| Number | Name | Date | Kind |
|---|---|---|---|
| 1878894 | Sallee | Sep 1932 | |
| 1927877 | Meyer | Sep 1933 | |
| 1938834 | Graf | Dec 1933 | |
| 2600849 | Collins et al. | Jun 1952 | |
| 2743024 | Schmitt et al. | Apr 1956 | |
| 3572703 | Greene | Mar 1971 | |
| 3764900 | Baldwin | Oct 1973 | |
| 4246452 | Chandler | Jan 1981 | |
| 4272649 | Pfeiffer | Jun 1981 | |
| 4369579 | Mizoule | Jan 1983 | |
| 4408103 | Smith, III | Oct 1983 | |
| 4550503 | Klawitter | Nov 1985 | |
| 4600083 | Parent et al. | Jul 1986 |
| Number | Date | Country |
|---|---|---|
| 685361 | Mar 1965 | ITX |
| Entry |
|---|
| Popular Science 6-1984 p. 14. |