Patent GB-124486-A (GB)
Title: Improvements in or relating to Aircraft.
Inventor: CHALLENGER GEORGE HENRY
IPC: F41A19/05
Filed: 1916-01-27
Abstract: 124,486. Vickers, Ltd., Challenger, G. H., and Savage, H. A. Jan. 27, 1916. Machine guns; fire between aircraft propeller blades controlling and synchronizing; ordnance breech mechanism. - Relates to guns mounted on aircraft and adapted to fire between the propeller blades, and consists in effecting the firing by means such as a cam driven synchronously with the propeller. In the form shown in Figs. 1, 5, and 9, the sear of a Vickers automatic gun A<2> is worked by a pawl C<1> on a lever C connected by a rod B<2> to a roller b<2> riding against a cam B; and this cam has a general spherical contour and is mounted on a shaft B<1> connected by gearing to a pump b driven by the propelling engine of the aircraft. The rod B<2> is enclosed and stayed by a tube E, and the shaft B<1> by a tube B<0>, which is further secured to the fuselage of the aircraft by means of a bracket. The rod B<2> is connected to the lever C bv a ball and socket joint B<3>, and the tube E is connected at one end by horizontal pivots e<2> to the tube B<0>, and at the other end by horizontal pivots e<1> to a fork C<3>, which is itself connected by a vertical pivot to a plate fixed to the gun; this arrangement allows angular adjustment within certain limits. The length of the rod B<2> is adjusted bv nuts b<3>, b<3x> on opposite sides of the ball and socket joint B<3>; and the roller b<2> is thrown in and out of action with the cam B by an eccentric D arranged around the pivot d of the lever C, the pawl C' being provided with a shoulder C<1x> to serve as an abutment when the eccentric is being adjusted. The eccentric D is operated by a handle D<1> or by a Bowden wire connected to a quadrant on the eccentric. The cam B is secured to its shaft B<1> by means of a disk B'x which is keyed to the shaft, and is secured to the cam by pins or screws b<x>, several holes for these pins or screws being provided in both the cam and disk to enable the position of the cam around its shaft to be adjusted. In a modification shown in Fig. 17, the rod B<2> works under tension instead of under compression, and is connected to the rolier b<2> through the medium of a two-armed lever E<x>. In this case, the rod B<2> is connected to the lever C at a point above instead of below the pivot of this lever, and the. eccentric D for throwing; the roller in and out of action is arranged at the pivot of the lever E<x> instead of at the pivot of the lever C. When a gun capable of being trained and elevated is used, the cam B is arranged, as shown in Fig. 18, at the intersection of the training and elevating axes Y, Z, and with its axis intersecting the axis X of the propeller. To provide a space for the cam B, the gun A<2> has a forked part a<2> connected by horizontal trunnions to a ring a rotatable over a horizontal base ring ax. The roller b<2> is carried by the gun, and rides to different parts of the spherical cam B as the gun is trained and elevated; in this way the cam is adjusted automatically to act always at the correct time. When the timing of the cam requires correction for training movements only, the arrangement shown diagrammatically in Fig. 19 may be used. The cam B is mounted on a horizontal shaft F<1> carried by the gun and connected by bevel-wheels f<1>, f to a vertical shaft F driven from the engine, and a universal joint fx is interposed between the shaft F and the spindle of the wheel f, one of the axes of the joint coinciding with the axis of elevation Z of the gun. When the gun is elevated, the cam B is uneffected; but when the gun is trained, the bevel-wheel f<1> rolls over the bevel-wheel f and alters the timing of the cam B to correspond to the changing direction of the gun. A similar arrangement may be used for automatically adjusting the time of the cam where only the elevation of the gun need be corrected for.