Patent GB-190710556-A (GB)
Title: Improvements in Rotary Engines.
Inventor: DRAPER STEPHEN HOPKINS
IPC: F01C1/20
Filed: 1907-05-06
Granted: 1908-04-30
Abstract: 10,556. Draper, S. H. May 5, 1906, [date applied for under Patents Act, 1901]. Movable-abutment type with intermittently rotating abutment. Motive fluid is supplied through the hollow hub of the abutment, which contains a cylindrical reversing-valve within which is situated an oscillating cylindrical cut-off valve. The abutment is intermittently rotated by a pawl-andratchet mechanism actuated by the main shaft. When the inlet valve is reversed, the pawl is reversed and the position of the exhaust ports altered. A built-up piston drum is used, and the weight of the vane is balanced by a counterweight within the drum. A drum f, Fig. 1, carrying a vane g is secured to a central shaft e, and comprises a rim h, Fig. 5, and hub j connected together by arms i. Disks m, Figs. 1 and 2, are screwed to the sides of the drum. The rim h is made with a counterweight to balance the weight of the vane g. In the upper part of the casing is situated a rotary abutment r mounted upon a hollow shaft q and carrying six arms t. The abutment arms are so shaped that the two arms on each side of the lowest one for the time being form a continuation of the circular casing. The shaft q and the hub of the abutment are formed with ports u by way of which the motive fluid is admitted to the working chamber. Two disks 29, Fig. 2, are fixed to the sides of the abutment and rotate therewith. Concentric with and in the same plane as the disks 29 are two annular disks 31, 32, which make contact with the disks m secured to the sides of the piston drum. One of the disks 32, Fig. 1, is provided with ports 33, Fig. 1, through which the motive fluid exhausts. The disks, piston vanes, and abutment arms are all suitably packed as indicated in the Figures. The abutment is intermittently rotated by the mechanism shown in Figs. 2 and 3. Two disks 2, 3 are mounted upon the abutment spindle q. The outer disk 2 is formed with teeth 4 ; the disk 3 is formed with notches 5. An eccentric 14 secured to the main shaft e rocks a disk 6, loosely mounted upon the spindle q, which is made with an arm 7 carrying a pawl 8. As shown in Fig. 3, the connexion between the eccentric-rod and the disk 6 is adjustable. The pawl 8 engages the teeth on the disk 2 so that the abutment is rotated step by step. A cam disk 15, mounted upon the main shaft e, reciprocates a plunger 21 which engages one of the notches in the disk 3 when the abutment is at rest, and holds it in position until the pawl again engages a tooth. A hollow liner 23, Fig. 2, which is normally stationary, fits inside the abutment shaft q, and is provided with a set of ports which periodically register with the ports in the shaft q. The liner 23 communicates with the supply pipe 53 by way of a steam-chest 24. Within the liner 23 is a hollow cylindrical cut-off valve 46, provided with ports which register with the ports in the liner and shaft. The cut-off valve is mounted upon a spindle 48, which passes through the centre of the abutment shaft and is connected to an arm 49, Figs. 2 and 3, oscillated by an arm 50 pivoted to the eccentric-rod. The cut-off valve 46 and liner 23 are made with longitudinal slits and tend to expand. The exhaust ports 33 in the ring 32 register with ports in the casing communicating with an exhaust pipe 55. The ring 32 is fitted with a pin 36 which projects through a segmental slot in the casing. A double-armed lever 37 pivoted to the casing engages the pin 36 and a pin fixed to a reversing-lever 28, secured to the liner 23. The upper part of the lever 37 can also rock a rod 41 carrying a tripping-lever 42 by means of which the pawl 8 can be thrown over to the position shown in dotted lines in Fig. 3. The direction of rotation of the abutment is thereby reversed. For reversing the engine therefore, the liner 23 and exhaust ring 32 are turned through a suitable angle and the pawl is tripped. The three operations are under the control of the one lever 28.