BALL LAUNCHER FOR A TUBING STRING

摘要

A ball launcher has a body and a ball conveyor. The body has a sidewall defining axial bore, an attachment for attaching to a tubing string, and at least one radial port that provides access though the sidewall to the axial bore. The ball conveyor is carried by the body adjacent to an associated radial port. The ball conveyor comprises an inner bore in communication with the associated radial port and extends laterally outward from the body. A shaft extends along the inner bore, the shaft having a helical flight having at least one turn around the shaft, the flight and a bottom portion of the inner bore defining a ball receiving space large enough to receive a ball to be launched. A drive source rotates the shaft in a first direction to cause the flight to advance one or more balls toward the radial port.