| Number | Name | Date | Kind |
|---|---|---|---|
| 2885139 | Werner et al. | May 1959 | |
| 3047142 | Heffley | Jul 1962 | |
| 3049260 | Stone | Aug 1962 | |
| 3073439 | Symonds, Jr. | Jan 1963 | |
| 3335932 | Brown | Aug 1967 | |
| 4238031 | Skaggs | Dec 1980 | |
| 4925149 | DiFrancesca et al. | May 1990 | |
| 5040684 | Knowles | Aug 1991 | |
| 5060801 | Vilas-Boas | Oct 1991 | |
| 5299685 | Chin | Apr 1994 |
| Number | Date | Country |
|---|---|---|
| 170265 | Jul 1993 | JPX |
| Entry |
|---|
| Tuscarora Plastics Packaging vol. 29, No. 3, Mar. 1984 p. 28. |