| Number | Name | Date | Kind |
|---|---|---|---|
| 196384 | Porteous | Oct 1877 | |
| 519728 | McGowan | May 1894 | |
| 888941 | Traxel | May 1908 | |
| 1250388 | Titus | Dec 1917 | |
| 1786357 | Miller | Dec 1930 | |
| 1987883 | White et al. | Jan 1935 | |
| 2580199 | Schmid | Dec 1951 | |
| 2598968 | Boosey | Jun 1952 | |
| 2605781 | Schmid et al. | Aug 1952 | |
| 2664096 | Murdock et al. | Dec 1953 | |
| 3017896 | Papacek | Jan 1962 | |
| 3770003 | Uroshevich | Nov 1973 | |
| 3885585 | Carpentier | May 1975 | |
| 3926206 | Anderson et al. | Dec 1975 | |
| 3926207 | Anderson et al. | Dec 1975 | |
| 4096877 | Arledge | Jun 1978 | |
| 4109671 | Hughes et al. | Aug 1978 | |
| 4202526 | Muller et al. | May 1980 | |
| 4282895 | Young | Aug 1981 | |
| 4653521 | Fillman | Mar 1987 | |
| 4653522 | Fillman et al. | Mar 1987 | |
| 4854339 | Hoeptner, III | Aug 1989 | |
| 5033500 | Hoeptner, III | Jul 1991 | |
| 5261441 | Anderson | Nov 1993 | |
| 5355907 | Hoeptner, III | Oct 1994 | |
| 5451030 | Reglebrugge et al. | Sep 1995 | |
| 5701925 | Mulligan et al. | Dec 1997 |
| Entry |
|---|
| "Merrill SP Pitless Units", Merrill Manufacturing, Storm Lake, IA "Campbell M1 Pitless Adapters", Campbell Manufacturing, Inc. |
| "Campbell M4 Pitless Adapters", Campbell Manufacturing, Inc., Bechtelsville, PA. |