US2212687A - Recoil device for machine guns - Google Patents

Description

Aug Z7, 1940. R. H; s. HUGHES 2,2l287 RECOIL DEVICE FOR MACHINE GUNS Filed June 18, 1957 3 Sheets-Sheet 1 a- N D a E au @s m u n. l \`\J 5 i a l ug- 27, 1940. R. H. s. HUGHESv 2,212,687

RECOIL DEVICE FOR MACHINE GUNS Filed June 18. 1937 3 Sheets-SheetI 2 4 7e m J f4@ Q y m ff i l l Amig. 2?, 1940. R.' H. s. HUGHES' 2,2287

REcoIL'DEvIGE FOR MAGHINE GUNS Filed June 18. 1937 s sheets-sheet 3 Patented Aug. 27, 1940 Robert H. s. Hughes, Baltimore, Ma., assigner of one-half to Milton Roberts, Baltimore, Md.

Application June 18, 1937, Serial No. 149,020

4 Claims.

This invention relates to machine guns of the type having reciprocable barrels, and particularly to means for controlling the recoil of the barrel and the rate of firing of the gun. By means of my invention, the rate of firing of the gun may be varied while the gun is in action.

In carrying out the invention, I provide in front of the muzzle of the gun barrel a recoil controlling attachment which is supported independently of the barrel and preferably upon the jacket which surrounds the barrel and is connected to the gun casing. This attachment comprises a hollow body having a seal port in line with the bore of the barrel and also having forwardly and rearwardly directed ports out of line with the bore of the barrel, and also laterally directed baille ports, for the discharge of the products of combustion. Valve mechanism is provided for closing all of the ports, or for opening the forwardly directed ports only, or for opening the rearwardly directed and baille ports only. By these means, as hereinafter explained, the recoil force applied to the barrel may be increased or decreased, as desired. I also provide in the gun casing means for adjusting the tension of the spring which returns the barrel and breech bolt to their firing positions, and I provide means under the control of the operator for simultaneously adjusting the valve mechanism on the recoil device and the spring tensioning means so that the rate of ring may be varied while the gun is in action.

In the accompanying drawings:

Fig. 1 is a side elevation of a machine gun equipped with my improvements;

Fig. 2 is a rear end view of the same, parts being broken away;

Fig. 3 is a vertical longitudinal section through a portion of the casing showing the mechanism for adjusting the tension of the spring for operating the bolt and for simultaneously actuating the flexible shaft which operates the portcontrolling means;

Fig. 4 is a section on the line 4 5 of Fig. 3;

Fig. 5 is a section on the line 5-5 of Fig. 3;

Fig. 6 is a section on the line E-S of Fig. 2;

Fig. 'I is a central longitudinal section through the forward ends of the gun barrel and jacket and through the recoil controlling device;

Fig. 8 is an end view of the controlling device, looking from right to left in Fig. 7;

Fig. 9 is a section on the line 9-9 of Fig. '7; and

Fig. 10 is a section taken diametrically through the valve which controls the baille ports and discharge ports.

Referring to the drawings:

I indicates a machine gun as a whole, 2 indicates the breech casing, 3 indicates the barrel jacket and 4 indicates the movable gun barrel,

the bore of which is indicated at 5. A front mounting bracket 4' and a rear mounting bracket 5 are secured to the breech casing, these brackets being adapted for connecting the gun to a suitable support. Rear and forward sights, 6 and 1, respectively, are shown mounted on the jacket.

The breech casing 2 is provided with the usual projectile feeding mechanism indicated at 3. Operating handles 9 are attached to the rear end of the casing 2, by means of supports l0, and a trigger mechanism Il is arranged close to the handles. l

My recoil device R is secured to the barrel jacket 3 and the forward end of the gun barrel is movable longitudinally within the rear portion of said device. The bolt i5 of the machine gun is conventionally shown in Figs. 3 and 5. The bolt has a socket I6 to receive the forward end of a rod il and the forward portion of a spring I8 which is coiled about the rod. The rear end of the rod ts within a socket I9 in a block 20. This block extends laterally through elongated slots 22 and 23 in the side of the breech casing and of a housing 2l which is attached to said casing and bears against an adjustable wedgeshaped stop 29, the slots forming a guideway for the block.

