Patent GB-419816-A (GB)
Abstract: 419,816. Gyroscopic apparatus. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A.-(Assignees of Carlson, B. G., and Carter, L. F.) April 19, 1933, No. 11504. Convention date, Nov. 12, 1932. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 30, 1933.] [Class 97 (iii).] Means provided for simultaneously locking a directional gyroscope with freedom around vertical and horizontal axes about one axis and adjusting it about the other include a member yieldable during adjustment to permit slight movement about the locked axis. In the form shown, the rotor 8 is mounted by horizontal bearings 9 in a ring 7, pivoting an horizontal trunnions 6, 6<1>, in vertical ring 5, journalled in turn on vertical bearings within the housing 1. The latter is provided with a window 2 for viewing the compass card 3 fixed on the ring 5 and an aperture 15 through which air is continuously withdrawn causing air to be supplied to rotor driving nozzles in a tube 10 through a screened aperture in the bottom plate 14. The locking and setting means comprise a short shaft 31 slidably and rotatably mounted in a gland 32 and provided with a thumb piece 30 at the outer end, a crowned gear 34 at the other end, and spring pressed blocks (not shown) adapted to engage annular recesses 33<1> in the gland 32 and yieldingly hold the shaft 31 in either its inner or outer positions. When moved to the inner position a flared opening at the inner end of the shaft 31 engages and rocks a finger secured to a shaft 39 to which is also secured a fork 40 with pins 41 engaging an annular groove 42 in a vertically slidable sleeve 43. A locking lever 46, pivoted at 47 to the ring 5 and formed with a seat 48 which engages the flattened middle portion 7<1> (Fig. 9) of a rounded surface 7x on the rotor bearing ring 7, is provided with a slidable pin 45 pressed downwardly by a spring and resting on the top of the slide 43. The arrangement is such that the lever 46 locks the gyro about the trunnions 6, 6<1> before the crowned gear 34 engages a gear 35 secured to the ring 5. Subsequent turning of the knob 30 rotates the gyro about the vertical axis and the locking lever 46 through the action of the spring pin 45 is adapted to yield slightly to the consequent precessional forces. Such forces are insufficient to overcome the spring unless the rotor is spinning at the proper speed and the movements of the lever 46 indicate proper functioning of the apparatus by means of a strip 50 fixed to the lever 46 and visible through a slot 51 in the housing 1. To enable an aircraft pilot to steer a course determined by a bomb sight operator, the compass card 3 may be read against an index mark on a ring 57 which may be rotated by gearing 58, 61, 62, 63 and a flexible shaft, turned either automatically or by hand in accordance with the movements in azimuth of the bomb sight. According to the Specification as open to inspection under Sect. 91, wandering of the gyro in azimuth is prevented by the small attractive force between a permanent magnet fixed at the rear of the housing 1 and one of a series of pieces of soft iron spaced around the periphery of the card. This subject-matter does not appear in the Specification as accepted.