The Works Of Messrs. Schneider And Co.

204 MESSES. SCHNEIDER AND CO.’S WORKS. parts and four interruptions ; there is only one clutch ejector, of the type already described. On the rear is a conical toothecl arrangement that gears into a pinion worked by the lever ; this produces the necessary partial revolution of the breech-screw. On the continuation of the breech-block and on its centre-line, is a pivot threaded on its outside circumference on two sectors, there being also two interruptions. Wh en the breech is closed, the block support lodges in a rabbet in the rear-end of the gun. This support is continued in the rear by a horizontal frame that forms a slide; as will be seen in Fig. 676, which shows the breech mechanism taken apart ; the right- hand side of the breech-block support frame is made with a circular groove on its lower surface, the groove ending in a semi-cylindrical bearing. The mechanism is carried entirely on the supporting frame, and consista of the conical gearing mentionecl above, and of the jointed hand-lever. On the first arm of the lever is a slide that carries the pinion centre, and which fits to the breech through a bayonet-joint, of which the breecl>block rear pivot forms one of the elements. The second arm ends in a roller, which, cluring the operation, moves in the lower groove of the support above referred to, and, by bearing on the bottom of the groove, insures the removal of the breech-block from the breech and its swinging to the side of the system. The working lever is fitted witli a jointed handle provided with a catch ; this, when the breech is com- pletely closed, enters a notch in the rear of the gun tube, and prevents accidentai opening of the breech. The firing device is repeating, and works by percussion ; it is similar to the one previously described. To open the breech, it is sufficient to turn round the hand-lever from left to right in a horizontal plane. During the first period the conical pinion effects the unscrewing of the breech-block ; during the second, the roller on the smaller arm bearing at the bottom of the groove helps to withdraw the block, which slides on the horizontal frame. The action continues without interruption by the swinging to the side of the whole mechanism. To close the breech, the hand-lever is turned from right to left. Cylindrical Breech Block, with Automatic Trigger- setting Action (Figs. 677 to 679, Plate CXVL).—In certain cases the method of working by conical pinions or entliess screws, described for preceding types, is replaced by a rack which acts direct on cylindrical toothed gearing in the rear part of the breech-block. A large number of quick-firing Schneider-Canet guns in service at the present time are fitted with this type of breech-closing arrangement. They have given the best results. The breech-block has two threaded parts and two interruptions. Its shape and dimensions are such that it is not necessary to draw it back to disengage it from the seat ; once turned, it is immediately withdrawn by its support. This pivots round a vertical hinge ; it contains a holding and guiding gear for the block, and sockets for the varions parts of the mechanism and firing device. The working gear proper consista of a hand-lever, a rack, and the toothed part eut in the rear of the breech-block. The lever is in one piece with the hinge-bolt, and is fitted with a pivot that works the rack, and a heel that effects the swinging round of the breech-block support. The rack is guided throughout in the support, and engages the teeth of the block ; on the other end is a socket in which fits the hand-lever pivot. The percussion piece is made with. two hélicoïdal curved planes, eut symmetrically one with the other ; on opening the breech, these ascend two similar planes eut in the breech-block. The main spring rests on a ribbed tube which butts on tlie breech-block, and cannot follow the longitudinal action of the percussion piece. A pin, which runs through tlie block support and the percussion piece, prevents the latter from turning round, while it permits the cocking of the system on opening the breech. Firing can also be effected by electricity, in replacing the percus- sion piece by a contact pin. The electric-firing device has a single pin, which, under the action of a spring, extencls slightly beyond the front of the breech-block, and which touches, when the breech is closed, the centre of the electric fuse, screwed in the bottom of the cartridge-case. An insulatêd wire unités this pin to a switch. The operator tires the gun by closing the circuit. To prevent missfires or delays in firing, all the contacts are covered with silver, and a few seconds bef'ore it is required, the battery is worked on a high shunt- resistance. The extractor is fork-shaped ; it disengages the empty cartridge-case and effects its éjection. To this end it is fitted on a boit provided with a stud, moving in an incline eut in a tube fitted to the hinge-bolt. Wlien the breech is completely closed, the hand-lever clutches the block-support automatically, and prevents ail accidentai opening of the breech. The catch being in the breech- screw and the trigger in the breech support—the trigger being, moreover, ejoverned by the end of the firing-lever placed on the rear end of the gun—the gun cannot be fired until the breech is completely closecl. To open the breech, it is sufficient to press on the handle to disengage the clutch at the heel, and to bring the lever, in one action, from left to right. In doing this, the lever withdraws the rack, and the breech-block becoming disengaged, pushes back the percussion-piece and sets its spring. When the breech-block is thrown back, the catch engages under a shoulder made on the rear of the percussion- piece, and keeps it cocked. When the block is quite unscrewed, the driving heel bears on the block support, and brings it to the side, while the latch bolt, pushed by its spring, engages in the rack and fixes the block in its support ; the extractor tlien disengages the empty cartridge-case and throws it back. To close the breech, this action is repeated inversely. To complété our review of the varions Schneider-Canet systems of breech mechanism for quick-firing guns of