Patent GB-624354-A (GB)
Title: Improvements in or relating to gun turrets and to the supply of ammunition thereto
IPC: F41A9/54
Filed: 1944-12-19
Abstract: 624,354. Feeding belted ammunition to turrets. BRISTOL AEROPLANE CO., Ltd., FONSECA, E. C. M. D., and WOTTON, J. Dec. 19, 1944, No. 25507. [Class 92 (ii)] A gun turret 5 which can rotate continuously in one or both directions of traverse is supplied with a belt of ammunition from an outside source 7, the belt being twisted as the turret rotates and the twist being resisted by means which is permitted to return the belt to a datum condition when it has been twisted through a predetermined angle or to a predetermined position. In the form shown, the belt passes from source 7 through a shoot 8 to an anchor point 10 on the fuselage 6 in line with the axis of rotation of the turret, and from point 10 extends a shoot 11 which twists as the turret rotates. The upper end of shoot 11 is attached to a guide 13 on a disc 14 which can rotate on balls 15 with respect to the turret floor 16. To disc 14 is connected a drum 17 fitted with a pair of rollers 20 and on a fixed platform 21 are mounted another pair 22; a cable 23 passes between these rollers and is connected to a spring 24 mounted, as shown, on the platform. The spring thus constantly tends to maintain the disc 14 and hence the upper end of shoot 11 in a predetermined position. The turret floor carries a spring-controlled plunger 27 which is urged towards a slot 26 in drum 17, but which is retracted, as shown in Fig. 2, from the slot by the co-operation of a roller 29 with a fixed ramp 30 when the disc 14, and the turret also, are in the above-mentioned predetermined position. In operation, the turret and drum are normally locked by plunger 27, and rotation of the turret twists the shoot 11 and stresses spring 24. When, however, the turret has turned through a complete circle in either direction from the predetermined position, the roller 29 encounters the ramp 30 and plunger 27 is disengaged from slot 26. Disc 14 now freed is drawn by spring 24 and cable 23 through a complete circle to untwist the shoot 11, and plunger 27 is again free to enter slot 26 when roller 29 is clear of ramp 30. A switch 40 is actuated by plunger 27 when the latter is retracted to open the firing -circuit of the gun 9 at this point, and also to render inoperative the electric motor of an electrically-driven stripping mechanism if such is provided. The opening of the firing circuit prevents a cartridge, which may be lying transversely of the guide 31 of the shoot 12 in the turret, from being drawn into fouling engagement with the guide during the rotation of disc 14 by spring 24. The Provisional Specification describes a modified construction in which two springs are employed for returning the disc to its datum position, and in which the disc has on its under face a pair of catches which can be engaged by a spring-pressed arm on the turret, the arm engaging a ramp on a fixed part of the aircraft. The arm by engaging the catches locks the disc to the turret except when the ramps are encountered when the disc is free to be returned by one of the springs. The Provisional Specification also describes modified details between the parts 11, 12, and refers to the use of ammunition belts as in Specification 543,842. Specification 624,357 also is referred to.