9701. Minue, W. E. April 23. Movable-abutment type; packing drums, vanes, etc.; valve-gear. - A compound rotary engine comprises a rotating outer casing provided with hinged vanes in each working chamber, and a fixed inner member through which the steam is introduced and exhausted. A rotating cut-off valve, which may be rotated through a small angle by hand to start the engine, if it has stopped in such a position that the supply of steam is interrupted, is combined with a governor - controlled throttle valve in the steam - supply channel in the inner member. The hinged vanes are cam - operated; and the rotating casing is surrounded by a vacuum chamber to prevent loss of heat. Packing rings and bars are provided. Figs. 1 and 2 show the rotating outer casing G surrounding the stationary inner member E. The righthand end of the casing is closed by a plate h<2>, to which is attached a shaft H<1> running in a bearing in the standard C. The trunnion h on the other end bears upon the member E. A partition g, secured to the casing G, divides the enclosed space into high and low pressure working chambers J, J<1>. The member E is fixed at one end in a ring D bolted to the standard B, and is supported at the other end by an annular extension e<3> projecting into a recess in the end plate h<2>. The member is stepped, as shown, and has blocks F secured to it in each chamber J, J<1> to form cylinder heads. Each chamber J, J<1> has working in it a pair of piston-vanes I, Fig. 2, fixed on rods i<2> which pass through the rotating casing G. The rods are rocked to allow the vanes to pass the blocks F by means of cranks i<4>, the ends of which run in a cam-groove d<2> in a flange d' of the stationary ring D. Each rod has attached to it a vane in the high-pressure chamber and a vane in the low-pressure chamber. The gear i<4>, d<2> is covered by a cap K containing oil. A ridge k<1> prevents leakage. Steam is admitted to a channel M and passes through ports m to an annular space m<1> and thence to the highpressure chamber J by a port N, Fig. 9. The exhaust from this chamber passes through an oblique channel U, V in the member E to the low-pressure chamber J from which it exhausts through a port W and passage w. The engine parts are arranged so that each chamber receives steam at the same time, and exhausts it at the same time. A cut-off valve P, containing ports adapted to register intermittently with the ports m, is rotated continuously by lugs Q engaging recesses in the rotating plate h<2>. The recesses are longer than the lugs Q, so that, in the event of the engine stopping with the ports out of register, the valve P may be rotated through a small angle by means of the hand screw P<1>. A ported sliding throttle-valve O on a rod o is operated by a governor o<2>. The governor is driven by the engagement of a pinion o<3> on its spindle with a toothed-wheel o<5> on the trunnion h of the casing G. A fly-wheel or pulley Z is bolted to the casing. To prevent loss of heat, a vacuum-chamber H<2> is provided. Packing-bars T, Fig. 12, are arranged at intervals around the chambers, as shown in Fig. 2. The bars are spring pressed, and are locked to one another by mortise and tenon joints. Screws t<2> prevent excessive movement into the chambers, and holes t<3> admit steam to the rear sides, to balance the pressures. Packing-rings r, Fig. 10, are provided where necessary. They are wedge-shaped split rings seated in wedgeshaped recesses in the member E so that they tend to move out of the recesses and so produce a tight joint. Pins r<1> prevent them from rotating. Packing-bars are also arranged on the hinge, and at the ends of the vanes I. A recess is formed at the back of each vane, so that, when the vane is closed in against the casing, steam is admited to the back to balance the pressures.