Patent GB-227489-A (GB)
Title: Improvements in or relating to wireless controlled aircraft
IPC: F41G7/00
Filed: 1923-07-09
Abstract: 227,489. Sperry, E. A. July 9, 1923. Selective distant coittrol systems.-Relates to aircraft provided with two gyroscopes, a stablizing gyroscope for controlling the elevators and the ailerons, and a steering gyroscope for controlling the vertical rudder, and provided also with means responsive to wireless signals for controlling the aircraft from a distance. According to the invention, the action of the wireless signals, and the action of means intended to prevent wide movements of automatic steering are transmitted to the gyroscopic steering device by a mechanism such as a differential worm gear, which superimposes the two actions on the gyroscopic device. Similar devices are provided in connection with the other controls, and the ailerons are arranged to bank the aircraft automatically when the steering rudder is operated. As shown in Fig. 1, the aircraft comprises a main body 201, a sustaining plane 206, a front propeller 202, ailerons 205, and vertical and horizontal rudders 203, 204. An air-driven electric generator 212 is provided for supplying power to the controlling gear. Electric lamps 121 used for answer back signals are placed on the sustaining plane 206. The wireless receiving set is situated in a space 209. The ground lead is attached to the engine and other metallic parts of the aircraft. The antennae 210 depends from the aircraft and extends out when the aircraft, after the) propeller has been started, acquires a sufficient speed to rise from a launching truck 207 running on rails 208. The aircraft may also be launched from the usual chassis or from pontoons on the sea. The gyroscopes 213, 252, Figs. 3, 4, and 5, are mounted on a base 220. The stabilizing gyroscope 213 comprises a rotor 214, Fig. 5, rotatably mounted on a vertical axis in a frame 215 pivoted on transverse horizontal pivots 216 in a ring 217, which is pivoted on fore and aft horizontal pivots 218 in brackets 219 on the base 220. A bail 227 is pivotally mounted on brackets 228 on the same base, and a roller 230 on the gyroscope rides in a groove 229 in the bail. The ring 217 carries contacts 224, 225, 226 co-operating with a pair of brushes 221, 222 for controlling a shunt wound electric motor 231 driving through suitable gearing a drum 232 connected by a cable 251 to the ailerons 205. The bail carries similar contacts 224<1>, 225<1>, 2261 co-operating with a pair of brushes 221<1>, 222<1> for controlling a motor 231<1> driving through suitable gearing a drum 232<1> connected by a cable 251<1> to the elevators 204. To prevent excessive movements of the ailerons, a follow-up mechanism is provided comprising a differential gear at the contact device connected by a link 243, a bell crank 242 and another link 241 to an arm 240 moved by the motor 231. Similar follow mechanism 241<1> is provided to prevent excessive movements of the elevators, which may also be controlled by a height responsive device. The steering gyroscope 252, Fig. 5, comprises a rotor spinning about an horizontal axis 254, 253 in a casing pivoted on an horizontal axis at right-angles to the rotor axis in a frame 255 itself pivoted on a vertical axis 258, 256 in a fixed frame 257 on the base 220. This gyroscope is at first locked by a plunger 462 engaging the spindle 253 and itself locked by the armature of an electromagnet 460. The plunger is pulled out by a, spring 463 and unlocks the gyroscope when, a given time after the aircraft is launched, a retarded relay 500, Fig. 12, energizes the electromagnet 460 and thereby releases the plunger. The spindle 256 of the frame 255 carries slip rings 259 co-operating with brushes 260 for supplying current for spinning the gyroscope, and for the control contacts 262, 263 carried by a worm wheel 264 free from the spindle 256 and co-operating with a contact roller 261 movable round the vertical axis with the gyroscope. These contacts command relays 268, 269, Fig. 12, which control a servo-motor 265 operating the vertical rudder through suitable gearing driving a drum 266 connected by a cable 267 to the vertical rudder. Excessive movements of the rudder are prevented by a follow up mechanism comprising a link 271 transmitting the motion of the servomotor to a rocker 274, which displaces a worm 280 longitudinally along a shaft 281 and thereby rotates the worm wheel 264 carrying the contacts 262, 263. The wireless steering control is superimposed on this follow up action by the rotation of the worm shaft 281. Further, when the steering rudder is operated, the aircraft is banked automatically by means of a differential gear at the contact device 224, 225, 226 connected by a link 285, a bellcrank 284 and a link 253 to the rudder operating gear whereby motion therefrom is' superimposed over other movements and transmitted to the contacts. The wireless control of the elevators is similarly transmitted to the contact device 224<1>, 225<1>, 226' by a differential gear connected by a link 330 to the corresponding member 307, Fig. 8, of the controlling-gear of the wireless receiving apparatus. This controlling- gear as shown, in Figs. 8, 9, 10, and 11, comprises six electromagnets U<1>, D', S<1>, S<1>, L<1>, R' controlling the drive of two independent shafts 307, 308 from a continuously rotating motor 317. This motor continuously reciprocates two platforms 294, 296 by means of two connecting-rods 326, 325 coupled to cranks on shafts 323, 320 driven continuously round by the motor. The platform 294 carries four pawls 297 298. 