| Number | Name | Date | Kind |
|---|---|---|---|
| 1125855 | Mapes | Jan 1915 | |
| 1707539 | Propp | Apr 1929 | |
| 2347041 | Filsinger | Apr 1944 | |
| 2986470 | Fishmeister | May 1961 | |
| 3400263 | Yakim | Sep 1968 | |
| 3690902 | Dahl | Sep 1972 | |
| 3736214 | McBirnie | May 1973 | |
| 3819455 | MacKendrick | Jun 1974 | |
| 4187532 | Naffier | Feb 1980 | |
| 4416075 | Bauer | Nov 1983 | |
| 4510556 | Johnson | Apr 1985 | |
| 4721455 | Barfus | Jan 1988 | |
| 4803604 | Nichols et al. | Feb 1989 | |
| 4866580 | Blackerby | Sep 1989 | |
| 4884966 | Wexler | Dec 1989 | |
| 4938688 | Wexler | Jul 1990 | |
| 5006971 | Jenkins | Apr 1991 | |
| 5174645 | Chung | Dec 1992 |
| Number | Date | Country |
|---|---|---|
| 550274 | May 1932 | DEX |
| Entry |
|---|
| Science Fair 200 in 1 Electronic Pocket Kit instruction pages; Radio Shack. |