This is a divisional of copending application(s) Ser. No. 07/681,584 filed on Apr. 8, 1991.
Number | Name | Date | Kind |
---|---|---|---|
1178731 | Knorr et al. | Apr 1916 | |
2811542 | Speier et al. | Oct 1957 | |
3355473 | Clark et al. | Nov 1967 | |
3772346 | Hess | Nov 1973 |
Number | Date | Country | |
---|---|---|---|
Parent | 681584 | Apr 1991 |