GB526279A - Device for testing instruments and particularly gyroscopic aircraft instruments - Google Patents

Abstract

526,279. Indicating-apparatus. REID, G. H. March 11, 1939, Nos. 7916 and 21126. [Class 106 (iv)] [Also in Groups XX and II] An apparatus for testing the longevity and accuracy of gyroscopic and other instruments under running conditions comprises a structure adapted to carry the instrument and mounted upon a base with freedom to move angularly about three axes mutually at right-angles, and driving means arranged to oscillate the structure about at least two of the axes. As show in Fig. 1, an electric motor 11 is coupled by a reduction gear box 13 to a shaft 37 which drives a number of crank discs 43 one to each instrument-holding table 34. The instruments 51, Fig. 2, are attached to upstanding brackets 50 and are supplied with power through flexible tubes 52. Recesses 45, 46, in the crank discs may be selectively engaged by adjustable rods 47 slidable in the tables. When either of the recesses 45 are engaged, the table receives both a pitching and a yawing movement about a ball pivot 35 due to the rotation of the crank disc, and is also given a rolling movement by the engagement of lateral pins 53, 54 with inclined cam surfaces 55. After a predetermined number of movements a trip disc 22 throws over a switch 25 and reverses the motor. When the rod 47 is engaged in a central recess 44 the table remains in a level neutral position. In a modification, Fig. 5, primarily for testing air-driven gyroscopic instruments, the instruments are all mounted on the same table 60, and this is given up-and-down and lateral movements (rolling and yawing) by a crank arm 68, the pitching movements being imparted by telescopic rods 73, 74 restrained to rock in the pitching direction by appropriate arrangement of the pivots 76, 78. Air for driving the instruments is supplied through a connection 64, cocks 66 and flexible tubes.