| Number | Name | Date | Kind |
|---|---|---|---|
| 2570625 | Zimmerman et al. | Oct 1951 | |
| 2707106 | Cunningham | Apr 1955 | |
| 2961796 | Davis | Nov 1960 | |
| 2994984 | Luchsinger | Aug 1961 | |
| 3074206 | Fischl-Bernfi et al. | Jan 1963 | |
| 3134595 | Chenoweth et al. | May 1964 | |
| 3217446 | Steert | Nov 1965 | |
| 3407530 | Grant et al. | Oct 1968 | |
| 3550936 | Puttick | Dec 1970 | |
| 4102038 | Eagan | Jul 1978 |
| Number | Date | Country |
|---|---|---|
| 174226 | Mar 1953 | ATX |
| Entry |
|---|
| Welch Scientific Company Catalog Scientific Apparatus and Supplies Copyright 1965, Title Page and p. 171. |