Patent ID: 7423932

Claim:
A pressure signal pulse generating apparatus for use in a drill string suspended in a well bore to generate changes in the resistance to the flow of a mud stream flowing down the bore of said drill string, said changes containing characteristics that are interpreted at the surface to derive information encoded into the changes at the down hole location, the apparatus comprising: a) a body comprising a serial element of said drill string; b) a signal valve, situated in said body, through which at least part of said mud stream flows, and comprising an orifice and a cooperating poppet arranged to move between a generally closed position and a generally open position; c) at least one motor, situated in said body, arranged to rotate said poppet; d) a controlling instrument situated in said body; and e) a rotary-to-linear motion converter arranged to axially move said poppet relative to said orifice in response to controlling actions of said instrument.