| Number | Name | Date | Kind |
|---|---|---|---|
| 172707 | Nishwitz | Apr 1887 | |
| 801961 | Balmer | Oct 1905 | |
| 1376910 | Wright | May 1921 | |
| 1377115 | Clayton | May 1921 | |
| 1630415 | Blume et al. | May 1927 | |
| 2582503 | Oehler | Jan 1952 | |
| 2689511 | Begeman et al. | Sep 1954 | |
| 3804179 | Johnson | Apr 1974 | |
| 4121669 | Sosalla | Oct 1978 | |
| 4250970 | Pfenninger | Feb 1981 | |
| 4425972 | Steinberg | Jan 1984 | |
| 4428437 | Steinberg | Jan 1984 | |
| 4452315 | Swanson | Jun 1984 | |
| 4466492 | Steinberg | Aug 1984 | |
| 4485878 | Uken | Dec 1984 | |
| 4591002 | Meinert | May 1986 | |
| 4622906 | Melgoza | Nov 1986 | |
| 5133414 | Youngkrantz | Jul 1992 |
| Entry |
|---|
| "The Renaissance of Rotary Hoes", By: Charlene Finck, Farm Journal, May 1990. |
| Yetter Tool Bar Rotary Hoe from pp. 6-7 of Yetter Mfg. Co. catalog (date unknown, admitted prior art). |
| May-Wes Speedshields ad from "Successful Farming", Aug., 1990. |