Drill string sub with self closing cable port valve

摘要

A side-entry sub for use in conjunction with wireline cable. The sub has a cable entry port provided with a self-closing valve for sealing the port upon withdrawal of the cable. In one embodiment, the self-closing valve is characterized by a housing member supporting a closure disc which is integrally molded with a resiliently deflectable support member having an elastic memory which biases the valve in the closed position. In an alternate embodiment, the self-closing valve comprises a ball valve, biased in the closed position by magnetic or spring means, and having a passageway through which the cable may pass. When the cable is inserted through the passageway, the ball valve is held in the valve open position. When the cable is removed from the passageway, the ball valve automatically closes.