Data processing: measuring – calibrating – or testing – Measurement system – Dimensional determination
Reexamination Certificate
1998-07-29
2001-01-16
Hoff, Marc S. (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system
Dimensional determination
C702S155000, C033S555100
Reexamination Certificate
active
06175813
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed to measuring geometrical dimensions of a part and, more particularly, to a method and apparatus for measuring the diameter of a part, such as a ring.
Measuring the diameter of a ring has become an important step in the manufacture of a bearing. A number of known mechanical measurement techniques exist for measuring the diameter of a part. The mechanical measuring techniques commonly include the use of air gauges, calipers, micrometers, and pi tapes, to name a few. The pi tape measurement approach uses a measuring tape that includes the &pgr; function included with the dimensional units in inches or centimeters, such that the circumferential measurement units are divided by the well-known ratio of circumference of a circle to its diameter, e.g., &pgr;=3.14159265. As the pi tape is physically wrapped around the measured circumferential surface of the part, the measurement units provide an actual part measurement converted on the tape to a diameter unit. The caliper and micrometer measurement techniques likewise include mechanical methods of taking actual physical measurements to measure the diameter of the part.
In lieu of the mechanical techniques, a more recent approach called a coordinate measuring machine has been developed and used to establish coordinates for a given part surface. The coordinate measuring machine uses an algorithm to approximate the diameter of the part. This is generally accomplished by way of a “best fit” approach in which the circumference of the part is approximated and matched up with a best fit circle. However, the coordinate measuring machine only provides an approximate dimension and can be adversely affected by a non-round shape of the part, as well as various features that may be present on the measured part.
Accordingly, there is a need to provide for an accurate measuring apparatus to measure the diameter of a part quickly and with high reliability. Further, there is a need to provide for such a measuring apparatus and method that can achieve accurate measurements of parts that are out of round, and particularly for a ring shaped part.
SUMMARY OF THE INVENTION
The present invention improves the accuracy and automation for measuring the geometric dimension of a part such as the diameter of a ring shaped part. To achieve this and other advantages, and in accordance with the purpose of the invention as embodied and described herein, the present invention provides for an apparatus and method for measuring the geometric dimension of a part. The apparatus includes a rotational device for holding a part to be measured and for rotating the part through a plurality of angular positions. A measuring device measures distance from each of the plurality of angular positions on the measured surface of the part to the center of the part as measurements are taken along the surface of the part at each successive angular position. A distance is calculated between successive measured positions on the part as a function of the measured radii and angle of rotation between successive angular positions. A plurality of the distances as taken through a complete rotation of the rotational device are summed together to provide a circumference measurement of the part. A diameter measurement of the part is determined by dividing the circumference measurement by &pgr;.
REFERENCES:
patent: 1439321 (1922-12-01), Page
patent: 2969598 (1961-01-01), Voltaire et al.
patent: 3144718 (1964-08-01), Brehm
patent: 4322888 (1982-04-01), Garzione
patent: 4347667 (1982-09-01), Albertazzi
patent: 4464839 (1984-08-01), Sadeh
patent: 4563824 (1986-01-01), Baun
patent: 4586145 (1986-04-01), Bracewell et al.
patent: 4596074 (1986-06-01), Allen
patent: 4679447 (1987-07-01), Sieradzki et al.
patent: 4700484 (1987-10-01), Frank et al.
patent: 4725963 (1988-02-01), Taylor et al.
patent: 4729174 (1988-03-01), Caron et al.
patent: 4821425 (1989-04-01), Currie et al.
patent: 4866642 (1989-09-01), Obrig et al.
patent: 4926309 (1990-05-01), Wu et al.
patent: 5131166 (1992-07-01), Weber
patent: 5317811 (1994-06-01), Berwick
patent: 5563798 (1996-10-01), Berken et al.
patent: 5694339 (1997-12-01), Ishitoya et al.
patent: 204757 (1956-12-01), None
patent: 253740 (1988-02-01), None
patent: 58-70101 (1983-04-01), None
patent: 62-231109 (1987-10-01), None
patent: 3176608 (1991-07-01), None
Thomas George B., and Ross L. Finney. Calculus and Analytic Geometry 8th Edition. pp. A-3—A-5.
“Formscan Model 1600” (4 pages), Published by Federal Products Company, Instrumentation Group Esterline Technologies, Providence, Rhode Island, (No Date).
Clough Stephen K.
Larsen Robert L.
Purchase Mike R.
Barbee Manuel L.
Hoff Marc S.
Kaydon Corporation
Price Heneveld Cooper DeWitt & Litton
LandOfFree
Circumferential diameter measuring apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circumferential diameter measuring apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circumferential diameter measuring apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2481024