Telescopic ball bar gauge

• US 7,997,001 B1
• Filed: 06/14/2010
• Issued: 08/16/2011
• Est. Priority Date: 06/14/2010
• Status: Expired due to Fees

• Current Assignee: King Fahd University of Petroleum & Minerals (Government of Saudi Arabia)
• Original Assignee: King Fahd University of Petroleum & Minerals (Government of Saudi Arabia)
• Inventors: Mekid, Samir
• Primary Examiner(s): BENNETT, GEORGE B
• Application Number:
  US12/801,545
• Time in Patent Office: 428 Days
• Field of Search: 335/02, 337/06, 337/83, 337/87, 337/88, 337/89, 338/09, 338/10, 338/11, 338/12
• US Class Current: 33/783
• CPC Class Codes: G01B 21/042 Calibration or calibration artifacts G01B3/30, G01B9/02072 take precedence
• CPC Class Codes: G01B 3/30 Bars, blocks, or strips in which the distance between a pair of faces is fixed, although it may be preadjustable, e.g. end measure, feeler strip

Abstract

The telescopic ball bar gauge provides a pair of movable test measuring points that are spaced apart a known distance so that the points may be contacted by a machine probe of a coordinate measuring machine or the like to generate test data. This allows varying inaccuracies within the machine to be detected and accounted for during normal operation of the machine. The telescopic ball bar gauge includes a plurality of telescoping segments forming at least one linear variable differential transformer. The at least one linear variable differential transformer is used to measure the linear distance between two balls mounted on opposed ends of the ball bar gauge. A transmitter in communication with the at least one linear variable differential transformer transmits a measurement signal representing the linear distance between the two balls.

Claims

1. A telescopic ball bar gauge, comprising:

a telescopic rod having first and second telescopic segments;

first, second and third annular solenoid coils mounted within the first telescopic segment, the first, second and third annular solenoid coils being mounted about a central tube, the second telescopic segment being slidable within the central tube to form a linear variable differential transformer; and

first and second balls, the first ball being mounted to a free end of the first telescopic segment, the second ball being mounted to a free end of the second telescopic segment;

wherein the linear variable differential transformer generates a measurement signal corresponding to a linear distance between the first and second balls.

2. The telescopic ball bar gauge as recited in claim 1, further comprising means for transmitting the measurement signal.

3. The telescopic ball bar gauge as recited in claim 2, wherein said means for transmitting the measurement signal comprises a wireless transmitter in communication with the linear variable differential transformer.

4. The telescopic ball bar gauge as recited in claim 2, wherein said first telescopic segment is substantially flexible.

5. The telescopic ball bar gauge as recited in claim 4, wherein said second telescopic segment is substantially flexible.

6. The telescopic ball bar gauge as recited in claim 5, wherein each of said first and second balls is formed from stainless steel.

7. The telescopic ball bar gauge as recited in claim 1, wherein the linear distance between said first and second balls is less than about 50 mm when said telescopic rod is fully extended.

8. The telescopic ball bar gauge as recited in claim 7, wherein the linear distance between said first and second balls is greater than approximately 20 mm when said telescopic rod is fully collapsed.

9. A telescopic ball bar gauge, comprising:

a telescopic rod having first, second and third telescopic segments;

a plurality of first annular solenoid coils mounted in the first telescopic segment, the plurality of first annular solenoid coils being mounted about a first central tube, the second telescopic segment being slidable within the first central tube to form a first linear variable differential transformer;

a plurality of second annular solenoid coils mounted in the second telescopic segment, the plurality of second annular solenoid coils being mounted about a second central tube, the third telescopic segment being slidable within the second central tube to form a second linear variable differential transformer; and

first and second balls, the first ball being mounted to a free end of the first telescopic segment, the second ball being mounted to a free end of the third telescopic segment;

wherein the first and second linear variable differential transformers generate a measurement signal corresponding to linear distance between the first and second balls.

10. The telescopic ball bar gauge as recited in claim 9, further comprising means for transmitting the measurement signal.

11. The telescopic ball bar gauge as recited in claim 10, wherein said means for transmitting the measurement signal comprises a wireless transmitter in communication with the first and second linear variable differential transformers.

12. The telescopic ball bar gauge as recited in claim 10, wherein said first telescopic segment is substantially flexible.

13. The telescopic ball bar gauge as recited in claim 12, wherein said second telescopic segment is substantially flexible.

14. The telescopic ball bar gauge as recited in claim 13, wherein said third telescopic segment is substantially flexible.

15. The telescopic ball bar gauge as recited in claim 14, wherein each of said first and second balls is formed from stainless steel.

16. The telescopic ball bar gauge as recited in claim 9, wherein the linear distance between said first and second balls is less than about 50 mm when said telescopic rod is fully extended.

17. The telescopic ball bar gauge as recited in claim 16, wherein the linear distance between said first and second balls is greater than about 20 mm when said telescopic rod is fully collapsed.

18. A telescopic ball bar gauge, comprising:

a telescopic rod having a plurality of telescopic segments, the plurality of telescopic segments including at least a first segment and a sliding end segment;

at least one set of annular solenoid coils mounted in one of said telescopic segments adjacent the sliding end segment, the at least one set of annular solenoid coils being mounted about at least one central tube, the sliding end segment being slidably received within the at least one central tube to form at least one linear variable differential transformer; and

first and second balls, the first ball being mounted to a free end of the first segment, the second ball being mounted to a free end of the sliding end segment;

wherein the at least one linear variable differential transformer generates a measurement signal corresponding to linear distance between the first and second balls.

19. The telescopic ball bar gauge as recited in claim 18, further comprising means for transmitting the measurement signal.

20. The telescopic ball bar gauge as recited in claim 19, wherein said means for transmitting the measurement signal comprises a wireless transmitter in communication with the first and second linear variable differential transformers.