| Number | Name | Date | Kind |
|---|---|---|---|
| 100772 | Kelly | Mar 1870 | |
| 757950 | McElwain et al. | Apr 1904 | |
| 1212634 | Hathaway | Jan 1917 | |
| 2671667 | Flory | Mar 1954 | |
| 2784616 | Quackenbush | Mar 1957 | |
| 3060772 | Crump | Oct 1962 | |
| 3083593 | Cotter | Apr 1963 | |
| 3146675 | Anderson | Sep 1964 | |
| 3320832 | Jensen | May 1967 | |
| 3620636 | Godard | Nov 1971 | |
| 3907452 | Tripp | Sep 1975 |
| Number | Date | Country |
|---|---|---|
| 2,317,779 | Oct 1974 | DEX |
| Entry |
|---|
| "Safety Devices", p. 134, American Machinist, May 10, 1945. |