As in machine guns generally, the bolt l5 is adapted to be moved rearwardly after iiring by the recoil of the barrel and the force of this rearward movement of the barrel is used to cause ejection of the empty cartridge, to extract a cartridge from the cartridge belt and deposit it into the breech, and, lastly it cocks the gun. The spring I 8 is compressed by the rearward movement of the bolt and as the spring expands and moves the bolt forward the bolt loads the cartridge, locks the breech and fires the gun,

In the present invention the tension of the spring is adjustable by moving the stop 29 vertically. A vertically arranged shaft 24 extends through openings 25 and 26 in the housing 2l and a collar 21, pinned to the upper end of the shaft, supports its. The portion of the shaft within the housing is threaded as indicated at 28 and this threaded portion extends through a threaded opening 30 in the stop. The block 20 has a beveled face 3| which engages the oppositely beveled face of the wedge-shaped stop 29. It will be-evident that if the threaded shaft is turned to adjust the stop 29 upwardly the block 20 will be moved to increase the pressure on the spring I8, and if the threaded shaft is turned to adjust the stop 29 downwardly, the pressure of the block 20 against the spring will be decreased.

A gear casing 32 is secured to the lower side of the breech casing, as shown in Figs. 3 and 4. The lower portion of the shaft 24 extends through an opening 32 in the upper wall of the casing and on the lower end of the shaft is secured a bevel pinion 33 which meshes with a bevel gear 34 rotatably mounted on a stationary shaft 35 which is supported in the side Walls of the housing 32. A pinion 36 which is secured to and rotates with gear 34 meshes with a large gear 31 secured to a shaft 38 which extends through and is journaled in the side walls of the caslng 3.2.

As shown in Fig. 6, the lever arm 39 is pinned to the end of the shaft 38 at the rear of the casing 32. 'I'he lever arm is slotted as at 40 and latch member 4l extends therethrough and is pivoted as at 42. As shown in Figs. 2 and 4, a toothed segment 44 is suitably secured to the casing 32. The latch 4l is provided with a tooth 45 which is adapted to engage the segment 44. One end of a helical spring 46 is fitted within a socket 41 in the arm 39, and the other end of the spring bears against the latch #il to normally hold its tooth in engagement with the toothed segment d. A pointer 50 on the arm 38 indicates on an arcuate scale i9 the setting of the arm.

From the foregoing it will be evident that by moving the arm 3S motion is transmitted through the gear train 31, 36, 9@ and 33, to the shaft 2li upon which is threaded the wedge 29. of the shaft 2li will move the wedge vertically to increase or decrease the pressure on the driv ing spring i8. By the same movements of the arm 39 a cable i239, attached to one end of the shaft 38, will be rotated. This cable, which is encased in a exible non-rotative covering H0, operates the port controiling valves of my re coll device R so that any adjustment of the valves is accompanied by an adjustment of the spring tensioning device. The forward end of the cable is connected to a shaft it journaled in lugs 91 and 98 depending from the body of the recoil device, and this shaft carriesv gears lil and 804 for operating the valves. The recoil device R, as shown in Figs. 7 to 10, comprises a hollow body 68 having a sleeve 5| which extends within the forward end of. the jacket 3 and is secured to the jacket by a collar 63 which is threaded onto the sleeve as shown at 62 and also has a threaded connection 64 with the inner wall of the jacket. A set screw 65 engaging the jacket, collar and sleeve, prevents relative rotation of these parts. The recoil device is thus secured to and supported by the jacket which connects it to the breech casing. 'I'he forward end of the gun barrel is externally threaded, as indicated at 68, andan internally threaded collar 61 is threaded onto the barrel and secured against rotation thereon by a set screw 69. This collar has a smooth periphery and forms a bearing for the gun barrel within the sleeve of the recoil device. The forward end of the collar 61 is substantially flush with the forward end of the gun barrel and forms with the end of the barrel a shoulder 18 of substantial area against which the gas pressure is applied in the operation of the gun.

