GB854255A - Free piston engines - Google Patents

Abstract

854,255. Free piston engines. STEWART-WARNER CORPORATION. Jan. 21, 1959 [Jan. 23, 1958], No. 2309/59. Classes 7(1) and 7(2). A free piston engine comprises a pair of opposed free pistons capable of relative movement and disposed within a cylinder with a cushioning compression chamber between them and a pair of combustion chambers at opposite outer ends of the cylinder. The invention is shown applied to free piston gas generators. In Fig. 1 the principal air compression chamber 10 is located between the heads 4 of the two pistons an auxiliary compression chamber 11 is located between each of the pistons and the adjacent cylinder section of the engine block. These auxiliary chambers constitute a pneumatic sensing mechanism. The action of air compressed in the chambers 11 is used to effect initiation of the power stroke. The power stroke initiating device 23 may be an actuator for the plunger of the injection nozzle 8. It is stated that the pistons will be driven to approach synchronism and within a few strokes will be completely synchronized. Starting may be effected by supplying air through the valves 14. In a modification (not shown) the fuel injection is controlled by pressure actuated circuit making devices and solenoids. Each solenoid is incorporated in a solenoid fuel valve or solenoid controlled injection mechanism. In Fig. 6 the space 44 between the pistons 45, 47 is utilized as a bounce space and the spaces 46 are compression spaces. The cross timing devices are worked from the combustion chambers. In Fig. 7 the conduits 65 connected to injector mechanisms 58 lead directly to one another likewise conduits 66 connected to combustion chambers 53 (or to auxiliary air compression chambers 11 in Fig. 1) lead directly to one another. Intermediate portions of the connected conduits 65 and the connected conduits 66 are joined one to the other by a short conduit 67. Specification 434,921 is referred to.