PIPE LOCATOR METHOD AND APPARATUS

• US 3,653,050 A
• Filed: 12/29/1969
• Issued: 03/28/1972
• Est. Priority Date: 12/29/1969
• Status: Expired due to Term

• Current Assignee: Herbert L. Eggleston Jr
• Original Assignee: Herbert L. Eggleston Jr
• Inventors: Eggleston, Herbert L. Jr.
• Primary Examiner(s): Bennett, Jr., Rodney D.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US04/888,445
• Time in Patent Office: 820 Days
• Field of Search: 61/72.1 324/3,67 325/28,112,361 340/18DC 343/112A,112D,113PT,101,107,788,888,873
• US Class Current: 342/458
• CPC Class Codes: G01S 1/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

A method is disclosed of measuring the depth of an underground pipe by drilling a vertical hole which extends below and beside the pipe, transmitting electromagnetic energy into the pipe, coupling a small antenna to a receiver which is tuned to the frequency at which the pipe is energized, dropping the antenna down into the hole, and observing the maximum signal indicated by the receiver as the center of the antenna reaches the depth of the pipe. Also disclosed is a receiver having a flexible cable connected to its input, the other end of the flexible cable being connected to the upper end of a handle member, the handle member having a small antenna attached to its lower end as an extension thereof, and including conductor means carried by the handle member which electrically connects the antenna to the flexible cable. More specifically, the antenna is disclosed as a small ferrite rod antenna, and the handle member as a metallic tube having an insulated coaxial conductor carried within its interior, the upper end of the handle member being threaded for the threaded attachment of a superimposed handle member extension and also having a jack for connection of the flexible cable.

Claims

1. The method of measuring the depth of an underground pipe comprising the steps of:

drilling a generally vertical hole so that it extends beside and on below the pipe;

transmitting electromagnetic energy to the pipe at a predetermined frequency;

coupling a small ferrite rod antenna to a receiver which is tuned to said predetermined frequency;

lowering the ferrite rod antenna into the hole while maintaining its longitudinal axis essentially vertical and hence perpendicular to the longitudinal axis of the pipe;

observing the maximum signal indicated by the receiver as the longitudinal center of the antenna reaches the same depth as the pipe; and

measuring the distance from the center of the antenna to the surface of the ground.

2. Pipe locator apparatus comprising:

a receiver adapted to receive signals at a predetermined frequency, said receiver including a built-in loop antenna and a switch for disconnecting said loop antenna;

a ferrite rod antenna including an elongated ferrite rod and an insulated conductor wound helically thereon;

an elongated handle member supportingly attached to said antenna in longitudinal alignment with said ferrite rod, said antenna extending from the lower end of said handle member;

conductor means attached to said antenna and extending the length of and supported by said handle member; and

flexible cable means connected to said conductor means at the upper end of said handle member;

said receiver also including means for removably attaching said flexible cable means in place of said loop antenna, whereby the other end of said cable means may be connected to said receiver for supplying thereto signals acquired by said antenna.

3. Pipe locator apparatus comprising:

a receiver adapted to receive signals at a predetermined frequency;

a ferrite rod antenna including an elongated ferrite rod and an insulated conductor wound helically thereon;

an elongated handle member supportingly attached to said antenna in longitudinal alignment with said ferrite rod, said antenna extending from the lower end of said handle member;

conductor means attached to said antenna and extending the length of and supported by said handle member; and

flexible cable means connected to said conductor means at the upper end of said handle member and having its other end connected to said receiver for supplying thereto signals acquired by said antenna;

said handle member including a metallic tube, said conductor means being disposed inside said tube and terminating in a connector fixedly supported in the upper end of said tube, and said flexible cable means being provided with a mating connector for removable attachment to said handle member.

4. Apparatus as claimed in claim 3 wherein said mEtallic tube is threaded at its upper end, and which further includes a handle extension formed from a metal tube and having its lower end threaded for mechanical connection to said handle member, said handle extension including additional conductor means disposed therein for electrical connection between said flexible cable means and said ferrite rod antenna.

5. The method claimed in claim 1 which includes the additional steps of attaching the ferrite rod antenna to the lower end of an elongated measuring stick, and manipulating the measuring stick from its upper end in order to lower the antenna into the hole.

6. Pipe locator apparatus comprising:

a receiver adapted to receive signals at a predetermined frequency;

a ferrite rod antenna including an elongated ferrite rod and an insulated conductor wound helically thereon;

an elongated handle member supportingly attached to said antenna in longitudinal alignment with said ferrite rod, said antenna extending from the lower end of said handle member;

conductor means attached to said antenna and extending the length of and supported by said handle member;

flexible cable means connected to said conductor means at the upper end of said handle member and having its other end connected to said receiver for supplying thereto signals acquired by said antenna; and

which further includes an epoxy-glass tube attached to the lower end of said handle member as an extension thereof, said ferrite rod and conductor being concentrically disposed within said tube and encapsulated in insulating material, and an end plug attached beneath said tube.

7. Pipe locator apparatus comprising:

a receiver adapted to receive signals at a predetermined frequency;

a ferrite rod antenna including an elongated ferrite rod and an insulated conductor wound helically thereon;

an elongated, hollow, metallic handle member;

electrical insulating means attaching said antenna to the lower end of said handle member such that said ferrite rod is in longitudinal alignment with said handle member;

conductor means attached to said antenna and extending upward within said handle member throughout the length thereof; and

flexible cable means connected to said conductor means at the upper end of said handle member and having its other end connected to said receiver for supplying thereto signals acquired by said antenna;

said handle member having graduated scale markings on its exterior surface indicating the distance above the longitudinal center of said ferrite rod;

whereby said handle member may be used for inserting said ferrite rod antenna down into a hole, for removing it from the hole, and also for measuring the depth of the longitudinal center of said ferrite rod below the surface of the ground.

8. Apparatus as claimed in claim 7 which further includes an electrically insulative housing within which said ferrite rod antenna is contained, said housing being of elongated cylindrical configuration and having the same external diameter as said handle member.

9. Apparatus as claimed in claim 8 which further includes a metallic end plug attached to the lower end of said housing.

10. Apparatus as claimed in claim 9 wherein said metallic end plug includes means for aligning the longitudinal axis of said ferrite rod concentric to the longitudinal axis of said handle member.