Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4972601 | Coilable tape rule with improved connection between spring and blade | Dudley V. Bickford, Henry R. Cofek, Hugh Michael Robinson | 1990-11-27 |
| 4928346 | Hand-held vacuum cleaner with power brush | Donald E. Elson, Burton E. Gerke, Jr., Michael E. Bitzel, Stanley J. Rodowsky, Jr., William R. Lessig, III +2 more | 1990-05-29 |
| 4841594 | Cordless vacuum cleaner with power brush | Donald E. Elson, Burton E. Gerke, Jr., Michael E. Bitzel, Stanley J. Rodowsky, Jr., William R. Lessig, III +2 more | 1989-06-27 |