Rolling-ball thermoelectric potential probe and housing for nondestructive testing of metallic and semiconductor objects

• US 5,544,953 A
• Filed: 05/18/1994
• Issued: 08/13/1996
• Est. Priority Date: 05/18/1994
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Viertl, John R. M.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): HIRSHFELD, ANDREW HOWARD
• Application Number:
  US08/245,269
• Time in Patent Office: 818 Days
• Field of Search: 374/4-7, 374/137, 374/152-154, 374/163, 374/164, 374/179, 374/208, 374/210, 136/221, 136/229, 136/230, 73/566.5, 73/104, 73/105
• US Class Current: 374/164
• CPC Class Codes: G01B 7/06 for measuring thickness measuring during the manufacture of coatings C23C14/54

Abstract

A thermoelectric potential probe inspects the surface coating thickness of a turbine bucket blade using a rolling ball probe head to traverse the surface of the bucket. The probe may be hand-held or affixed to a computer controlled robotics coordinate measuring machine. The rolling ball head has embedded heating elements and is a thermal-electric sensor that gathers data regarding the thickness of coating on a turbine surface.

Claims

1. A thermoelectric potential probe comprising:

a rotatable rolling-ball probe head for contacting a surface of a test object, said probe head being substantially spherical and having a plurality of internal thermocouples;

wherein said probe head is solely supported by a rotatable tubular axle having a first end fixedly attached to said probe head and a second end rotatably attached to a support base for said probe, and

wherein said probe head has a plurality of holes, and said holes each of said plurality of thermocouples is disposed adjacent an outer surface of the probe head in a distal end of a respective one of said holes each having a proximate end adjacent the first end of the tubular axle, wherein each of the proximate ends are disposed at the outer surface of the probe head.

2. A probe as in claim 1 further comprising an internal thermal heating element disposed within an additional hole in said probe head.

3. A probe as in claim 1 wherein said plurality of holes is three holes arranged symmetrically about an axis of rotation of the probe head, and said plurality of thermocouples comprises three thermocouples each mounted in a respective one of said three holes in said probe head.

4. A probe as in claim 1 wherein said probe head is formed substantially of copper.

5. A probe as in claim 4 wherein said probe head is coated with Rhodium.

6. In a thermoelectric potential probe having a probe shaft with a first end supporting a rotatable rolling-ball probe head for contacting a test object, the rolling-ball probe head comprising:

a substantially spherical body having an outer surface and an axis of rotation about an axis of the probe shaft, and said body being rotatably attached to the first end of the probe shaft by a post extending between the body and probe shaft;

an internal thermal heating element within the body;

a plurality of holes in said body, wherein each hole has a distal end adjacent to the outer surface of the body and wherein the distal ends of the holes are arranged symmetrically about the axis of rotation, and each hole has a proximate end adjacent the post, wherein each of the proximate ends are disposed at the outer surface of the body, and

a thermocouple mounted in the distal end of each of said holes.

7. In a thermoelectric potential probe having a probe shaft having a first end supporting a rotatable rolling-ball probe head for contacting a test object, wherein the rolling-ball probe head comprises:

a substantially spherical body having a surface and an axis of rotation about an axis of the probe shaft;

an internal thermal heating element within the substantially spherical body;

a plurality of holes in said substantially spherical body, wherein each hole has a distal end proximate to the surface of the body and wherein the distal ends of the holes are arranged symmetrically about the axis of rotation, and

a thermocouple mounted in the distal end of each of said holes, and

wherein the substantially spherical body includes a substantially flat shoulder region and said plurality of holes each has a proximate end in said shoulder region.

8. A rolling-ball probe head as in claim 7 wherein the plurality of holes is three holes.