Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4422068 | Intrusion alarm system for preventing actual confrontation with an intruder | John M. Helft | 1983-12-20 |
| 4290059 | Liquid level alarm for remotely indicating when less than a predetermined quantity of fuel oil remains in a storage tank and method for installing the same | John M. Helft | 1981-09-15 |