Patent GB-588138-A (GB)
Title: Improvements in gun turrets
IPC: F41A27/02
Filed: 1943-10-21
Abstract: 588,138. Ordnance mountings. BENDIX AVIATION CORPORATION. Oct. 21, 1943, No. 17391. Convention date, Feb. 4, 1942. [Class 92 (i)] [Also in Group XXXVII] Relates to electrically-operated upper gun turrets for tanks, trucks, torpedo boats, aeroplanes or land fortifications, of the kind comprising a rotatable column supporting the gunner and-carrying towards its upper end a rotatably guided frame which supports the guns, the latter moving with the turret in azimuth and rotatable about a transverse elevation axis. According to the invention, an electric power circuit is connected to the means for rotating the base of the column and for rotating the guns in elevation, and a single manual control for the power circuit is mounted on the column. In the construction shown in Fig. 4, two guns 112 on an aircraft are movable in elevation about a shaft 114 journalled in brackets on a frame 110, the frame being carried by a rotatable vertical column 108. The turret, which has a transparent canopy 118 secured to frame 110, is operated by a gunner on a seat 122. secured to the column, the operating means consisting of a handle 402. The rear part of the frame receives the gunner's body and is fitted with rollers 170, 172 which grip either side of a cylindrical rim 174 secured to the longitudinal members 176 of the aeroplane 100. The foot of the column is rotatably mounted in a base 106 which houses a highspeed electric azimuth motor. Control box.-The control handle is mounted in a control box 400 which, as shown in Figs. 8 and 9, houses an electric motor 430 driving a shaft 440. On the shaft are two pairs of cams 442 which serve to lift grounded -arms 444 away from contacts 450 against the action of springs 448. The length of time during which contact is maintained as shaft 440 rotates depends upon the angular position of arms 452 upon which contacts 450 are mounted. The movement of the arms 452 is effected by the control handle which when moved about pivot 480 produces axial displacement of a shaft carrying a cam 464, the latter operating through a spring-controlled pivoted lever 454 to move one pair of arms 452 associated with the azimuth circuit. Movement of the control handle about horizontal axis rotates a sleeve 474 carrying a cam 472 serving to actuate a similar spring-controlled lever 470 which moves the other pair of arms 452 associated with the elevation circuit. Elevating and training circuit.-A simplified circuit diagram is shown in Fig. 13. Considering the actuating of the azimuth motor 128 only, when the gunner grips the control handle 402 he closes a switch 51 and energizes a relay L2, thus causing current from source B1 to flow through wires 16, 19, leading to the .motor armature A1. Wire 16 also supplies current to motor 430, in the control box, and to a relay L3, thus energizing the latter during the time intervals when cams 442 allow arms 444 to become grounded via contacts 450. When the arms 444 are not energized, current passes through wire 17, 18 of the relay and thence via wire 19 to the field winding F1 of motor 128, and the latter moves the gun in azimuth at a speed determined by the position of cam 464. When a high speed of rotation is desired, the control handle is moved to an extreme position causing a switch S8 to close, thereby energizing a relay L7. This relay then short circuits a resistance R1 in wire 18 and thereby increases armature current, and also opens a normally closed switch S6, thereby breaking a shunt around field resistance R4 and decreasing the field current, the combined effect causing the motor to work at high speed. The position of cam 464 also determines the direction in which the motor operates, the cam serving to open or close a switch S10 in circuit which a relay L6 serving to actuate a switch, as shown, in circuit with the field winding F1. Similar relays, cams and switches are provided as shown for controlling the elevating motor 146<1>. In Fig. 14 (not shown) the complete circuit is shown, the circuit including relays which when energized produced a dynamic braking action on the motors by making them function as generators. The relays come into operation when the control handle is released, or when cams, suitably arranged on shafts driven by the elevating and training motors, cause the opening or closing of circuits, such cams serving, by this arrangement, to prevent the guns from firing at parts of the aeroplane.