299. 300 attached to the armatures of the electromagnets U<1>, D<1>, S<1>, S<1> and adapted to engage toothed wheels 310, 309, 312, 311 when the electromagnets are energized. These toothed wheels are all on the shaft 307 and have teeth over part of their circumferences only, as shown. When the pawl 297 is put in action by the electromagnet U<1>, the shaft 307 is rotated in one direction to the extent provided by they teeth on the wheel 310, and this limited movement of the shaft 307 is transmitted by the link 330 to the mechanism described above for controlling the elevators. To bring the elevators back, the electromagnets S' have to be energized whereby the pawl 299 or 300 return the shaft 307 to its original position. The action of the electromagnet D<1> is similar to that of the electromagnet U<1> but in the opposite direction, the electromagnet U<1> being used to make the aircraft rise, and the electromagnet D<1> t o bring it down. For quick descents, the following means is provided : the link 330 is connected by a pin 332, Fig. 10, to a slot 331 in a crank 329 on the shaft 307; and the pin 332 is held at the bottom of the slot against the action of a spring 335 by a catch 334, which is released under wireless or time control by an electromagnet 333, when it is desired to bring the aircraft down quickly. The other reciprocating platform 296 carries two pawls 301, 302 attached to the armatures of the electromagnets L<1>, R<1> and adapted to engage toothed wheels 315, 314 on the shaft 308 when the electromagnets are energized. One electromagnet causes the shaft to rotate in one direction and the other electromagnet in the other direction. The rotation of the shaft 308 in one direction or the other is transmitted by a bevel gear 328, 327 to the shaft 281, which imparts this steering control to the steering gyroscope as described above. The wireless system comprises transmitting apparatus and receiving apparatus indicated diagrammatically in Figs. 2 and 12 respectively. A wireless transmitter 56, Fig. 2, of ordinary kind is controlled by a relay 104 from an electric selector device comprising a spindle 1 driven at a constant speed by a shunt-wound motor 5 under the control of a centrifugal governor 40. A disc 14 is driven frictionally from a disc rotating with the spindle 1, and carries two slip rings 29, 30 and an arm 17, which is pivoted to the disc and can move between two stops 18, 19, being normally maintained against the stop 19 by a spring. A number of keys Q, U, R, A, 8, E, D L is arranged around the disc 14, and adapted to be pressed down into the path of the arm 17; and a shouldered disc 23 is adapted to, hold down the key that is last pressed down, and to release any previously actuated ones. When the key O is pressed down, the arm 17 is stopped by it and moved from the stop 19 to the stop. 18, when the disc 14 is also stopped and the electric circuit broken. When, after this, another key is pressed down, the arm 17 is released from the key O and stopped by the other key after a period of time depending on the distance between the two keys, during which the electric circuit is closed by contact between the arm 17 and the stop 19. The! wireless signal sent out lasts for the same time, and this causes corresponding contacts at the receiving apparatus to come into operation. Signals may also be sent by means of a hand-operated switch I; and a circuit breaker K is also provided, enabling the keys to be operated without affecting the circuit. A lamp 54 is connected in the electric circuit to indicate that the sending means operate. The receiving apparatus, fig. 12, comprises an ordinary wireless receiving set 57 with a relay 110 controlling an electromagnet 58, which commands a friction drive between the shaft of a switch arm 60 and a. motor 68 rotating at a constant speed under the control of a centrifugal governor. The speed of rotation of the switch arm 60 is the same as that of the arm 17 of the sending apparatus; the position at which the arm 60 is stopped under the control of the electromagnet 58 when a wireless signal is received therefore corresponds to the posttipn of the arm 17 at the sending station; and' the arm 60 in that position co-operates with contacts O, U, R, A, S, F, D, L to operate relays to perform the corresponding function on the various controlling- devices of the aircraft. Lamps 120, 121 are connected in the ci