Patent GB-455630-A (GB)
Title: Fluid pressure motors of the oscillating type
IPC: F02N13/00
Filed: 1935-04-23
Abstract: 455,630. Oscillating - vane engines. COFFMAN, R. A., 4733, Center Avenue, Pittsburg, U.S.A. April 23, 1935, No. 12276. [Class 110 (ii)] [See also Groups XXVII and XII] A fluid-pressure motor suitable for starting aeroplane and like engines comprises a driving member 106, movable in a toroidal chamber 105 and actuating a driven member 110 which is advanced axially into clutching engagement with an operated element, e.g. of an engine to be started. The motor includes a carrier 140 for a number of charges of ignitable fuel for actuating the member 106, and means controlled by the operation of the member 106 for intermittently turning the carrier in a plane parallel to the plane of rotation of the member 106 to bring successive charges to operative position. As shown in Figs. 3 and 7, the driving member 106 is a sleeve carrying a vane 107 moving in the toroidal chamber 105, and drives the sleeve 110 through planetary gearing 114 meshing with a gear ring 115 and a sun gear 118 splined on the sleeve 110, as described in Specification 455,686. The sleeve 110 is advanced into clutching engagement with engine member 137 by a spring 126 acting in conjunction with a stationary cam ring 124 engaged by a radial pin 123 carried by the sleeve 110. The cartridge carrier 140 rotates about a bearing member 142 supported by an annular ring 144 attached to the motor housing and enclosing the planetary gearing 114, the cartridges being protected from heat generated in the motor by insulation 143. The carrier 140 is closed at the rear by a plate 150 and carries cartridge tubes 141 bearing against a metal ring 148 faced with asbestos and clamped between the motor housing and the ring 144. Step-by-step rotation of the carrier brings each tube 141 in turn into firing position, in which it registers with the inlet port 190 of the motor. The rear end of the tube 141 is then engaged by a breech block 203 carried by a plate 198 connected through two tension rods 196 and a compression rod 199 to a fulcrum plate 194 connected to a piston 191, exposed to the combustion pressure in the inlet port 190. The rod 199 is attached to the plate 198 by a bolt 200 passing through a key plate 201, which is slotted to engage with channels on the rods 196 ; the latter are secured to the fulcrum plate 194 and pass through the plate 198 and through guides 197, springs 208 being interposed between one of the guides 197 and a pin 209 extending through the rods 196. The means for actuating the carrier 140 comprises a plate 157 rotatable on the hub 151 of a back plate 146 fixed to the ring 144. The plate 157 is normally held in the position shown in Fig. 21 by a spring 176 connected at its ends to a stud 177 on the plate 157 and to a spring carrier 175 keyed to the hub 151 of the plate 146. On the front of the plate 157 is a pin 158 extending through a slot 154 of the back plate into the path of a projecting member 125 on the gear ring 115, which has a limited rotary movement allowed by the engagement of slots in the gear ring by screws 117 securing the gear ring to the ring 144. Also on the front of the plate 157 is a pivoted latch 159 lying in a slot 155 of the back plate 146 and having an operating head 159<1> for engagement with the gear shaft 113<a> of one of the planet wheels 114. On the rear face of the plate 157 is pivoted a cam lever 161 held by a spring 163 in contact with a pin 162, and having an inclined face 180, Fig. 19, for engagement with a pin 179 carried by the breech block 203. The rear face also carries pins 171, 172, and a pivoted crank 164 carrying a pawl 168 acting on pins 170 on the inner face of the carrier 140 ; a pin 164<1> on the other end of the crank 164 engages a slot 167 in the plate 157 and a slot 156 in the back plate 146. An arm 173 lying between the pins 171, 172 is rotatably mounted on the hub of the plate 157 and carries at each end an operating head 183, which is urged radially outwards by springs 185 and is shaped as shown in Figs. 16 and 17. During the clockwise rotation of the sleeve 110 by fluid pressure in the motor, the mechanism is brought into successive positions in which (1) the lever 161 is partly depressed by the pin 179 and the pawl 168 rides over one of the pins 170 ; (2) the pawl 168 rides over a guard 153 out of contact with the pins 170, and the arm 173 is moved forward by the pin 171 into a position in which the heads 184 are telescoped into the arm by the pins 170 ; (3) the pin 158 is at the end of the slot 154 and prevents further clockwise move ment of the member 125, the lever 161 is freed from the pin 179 and moved by spring 163 into engagement with pin 162, the latch 159 engages the notch in the end of slot 155, and the arm 173 is moved forward to clear the pins 170 by which the heads 184 were telescoped. The return (counter-clockwise) movement of the sleeve 110 of the motor brings the mechanism into positions in which (1) the shaft 113a re-engages the member 125 and lifts the latch 159 out of its notch, allowing the spring 176 to return the plate 157, so that the face 180 of the lever 161 causes the pin 179 to lift the breech block 203 awav from the cartridge carrier 140 ; (2) the carrier 140 is lifted away from the ring 148, by the engagement of faces 185 on the heads 184 with the pins 170, and is turned by the pawl 168 to bring a new cartridge into firing position, the parts of the mechanism then being in the positions shown in Fig. 21 and the carrier being urged into contact with the ring 148 by a spring 210 and the breech block 203 being brought against the cartridge by a spring 205. Firing can then be effected by closing a circuit supplying current to the firing pin 204. Should a cartridge fail to fire, the magazine may be turned by hand by means of a rear extension of the stud 177. The composition of the fuel cartridges and the means employed for ignition may be as described in Specification 444,172, [Group XII]. To vary the duration of the generation of fluid pressure, a cartridge of the solid or single-pellet type may be used. Large particles of fuel are excluded from the expansion chamber of the motor by a grating 212<a>. An exhaust valve 213 is actuated by the vane 107 at each end of its stroke, as described in Specification 455,685, and used cartridges are ejected from the cartridge tube 141 into a discharge tube by exhaust gases tapped from the exhaust duct 219 through passages 226, 227.