US 916885 A
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APPLIUATION FILED JUNE 2s, 190s.
Patented Mar. 30, 1909.
[Zfentor: WML MW III-Ill UNITED snifrns A'rnivr onnon.
B LIBAM PERCY MAXIM, 0F HARTFORD, GONNETICUT, ASSIGNQR TO MAXIM SILENT FIREARMS COMPANY, QF NEW YORK.' N- Y A CORPORATION 0F JEBSEY SILENT FIREABM.
Speeicetn'on of Lettera Patent. Patented. MareliSO. 19W.
, Alv'rlcetion filed June 28, 1908. aerial No. 0.99.
To all whom 'it may concem:
Beit known that I, HIRAM PERCY MAXIM, a citizen of the United States,
invented certain new and useful Im rovements in Silent Firearms, of which t e following is a specification, reference being had to the accompanying drawing, forming a part hereof.
Various attempts have been made heretofore to render noiseless the discharge of firearms by preventing the sudden release of the powder gases at the muzzle of the firearm. In some of the devices designed for this purpose the bore of the flrearm is obstructed-mechanically after the passage of the projectile and the gases which follow the projectile are diverted through orts provided for the purpose into cham ers from which they are allowed to escape gradually. Devices`of this character are more or less effective in reducing or preventing the noise of discharge, but in some cases they are objectionable upon other grounds. In other of the devices designed for the purpose the mechanical obstruction of the bore is avoided and provision is made for the escape of the gases from the bore of the firearm in rear of the muzzle either directly into the atmosphere or into a surrounding chamber from which they subsequently escape, it be ing the intention in such cases that the escape of the gases shall be so gradual as at least to diminish the noise of discharge. In still other of the devices in which the mechanical ob-` struction of the bore' is avoided, deflectors perforated for the passage of the projectile, are disposed beyond the muzzle for the purpose of distributing the gases of explosion over a large area and of directing them either laterally or rearwardly or both laterally and rearwardly, it also being proposed in some cases to restrict somewhat the escape of the gases. Practically, however, devices of the two classes last mentioned, at least so far as produced hitherto, have had, in some cases, no substantial eiiect in reducing the noise of discharge, and in some cases have been able at theA most only to modify the noise of discharge.
In the resent invention it has been discovered tiiat the noise of the discharge of a rearm, so far as it is due to the escape of powder gases into the atmosphere, can be overcome if the gases, following the project residing 'Hartford, in the State of Connecticut, have Ated to escaplp 4 'i ile, are made to dissipate their; energyf-by I.
being given a rotary o rwhirling rnovementriI a suitable chamber, the velocity being.' s; great that the ases are held b Acent` 1if1 1gal action against he wall of the c amber until" by friction against such wall the velocity-is graduallyretarded and the gradually throu hfano l` nm which may eand is preferabigy the/ ogriing for the assage of the projectile. Such man@ ment o rotation of the body of gas maytdke place about an axis coincident with the ahi of the bore of the firearm er otherwise, and
while theoretically the entire body of. gases of a Single dishlgf might receivetiie desired` rotary or whirling movement-in a?" smears. permits single chamber, practially, on account of the? considerable size which a single chamber .would necessarily have, it is desirable to ro vide a succession of diaphragme, partitions or spreaders forminga succession of chambers among which the gases of a single discharge are distributed and from one to' another ofv l which the gases may pass in succession astheirfvelocity is `suecesswely reduced, the direction of movement of the gases being preferably reversed in the assage from one chamber to the next an an. oscillation of the gases being thus produced, whereby their ener is the more quickly dissipated. Such cham' ers, however, might be made to communicate with the bore of the rearm at different points along its length, but are prefer-- ably located at the true muzzle of the lirearm, that is, at the point where the projectile has already received its maximum impetus, and constitute an/extension of the barrel.
The invention will be more fully explained hereinafter with reference to the accompanying drawing in which two different forms of the devices for developing the desired rotary movement of the gases are shown as illustrative of the nature pf the invention.