The body 60 has a cylindrical combustion chamber 10 therein, the rear part of the ch'amber being formed by the part 6In of the sleeve 6l which extends forwardly from the gun barrel, this portion of the chamber wall having a series of bailie ports 19 extending therethrough, and an inwardly extending annular shoulder lilb is formed at the forward end of Said portion, and from this shoulder the inner side wall of the Rotation chamber extends forwardly uto the periphery of an annular shoulder 14 at the forward end of the chamber. The body has a tubular extension 1| at its forward end through which extends a seal port 12 which is in axial alinement with the bore of the barrel. From the forward part of the chamber discharge ports 13 extend rearwardly and outwardly through its wall, the outer ends of the discharge ports being forward-of the baffle ports, so that when the ports are open and the gun is red the discharge from the rearwardly directed ports will be intercepted by the discharge from the baille ports, the arrangement of ports in this respect being similar to the arrangement of ports in my Patent No. 2,191,484, dated February 27, 1940.

In addition to the rearwardly directed ports and baille ports I also provide intermediate the rearwardly directed ports, a circular series of forwardly directed ports 11, these commencing as grooves 11n in the side Wall of the chamber at the shoulder 10 and extending through the forward wall of the chamber adjacent the tubular extension 1l, these forwardly extending ports be ing in line with the shoulder 18 on the gun barrel.

An annular valve 88 surrounds the bodyportion and is movable to open and close the rearwardly directed discharge ports and the baille ports. As shown in Fig. 10, the valve has spaced openings 82 and correspondingly spaced openings 83 adapted to register with the baille ports 19 and rearwardly directed ports 13, respectively, in one position of the valve, to open said ports, and in another position of the valve all ofA the ports will be closed.

On the forward end of thebcdy is arranged a disk-like valve 81, with circularly spaced openings 86 adapted to register with the' forwardly directed ports 11 in one position of the valve and to close said ports in another position of the valve.

The gear H00 on the shaft l has a tooth |82 adapted to engage a notch 94 in the edge of the valve 81 which controls the forwardly directed ports, and the periphery |03 of this gear is adapted to engage arcuate surfaces 95-96 at opposite sides of the notch to hold the valve in any position of adjustment. Similarly the gear |04 on Shaft IDI has a tooth |01 adapted to engage a notch 9| at the periphery of the valve and the periphery |08 of this gear is adapted to engage arcuate surfaces 92 and 93 at opposite sides of the notch 9| to hold the valve in any position of adjustment. Cooling fins 84 are provided on the valve 80- and such fins 88 are also provided on the valve 81, and ns I2 (Fig. '7) may be provided on the body of the recoil controlling device, to dissipate the heat from these ports when the gun is in action, so that the valves will t closely and not be distorted by excessive heating of the ports.

In the positions shown in Figs. 7, 8 and 9 all valve controlled ports are closed, the control lever 39 is in the mid position as shown in Figs. 2 and 4 and the wedge 29 for adjusting the pressure on the spring I8 is also in mid position. In this position of the lever 39 the highest gas pressure prevails in the combustion chamber of the recoil device when the gun is fired, and hence the greatest gas pressure is applied to the shoulder 18 on the gun barrel and there is practically no recoil pressure applied to the barrel jacket, on which the recoil controlling device is mounted. InI this mid position of the control lever the greatest rate of re results because the gun bar- 4amasar rel is driven backwardly at high velocity and the pressure of the spring I8 is such as to ensure rapid return of the breach block and barrel.

Moving the control lever to the left in Fig. 2 (to the right as viewed in Fig. 4) adjusts the wedge 39 upwardly and increases the pressure on the spring I8 and turns the shaft 38, cable I 09 and shaft IOI counter-clockwise as viewed in Fig. 8. With a suiicient movement the tooth |02 on the gear |00, engaging the notch 94 in the valve 81, will completely uncover the forwardly directed ports, while the rear valve 80 will remain closed; or by a shorter movement of the lever the forward ports can be only partly opened, leaving the rear valve closed. Opening the forward ports lessens the gas pressure in the combustion chamber when the gun is fired, and hence the gun barrel will not be driven backward with the same velocity as when these ports are closed and although the wedge 39 will be adjusted upwardly in opening the forward ports, increasing the tension of the spring I8, the stored energy in the spring will not compensate for the slowing down of the rearward movement of the barrel, and the rate of fire will be decreased. The amount of decrease will depend upon the extent to which the forwardly directed ports are open.

