GB191020119A - Improvements in or relating to Loading Apparatus for Heavy Guns. - Google Patents

Abstract

20,119. Dawson, Sir A. T., and Horne, J. Aug. 29. [Cognate Application, 25,558/10.] Loading-appliances. - Relates to automatically-reversible chain and telescopic rammers, and consists in the provision in an hydraulic system, of a cut-off valve for controlling a reversing-ram, by which the withdrawal of the rammer is automatically effected at the end of the short powder-charge ramming - stroke. The operation of the reversing-mechanism is controlled by a device on the hand-lever of the main control valve, and by a part of the rammer when this has moved through a definite distance. The reversing- apparatus for a chain rammer is shown in Fig. 1. The main control valve C<Î> of the motor for driving the rammer D, D', is actuated by a hand-lever C through a rod c'. A small differential ram e<Î>, normally exposed to pressure on each face, is located in proximity to the free end E<1> of a lever E<2> connected to the valve-rod c<4>. The pressure on the right-hand face of the ram e<Î> is controlled by a cut-off valve D<Î>; the pressure fluid enters the valve cylinder by the pipe d<4>, and passes to the ram e<Î> by the pipe e. The valve D<Î> tends to move to the right, under the fluid pressure, so as to open the pipe e to the exhaust e<3>, but such movement is normally prevented by a bell-crank lever d<1>, one arm d<Î> of which is jointed to the stem of the valve D<Î>, and a second arm d<2> bears against the rammerchain D. A third arm D<3> on the lever d<1> rests upon a stop d<3> on a spring-controlled lever L<1>. When the rammer is to be automatically withdrawn, a sliding-rod c mounted on the handlever C is pressed down from an inoperative position into the position shown, so that when the lever C is rocked into the " ram " position, shown by the dotted line, the rod c acts through a lever L and rod d upon the lever L<1> and withdraws the stop d<3>. When, therefore, the end of the rammer-chain passes over the arm d<2> of the lever d<1>, the valve D<Î> is freed, and the pipe e is opened to exhaust. The pressure on the left-hand face of the ram e<Î> then becomes effective; the ram is moved to the right, and, acting upon the arm E<1> of the lever E<2>, reverses the valve C<Î> and throws back the handlever C. In one modification, the ram e<Î> and valve C<Î> are combined in one casing, and in a second modification, the stop controlled by the rod c acts upon the spindle of the ram e<Î> instead of upon the lever d'.