Patent GB-618098-A (GB)
Title: Aviation trainer artificial horizon simulator
IPC: G09B9/24
Filed: 1946-10-18
Abstract: 618,098. Ground aircraft trainer. LINK AVIATION, Inc. Oct. 18, 1946, Nos. 31089 and 31090. Convention dates, Oct. 18, 1945. [Class 4] A ground aircraft trainer, particularly of the type described in Specifications 370,128 and 481,375 is provided with an artificial horizon indicating device mounted on the dummy instrument panel arranged to indicate automatically the angle of bank appropriate to the aircraft taking into account its assumed airspeed in addition to the other relevant factors. The pedestal 15, on which the dummy aircraft is pivotally mounted for banking and pitching movements, has an ear 46 to which is pivoted an arm 48, the upper end of which is coupled to a lever 50 provided with a roller 52 that may run along the rod 42. A slot 54 in the upper end of lever 50 engages a stud 56 at the lower edge of a sector 58 rotatable on a shaft 60 journalled in the frame member 62 secured to the floor of the dummy aircraft 12a. When the dummy aircraft is given a pitching movement, the arm 48 tends to reciprocate the lever 50 along the rod 42 and the sector 58 is therefore rotated about the shaft 60. This movement is communicated to the artificial horizon simulator 72 on the instrument board by a cable 64, secured to the lower edge of sector 58, this cable being secured at its other end to a pulley 66, subject to the torque of a coiled spring 67a. Also secured to pulley 66 is a further cable 64a which passes over pulleys 68 and 70 to the instrument 72. Inside the instrument 72, Fig. 3, the cable 64a passes through a plate 146, around a pulley 148, through a central hole in a casting 126 and is anchored to a pulley 151 journalled in ears 130e integral with the pivoted casting 130. The pulley 151 is subject to the torque of a coiled spring, which opposes but is not as strong as the spring 67a acting on the pulley 66 so that cables 64 and 64a are always kept taut. The pulley 151 has at one end of its shaft 164, a spur gear 166 engaging a gear sector 168 to which is secured by its rearward extension 174 the horizon bar 172. Pitching movements of the dummy aircraft, relative to its fixed pedestal 15, by movements in cables 64 and 64a therefore produce a corresponding vertical displacement of the horizon bar 72, relative to the aeroplane simulating element 124. A shaft 330, Fig. 2, receives angular movements depending on one or a number of factors influencing the assumed airspeed of the dummy aircraft, such as throttle position, altitude of the aircraft, manifold pressure, &c. On the shaft 330 is mounted a disc 332 having a spiral groove 344 which engages a stud 348 carried by an arm 334 rotatable on a further stud 350 secured to the carriage 340. Angular movements of the shaft 330 according to variations in the assumed air speed of the dummy aircraft, thus produce corresponding translational movements of the carriage 340 on the rods 342 running fore-andaft and secured to the frame 388. A link 354 connects a stud 352 projecting from the righthand ear 34 of the universal joint 14 above the pedestal 15, to an arm 356 which rotates with a transverse shaft 358 mounted in the frame end 62. A wheel 360, secured on the shaft 358, is coupled by endless belts 364, 370 and 374, having studs which engage with the pulleys 366, 372 and 376 rotatable in link arms 378, 382 and 386, to a shaft 388 journalled in the carriage 340 and having secured to it at one end the crank arm 390, which has a slot in it that engages a stud 402 projecting from a cam 394. Banking movements of the dummy aircraft therefore by rotating shaft 358 coupled by endless belts 364, 370 and 374 to the shaft 388, produce corresponding angular movements of the crank arm 390 which is moved for-andaft with the carriage 340 according to variations in the assumed air speed of the dummy aircraft. The stud 402, which engages the slot in the crank arm 390 therefore receives a movement which is a combination of the effects of both airspeed and banking movements and rotates the cam 394 accordingly. The cam 394 moves a roller 412 carried on a stub shaft 410 secured to an arm 406 at the lower end of which is a sector 408 secured to a cable 414. The cable 414 is secured at its other end to a pulley 418, similar to pulley 66 and also subject to spring torque. The pulley 418 has secured to it a further cable 414a which passes over pulleys 420, 422 and 424 to the artificial horizon simulator 72. The cable 414a passes through plate 146 and is secured to a pulley 426 subject to the torque of an opposing but weaker spring than that on pulley 418. Pulley 426 has secured to its shaft 428 spur wheel 430 which engages a toothed sector 432 concentric with the axis of the instrument and integral with the casting 130. Rotation of the cam 394, according to variations in assumed air speed and banking movements, therefore by means of sector arm 408, cables 414, 414a and pulley 426 produce a corresponding rotation of the casting 130. Since this casting 130 has pivoted to it the toothed sector 168, to which is secured the rearward extension of the horizon bar 174, the horizon bar 172 receives a rotational movement about the axis of the instrument that is dependent on variations in the assumed air speed and degree of bank, this rotation being superimposed on the vertical displacements thereof which are dependent on variations in pitch of the dummy aircraft.