The Works Of Messrs. Schneider And Co.

15-CENTIMETRE MORT AR ON BEAM MOUNTING. 271 The oscillating motion is limited by a special type of brake, styled the Schneider-Canet circular brake; it con- sists of a shaft (Fig. 888) made with three ribs parallel with its centre line and placed in the Blocks of the slide, in which it is held by two nuts. Romid this shaft is a cylindrical jacket of gun-metal, the inner surface of which is made with three ribs of the same shape as the preceding ones. This jacket is almost entirely surrounded by the drum of the beam, the trunnions of which rest also in the blocks of the slide. The gun-metal jacket is made at its lower part with two lugs, to which are fitted the rods of the recuperator cross-bar ; this bar bears on a set of Bellevile springs lodged in a horizontal cylinder bolted on the slide. A sliding piece, which travels on the screw of the elevating mechanism, goes through a groove to disengage the jaw. A scale is traced round the circum- ference of the slide. The drum of the beam is provided in front with a semi-cylindrical box, with an axle formed of an endless screw worked through differential gearing, on which the wheel acts for elevating the gun. When the wheel is turned, the slide which moves on the endless screw is displaced in a direction corresponding with. the rotation, and travels on the hélicoïdal slide of the jacket, the latter remaining fixed on its axle. Owing to this motion, the beam, and with it the gun, takes an incline which corresponds with the revolutions of the wheel. A scale marked on the left trunnion of the beam complétés the elevating mechanism. When fired, the gun falls to the rear by turning round Fig. 885. 120-Millimetre Gun, on Central-Pivoted Disappearing Carriage. 15-Centimetre, Howitzer on Central-Pivoted Carriage with Circular Brake. on the drum, its end being held in a helicoidal groove made on the circumference of the jacket. When the mounting is in battery, the liquid is in the spaces between the pallets on the shaft and those on the jacket ; when the gun is fired, its oscillation round the beam trunnions causes the beam to pivot, the jacket being drawn with it. The liquid then escapes through the openings between the central shaft and the extreme edges of the jacket pallets. The openings are made of a suitable section, in order to ensure a practically constant pressure in the recoil cylinder during the whole time recoil lasts. The o-un is trained by acting direct on a lateral lever, which is carried on the bedplate. The smaller arm of the lever forms a jaw which holds the rim of the slide, and the rin» of the bolster to fix the mounting. When the gun has to be trained, it is only necessary to raise the lever the beam trunnions, and the hydraulic cylinder begins immediately to work, deadening part of the recoil force^ this force being made use of to compel the liquid to flow between the extreme edges of the pallets and the opposite wall. At the same time, the two lugs on the jackets cause the sets of springs of the recuperator to be pressed down. When the recoil is spent, the springs relax and run the system out again. All this takes place autoinatically and without any shocks. 15-Centimetre (5.905-In.) Mortar on Beam Mounting : Weight of gun... ,, mounting ,, projectile Muzzle velocity Elevation Training 440 kg. 1800 kg. 32 kg. 200 m. from 0 deg.to + 60 deg. through 360 deg. 970 Ib. 3967 Ib. 70 Ib. 656 ft. from 0 deg.to 4- 60 deg. through 360 deg.