| Number | Name | Date | Kind |
|---|---|---|---|
| 1499735 | Hynes | Jul 1924 | |
| 1515834 | Campbell | Nov 1924 | |
| 1627801 | Mitchell | May 1927 | |
| 2142236 | Campbell | Jan 1939 | |
| 2644408 | Dorey | Jul 1953 | |
| 2749770 | Dorey | Jun 1956 | |
| 2893327 | Lunde | Jul 1959 | |
| 3082703 | Dorey | Mar 1963 | |
| 3110270 | Ingram | Nov 1963 | |
| 3316859 | Floehr | May 1967 | |
| 3387570 | Pulcrano et al. | Jun 1968 | |
| 3397654 | Snyder | Aug 1968 | |
| 3682105 | Marulic | Aug 1972 | |
| 3683820 | Floehr | Aug 1972 | |
| 3709152 | Gutridge | Jan 1973 | |
| 3710729 | Schuller | Jan 1973 | |
| 3837294 | Fossett | Sep 1974 | |
| 3893398 | Fischer | Jul 1975 | |
| 3933100 | Dugge | Jan 1976 | |
| 3956996 | Fischer | May 1976 | |
| 4224879 | Van Auken | Sep 1980 | |
| 4256042 | Fischer | Mar 1981 | |
| 4262603 | Morse | Apr 1981 | |
| 4301741 | Chierchi | Nov 1981 | |
| 4432267 | Blout | Aug 1982 | |
| 4664038 | Davis | May 1987 | |
| 4766820 | Ritter et al. | Aug 1988 | |
| 4843974 | Ritter et al. | Jul 1989 | |
| 5353713 | Dohr et al. | Oct 1994 | |
| 5448955 | Dugge et al. | Sep 1995 | |
| 5507235 | Dugge et al. | Apr 1996 |
| Entry |
|---|
| Advertisement-"Geaps-Snap-Lock Gravity Outlet Gates", Trinity Industries, Inc., RSB-Geaps 0995-2. |
| Miner Promotional Sheet No. Mem 1038-922-1M (Sep. 18, 1992). |
| Association Of American Railroads, Specification For New Gravity Outlet Gates On Covered Hopper Cars, Sep. 1, 1992, C-11 To C-13.4. |