Patent GB-455431-A (GB)
Title: Improvements in or relating to naval gun fire control systems
IPC: F41G5/16
Filed: 1935-01-10
Abstract: 455,431. Gun fire -control systems. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A. Jan. 10, 1935, No. 25358/36. Convention date, Jan. 10, 1934. Divided out of 455,207. [Class 92 (ii)] [See also Group XIX] Relates to atrunnion-tilt error-prevention device for use in a gun fire -control system mounted on an unstable naval platform in order to determine the angular co-ordinates in one reference frame of a line of sight or a line of fire when the angular co - ordinates in another reference frame moving with respect to the first are known. The invention comprises the following parts in combination :-(1) A first member 1 representing one frame and having a second member 19 adjustable relatively thereto by elevating and training repeater motors ER, TR to represent the said line, (2) a third member 5 representing the second frame and having pitch and roll repeater motors PR, RR for positioning it with respect to the first frame, (3) means for measuring the angular co - ordinates of the member 19 with respect to the member 5 including a fourth member 15 rotating in azimuth on the member 5, and (4) a follow-up system including a motor F for controlling a plane in the member 15 so that it intersects the said line of the member 19. The trunnion-tilt error-prevention device shown is that described in connection with the complete gun fire-control system forming the subject-matter of Specification 455,207. The relative movements between the plane of the ship's deck and the stable plane are materialized by the ring member 5 gimbal-mounted on axes 4, 6 in the member 1 connected to the ship. Pitch and roll movements are conveyed from transmitters at a master gyroscope to the repeater motors PR, RR which control the ring 5. The member 15, in the form of second ring movable within the first, carries on trunnions 18 a semicircular guide 17 for the outer end of the radial arm member 19 which is positioned in elevation and azimuth by repeater motors ER, TR. The latter operate to elevate the arm 19 by rack gears 26, 28 and to train the arm by a gear 23 and shaft 22. The resulting elevation of the guide 17 and rotation of the ring 15 are measured by transmitters E<1>T, T<1>T, actuated by toothed gears x, 16 and conveyed to repeater motors which position the line of sight or the line of fire of the gun. The gear 16 on the ring 15 is engaged by a pinion on the shaft of a follow-up motor F which is in circuit with contacts 32, 32<1> on the guide 17 arranged on each side of a central insulated gap 32<11>. The circuit through the motor is controlled by the passage of a trolley 31 on the arm 19 to one side or the other of the gap. The motor F is thereby actuated in one direction or the other to position the ring 15 so that the trolley returns to the gap. The gap may be in the form of inner contact portions 32a, 32'a with extra insulation 95, 96. The outer contact portions 32b, 32<1>b are then connected to a signal lamp 97 situated near the gun as a warning not to fire until the trolley is at or near its central position. Reference has been directed by the Comptroller to U.S.A. Specification 1,880,174.