Long Beach, CA, United States of America

Keystone Engineering Company

Calculating rank

USPTO Granted Patents = 7

% Expired Patents = 71.4

EPO Patents = 2

Forward Citations = 18

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4 inventors (with patents filed for the assignee):

Wayne H Tuttle (5 out of 9 patents)

Ian Ballinger (4 out of 4 patents)

Conrad M Fritz (2 out of 3 patents)

4. Robert Manning (1 out of 2 patents)

5. Jeffry K Pearson (5 patents)

6. David Adams (1 patent)

7. Marcial Alexander Anaya (1 patent)

7 patents: Sort by Forward Citations

1. 10611503 - Center of mass control of liquid tanks for spacecraft use (2020-04-07),

2. 10479532 - Stress relieved welds in positive expulsion fuel tanks with rolling metal diaphragms (2019-11-19),

3. 10139047 - Stress relieved welds in positive expulsion fuel tanks with elastomeric diaphragm (2018-11-27),

4. 10088103 - Method of fabricating space satellite tank components utilizing additive manufacturing and spin forming (2018-10-02),

5. 9840752 - Method and apparatus for performing a localized post-weld heat treatment on a thin wall metallic cylinder (2017-12-12),

6. 4523793 - High-performance low-torque anti-friction bearing assembly (1985-06-18),

7. 4400042 - High performance low torque anti-friction bearing assembly (1983-08-23),

Company Overview

Keystone Engineering Company is a leading engineering firm that provides innovative solutions in the areas of civil, structural, and mechanical engineering. With over 20 years of experience, we specialize in designing and building high-quality infrastructure projects for various industries including oil and gas, petrochemical, and construction. Our team of highly skilled engineers and professionals are committed to delivering exceptional service to our clients, ensuring cost-effectiveness and timely project delivery. Visit our website to learn more about our services and projects.

Profile summary synthesized from public USPTO records and patent filings.

Company Badge

USPTO Data Jan 1 1976 - Oct 27 2026

7 Patents

#30 in Long Beach, CA

#9,511 in California

#39,950 in US

Long Beach, CA, United States of America

Keystone Engineering Company

Forward Citations = 18

4 inventors:

Wayne H Tuttle (5 out of 9 patents)

Ian Ballinger (4 out of 4 patents)

Conrad M Fritz (2 out of 3 patents)

4. Robert Manning (1 out of 2 patents)

5. Jeffry K Pearson (5 patents)

IDiyas Innovation Intelligence. (2026). Company Patent Portfolio: Keystone Engineering Company. Retrieved from https://idiyas.com/company/keystone-engineering-company

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

Data Sources: USPTO Patent Grant XML, Patent Center, EPO & CIPO • Normalized by IDiyas Innovation Graph. Methodology & provenance architecturePlease report any incorrect information to [email protected]

2 patents (EPO):

Data Sources: USPTO Patent Grant XML, Patent Center, EPO & CIPO • Normalized by IDiyas Innovation Graph. Methodology & provenance architecturePlease report any incorrect information to [email protected]