Patent ID: 8573301

Claim:
A ball and plug dropping head for use in sequentially dropping one or more balls and plugs into a well tubing, comprising: a) a housing having an inlet at its upper end adapted to be fluidly connected in line with the lower end of a top drive, an outlet generally aligned with the inlet; b) a main flow channel that connects the inlet and the outlet; c) a plurality of inner valving members spaced between the inlet and the outlet, each valving member having an inner valve flow bore, and being movable upon a valve stem between open and closed positions; d) one or more bypass fluid flow channels that enable fluid to bypass the inner valving members when a said inner valving member is in the closed position; e) at least one of the inner valving members having a cross section that, in the closed position, does not valve fluid flow in the main flow channel; f) wherein fluid flow in the main channel flows around the inner valving member via the bypass fluid flow channel when it is in the closed position and through the inner valving member when it is in the open position; g) wherein in the open position each inner valve flow bore permits a ball or plug to pass therethrough, and circulating fluid to pass downwardly therethrough when neither a ball nor plug is in the valve flow bore; h) one or more outer valving members mounted on the valve stem and that each occupy a position in the bypass channel; i) wherein the outer valving member opens the bypass channel when the inner valving member is in the closed position; and j) wherein the outer valving member closes the bypass channel when the inner valving member is in the open position.