GB620420A - Improvements in mortar-armament - Google Patents

Abstract

620,420. Guns. CLARKE, C. V. Aug. 26, 1946, No. 25533. [Class 92 (ii)] A gun of the mortar type especially intended for use on infantry support tanks, has a pivoted barrel chamber adapted to be set into motion by hydraulic power by the feeding of a round into it, the chamber rotating into alignment with the barrel and a breech-block which closes the end of the chamber and fires the round, the chamber then being returned tc its loading position. The Figure shows the barrel chamber in its loading position. A round is fed down the feed shoot 6 nose first and strikes the rubber pad 12, moving the lever 13 which opens a valve 16 to initiate the flow of oil from a supply line 16<SP>1</SP> to a line 17 supplying a piston and cylinder 18. The fluid also flows into the space 16<SP>9</SP> allowing the valve seating 16<SP>6</SP> to lift and further increase the flow. Movement of the piston 19 rotates the chamber by means of an arm 20 against the action of a spring 21 until the arm 20 impinges on a depressable stop 22 when the chamber is aligned with the bxeechblock 9 and the gun barrel 33. This stop 22 opens a valve 151 extending the oil flow to a cylinder in which a piston 26 moves to rotate the breech-block forwardly by rack gearing engaging a screw-thread on the block which is moved into engagement with the lower end of the chamber, which moves axially against the action of springs 37 into engagement with the gun barrel 33. As movement of the breechblock ceases, pressure is built up in another cylinder to move a piston 27 and a lever 31 which cocks the firing pin and then slips past it, thus firing the round. As the round leaves the gun barrel, explosion gases enter a chamber in the side of the extension, operating a lever 39 which moves the supply valve 41 to connect the supply line 41<SP>1</SP> and the line 16<SP>1</SP> to a reservoir when the spring 21 returns the chamber to its loading position. To ensure a positive return of the valve 41, a link 46 connects this valve to the arm 20. To cope with a misfire, when the chamber will be in the firing position, the mechanism associated with the valve 16 is arranged to pivot on a pin 48 with the pad 12 the lines 17 and 161 being made flexible and a lever (not shown) being provided which moves the lever 39 to operate valve 41 and connect supply lines 41<SP>1</SP> and 17 to the reservoir, when the chamber returns to the position shown and the round falls out through the hole 49. A movable shield 1<SP>1</SP> prevents a round entering the casing, when the chamber is in the firing position. An exhauster fan may be fitted to the casing at outlet 51 to draw air in at inlet 50. The casing may also be provided with cooling fins.