| Number | Name | Date | Kind |
|---|---|---|---|
| 4072486 | Joseph | Feb 1978 | |
| 4707594 | Roth | Nov 1987 | |
| 5175873 | Goldenberg et al. | Dec 1992 | |
| 5221838 | Gutman et al. | Jun 1993 | |
| 5422934 | Massa | Jun 1995 | |
| 5465193 | Tracy | Nov 1995 | |
| 5500643 | Grant | Mar 1996 | |
| 5648771 | Halgren et al. | Jul 1997 | |
| 6067074 | Leuders | May 2000 |
| Entry |
|---|
| Instruction Manual for Tango; p. 1-38; Nov. 27, 1995; items 10-11 are separate keypads. |