| Number | Name | Date | Kind |
|---|---|---|---|
| 1609186 | Peruzzi | Nov 1926 | |
| 2319919 | Clark | May 1943 | |
| 2534010 | Frye | Dec 1950 | |
| 2915235 | Rueckert | Dec 1959 | |
| 3021044 | Schubert | Feb 1962 | |
| 3023945 | Layne, Sr. | Mar 1962 | |
| 3112058 | Martin | Nov 1963 | |
| 3310219 | Dlugopolski | Mar 1967 | |
| 3357628 | Fish | Dec 1967 | |
| 3385424 | Thompson et al. | May 1968 | |
| 3826420 | Bamburg et al. | Jul 1974 | |
| 3889868 | Bruckner et al. | Jun 1975 | |
| 3933300 | Dempster | Jan 1976 | |
| 4168028 | McCall | Sep 1979 | |
| 4365710 | Swanson | Dec 1982 | |
| 4693411 | Snyder | Sep 1987 | |
| 4913290 | deGroot | Apr 1990 |
| Number | Date | Country |
|---|---|---|
| 20171 | Dec 1980 | EPX |
| 1512508 | Feb 1968 | FRX |
| 1526302 | Sep 1978 | GBX |
| Entry |
|---|
| The Wiley Encyclopedia of Packaging Technology, John Wiley & Sons, pp. 492,493 (1986). |