Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5209715 | Automatic force generating and control system | Christopher W. Walker, Michael M. Szafranski, Sung-Hak Kim, Steven Frank | 1993-05-11 |
| D329073 | Exercise bicycle | — | 1992-09-01 |
| D325610 | Physical exerciser | Christopher W. Walker, Michael M. Szafranski, Sung-Hak Kim | 1992-04-21 |
| D324377 | Five slot computer housing | Philip G. Yurkonis, James G. Ammon, Alfred Lockwood, Herbert Pfeifer, Nick Brawne | 1992-03-03 |
| 5058888 | Automatic force generating and control system | Christopher W. Walker, Michael M. Szafranski, Sung-Hak Kim, Steven Frank | 1991-10-22 |
| D320007 | Computer housing | Craig M. Leverault, Peter Ta | 1991-09-17 |
| D314950 | Twelve slot computer housing | Tuan T. Vu, Michael J. Lee, Siamak Z. Salimpour, Philip G. Yurkonis, Herbert Pfeifer +1 more | 1991-02-26 |
| D306288 | Keyboard | Herbert Pfeifer | 1990-02-27 |
| D304823 | Computer housing | Herbert Pfeifer | 1989-11-28 |
| D303662 | Cursor control | Herbert Pfeifer | 1989-09-26 |