Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4956974 | Replacement method and apparatus for a cryogenic refrigeration unit | David C. Planchard | 1990-09-18 |
| 4906266 | Replacement method and apparatus for a cryogenic refrigeration unit | David C. Planchard | 1990-03-06 |