Patent GB-753096-A (GB)
Title: Motion producing means for ground aviation trainers
Inventor: SMITH ROBERT L
IPC: G09B9/14
Filed: 1954-07-21
Abstract: 753,096. Ground aviation trainers. LINK AVIATION, Inc. July 21, 1954, No. 21323/54. Class 4. [Also in Group XXIX] An aviation trainer comprises a fuselage movable relatively to a base by an actuating system including a control member, means for initially displacing the control member from a predetermined neutral position to operate the system, and a connection from the fuselage to the control member to move the control member in the opposite direction to its initial displacement when the fuselage moves. In the embodiment described, the system is hydraulic, and is used to simulate the effects of rough air. In Fig. 1, the fuselage 16 is universally jointed to a pillar 14 on the base, at 18. A jack 33 controls pitching movement, and a jack 37 rolling movement. Pins secured to a rod 260 are adapted to pin rods 254 to cylinders 250 to lock the fuselage for ingress or egress. The pupil has a seat 41 and the instructor a seat 38a. The rough air computer (Figs. 5 and 6) rocks a lever 164 to pull wires 126 and 126a kept in tension by a spring 188, to reciprocate the valve member of a hydraulic valve 92 which controls the jack 37 to move the fuselage in roll. A wire 194 connected to the fuselage at 37b (Figs. 1 and 5) rocks a lever 180 pivoted at 192 to readjust wire 126 and recentre valve 92. Corresponding apparatus vibrates the fuselage in pitch. A quadrant gear 230 on lever 180 also adjusts the instrument indications correspondingly. Lever 164 is rocked by means of a cog wheel 148 driven by motor 146 and driving two irregular cams 140, 142 on an axis 144 at slightly different speeds. A lever 154 is pivoted to fixed structure at 156 and bears a cam follower 158 resting on both cams 140, 142, and the end of lever 154 is pivoted at 160 to a rod 162 pivoted at 166 to the lever 164. One end of this is secured to wire 126, and the other end to a plate 168 adapted to be rotated about axis 144 by an electric motor 170. A finger 173 on the plate 168 is adapted to actuate switches 210, 212, 216, 218, 214. In Fig. 6, the instructor's switch 200 may be put in the positions " off," " “," " ¢," " ¥ " or " full. " In any but the off position, the contacts 200a operate a relay 202 closing contacts 202a, 202b, the latter closing a relay 208 to affect the instrument readings, and a relay 204, which allows a 115 V.A.C. supply to reach motor 146 through contacts 202a, 204a, to rotate cams 140, 142. The closing of contact 202a also operates motor 170, which is reversible. A switch 270 is opened if the fuselage is locked by rod 260 (Fig. 1). Initially, the finger 173 is at switch 210, when pivot 166 is close to pivot 156, and rocking of lever 154 does not rock lever 164.. The NO contact of switch 210 is also closed. Operation of relay 204 closes contact 204b, thus relay 205 is energized, and holds itself by making contact 205a, and also earths the lower shading coil of motor 170. As motor 170 rotates, finger 173 leaves switch 210, so that 115 V.A.C. is fed to motor 170 independently of contact 202a, and relay 205 holds itself energized by contact 205a. If the switch 200 is in, say, the ¢ position, then when switch 216 is operated by finger 173, it removes the earth from relay 205, which is de-energized, to earth the upper shading coil of motor 170, reversing its rotation, until it again reaches switch 210, when the cycle repeats. Thus the magnitude of the rough air effects is cyclically varied by varying the position of pivot 166 relatively to pivot 156. Similarly, if the instructor chooses say the ¥ position, the finger 173 will reciprocate between switches 210 and 218, and so on. If the instructor switches off before a cycle finishes, relays 202 and 204 are de-energized stopping motor 146, but motor 170 is still supplied by switch 210 and continues to rotate. Opening contact 204b de-energizes relay 205, if not already de-energized, so that finger 173 moves toward switch 210, and on reaching it, the switch is operated to stop motor 170.