Patent GB-368794-A (GB)
Title: Improvements in rotary internal combustion engines
IPC: F02B53/00
Filed: 1930-09-08
Abstract: 368,794. Rotary engines. TACKMAN, J., 584, West 152nd Street, New York, U.S.A. Sept. 8, 1930, No. 26804. [Class 110 (ii).] In a rotary internal-combustion engine of the kind comprising a plurality of concentric cylinders 1, 2, 3, spaced' to provide annular working spaces O. P, Q in which are arranged rotor members 5, 6, 7 all mounted on a common shaft 4 and having oppositely disposed cam surfaces which constitute, during rotation, cam tracks for abutment elements 17 slidably mounted in the cylinder walls, each of the elements 17 comprises a primary member, traversed by a byepass channel, and auxiliary members which are moved, relatively to the primary member, by the cam surfaces of adjacent rotors to open and close the byepass channel. In the form shown in Fig. 6, the primary member comprises bars 17c, held in spaced relation by projections on plate members 17a and recessed on each side for a part of their length so that a passage extends through the whole assembly. The auxiliary members are constituted by rockers 17b fitting snugly into the concave faces of the members 17c and formed with recesses adapted, as the rockers are rotated by the cam surfaces of the rotors, to open and close the channel through the abutment. The rockers may be held tightly against the rotors by the provision of spring-mounted wearing strips 17d or by supplying compressed air behind them. A modification is described in which the body of the abutment is formed of two parts only, each member 17a being formed integral with one of the bars 17c. Fig. 8 shows a further construction in which the rockers 17b carry gears meshing with a pinion mounted on a valve 17e which is formed with a slot adapted to communicate with cross-slots in a central member 17a and thus complete a channel through the abutment. The cylinders 2, 3 and the oppositely disposed cylinder heads 10, 11, 15, Fig. 2, are all cooled by water supplied through pipe 45. Fuel mixture is supplied from a carburetter to a manifold 28 by a pipe 32 and is delivered to the working chambers through inlet ports 19 controlled by valves 20 ; exhaust takes place through ports 29 controlled by valves 14, passages 9, ports 21 controlled by valves 24, and chambers 22 communicating with exhaust pipes 33. The valves 14, 20, 24 are all controlled by a wheel 30 which is formed with cam grooves 26, 27 to receive the valve stems and is adapted to be moved by a lever 30a into various positions to control the method of working in either the forward or reverse direction. The engine may be worked by utilizing the expansive pressure in one or any number of power chambers independently or the pressure may be compounded through successive larger power chambers. A method of working is described in which fuel charges are separately ignited in two power .chambers of different area, the partly expanded gases from the chamber of smaller area being passed into the chamber of larger area to augment the power impulse developed therein. Ignition is effected by spark plugs 23 connected by leads 39 to a distributing ring 40 on which are arranged contacts 41 having gaps adapted to be bridged by conductors 42 carried on the stems of the exhaust valves 14 when the latter are closed. The contacts 41 are connected by further leads 39 to contacts 38 arranged on a ring 43 and adapted to be successively engaged by a wheel 37 mounted on an arm 36 rotating with the shaft 4. The ring 43 can be adjusted to advance or retard the ignition by a handle 43a which is secured in the adjusted position by a pawl and ratchet device 43b, 44. A modified form of engine is described in which the shaft 4 is formed in two telescoping portions, gearing being interposed between the rotors and these shafts so that the latter are driven in opposite directions.