US2750849A

US2750849A - Gas relief valve for firearms

Info

Publication number: US2750849A
Application number: US425771A
Authority: US
Inventors: Earle M Harvey
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-04-26
Filing date: 1954-04-26
Publication date: 1956-06-19
Anticipated expiration: 1973-06-19

Description

June 19, 1956 E. M. HARVEY 2,750,849

GAS RELIEF VALVE FOR FIREARMS Filed April 26, 1954 2 Sheets-Sheet 1 36 4 3 2| I6 31 23 jg ATTOBNE Y5 June 19, 1956 E. M. HARVEY GAS RELIEF VALVE FOR FIREARMS 2 Sheets-Sheet 2 Filed April 26, 1954 INVENTOR. Era-r1 E M H'ELTV E BY WJZMMa Mpwr A TTOENE Y5 GAS RELIEF VALVE FOR FIREARMS Earle M. Harvey, Agawam, Mass., assignor to the United States of America as represented by the Secretary of the Army Application April 26, 1954, Serial No. 425,771

2 Claims. (Cl. 89-193) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to gas systems for automatic firearms and more particularly to gas regulators therefor.

When gas operated firearms are used to launch grenades, a breakage of the recoiling parts of the firearm is oftentimes experienced. This is due to the restriction of the gases at the muzzle of the firearm by the grenade which causes excessive gas pressure to be received by the gas cylinder and consequently a high velocity of the operating rod and its associated members. From high speed photography, it is determined that the velocity of the operating rod is approximately twice as great at recoil position when a grenade is launched as when a round of service ammunition is fired.

High speed photographs also reveal that the velocity of the recoiling parts vary from round to round in ammunition of the same lot. This variation is obviously undesirable in automatic weapons as it produces undue intermittent strain on the operating parts through the unevenness of operation. Further, it is sometimes necessary to use a lot of ammunition having a pressure higher than that best suited to the firearm which, in firearms having conventional gas systems, oftentimes causes breakage of parts.

It is, therefore, an object of this invention to provide for gas operated firearms, a gas regulator device for maintaining the operating gases of the gas system below a predetermined level.

It is another object of this invention to provide for gas operated firearms a gas regulator device for maintaining the gases in the gas system thereof below a safe pressure during the launching of a grenade.

It is a further object of this invention to provide for gas operated'firearms a gas regulator device for maintaining its gases in the gas system below a predetermined level and having time delay means to retard operation thereof by gases temporarily above the predetermined level of pressure.

It is the specific object of this invention to provide a regulatable valve easily installed in the gas cylinder of a conventional gas system for automatically maintaining the gases therein below a predetermined pressure.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a fragmentary partially cross-sectioned side view of the front end of a firearm with the gas regulator installed thereon and the relief valve shown in normal closed position;

Fig. 2 is similar to Fig. l but showing the relief valve opened by excessive pressure of the gases in the gas' hired rates Ratent Fig. 5 is a perspective exploded view of the relief valve.

Shown in the figures is a firearm having a barrel 12 and a gas cylinder 13 with a gas port 14 providing communication therebetween. The threaded closure member for the front end of gas cylinder 13 has been removed and threadably mounted in place thereof is a relief valve 15. Relief valve 15 includes a hollow cylinder member 16 suitably threaded at the rear end for mounting to the front end of gas cylinder 13 and having a flatted portion 17 arranged to cooperate with a suitable wrench to aid assembling and disassembling. Provided in the inside of cylinder member 16 is a reduced diameter portion 18, arranged between a front shoulder 19 and a rear shoulder 20, from which there extends to the outside of cylinder member 16 a plurality of radial ports 21. Disposed forwardly of front shoulder 19 is a chamber 22 which is terminated by a threaded portion 23 and is provided with a longitudinal channel 24.

Slidably disposed in chamber 22 is a valve member 25 having a rod portion 26 which is slidably received by reduced diameter portion 18, a trio of wing portions 27 which serve to maintain rod portion 26 in alignment with the reduced diameter portion during reciprocation and a forwardly extending cylindrical stud 23 arranged to be received by the rear end of a coiled compression spring 29. Wing portions 27 also provide the seat for the rear end of spring 29 and limit the rearward travel of valve 25 by the engagement thereof with shoulder 19. Slidably mounted in chamber 22 forward of spring 29 and engaged therewith, is a cylindical follower member 30. A lug 33 extends from the circumference of follower 30 to be slidably received by channel 24, permitting non-rotating longitudinal movement of follower 30.

A threaded hole 34 extends axially through follower 30 and arranged for cooperation therewith is an adjustment member 35. Adjustment member 35 is provided with a head'portion 36 suitably adapted, as noted by 3'7, to receive the extractor rim of a cartridge for turning and a rearwardly adjacent cylindrical bearing portion 33. Also a threaded portion 39 cooperable with hole 34 and a shank portion 40 extends rearwardly from such threaded portion for engageable cooperation with stud 23 for limiting the forward movement of valve member 25 to where rod portion 26 unblocks ports 21. Rotatably and slidably disposed on bearing portion 38 is a cylindrical mounting member 41 having a portion 42 of similar diameter as cylinder 16 and a threaded portion 43 of smaller diameter. Portion 43 extends rearwardly from an annular shoulder 44 formed by the junction thereof with portion 42 and is arranged to threadably cooperate with portion 23 of cylinder 16. Portion 42 is provided with lateral holes 45, arranged to receive a spanner wrench, and an annular groove 46, rearwardly adjacent shoulder 44 which receives a split friction ring 47 for securing mounting member 41 against displacement to cylinder 16.

