controller: Device including a gate, valve, or other means to vary or cut off the flow of material through the discharge outlet, and wherein the state or position of said means is regulated in response to rotation of a ground wheel.
(1) Note. A reciprocating or rotating apertured feed plate is considered to be a discharge controller if during the operation of the device the aperture(s) intermittently assumes a position in simultaneous registry with a supply and an outlet, and is considered to be a discharge assistant when the aperture acts as a trap, i.e., the aperture alternately registers with the supply and then the discharge outlet, thereby separating and carrying a portion of material from the supply to the outlet. Devices of the latter type will be found in subclasses 620 and 623+.
SEE OR SEARCH THIS CLASS, SUBCLASS:
620, for a device having a reciprocating feed plate.
