| 摘要 |
An irrigation controller for use with a plurality of electrically or hydraulically activated valves for automatically regulating time, location and duration of irrigation. An indexing rotary switch or rotary hydraulic pilot valve sequentially activates the valves. Adjustable timing units for each of the valves determines the dwell time of the rotary switch or valve on each valve. Hour and day timer wheels determine the days and time of day for the start of the rotary switch or valve. Each day and hour wheel contains two concentric circles of two or three position pins allowing selection from a multitude of combinations to achieve any possible watering desired. Interchangeable seven and six day wheels allow the controller to be utilized both for selection of given days of the week and alternate or every third day watering. A day wheel adjuster allows either the seven or six day wheel to be used with the hour wheel without any changes being required in the gearing between the wheels. An elastomeric band between the ratchet and pawl of the indexing means silences the controller for quite operation. A standard lawn sequence operates each time the indexing of the rotary switch or valve occurs. Less frequent shrub watering is possible in the electrical version by selection of a combination of the rotary switch, an override switch, and a special shrub switch. A drip station, independent of the rotary switch, operates directly with the conjunction of selected pins on the day and hour wheels.
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