The Works Of Messrs. Schneider And Co.

SINGLE-MOTION BREECH-MECHANISM. medium calibre, we will add particulars of a one-motion type which, at the present time, is being fitted to a large number of guns in course of construction for varions Governments at Creusot and at Havre. The engravings illustrating this description are reproduced from photo- graphs, typical examples of the varions calibres having been selected. Cylindrical Breech-Screw, with Repeat-Firing Action, Operated Laterally (Figs. 680 to 682, Plate CXVII.).—In this mechanism several features of tlie breech-pieces already described are reproduced, but with tlie important improvement of a special device by which a handle is placed within easy reach of the man training the gun, and by which, without being obliged to take his eye off the tangent sights, he can fire immediately the aim cornes in the line of sight. The main parts of this mechanism are the breech-block and support, the operating details, the extractor, the firing device and controller, and the safety arrangement, The breech-block is cylindrical, with four threaded parts and four interruptions. At the rear it ends in a flange which checks its travel in the supporting ring; in this flange is placed a conical toothed ring which operates the screwing and unscrewing of the block. The two clutches that form the extractor are jointed opposite each other in front of the block. The middle of the breech- block is extended at the rear by a hollow cylinder of small diameter, the surface of which is formed with two threaded parts and two interruptions ; this constitutes the pivot around which the breech-block turns in its angular move- rnents in the seating of the enn. The ring supporting the block is lodged in a recess made in the rear of the gun, the support consisting of a frame perpendicular to the face of the breech. This support carries the block and the whole of the mechanism during the periods of opening and closing, and it pivots round a vertical liinge-bolt. The two sides of the support form a path for the slide that carries the operating apparatus, the left side ending in a sector in the lower surface of which a circular groove is cut. The operating device consista of : 1. The working lever formed of two horizontal arms, the longer one ending in a vertical handle; at the end of the smaller arm and on a vertical axis is a roller which, travelling in the circular groove above mentioned, allows the breech-block to be removed from the seating when it has been turned through 45 deg. 2. Of a pair of bevel-toothed wheels arrangée! so as to cause the breech-block to turn until the threads are ail disengaged ; this gear consista of a pinion keyecl on a vertical axis fitted to the working lever, and a conical toothed ring fitted in the flange of the breech-block. 3. Of a brass guide-block formed by the junction of two hollow cylinders, the centre lines of which meet at 90 cleg. The vertical cylinder which receives the axis mounted on the working lever is fitted at its lower part with slide- 205 i blocke which move in the slides of the support frame ; the horizontal cylinder, through the centre of which the firing device passes, is connectée! to the breech-block by a bayonet joint, one of the elements of which projects beyond its rear face. This arrangement, which leaves the mechanism free for the unscrewing of tbe breech-block, also allows it to be removed from the seating by acting on the working; lever. The extractor consists of two clutch levers carried in the breech, and which withdraw the cartridge-case during the removal of the block. These levers which, when the breech is completely closed, engage the flange of the cartridge-case, fit in grooves of suitable shape, eut in the thickness of metal at the rear of the gun. In order to keep clear of the flange during the closing action of the breech, these levers oscillate round a centre fixed tangen- tially with the breech-block, their smaller arm being permanently pressed outwards by a spring. The repeat-firing action is composée! of the following parts : the striker, the catch, and the Control device. The striker consists of three principal parts : (a) the striker proper, with a pin that is driven against the fuse ; (b) the percussion hammer, consisting of a cylinder of sufficient size to transmit to the striker the necessary force for firing the fuse, and on which the firing spring aets, this spring being relaxed when the gun is not cocked ; (c) the trigger, formed like a hollow prism, the centre line of which is normal to that of the whole mechanism in the rear of the hammer. This prism contains a small cylinder ending in an abutment, and which can be moved to and fro in a straight line, under the action of a spii-al spring surrounding it. The striker is lodged in the centre of the bocly of the breech-block, and as long as the catch is left undisturbed, the pin is withdrawn within the front surface of the block. The catch consists of a rectangular frame, one of tlie sides of which forms a hinge with a vertical axis fixed in two projections on the slide-block. This hinge carries on its inner surface a finger which engages the butt-end of the trigger, and enables this to be drawn back, as well as the hammer to which it is connectée!, tliis operation also pressing down the firing spring. A working arm projects from the catch, and is turned to the right, ending in an abutment dise on which the transmission-rod acte, and of which the butt in the hand of the gunner forms part. The front end of this working arm bears against the spring piston of the device for safety against prématuré fire. The opposite side of the catch frame ends in a lever provided with a ring, to which the firing line is tied when. the gun is trained and fired by two men. In this case, the lateral working arm is not used. A mechanical training device, on the Schneider-Canet system, enables the man training the gun to fire imme- diately the target appears in the line of sight. This is most important for naval service, owing to the mobility of the aim and of the firing platform. In such cases, it is very désirable that the gunner who has charge of training the