Number | Name | Date | Kind |
---|---|---|---|
3654392 | Beinhocker et al. | Apr 1972 | |
3937004 | Natori et al. | Feb 1976 | |
5129654 | Bogner | Jul 1992 | |
5619181 | Murray | Apr 1997 | |
5666331 | Kollin | Sep 1997 |
Entry |
---|
Digital and Analog Chess Clocks, pp. 1-3, http:/?www.chessmate.com/chessclocks.html. |