| Number | Name | Date | Kind |
|---|---|---|---|
| 1732322 | Wilson et al. | Oct 1929 | |
| 1771765 | Benson | Jul 1930 | |
| 2266828 | Sykes | Dec 1941 | |
| 2300473 | Winkle | Nov 1942 | |
| 2501815 | Hamm | Mar 1950 | |
| 2617549 | Egger | Nov 1952 | |
| 2641402 | Bruun | Jun 1953 | |
| 2661889 | Phinney | Dec 1953 | |
| 2969901 | Behrens | Jan 1961 | |
| 3237834 | Davis et al. | Mar 1966 | |
| 3779157 | Ross, Jr. et al. | Dec 1973 | |
| 3785254 | Mann | Jan 1974 | |
| 3890762 | Ernst et al. | Jun 1975 | |
| 3908523 | Shikaya | Sep 1975 | |
| 4080880 | Shikay | Mar 1978 | |
| 4146660 | Hall et al. | Mar 1979 | |
| 4176054 | Kelley | Nov 1979 | |
| 5009326 | Reaves et al. | Apr 1991 | |
| 5092485 | Lee | Mar 1992 |
| Entry |
|---|
| "The Wiley Encyclopedia of Packaging Technology", John Wiley & Sons, pp. 66-69, 1986. |