This application is a division of application for U.S. Letters Patent, Ser. No. 511,909 filed on July 8, 1983, now United States Pat. No. 4,490,544 issued on Dec. 25, 1984.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2603560 | Stewart | Jul 1952 | |
| 2787631 | Stevens | Apr 1957 |
| Number | Date | Country |
|---|---|---|
| 49-110628 | Sep 1973 | JPX |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 511909 | Jul 1983 |