Rotary external combustion engines

Claim 1

A ROTARY EXTERNAL COMBUSTION ENGINE COMPRISING: A SINGLE PAIR OF MESHING ROTORS, ONE OF SAID ROTORS HAVING A PLURALITY OF HELICAL GROOVES THEREIN AND THE OTHER OF SAID ROTORS HAVING A PLURALITY OF HELICAL TEETH TO MESH AND MATE WITH SAID HELICAL GROOVES; A CASING CLOSELY SURROUNDING SAID ROTORS AND HAVING AN AIR INLET PORT THEREIN FOR ADMITTING AIR INTO THE CONFINED REGION BETWEEN SAID CASING AND ROTORS NEAR ONE END THEREOF ON THE SIDE OF THE ROTORS WHERE THEY ARE ROLLING TOGETHER, SAID ROTORS ACTING PROGRESSIVELY TO DIMINISH THE VOLUME OF THE AIR AS IT IS MOVED BY SAID TEETH TOWARD THE OPPOSITE END OF SAID ROTORS; SAID CASING HAVING A COMPRESSED AIR DISCHARGE PORT THEREIN ADJACENT SAID OPPOSITE END OF SAID ROTORS; AND A HOT GAS INTAKE PORT IN THE SIDE OF SAID CASING OPPOSITE FROM SAID AIR INLET PORT AND ADJACENT THE FIRST MENTIONED ENDS OF SAID ROTORS, SAID HOT GAS INTAKE PORT COMMUNICATING WITH THE REGION WHERE THE TEETH OF THE TOOTHED ROTOR BEGIN TO LEAVE SAID GROOVES; A CONDUIT FOR CONDUCTING THE COMPRESSED AIR FROM SAID COMPRESSED AIR DISCHARGE PORT TO SAID HOT GAS INTAKE PORT; MEANS FOR INTRODUCING FUEL INTO SAID CONDUIT; MEANS FOR IGNITING THE FUEL AND AIR IN SAID CONDUIT, THE MIXTURE OF FUEL AND AIR THAT IS HEATED AND EXPANDED BY ITS COMBUSTION ACTING TO SEPARATE THE HELICAL