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CIPO Patents = 5

Forward Citations = 133

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7 inventors (with patents filed for the assignee):

Rex E Duhn (10 out of 17 patents)

Robert K Meek (8 out of 12 patents)

Jay C Duhn (2 out of 2 patents)

4. Gary A Card (1 out of 1 patent)

5. William D Chapman (1 out of 2 patents)

6. Aaron B Speirs (1 out of 1 patent)

7. Kenneth D Webster (1 out of 1 patent)

11 patents: Sort by Forward Citations

1. 7726393 - Wellhead isolation tool and wellhead assembly incorporating the same (2010-06-01),

2. 7520322 - Wellhead isolation tool and method of fracturing a well (2009-04-21),

3. 7493944 - Wellhead isolation tool and method of fracturing a well (2009-02-24),

4. 7416020 - Wellhead isolation tool, wellhead assembly incorporating the same, and method of fracturing a well (2008-08-26),

5. 7322407 - Wellhead isolation tool and method of fracturing a well (2008-01-29),

6. 6920925 - Wellhead isolation tool (2005-07-26),

7. 6588510 - Coil tubing hanger system (2003-07-08),

8. 6543533 - Well tubing rotator (2003-04-08),

9. 6199914 - Drilling quick connectors (2001-03-13),

10. 5303774 - Ring seal packer (1994-04-19),

11. 4974676 - Ground subsiding wellhead (1990-12-04),

Duhn Oil Tool, Inc. is a leading provider of high-quality oil tools and equipment for the oil and gas industry. With a focus on innovation and reliability, we deliver top-notch products and services to our clients worldwide. Our team of experts is dedicated to meeting the needs of our customers and ensuring the success of their projects. Visit our website to learn more about our offerings and how we can help you achieve your goals.

This text is generated by artificial intelligence and may not be accurate.

Company Badge

USPTO Data Jan 1 1976 - Dec 9 2025

11 Patents

#10 in Bakersfield, CA

#6,325 in California

#26,680 in US

#50,159 in the World

Bakersfield, CA, United States of America

Duhn Oil Tool, Inc.