| Number | Date | Country | Kind |
|---|---|---|---|
| 2-070810 | Mar 1990 | JPX | |
| 2-183451 | Jul 1990 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1138675 | Lockwood | May 1915 | |
| 1337017 | Kenworthy | Apr 1920 | |
| 1573183 | Mehlum | Feb 1926 | |
| 1658799 | DeVogel | Feb 1928 | |
| 1977668 | Dallas | Oct 1934 | |
| 2499869 | Luchansky | Mar 1950 | |
| 3922082 | Cavallaro | Nov 1975 | |
| 4541710 | McLeish | Sep 1985 |
| Number | Date | Country |
|---|---|---|
| 0429303 | May 1991 | EPX |
| 0448051 | Sep 1991 | EPX |
| 2743967 | May 1979 | DEX |
| 2939287 | Apr 1981 | DEX |
| Entry |
|---|
| Patent Abstracts of Japan, vol. 8, No. 240 (M-336)(1677) 6 Nov. 1984Pand Jp-A-59 118 647 (Fuji Xerox) 9 Jul. 1984 * abstract *. |