In said drawing-Flgure 1 is a view in side elevation of an ordinary s orting riiie or shoulder arm provided wit one embodiment of the invention. Fig. 2 is a detail view, in longitudinal section and on an enlarged scale, of the device or appliance shown in Fig. 1. Fig. 3 is a view slmilar to Fig. 2, but showing a different form of means for settin up the rotary orq'hirling movement of t e gases. Fig. 4 is a view in transverse section on the plane indicated by the line 1m-44 ef Fig. 3.
cross ixectionan kof .teraorlesslen hacof thefbartelgfor the-passage of the ro- `jec'lile but fpreferably, ha
' series o diaphr n' 1 y Obviousl'r the invention` is applicable anyform o firearm, whether pisto 3,. shoulder arm, machine or heavyordnance, but'anl explanationo the nature of the invention m connection with the application to .ashoulder arm will be suilicient.` The rifle represented in Fig. 1 if the drawing comprises a barrel a,
a stock jand firing' v'mechanism c. At'the' end or i ,zle of the barrel a is secureda icasing d' erabl substantially circular its walls ot` er- A, .Within t e casing 4d is a 1s, partitionsjor spreaders e-having an ope i l in line with the 'bore of im r orate.
-the barrel for theassageyof the projectile andl forming cells or separate chambers in each of which rotary'movement of the body l of the gases following the'projectile'is established, Inftheforrny of the device shown in Fig. 2, each of such cells-is annular, vwith reference 'to 'the axis` of the barrel-of the firearm,v about which it is disposed, the diaphragm being spiral or conchoidal in cross section about the opening for thepassa e of the projectile, with the mouth or wall a out the opening directed toward .the breech of the vfirearm so that the gases which follow the projectile from the muzzle of the firearm, as
they expand or diverge, are directed, by the guiding surface presented by the diaphragm or cell wall, into the adjacent chamber or cell and so that the body of gas lwithin the cell has a whirling o r rotary movement about a substantially circular or annular line or axis,
the main portion of the chamberbeing genof the gases about a stationary axis.
' vthe gases is gradually reduced, the energy of the gases belng thus dissipated. When the velocity is so far reduced as to be exceeded by the expansive force of the gases, the rotary mov ement in thechamber will cease and the gases will ind their way out through thev annular opening throu'gh which they1 entered, in a reverse direction, and t ence through the opening for the passage of. the
projectile into the nextcell orv chamber and eventually into the atmosphere. Obviously the cell or chamberlnearest the muzzle of the -rearm will be fillediwith" the whirling gases at the highestpressure and successive cells or chambers alsoreceive gases from the central'column following' the projectile, but at a gradually reduced pressure and velocity.
Theynumber of "diaphragme, partitions or j lIquired to have anmundesirab Wai-r, z
t sre-aders'fl to de i' iipon the` c is'to be 'applied and Qiitlle ammunition used,
aracter `of the; tow 'ch'the devid the degl-'ceto which the noise of discharge is `to be reduced and, inversely, the diameter which it is practicable to permit the outer vcasing t'o have.
