Patented April 21, 1931
If an object in your hands says PAT. APRIL 21, 1931, it may be one of these.
| Patent | Title | Inventor | Of |
|---|---|---|---|
| US 1,801,628 | LOCK MECHANISM | Colvin L. Johnson | St. Louis, Missouri |
Three centuries of keeping things shut
If an object in your hands says PAT. APRIL 21, 1931, it may be one of these.
| Patent | Title | Inventor | Of |
|---|---|---|---|
| US 1,801,628 | LOCK MECHANISM | Colvin L. Johnson | St. Louis, Missouri |