| Number | Name | Date | Kind |
|---|---|---|---|
| 951436 | Duryea | Mar 1910 | |
| 998283 | Duryea et al. | Jul 1911 | |
| 1844516 | Meyer et al. | Feb 1932 | |
| 2586462 | Forster | Feb 1952 | |
| 2899737 | Nilson | Aug 1959 | |
| 3006633 | Schoenberger, Jr. | Oct 1961 | |
| 3437506 | Falberg | Apr 1969 | |
| 4053845 | Gould | Oct 1977 | |
| 4161436 | Gould | Jul 1979 | |
| 4299410 | Jukola | Nov 1981 | |
| 4420282 | Axelrod | Dec 1983 | |
| 4505629 | Lynch | Mar 1985 | |
| 4547000 | Sallinen | Oct 1985 | |
| 4565477 | Axelrod | Jan 1986 | |
| 4656905 | Ginzburg et al. | Apr 1987 | |
| 4704583 | Gould | Nov 1987 | |
| 4791846 | Kirkpatrick | Dec 1988 | |
| 4911475 | Lerman | Mar 1990 | |
| 4925354 | Cote | May 1990 | |
| 5078424 | Kadish | Jan 1992 | |
| 5127786 | Cross | Jul 1992 |
| Number | Date | Country |
|---|---|---|
| 0077795 | Jan 1985 | EPX |
| 3152075 | Aug 1985 | DEX |
| 490869 | Mar 1952 | ITX |
| Entry |
|---|
| "Open Sesame"-American Printer, Sep., 1991 pp. 46, 48-49. |
| "Bound To Stay Open"-American Printer, Mar. 1991 pp. 53-56. |
| "For Short Runs", Otabind-RepKover.TM., Jun. 19, 1991. |