Down-the-hole Drill Reverse Exhaust System

A down-the-hole drill actuator assembly comprising:

• a casing;
• a backhead configured within the casing, the backhead including:
• a cylindrical member,
• a central bore within the cylindrical member,
• a check valve assembly within the central bore,
• a supply inlet in communication with the central bore,
• an exhaust valve stem in communication with the central bore, and
• at least one exhaust port in communication with the exhaust valve stem;
• and
• a piston housed within the casing and operatively associated with the backhead, the piston comprising a bore partially sized to exhaust a portion of a fluid within the casing there through.

An actuator assembly comprising:

• a casing;
• a piston housed within the casing, the piston comprising a thru-bore sized to allow a fluid within the casing to partially exhaust through;
• a drill bit connected to a distal end of the casing and operatively associated with the piston;
• and
• a backhead connected to a proximal end of the casing and operatively associated with the piston, the backhead comprising:
• an exhaust port, and
• an exhaust valve stem in communication with the exhaust port, and wherein the exhaust port exhausts the fluid,
• a drive chamber formed within the casing and in communication with the exhaust valve stem,
• a return chamber distal to the drive chamber, formed by an inner wall surface of the casing and an outer surface of the piston, and
• wherein the fluid is supplied to the drive chamber through the supply inlet, and wherein the casing, piston, and backhead are configured to exhaust fluid within the drive chamber through the exhaust port, and exhaust fluid within the return chamber through an opening in the drill bit.