Pocket Watch Database
Patent Archive
#2175021
Patent Information
Microphonic Apparatus
Thomas B. Gibbs
October 3, 1939
Patent #2175021
| Patent Number: | 2175021 |
| Description: | Microphonic Apparatus |
| Inventor(s): | Thomas B. Gibbs |
| Patent Date: | Oct 3, 1939 |
| Registration Type: | Patent |
| External Research: | https://www.google.c… |
| Patent Document: |
