METHOD OF TRANSLATING THE LOCATION OF A PREDETERMINED POSITION ON ONE SIDE OF A SUBSTANTIALLY NONFERROUS STRUCTURAL BARRIER OF A BUILDING TO AN OPPOSITE SIDE OF SAID BARRIER

• US 3,836,848 A
• Filed: 11/01/1972
• Issued: 09/17/1974
• Est. Priority Date: 01/07/1970
• Status: Expired due to Term

• Current Assignee: Maurice E. Blevins
• Original Assignee: Maurice E. Blevins
• Inventors: Blevins, Maurice E.
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US05/302,666
• Time in Patent Office: 685 Days
• Field of Search: 324/52,67,3,8,71 325/310 340/258
• US Class Current: 324/67
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00

Abstract

A device for locating objects through a substantially nonferrous barrier, the use of which may also be applied for determining the thickness transmitter such a barrier and for localized surveying. An audio oscillator serves as a transmitter which emits signals that are picked up by headphones connected to a resonant tuned circuit. The transmitter is placed on or adjacent an object to be located and is set to transmit. Signals from the transmitter may then be located by the headphones and the peak sound from the signal or a null in the signal may be detected to pinpoint the position of the transmitter on the opposite side of the barrier. Whether or not the peak sound or the null is detected depends upon the attitude of the tranmitter coil with respect to the receiver coil. For measuring thickness of a particular barrier, the transmitter is located as stated above after which a null circle is detected radially out from the point where the tranmiter was located. The distance between the point of location of the transmitter and the null circle is a function of the thickness of the barrier. Alternatively, the null circle diameter may be detected and used to determine barrier thickness.

Claims

1. Apparatus for locating a desired object through a substantially nonferrous barrier comprising:

a. transmitting means, said transmitting means comprising an audio oscillator operating in a frequency range of from about 400 cycles per second to about 1 kilocycle per second, a power source for said audio oscillator and a housing to contain said oscillator and said power source;

b. receiving means for detecting signals transmitted by said transmitter means, said receiving means comprising a resonant circuit operating at the same frequency as said transmitting means, non-metallic housing to contain said resonant circuit and display means for indicating the signal picked up by said receiving means; and

c. means provided on said receiving means housing to mark on said barrier a point in question, said point on said barrier having been selected on one side of said barrier and translated to an opposite side of said barrier by locating said transmitting means with said receiving means; and

wherein the receiving means housing has a straight edge member secured thereto and extending outwardly therefrom, said straight edge member being useable as a guide for producing an ordinate on said barrier, at the location of the receiver upon detection of a predetermined signal, said ordinate being useable to better locate the said desired object.

2. Apparatus for local surveying comprising the apparatus as defined in claim 1 wherein the transmitter means housing has means received thereon to removably secure said transmitter means to said barrier.

3. Apparatus as defined in claim 1 wherein the transmitter means housing has level indicator means received therein.

4. Apparatus for locating a desired object through a substantially nonferrous barrier as defined in claim 1 wherein the resonant circuit contains a unidirectional coil.

5. Apparatus for locating a desired object through a substantially nonferrous barrier as defined in claim 1 wherein the resonant circuit contains a multidirectional coil.

6. Apparatus for determining the thickness of a substantially nonferrous barrier comprising:

a. transmitting means, said transmitting means comprising an audio oscillator operating in a frequency range of from about 400 cycles per second to about 1 kilocycle per second, a power source for said audio oscillator and a housing to contain said oscillator and said power source;

b. receiving means for detecting signals transmitted by said transmitter means, said receiving means comprising a resonant circuit operating at the same frequency as said transmitting means, a non-metallic housing to contain said resonant circuit and display means for indicating the signal picked up by said receiving means; and

c. means provided on said receiving means housing to mark on said barrier a point in question, said point on said barrier having been selected on one side of said barrier and translated to an opposite side of said barrier by locating said transmitting means with said receiving means; and

wherein the receiving means further comprises a retractable tape measure mounted thereon, said tape measure being useable to measure a null circle detected by said receiving means, whereby said null circle measurement may be used to determine the thickness of said barrier.

7. Apparatus for determining the thickness of a sUbstantially nonferrous barrier as defined in claim 6 wherein the tape measure is calibrated to read directly in barrier thickness.

8. Apparatus for determining the thickness of a substantially nonferrous barrier as defined in claim 6 wherein said marking means is secured to said receiving means housing and extends outwardly therefrom, and wherein said tape measure is received under spring tension around said marking means.