Abstract: A rack and pinion gear train actuator for a pintle valve. A motor shaft has a pinion gear that engages a large reduction gear having an integral hub gear. The hub gear is a planet gear for a ring gear segment that pivots on a shaft and includes a pinion gear segment that engages a linear rack. The rack is attached to a valve pintle shaft, causing the valve to be opened and closed in response to rotation of the motor shaft. The pintle shaft, return spring, rack, and gears are all assemblable by slip fit. The actuator has a high actuation force, a fast response time, and compact design by virtue of a rack and internal gearing. The stroke of the rack may be changed for use with pintle valves having differing strokes by varying the angle through which the motor operates.

Abstract: A dual-poppet valve comprising a valve body having spaced-apart coaxial valve seats and being arranged such that first and second poppets both open into the primary chamber. A first pintle shaft engages the first poppet, and a second pintle shaft engages the second poppet. A motorized actuator having a gear transmission includes a pinion gear. The pintle shafts include opposing gear racks, and the pinion gear engages both racks. Thus, rotation of the pinion gear in a first direction causes both poppets to be lifted from their seats simultaneously, in opposite directions; and counter-rotation engages each poppet with its respective seat. In closing, one poppet engages its seat slightly before the other poppet engages the other seat. The first pintle slides through the first poppet until the second poppet is fully seated by the actuator. The force of the spring fully engages the first poppet with the first seat.