Number | Name | Date | Kind |
---|---|---|---|
3201948 | Schramm | Aug 1965 | |
3471953 | Wyatt | Oct 1969 | |
3575006 | Rugroden et al. | Mar 1971 | |
3583168 | Harton | Jun 1971 | |
3851489 | Richardson | Dec 1974 | |
3948059 | Pampa | Apr 1976 | |
4332511 | Bradley et al. | Jan 1982 | |
4650370 | Kassner et al. | Mar 1987 |
Number | Date | Country |
---|---|---|
410900 | May 1934 | GBX |
Entry |
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Publication by the Charles Machine Works, Inc. entitled "Ditch Witch 6510" dated Jul. 1986. |
Publication by the Charles Machine Works, Inc. entitled "Earth-Coupled Water Source Heat Pump" dated Sep. 1987. |
Publication by the Charles Machine Works, Inc. entitled "Earth-Coupled Water Source Heat Pump" dated Sep. 1987. |