Abstract: A downhole tool configured for inclusion in a drill string, typically as part of a bottom hole assembly. The downhole tool configured to improve passage of the drill string through a borehole. Additionally, the downhole tool is suitable for use in a method for improving passage of a drill string through a borehole.

Abstract: A downhole tool comprises a tool housing defining a flow passage therethrough from a first to a second end thereof. A poppet is axially movable on a poppet mandrel positioned in the tool housing. The poppet mandrel has at least one outlet port defined therein. A pilot valve is rotatable about the poppet mandrel. Rotation of the pilot valve opens and closes the at least one outlet port in the poppet mandrel to permit and block flow therethrough, and wherein the opening and closing of the at least one outlet port moves the poppet axially on the poppet mandrel.

Abstract: A ram air cooling system for cooling electronic components in an aircraft ovides automatic switching from a high ram air speed cooling mode (ACM) to a low ram air speed cooling mode (RAM). The cooling system receives variable speed ram air during the flight of the aircraft and includes an automatically controlled valve for either directing high speed ram air to a precooling means prior to cooling the electronic components or directing low speed ram air directly to the electronic components without precooling. The automatically controlled valve is controlled by programmable logic module means for comparing the cooling efficiency of the electronic components by precooled ram air with the cooling efficiency of the electronic components by the non-precooled ram air. The cooling efficiencies are calculated from temperature measurements of the ram air at several locations in the system of the invention.