| Number | Name | Date | Kind |
|---|---|---|---|
| 2522906 | Smith | Sep 1950 | |
| 4320618 | Dandl | Mar 1982 | |
| 4409782 | Westergaard et al. | Oct 1983 | |
| 4872565 | McAlpine | Oct 1989 |
| Entry |
|---|
| One page advertisement on New Horizons Tree Shakers, published in Oct. 1988 issue of WCTPA Quarterly Journal, p. 14. |