Moving the control lever to the right in Fig. 2 (to the left as viewed in Fig. 4) adjusts the wedge 39 downwardly and decreases the pressure on the spring I8 and turns the shaft 38, cable |09 and shaft IOI clockwise, as viewed from the forward end of the control device, Fig. 8, or counterclockwise as viewed in the section, Fig. 9. In this movement the tooth I02 on the gear |00 moves out of engagement with the valve 81, leaving the forwardly directed ports closed and the tooth |01 on the gear |08 moves the valve 80 to open the rearwardly directed ports I3 and the baille ports 19. If the movement of the control lever is sufficient to completely open the rearwardly directed ports and the baille ports, the gas pressure in the combustion chamber when the gun is red will be at a minimum and the pressure applied to the spring I8 by the wedge 29 will be at a minimum and the rate of re will be slowed down both by the reduced rearward velocity of the gun barrel and decreased energy stored in the spring which returns the barrel. In intermediate positions of the control lever the rearwardly directed ports and baille ports may be only partly opened and the gas pressure, acting against the gun barrel when the gun is red, will be greater or less according to the position of the valve 80 so that the velocity with which the barrel is driven backwardly will be varied accordingly, thus varying the rate of re.

One important advantage of being able to change the rate of re while the gun is in action, is that the gunner may change the rate so as to eliminate what is commonly called resonance. While at one speed there may be vibration, annoying the gunner, a slight adjustment of the rate of fire may substantially reduce this cause of annoyance.

I claim:

1. The combination with a machine gun comprising a reciprocable barrel, a breech bolt and a spring adapted to be placed under tension by the recoil of the barrel and to return the bolt and barrel to firing positions, of a hollow recoil attachment supported independently of the barrel at its muzzle, said attachment having in its wall a seal port in line with the bore of the barrel and having also forwardly directed ports and rearwardly directed ports, out of line with the bore ofthe barrel, for the discharge of the products of combustion to the atmosphere to affect the force of the recoil, port controlling means adjustable on the attachment for varying the effective areas of said forwardly and rearwardly directed ports, means for adjusting the tension of said spring, and manually controlled means for simultaneously moving said port controlling means and said spring tension adjusting means.

2. The combination with a machine gun comprising a reciprocable barrel, a breech bolt, a spring adapted to be placed under tension by the recoil of the barrel and to return the bolt and barrel to firing positions and means for adjusting the tension of said spring, of a hollow recoil attachment supported independently of the barrel at its muzzle, said attachment having in its wall a seal port in line with the bore of the barrel and having also forwardly directed ports and rearwardly directed ports, out of line with the bore of the barrel, for the discharge of the products of combustion to the atmosphere to affect the force of the recoil, a valve adapted to open and close the forwardly directed ports, a valve adapted to open and close the rearwardly directed ports, manually controlled means for moving said valves in succession to either their open or closed positions, as desired, and for simultaneously adjusting said spring tensioning means.

3. The combination with a machine gun comprising a reciprocable barrel, a breech bolt, a spring adapted to be placed under tension by the recoil of the barrel and to return the bolt and barrel to firing positions and means for adjusting the tension of said spring, of a hollow recoil attachment supported independently of the barrel and its muzzle, said attachment having in its wall a seal port in line with the bore of the barrel and having also forwardly directed ports and rearwardly directed ports, out of line with the bore of the barrel, and balile ports at the rear of rearwardly directed ports, a valve adapted to open and close the forwardly directed ports, a valve adapted to open and close the rearwardly directed ports and baffle ports, manually controlled means for moving said valves in succession to either their open or closed positions, as desired, and for simultaneously adjusting said spring tensioning means.

4. 'Ihe combination with a machine gun comprising a casing and a barrel jacket extending forwardly from the casing, of a hollow recoil controlling attachment having a sleeve fitting within and secured to the forward end portion of the jacket, a reciprocable barrel withinthejacket.

said barrel having an external collar at its fortheir peripheries, and manually controlled means for operating said valves from the rear end of the gun.

ROBERT H. S. HUGHES.

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