Number | Name | Date | Kind |
---|---|---|---|
3678780 | Ponting | Jul 1972 | |
4214133 | Wolford et al. | Jul 1980 | |
4774852 | Matt | Oct 1988 | |
4885437 | Tenniswood et al. | Dec 1989 |
Entry |
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Copy/Brochure/StoneL, Fergus Falls, MN, pp. 2/3, Valve positioned sensor to minimize install/operational costs (no date). |
Copy/Brochure/Westlock, Saddle Brook, N.J., discloses several forms of valve position monitors 1988. |
Copy/Brochure/Automax, Cincinnati, OH, "Centura CPL Series Electric Rotary Actuators", pp. 2/4 Aug. 1992. |