US1637400A - Automatic arm - Google Patents

Description

Aug. 2, m7. msmw' P. VON KIRALY ET AL AUTOMATIC ARM Filed Oct. 5, 1925 Aug. 2,, EQZZ. 1,637,490

P. vow KIRALY ET AL AUTOMAT I C ARM Filed Oct. 5, 1925 2 Sheets-Sheet 2 Patented Aug. 2, 1927.

PAUL VON KIRALY AND JOSEF LovAsz, or BUDAPEST, HUNGARY.

AUTOMATIC ARM.

Application filed October 5, 1925, Serial No. 60,661, and in Germany October 6, 1924.

Our invention relates to automatic arms, having a barrel arranged for short recoil. which recoil movement is transmitted to the breech bolt and involves an improved transmission of the recoil momentum of the barrel to the breech bolt, then an increased delay in the opening of the bolt and means for dislodging the spent shell by means of a front blow.

To these ends we employ a special lever mechanism, then specially formed governing working surfaces of the main parts of the Fig. 5 is a cross section through the bolt.

Fig. '6 shows the working surfaces of the slide.

.the lever mechanism.

Fig. 8 shows the working surfaces of the slide with slowly increasing elevation. The corresponding surfaces of the bolt 5 are drawn with dotted lines.

Fig. 9 shows our invention as applied to a block bolt and with an unlocking lever.

Fig. 10 shows the same mechanism, but

. without an unlocking lever. The mechanism consists of a barrel 1 to which a recoil movement of about /g- /g inch, in the case, is allowed. The spring 4 holds the barrel 1 in its foremost position and returns it thereto after each recoil movement.

The positively locked breech bolt, whlch is of the straight pull type, consists, as usual, of two main parts, the bolt 5 which supports the bottom of the shell and a slide 7 which operates the bolt.

The bolt is shown in Figs. 1-S as a turning boltbut any other bolt system (block or looking lever bolt etc.), can be chosen.

In the form of the inventionas shown in Figs. 1-8, the slide 7. is situate'dbelow the Fig. 7 is a'lateralview of another form of.

bolt 5. It can, as a matter of course, be placed on any other side of it, or in it, or around it.

This slide 7 carries working surfaces, of which'the one opens the bolt, the other closes it.

The opening surface 9 is shaped as a long drawn curve, rising at first, but slightly, and farther on more rapidly. (See Fig. 8). Thus, in the first phase of the backward movement of the slide 7 but a small fraction of the unlocking movement of the bolt is performed, the balance of it being done by the farther, more steeply inclined part of the surface 9.

If the recoil movement of the slide 7 must in its first phase be further facilitated, then the elevation of the foremost part of the opening surface 9 of the slide 7 can be reduced to zero, so that in that case the opening surface 9 consists of a straight part and of a curved one (Fig. 6). It then allows to the slide 7 a free movement, within which it does not engage or influence the bolt 5.

The two main parts of the bolt can be made to engage one another by means of grooves and threads, or of lugs, 01 of an arm,

- or in any other way.

- The slide 7 is supported by a closing spring 12 by which the forward movement of the breech bolt is effected.

The firing mechanism can be freely chosen and constructed.

Between the barrel 1 and the slide 7, a main lever (26, 30) is inserted (Figs. 1, 2, '3, 4 and 7). This main lever can equally well be situated either on the barrel, or on the case, or on the slide, or on the bolt. It causes the barrel to transmit to the slide 7 the greatest part of its recoil momentum. For this purpose the main lever 26, 30 is so formed and so arranged that it accompanies the recoiling barrel in the first phase of its movement without working,- so that its accelerating effect upon the slide only makes itself felt in the last phase of the recoil movement of the barrel 1.

Whenever the main lever is pivoted on the barrel 1, or on one of the main parts of the breech bolt, the projection 29 of the case 2 gas which engages the short arm 28 of the main lever is placed some distance ahead of this short arm, so that this arm only can hit it in the last stage of the backward travel of the barrel. Thus the main lever only can accelerme curved and so formed that the farthest end breech bolt.

of the lever touches the corresponding operating surface 31, which can be situated either on the barrel 1 or on the bolt 5. Ac-

cordingly, during the first stage of the recoil movement of the barrel almost no acceleration of the slide 7 takes place. Now, during the continued rotation of the main lever 30 its point of contact with this operating surface 31 shifts towards the axis of the main lever 30, the leverage increases and so the accelerating effect of the main lever 30 is delayed in this case also, so that it only takes place in the last period of the mood movement of the barrel.

Generally a catch 15 is situated in the case,

the object of which catch is described later on.

Figs. 9 and 10 show our invention adapted for a bolt of the block system.

