| Number | Name | Date | Kind |
|---|---|---|---|
| 2131877 | King | Oct 1938 | |
| 2664167 | stergren | Dec 1953 | |
| 3041485 | Jolley | Jun 1962 | |
| 3659378 | Tong | May 1972 | |
| 3818632 | Tong | Jun 1974 | |
| 4218846 | Lahr | Aug 1980 | |
| 4378709 | Chitayat | Apr 1983 | |
| 4406085 | Rhodes | Sep 1983 | |
| 4511343 | Goldfarb et al. | Apr 1985 | |
| 4516648 | Berger et al. | May 1985 | |
| 4540380 | Kennedy et al. | Sep 1985 | |
| 4570502 | Klatt | Feb 1986 |
| Number | Date | Country |
|---|---|---|
| 1197365 | Aug 1961 | DEX |
| 154547 | Sep 1982 | JPX |
| Entry |
|---|
| "In New Products", Product Engineering, vol. 30, No. 1, p. 53. |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 122253 | Nov 1987 |