y not' be relength, it may be desirable toso form the muzzle of the In order that the device may e -iirearm, asby chambering the bore just back ofthe muzzle, as at as'to cause the ases to ydiver e more rapid' y than they woul other- `wise o afterf leaving-the muzzle. ,l
In thevform fhe' device shown in Figs. 3 and 4 the'bod of gasesiscaused to have a rotaryl or whir ing movement about an axis which is coincident with the axis' of the barrel ofthe firearm. In this form a casing g, preferably circular in cross section and of suitable-length, is secured to the muzzle of the barrel a. Interiorly, it is divided into successive cells or vchambers by successlve partitions h, having each an o ening i, for the passage of the rojectile, pre erably of somewhat greater iameter than the bore of the firearm. In each 'cell orchamber k, thus formed, are disposed a series of stationary blades or vanes l, like turbine vanes, ap-l proaching somewhat closely to the axis of the casing g but terminatin beforev they reach the Acircumferential wel? of the chamber so as to leave a clear annular space m adjacent to -the circumferential wall. As the gases leave the muzzle of the gu-n and expandl or diverge someof. the gases are directedvbyy "the guiding surfaces presented by the blades i or vanes lof the first chamber outwardl into the circumferential space m in whic the volume of the gases, so entrapped, is caused,y by the arrangement of such ades or vanes to acquire a rotary or whirling movement at a high velocity. As in the form of the device firstA described, the ,centrifugal action developed b the rapid rotary or whirlin movement hol the ases against the wa of the chamber, until tlieir energy is dissipated and their velocity is reduced to such an extent that it -is overcome by the expansive force of the gases, when the whirling motion ceases and the gases find their way back, in a reverse direction, through y the passages between the blades or vane's and through the o ening for the passage of the projectile into t ie next chamber, in which the action mayy be repeated but at less velocity yand pressure.l In this manner the pressure of the gases is gradually reduced until they escape at the extreme'forward endof the device, through the openingtherein for -thepassage of t e projectile, at such low'pressure that' the noise of discharge is absent. s
The preferab e construction, whether ofV one form or another, is one in which each, chamber, in which the energyof the gases is 55 gases of explosion into such chamber, wherecia-ese dissipated, .is generally `circular in cross section with reference to `the axis about 'which the rotarymovement takes place, and the guiding surface, by which :the gases are directed into such chamber, is substantially tangential with respect thereto, -so that the rotary movement of the gases within the chamber lis promoted. 1*"urthermore, the efficiency of such preferable construction being largely dependent upon the continuous wliir' er rotary movement -of the gases about a stationary axis, that is, upon the continuation .ef .the rotary movement until the velocity is reduced to a point where the centrifugal force is equalized by the expansive torce, when the rotary movement will cease and, under the influence oi the lexpansive force, the gases will pass to the next chamber, it is desirable, in such a construction, that the peripheral wall Aci" the chamber shall 'be generally circular, that is, that ift shall exten-d more than 180 about the axis, so that the gases shall be turned upon themselves and made to rotate continuously in the chamber itself, While at the same time the peripheral wall need not, and, in the construction -shown in Fig. 2, fior example, Icannot 4always be formed upon the arc of' a true circle. 'he description of the chamber as generally circular 1n cross section, wherever such description occurs the claims, is therefore to be understood with the meaning thus ex lained. y
t will be understood that the character, size and location of the chambers employed will be varied accerding to the conditi-ons of use. For examle, they may be larger or smaller and of ifferent contour to develop diierent degrees of friction, they may be made more or less elastic to diminish danger of breakage by shocks, their walls may be of different thickness, and successive chambers in a series may be varied in form so that those nearest the muzzle shall be subjected to less strain than if they were of uniform contour.
I claim as my invention:
1. A silencing device for iirearms, comprising a casing adapted to be secured at the muzzle ofthe firearm and having an opening therethrough in line with the bore of the barrel for the passage of the projectile and its walls im erforate except in line with the bore of the arrel, said casmg having therein a cham'ber and a guiding surface to direct the by the powder gases acquire a rotary or whirling movement about a stationary axis within the chamber and escape through the opening for the passage of the projectile after their energy is dissipated in such rotary or whirling movement.
2. A silencing device for firearms, comprisinga casing adapted to be secured at the muzzle of the firearm and 'having 4ain opening theretluough in line with the bore of the barrel for the passage of the projectile, said casing having therein -a chamber generally circular in vcross section and extending more than 180 about its axis'and a guiding surface substantially tangential lwith respect -to the .circular chamber to direct the gases of explosion into such chamber, whereby the powder gases .acquire a continuous rotary or whirling movement about .a stationary axis within the chamber, until their velocity is reduced to a (point where .the `centrifugal force is equalize by the-expansive force, and escape through .the opening for the passage of the projectile after their energy is .dissipated in such rotary or whirling movement.