According to the construction shown in Fig. 9 an unlocking lever B is'situated in the block bolt 5 and the slide 7 is provided at its rear end with a surface 8, by which the closing and locking of the bolt 5 is effected, and with a simple lug 12 placed at a certain distance from the lower arm of the unlocking lever R in order to insert a free movement between the two main parts of the The relative situation of the parts of the breech bolt at the end of the iltmlocking movement is shown by dotted mes.

Witlf'the mechanism shown in Fig. 10, the locking and unlocking of the bolt 5 is done by means of an arm of the slide 7 which projects into a recess T of the bolt 5. This arm of the recoiling slide strikes against the surface 12 of.the recess T, forcing the bolt 5 downwards and so unlocking the latter from the case 2.

The length of the free movement of the main parts of the breech bolt is controlled by the length of the recess T.

From this description it is seen, that barrel, slide and bolt recoil at first together,

without any change in their relative posi tions. In a later phase of the movement of the barrel the main lever 26, 30begins to work and increases the recoil velocity of the slide 7. This slide leaves then the barrel and recoils alone. The barrel and the bolt 5 have, in the meantime, finished their backward movement, they stand still and then begin to move forward, the bolt 5 still being.

firmly locked with the'barrel. After some 1 3 inches of recoil movement of the slide 7, during which it did not yet unlock the.

bolt, the surface 9 of the slide gets engaged with the corresponding surface of the bolt and only now, long after the barrel has absolved its recoil movement and after the main lever 26, 30 has displayed its accelerating effect, does the slide 7 open and rei'ect the bolt 5. The bolt 5 being uncontro led by any closing spring, recoils freely and extracts and ejects the empty shell.

So the main lever 26, 30 does not work on the bolt, but on the slide which thus receives and accumulates the recoil momentum of the barrel and utilizes it in a later moment, for operating the bolt 5.

It is also seen that the transmission of the recoil energy of the barrel to the slide, then the opening of the bolt by the slide both are performed in dilferent moments and by means of semielastic shocks. In order to make the best use of these shocks, certain correct proportions must exist between the masses of the barrel, of the slide and of the bolt, as well as of the weight of the whole arm or else'the breech bolt would not work correctly. If these proportions be correctly chosen, then the bolt 5 generally arrives in good time at its rearmost position in order to avoid being prematurely driven forward by the returning slide. In such cases, when a belated arrival of the bolt 5 in its rearmost position is inevitable, we employ a catch 15 which catches the returning slide 7 and retains it until the recoiling' bolt 5 depresses the nose 18 of the catch 15 and with it the catch 15 itself and thus releases the slide 7. Then the breech bolt is closed by the main spring 12.

The catch 15 can serve as interrupt0r also,

24 in a manner that, when depressed, it shifts the link 23 forward, until it releases the sear 24 which can then correctly re-engage the hammer.

The catch 15 can well be emplo ed to support by its forearm 16 and slide 7 in its foremost position. In this case, the catch 15 can be made use of as a safety device which prevents premature firing of the arm,' because it only releases the link 23 of the sear, in its uppermost position that is, when the bolt is completely closed.

Another useful feature of the breech bolt mechanism we have described is the fact that the very economical utilization and gradual transmission of the recoil momentum of the moving parts results in a weak and very elastic recoil of the entire arm, more so indeed, than is the case with most other automatic-arms. Consequently we can make arms of very light weight, or shoot more powerful cartridges from rifles of the usual weights.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:

1. In an automatic fire arm having a barrel arranged for short recoil and a bolt, the

' Combination with the barrel of a bolt actuating slide and a lever to actuate the slide, the lever being adapted to receive and to transmit to the slide the impact of the recoiling motion equal to more than twice the total recoil movement of the barrel, before the bolt isactuated by the slide.

2. An automatic fire arm as claimed -in claim 1, in which the operating surface of the slide by which it effects the opening of the bolt ends in a recess by which the'un-.

locking movement of the bolt is positively limited and the opening of the bolt is efi'ected by a blow.

3. An automatic fire arm, as claimed in claim 1, in which the slide has a closing surface, inclining at an angle which is greater than the angle of the opening surface.

4. An automatic fire arm, as claimed in claim 1, in which the weight of the slide is 1/5-1/3 of that of the barrel, or at least 1/10 of that of the total weight of the arm and the weight of the bolt is 1/1,51/4 of that of the slide thus providing proportions on which directly depends the functioning of the bolt mechanism. 7

5. An automatic fire arm, as claimed in claim 1, including a catch, pivoted in the case when in its rearmost position and retains it until the recoiling bolt presses the catch out of engagement with the slide.

In witness whereof we afiix our signatures.

JOSEF LovAsz. PAUL VON KIRALY.

and having a hose which engages the slide

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