Patent ID: 7644766
Filing Date: 2010-01-12
Classification: E21B

Abstract:
1. A flushing device for use in a drill assembly, the flushing device comprising: an inner sleeve, axially slidable relative to an outer sleeve, the inner and outer sleeves cooperate to define an inner passage for the flow of a fluid, and are permanently coupled such that there is substantially no rotational movement between the two sleeves; the inner passage having an inlet and an outlet; the outer sleeve having a plurality of flushing outlets; and an indexing mechanism which indexes between a first position, wherein the plurality of flushing outlets are blocked from the internal passage such that the flushing device is in a closed condition, to a second position, wherein the plurality of flushing outlets register with the internal passage such that the flushing device is in an open condition, the indexing mechanism comprises a travel stop mounted on the inner sleeve for rotation about the longitudinal axis thereof, the travel stop has a second end adapted to engage and mesh a portion of the outer sleeve, wherein the second end of the travel stop is configured to provide a plurality of fingers and corresponding slots which co-act with corresponding fingers and slots integral with the portion of the outer sleeve, whereby the position of the fingers and slots of the travel stop relative to the fingers and slots of the portion of the outer sleeve will determine whether the flushing device is in an open or closed condition; whereby when fluid flows through the flushing device, the flushing device is configured such that it remains in the selected open or closed condition regardless of the forces acting thereupon.