3. A silencing device for iirearms, comprising a casing adapted to be secured -at the muzzle ofthe rearm and having an opening therethrough in line with the bore of the barrel for the passage oi the projectile and its walls imperforate except in line with the bore `of the barrel, said casing having therein a chamber generally circular in cross section,
and .a guiding surface to direct the gases of explosion into such chamber, whereby the powder gases acquire .a rotary .or whirling movement about a stationary axis within v the chamber and escape through the .opening for the passage of .the projectile after .their energy is dissipated in such rotary or whirling movement.
4. A silencing device for firearms, comprising a casing adapted to 'fbe secured 4at the muzzle .of the iirearm and having lan .opening therethrough in .line with the bore of the barrel for the passage of the projectile and its walls imperforate except in line with the bore of the barrel, said casing having therein a series of chambers, each chamber having a guiding surface by which the powder gases are directed in a substantially tangential direction into the chamber, whereby the' powder gasesacquire a rotary or whirling movement within each chamber and escape from each chamber. to the next and eventually into the atmosphere through the opening for the passage of the projectile after their energy is dissipated in such rotary or whirling movement. l
5. A silencing device for firearms, comprising a casing adapted to be secured at the muzzle of the firearm and having an o ening therethrough in line with the bore of t 1e barrel for the passage of the projectile, said casing havin therein a series of chambers, each chamber t(being generally circular in cross section, and having a guiding surface by which the powder gases are directed in asubstantially tangential direction into the chamber, whereby the powder gases acquire a rotary or whirling movement within each chamber and escape from each chamber to the next'and 'eventually into the atmosphere' through vthe opening for the pas.sage of the projectile after their energy 1s dlsslpated m such rotary or whirling movement.
6. A silencing device for firearms, compusing a casing adapted to be secured at the muzzle of thefirearm andhaving an o ening therethrough in line with the bore of t 1e barrel for the assage of the projectile and its walls imperlbrate except in ine with the bore of the barrel, said casing having therein a series of chambers, each chamber being generallv circular inl cross section, and having a guiding surfacby which the are directed in a substantial y tangential direction into the chamber, whereby the powder gases acquire a rotary or whirling movement within cach chamber and escape from each chamber to the next and eventually into the atmosphere through the opening for the vpassage of the projectileafter their energy is dissip'aated in such rotar)T or whirling movement.
' 7. A silencing device for 'rearms, comprising a sup orting shell or casing imperforate exce t in ine with the bore of the barreland a diap ragm therein having .an opening for the passage ofthe projectile and substantially eonchoidal in crssjsection about the opening, formin an annular cell or chamber, such diaphragm aving an o ening forthe passage of the projectile and t e escape of the gases and having its mouth or Wall about such A opening direc ed toward the breech of the firearm Where y the lgases which follow the projectile are caused to acquire a rotary or whirlin movement in the cell about a substantia y circular or annular axis and the owder gasesv energy of the gases is dissipated in such r tary or whirling movement.
8. Av silencing device for firearms, comprising a supporting shell or casing and a. series ofor sreaders disposed in said g an forming therein a success,
diaphragms she l or casin sion of chambers, each of such dia hragms or spreaders having an openin for t e pass e of the projectile and for t e escape of t e grasesfrom each chamber into the next and om the last into the atmosphere and a.
guidingl surface by which the gases are made` the passage of theprojectile .and or the es-v cape of the gases from each chamber into the next and from the last into the atmosphere, the mouth or wall about said o e directedtoward the breech of pthe rearm,l
whereby the gases are caused to acquire a rotary or whirling movement inthe cell about a substantlall axis Vand the energy o the gases is dissipated in such rotary or whirling movement.
This specification si ned and witnessed this 25th day ofJune," D. 1908.
HIRAM PERoY MAXIM.
Signed in the presencel o- WILLIAM B. GREELEY, AMBRosii L. OSHEA.
circular or annular-