Number | Name | Date | Kind |
---|---|---|---|
24660 | Potts | Jul 1859 | |
D314820 | Sullivan | Feb 1991 | |
567231 | Glauber | Sep 1896 | |
925762 | Eager | Jun 1909 | |
1908821 | Cornell, Jr. | May 1933 | |
2086007 | Tompkins | Jul 1937 | |
2215318 | Bristol | Sep 1940 | |
3610288 | Carr | Oct 1971 | |
3645566 | Dyck | Feb 1972 | |
4067353 | DeHoff | Jan 1978 | |
4491349 | Rice et al. | Jan 1985 | |
4750411 | Eversole | Jun 1988 | |
4773197 | Sullivan | Sep 1988 | |
5036636 | Hasty | Aug 1991 | |
5080403 | Paolyccio | Jan 1992 |
Number | Date | Country |
---|---|---|
871635 | Jun 1961 | GBX |
Entry |
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Exhibit A-Photograph of prior air duct riser. |
Exhibit B-Photograph of prior air duct riser. |
Sales information from Northern Pipe Products and GPK Products, Inc. (Undated but believed to be prior art to the present application). |