Patent information:
| Patent: | Reissue 12,992 |
| Patented: | July 13, 1909 |
| Applied: | December 23, 1908 |
| Title: | Manufacture of Spar Insulators |
| Description: | Feldspar insulator material (reissue of 907,155) |
| Category: | Feldspar |
| Assigned to: | |
Patentee Information:
Class and subclass information:
| Class: | 501 | COMPOSITIONS: CERAMIC |
| Subclass: | 153 | CERAMIC COMPOSITIONS; Aluminum compound containing; |
Known specimens:
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