Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5857545 | Elevator system with overlapped roped-coupler segments | David W. Barrett, John F. Cassidy, Jr., Ernest P. Gagnon, Richard E. Peruggi | 1999-01-12 |
| 5816368 | Elevator cars switch hoistways while traveling vertically | David W. Barrett, John F. Cassidy, Jr., Ernest P. Gagnon, Andrew F. Peruggi, Richard E. Peruggi | 1998-10-06 |
| 4939679 | Recalibrating an elevator load measuring system | David H. Sorenson | 1990-07-03 |