| Number | Name | Date | Kind |
|---|---|---|---|
| 2110998 | McDaniels | Mar 1938 | |
| 2364834 | Whistler et al. | Dec 1944 | |
| 3786731 | Bobst et al. | Jan 1974 | |
| 4421000 | Murphy | Dec 1983 | |
| 4555966 | Klingel | Dec 1985 | |
| 4569267 | Klingel | Feb 1986 | |
| 4623089 | Scott | Nov 1986 | |
| 4650114 | Salvagnini | Mar 1987 | |
| 4685613 | Schambre | Aug 1987 | |
| 4929276 | Chun et al. | May 1990 | |
| 5044238 | Etcheparre et al. | Sep 1991 | |
| 5140879 | Haj-Ali-Ahmadi et al. | Aug 1992 | |
| 5400682 | Matsuura | Mar 1995 |
| Entry |
|---|
| IBM Technical DIsclosure, "Stroke Minimization of a Programmable Punch Tool", vol. 29, No. 5, Oct. 1986, pp. 1961-1964. |