GB881347A - Improvements in or relating to pulse jet engines - Google Patents

Abstract

881,347. Generating combustion products under pressure. CURTIS AUTOMOTIVE DEVICES Inc. Dec. 5, 1958 [March 4, 1958], No. 39333/58. Class 51 (1). [Also in Groups XXVI, XXVII and XXIX] A pulse jet-engine comprises a combustion chamber, a vibratory combustion chamber inlet valve controlling the supply of fuel and air to the combustion chamber, and an air inlet valve assembly having an air inlet chamber for supplying air to the combustion chamber inlet valve and an air inlet valve to allow free flow of air into the air inlet chamber but to prevent reverse flow from the air inlet chamber. As shown, the air inlet assembly 33 is in the form of a cubical chamber 34 connected by a fuel and air-mixing passage 17 of Venturi form to a combustion chamber 11 and has a circular arrangement of air intake ports 39 in each of four walls 35, 36, 37, 38, each such arrangement co-operating with a valve member 48 supported on a wall and having petal-like portions 51 overlying the ports 39. Each valve member 48 is supported or attached to the corresponding wall by a flat back-stop disc 53 and a bolt 52. The fuel and air-mixing passage has a forwardlyflared air intake mouth 18, and encloses fuel and starting air pipes 42 and 30. A plate 32 attached to the down stream end of the mixing passage has a number of ports 16 covered by a vibratory combustion chamber inlet valve 20 with petal-like portions and held in place by a backstop 21. When the engine is operating the periodic partial vacuum formed in the combustion chamber 11 opens the valve 20 and draws in air and fuel from the mixing passage 17. The resulting partial vacuum in the inlet chamber 33 opens the valves 48 allowing ambient air to enter. Pressure rise in the combustion chamber due to periodic combustion closes the valve 20 against the ports 16, thus sealing the inlet passage from the combustion chamber. If valve 20 is faulty, " blow-back " to the atmosphere is prevented because the resulting pressure rise in the chamber 34 closes the air inlet ports 39, thus isolating the chamber 34 from the atmosphere.