USD244483SExpiredUtility

Optical refraction testing instrument

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Assignee: NERTHUS INCPriority: Apr 4, 1975Filed: Apr 4, 1975Granted: May 24, 1977
Est. expiryApr 4, 1995(expired)· nominal 20-yr term from priority
Inventors:John E. TothVictor L. Copeland
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PatentIndex Score
4
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2
References
1
Claims

Claims

exact text as granted — not AI-modified
The ornamental design for an optical refraction testing instrument, substantially as shown.

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