主权项 |
1. A method of controlling a manually operated valve having a body, a passageway through the body, an articulable member mounted to a valve stem and positioned within the passageway, the position of the articulable member determining the degree of openness of the passageway and an original handle attachable to the valve stem to facilitate turning the valve stem, comprises the steps of:
(A) removing the original handle; (B) installing a switchbox on the valve, the switchbox having a housing removably attachable to the valve body, a shaft extending through the housing, one end of the shaft couplable to the valve stem such that movement of the shaft moves the valve stem, a shaft position sensor, a position sensor actuator coupled to the shaft, the position sensor actuator capable of interacting with the shaft position sensor to induce the shaft position sensor to acquire a state having an associated electrical property indicative of shaft position, a motion limiter coupled to the shaft for limiting the range of motion of the shaft and rotating conjointly therewith, a first lock member coupled to the shaft and rotatable conjointly therewith, a second lock member coupled to the housing, the first and second lock members selectively cooperative to allow the shaft to be locked in a first position, wherein the housing has a base and a cover coupled to the base via a fastener member, and wherein opposing mating surfaces of the cover and the base have a complementary castellated shape that (i) allows the fastener member to be recessed below an upper surface of the cover, and (ii) permits the motion limiter to pass over the fastener member during rotation of the motion limiter; (C) installing one of the original handle or another handle; (D) selectively monitoring electrical signals from the position sensor representative of a position of the shaft; and (E) selectively locking the valve in a first selected position. |