BALL CATCHER WITH RETENTION CAPABILITY

摘要

A ball catcher is designed to stop balls that are the same size or different sizes at an inlet on a seat that is connected to a movable biased sleeve. Once the ball or other shaped object lands at the seat the flow around it increases differential pressure on the seat and sleeve and displaces them against the bias. The ball goes into a surrounding annular space and cannot exit. A preferably spiral sleeve guide the movement of the balls in the annular space so that efficient use of the annular space is made to maximize the number of balls that can be captured per unit length of the annular space. As soon as the ball enters the annular space the sleeve shifts back to the original position to stop the next ball at the inlet. Once in the annular space, the balls cannot escape if there is a flow reversal. The central passage remains open to pass other tools and flow.