Abstract: A sorter is provided with a plurality of movable sorting trays and a movement control device for controlling the movement of the movable sorting trays. The control device includes a sensor for detecting that a part of a screw rod passes through an index point which is remote from a stop position by a predetermined distance, a sensor for detecting the rotation of the screw rod and outputting a predetermined number of pulses in accordance with a predetermined moving distance of the screw rod. The control device is constructed in such a manner that it sets a stop pulse number according to the predetermined distance, counts the pulses from when the sensor detects that the screw rod passes through the index point, stops the movement of the sorting trays when the stop pulse number is count up, and controls a timing of the stop of the sorting trays in accordance with a moving condition of the sorting trays.

Abstract: A ball valve is provided including coupled outer casing elements adapted to enclose a rotationally movable valve body having an axial flow passageway therethrough. An annular casing groove having an anular seal member mounted therein is located adjacent each of the opposite ends of the flow passageway for sealingly engaging the movable valve body. Each of the annular casing grooves includes an annular casing wall projecting toward the movable valve body, and each of the seal members includes a flexible leg extending between its associated casing wall and movable valve body. A first surface of each flexible leg engages the movable valve body and a second, opposed surface of each leg is spaced a predetermined distance from its associated casing wall to accommodate a flexion of the flexible leg. Each of the seal members has a secondary sealing surface extending from the first surfaces thereof, and the secondary surfaces are spaced from the movable body a distance less than the foregoing predetermined distance.