(
186830
of
186830
)
Full text is not available for this patent. Click on "Images" button above to view full patent.
United States Patent
1,358,622
Issue Date:
November 9, 1920
Current U.S. Class:
396/590
Current International Class:
G03B 17/48 (20060101); G03B 17/50 (20060101)
* * * * *