Extending through bearing portion 38 is a radial pin 48 one end of which projects from such bearing portion to be selectively received by a series of notches 49 in the rear end of mounting member 41. Pin 48 is arranged to permit restricted slidable movement of adjustment member 35, in respect to mounting member 41, to provide for movement of such pin in and out of notches 49. Provided around the perimeter of the front end of mounting member 41 is a series of inscribed numbers 51 which progress serially from l-4 and are so arranged that an index mark 52 in head portion 36 of adjustment member 35 aligns with one thereof when pin 48 is received in one of the notches 49. A stop pin 50 extends from the rear end of mounting member 41 for engagement with pin 48 to permit a single rotation of adjustment member 35.

The first of the numbers 51 is arranged to be indicated by index mark 52 when adjustment member 35 is rotated to bring'follower 3b contiguous the rear end of mounting member 41 and pin 43 is in position to be received by one of notches 59. The other numbers 51 are arranged to increase an adjustment member 35 is turned to move follower .30 against spring 2; and thereby bring greater resilience against valve member25. The bias of spring 29 against follower 3t), and so rearwardly against adjustment member 35, holds'the end of pin '48 resiliently in a selected one of the notches 49.

Thus, relief valve 15 is adjusted 10 a desired gas pressure by the insertion of the extractor rim of a cartridge in slot 37 and turning adjustment member 35 thereby to one of the four adjustment positions. The adjustment positions, as hereinbeforc explained, are identified by the alignment of indcxmarlc 52 With one of the numbers 51, and indexing is achievedtby'the reception of pin into the associated of notches 49. Yfhenever the gas sure received by gas cylinder 13 is over and above the predetermined pressure, either through excessively powered cartridges or through the restriction of the muzzle of the firearms by a grenade mounted thereon, tl e. gas pressure overcomes the preadjusted tension of spring 29 to the extent that valve member 25 is'forced rearwardiy until rod portion 25 thereof unblocks radial ports 21. Thereby, excessive gases in gas cylinder 13 are expelled into the atmosphere reducing the pressure in the gas cylinder to the predetermined value. The forward movement of valve member 25 is limited by the engagement of the end of stud 28 thereof with the end of shank portion ll of adjustment member 35.

it will be noted that valve member 25 must travel some distance before rod portion 26 thereof vents the gases out of port '21. Thus, surge Waves with temporary excessive peak pressures do not actuate valve member 25 suiliciently to vent gases to the atmosphere as the wave will have receded and the pressure on the valve member reduced accordingly before such valve member has had time to unblock ports The inertia of spring 29 also cooperates with the resiliency thereof in damping the surge waves.

it is elearl" apparent from the foregoing that there is here provided for a gas operated firearm, improved means for automatically maintaining the operating gases of the cylinder at an adjustable level, which is rugged in construction, is easily installed, and is handily regulatable.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

claim:

A gas regulator for a firearm having a gas cylinder, including a body member arranged to be threadably mounted to the gas cylinder, said body member being provided with a bore communicating with the gas cylinder and a larger diameterchamber extending forwardly therefrom, a plurality of ports extending radially from said bore to the outside of said body and intermediate the ends of said bore, a valve member slidable in said chamber, a rod portion on said valve member slidably received by said bore to releasably block said ports, and arranged to be moved to a ports unblocked position by gases in the gas cylinder, means for limiting the movement of said valve to a ports blocked position, the end of said rod being positioned beyond said port when said valve is in said port blocked position whereby said valve member is movable an interval before said ports are unblocked by said rod position, a compression coil spring mounted in said chamber for cooperation with said valve member to resiliently hold said valve in said ports blocked position, a mounting member threadably mounted in the front end of said body member, an adjustment member mounted for rotation in said mounting member, a follower threadably mounted on said adjustment member and arranged for slidable nonrotating movement in said chamber against said spring when said adjustment member is rotated whereby the gas pressure required to move said valve member to said ports unblocked position is regulatable, a shank portion on said adjustment member extending rearwardly to be engageable by said valve for limiting forward movement thereof to said ports unblocked position, a pin mounted radially in said adjustment member'and being'receivable in one of a plurality of notches in said mounting member for index'ng said adjustment member, said pin being resiliently held in a selected one of said notches by the bias of said spring against said follower, and means for indicating the one of'said notches in which said pin is re ceived.

2. For a firearm having a gas cylinder, a gas regulator including a body member threadably mounted to the gas cylinder, said body member being provided with a longitudinal bore communicating with the gas cylinder, a larger diameter chamber extending therefrom and an annular shoulder formed thereby, a plurality of ports extending radially to the outside of said body from said bore and between the ends thereof, a reciprocable valve member having a body portion slidably mounted in said chamber and a rod portion slidably mounted in said bore for releasably blocking said ports during movement of said body portion from engagement with said shoulder to a relief position, said valve member being movably responsive to gas'pressure in the gas cylinder, a spring biased against said body portion. to resist movement of said. valve member by said gas pressure, a rotatably mounted adjustment member extending longitudinally into said chamber through said spring for engagement by said valve member when in said relief position, a follower member threadably mounted on said adjustment member for cooperation with said spring to adjust the preload thereof when said adjustment member is rotated, and indent means assisted by said spring for indexing said adjustment member in one of a series of predetermined positions.

References Cited in the file of this patent UNITED STATES PATENTS