comprises a highly viscous fluid in combination with a conductive fluid or a salt which provides the viscous fluid with conductive properties.

4. A pitch sensor according to claim 1 wherein the flowable material is a dielectric fluid and the electrical property is capacitance.

5. A pitch sensor according to claim 1 wherein the pitch sensor is sized and configured for highly sensitive pitch measurements over a narrow pitch range.

6. A pitch sensor according to claim 1 wherein the pitch sensor is sized and configured to measure pitch over a wide pitch range.