Page:EB1911 - Volume 17.djvu/258

 of inserting, extracting and ejecting the cartridges, travels vertically in guides on the face of the lock. Projecting outwards from each side of its top are horns N (figs. 9 and 10). These travel round the edges of the cams M (fig. 8) situated on each side of the breech casing, and in conjunction with the spring W (fig. 8), compel the top of the extractor to take the path shown by the dotted lines and arrows in figs. 9 to 12.

The extractor (figs. 11 and 12) is recessed to take a movable plate (u) termed a “gib,” behind which is a spring (v). In the face of the gib is a recess (w) into which the base of a cartridge can just enter. On either side of the gib the face of the extractor has undercut flanges, open at the top and bottom, between which the base of a cartridge can fit the rim, being held in the undercuts (figs. 9 and 10).

It is clear from this arrangement that the base of the cartridge having been introduced between the flanges at the top of the extractor, can be pushed down, the spring (v) yielding, till arrested at the recess (w); and, as the lower edges of this recess are slightly sloped, further pressure will make it leave the recess (w) and slide over the face of the gib, leave it, and take up a position in front of the hole for the point of the striker (x), being now only prevented from slipping out of the extractor by the extractor spring (y). If this last be clear of the extractor stop (z) it will yield to pressure and the cartridge will be free. This is the action in the gun except that the cartridge is held firm and the extractor pushed against it.

In fig. 10 the extractor holds a cartridge (r) and a fired case (q) ready to be pushed into the empty breech and ejector-tube Q respectively. In the latter there is already a fired case (p), which will be driven by the fired case (q) beyond the ejector spring R. As soon as the lock reaches the face of the breech, the cartridge (r) and case (q) are deposited in the breech and ejector-tube respectively, and the extractor D rises under the action of the levers L and J, slides, as already explained, by the bases of the cartridges (r) and case (q), and then over the base of the cartridge (s) in the belt (g). Assuming the push-lever (n) to be pressed, the gun fires immediately this has occurred, and the bullet of the cartridge (r) is expelled. The position is now that shown in fig. 9. The barrel now recoils and the lock is withdrawn, taking with it the fresh cartridge (s) from the belt and the now fired case (r). The extractor travels horizontally for a time and then drops (as shown by the dotted line and arrows), assuming the position shown in fig. 12, which is exactly similar to that in fig. 10 but with different cartridges; continuing the action, the position shown in fig. 11 is arrived at. It will thus be seen that each cartridge makes two complete journeys with the extractor; the first as a live cartridge from the belt to the breech, the second from the breech to the ejector-tube, the forward journey being always on a lower level than that of the backward one. The sections in figs. 11 and 12 clearly show the cocking and firing mechanism and the safety arrangement. The lock is cocked, after firing, by the arm of the “tumbler” K, being pressed down by the side lever J as it swings down when following the crank E’. Safety against firing before the breech is closed is provided by the projection on the safety lever V, which does not clear the striker T until lifted by the side lever J at the top of its travel, that is, when the crank E’ has passed the axial line as already explained.

The lock in its rearmost position is kept in place by the block Z on the under side of the cover of the breech casing. When in this position it is clear of the guides O on the side-plates, and if the cover be opened it can be turned up, unscrewed by a turn through an eighth of a circle (the screw-thread U being interrupted in four places) and removed. To prepare the gun for firing, the crank handle is pushed over by hand to the buffer-spring, thus withdrawing the extractor, and held in this position; the tongue on the end of a filled belt is then pushed through the feed-block from the left and pulled as far as it will go from the opposite side. This places a cartridge above the breech ready to be seized by the extractor. The crank handle is now released and the lock flies forwards. The crank handle is now again pushed over and let go, and the first cartridge thus taken from the belt and placed in the breech. The gun is ready to fire.

To remove a partially filled belt, the crank handle must be pushed over, thus freeing the extractor from the belt, and the latter withdrawn after pressing a spring catch under the feed block which releases the pawls. The gun now has two live cartridges in it—both in the extractor. Letting go the crank handle, one of them is deposited in the ejector-tube, and again pushing over and letting go the crank handle does the same with the second.

Fig. 13 shows the feed-block and the cartridge belts. The greatest number usually carried in a belt is 250.

The gun is sighted to 2,500 yds. and has a folding tangent sight as shown. Its weight varies from 50 to 60 ℔, and it can fire about 450 rounds per minute.

[The diagrams have been made from drawings, by permission of Messrs. Vickers, Sons & Maxim.]

The Hotchkiss gun, figs. 14 to 16, which has been adopted by the French army and navy and elsewhere, depends for its action on the use of a small portion of the gases of the cartridge itself. The barrel A is firmly attached to the receiver or frame B, the latter

containing the breech and firing mechanism. Under the barrel A, and communicating with it by a port (c) near the muzzle is a cylinder or tube C. When the gun is fired, and the bullet has passed the port (c), a portion of the gases of explosion passes into the cylinder C and drives back the piston F contained in it, a lug on the under part of the piston compressing the spring M, the latter, when the trigger N is pulled, driving back the piston again. The reciprocating motion of the piston performs all the processes of loading and firing the gun, and the action is continuous as long as the trigger is kept pressed back.

The piston F, enlarged and suitably shaped at the rear, actuates the breech-block H and firing pin or striker J; and, by suitable cam grooves (f&#8202;) at about the centre of its length, works the larger feed-wheel U of the feed-box S; the smaller wheel U on the same axis in turn imparting a step-by-step motion to the metal feed-strips, each containing 30 cartridges, so that fresh cartridges are placed one by one before the face of the breech block ready to be pushed into the breech when the fired cartridge has been extracted and ejected.

On the under surface of the piston F, in rear, is a recess or sear (f&#8202;) in which the nose of the trigger N engages, holding back the