US2476438A - Choke structure for gun barrels - Google Patents

Description

July 19, 1949., l l Lf wRlGH-r 2,476,438 I CHOKE STRUCTURE FOR RUN BARRELS Filed May 4, 1945 2` sheets-sheet 1 July 19, 1949. L. H. WRIGHT 2,476,438

CHOKE STRUCTURE FOR GUN BARRELS Filed May 4, 1945 2 sheets-sheet 2 I I En 4- INVENTOR. ee H. Mfr/51h!- Patented July 19, 1949 UNITED ses TENT Claims.

This invention relates to a gun choke and has to do particularly with a choke for the barrel of a shot gun.

The desirability of a choke construction in the barrel of a shot gun is well known to those versed in the art of manufacturing and versed in the use of the gun. Suilce it to say that the choke of a barrel is a controlling factor in governing the shot pattern. A barrel with no choke, that is a' cylinder bored barrel provides a relatively wide pattern of the shot at a given distance. In other words, the shot spreads. A similar barrel with a choke keeps the shot from spreading so much with the result that at the same distance the pattern is relatively smaller and the shot are more closely related. A skilled hunter can tell whether or not he wants a choked action in taking a particular shot and, suffice it to say, often it is desirable to have no choke, or little choke, when the iirst shot is fired at a game bird or other game animal, but to have a choke action for subsequent shots because the game is moving away. Experienced hunters frequently own several barrels or guns, each bored differently for obtaining different choke actions or for no choke action at all and the two barrels of a double-barrel shot gun are frequently arranged so that one has no choke structure.

The present invention aims to provide an improved gun barrel choke construction which may be constructed as an attachment to be mounted upon a gun barrel or which may be constructed and manufactured as a part of the gun barrel. In accordance with the invention, an automatic action is obtained. For example, the structure may be initially set so that when the gun is first fired there is no choking action. And upon the second or subsequent shots being red, there is a choking action. The operation of the choke takes ple-.ce automatically and incident to the forces developed in the firing of a gun. As will be seen later, it is thought that this action is due to the recoil. The invention also aims to provide a construction which is capable of adjustment so that the choking action obtained may be governed by the will of the user, or so that the stiucture may be locked in any given position so that the same condition prevails through a sequence of ired shots with a substantially equal choking or no choking as desired.

ther objects of the invention will become apparent and will be better understood as the following detailed description is considered with the accompanying drawings:

Fig. 1 is a side elevational view of the end of 55 30 member 3.

40 an element 6, provided with a detent 1.

50 shown at I6.

2 a gun barrel with the choke construction applied thereto with some parts cut away to show the interior structure.

Fig. 2 is a view similar to Fig. 1 showing the 5 choke structure shifted to choke position.

Fig. 3 is an enlarged cross sectional View taken substantially on line 3-3 of Fig. 1 with the structure in non-choking position.

Fig. 4 is a further enlarged cross sectional View 1o illustrating the parts in choking position.

Fig. 5 is a view illustrating the barrel extension which provides choking action.

Fig. 6 is an end elevational view looking at the left hand end of Fig. 5.

Fig. '7 is an enlarged detail of one of the rotary a form where the structure is incorporated directly in a gun barrel.

As illustrated in Fig. 1, the barrel of a shot gun is shown at l with its normal end illustrated at 2. When the choke is to be attached to a barrel, as illustrated in Figs. 1, 2 and 3, it is preferred that the barrel be cylindrically formed internally so that it has no normal choking action in and of itself.

Mounted on the barrel is a barrel extension Preferably, this member telescopes over the end of the barrel. To mount the member the end of the barrel is preferably externally threaded and its end may be reduced somewhat in thickness and the extension is internally threaded, the cooperating threads being illustrated at 4. To hold the extension in place so that it does not turn on the barrel, the extension on the barrel may be pinned together as at 5. As illustrated in Fig. 5, the extension is provided with The forward portion of the extension is reduced in eX- terior diameter so as to provide a shoulder and a bearing surface 9. The end of the extension is provided with a plurality of slots lil to thereby form between each pair of slots a yieldable finger or segment I5. These slots, as shown in Fig. 6, are preferably of V-shape with the V-structure opening outwardly. As a result the edges of the segments meet substantially at line contacts as These segments are formed so that they normally are in choking position with the segments contacting or substantially contacting at the line contacts I6. The segmented portion is formed with a raised bead-like structure adjacent its end providing a contact surface I1, which mediate sleeve member 24 with an internal con-..-

tacting surface 25. The surfaces 23 and 25 are angularly disposed so as to cooperatecwiththe,

surfaces I'i and I8. There is another-.Yinnerpr ring-like member 26 arranged to slideon the surface 9 while the right hand endzofzthenpieceyw I slides on the surface 2 I.

sleeve so that all move in unison. The sight Z'Imay be in the form of a rivet orv4 key forhold-f ing' th'e'ring'221in place and a prin 2-'may-f hold I The sleeve -1-2 BQ? adjacent its the ring in place. right 'hand end, as Fig. 3 viewed', is of somewhat thicker-metal-than its remaining @portion and it is provided-with a slot^3l1wlf1ichy slidablyts over Vthe'elementl on the extension. This holds the parts against turning :and -yetpermits'the outer control memberftoslideaxially relative-to the extension'- piece '1 3. f

Mounted -on-the outer-control member 2i) 'is va stud 3i which servestasfa fulcrum for a member ini'the-nature of a rackforfrat'chet. This member is generally illustrated'-'at. 32 iand Iit has-in-v cliriedl `teeth 33v for 'cooperation-with? detent H'I. The member 32 has a thuinbrpiece Slljfwhich when pressed raises the-rack 'from-fthe ldetent l. A

spring 35 which is secured to the post 3l normally pressesl'the' ratchet: so'lthatzitengages the `detent` 1. T

There are two rotary camelikenadjustable de" vicesffrotatably Vmounted onthe outer member 20 andthese are positioned niopposite sides of ther key. On'efofthesesmembersi'isfshown in Fig. '7 an'd-it is in vtheform. of asplitringfgenerally il" lustrated atllll havingf a roughened' or `knurled operating edge-13|;4` Thezsplit'isillustrated at142; The axially extending portion, astillustrated at z 43"gradually increases. in-wi'dtlr so as* toprovide a camesurfacetM; Thus; exceptuforza relativelyV i fiat spot 45 and a relativelyflatspot'46;the' sur'- v facedllis'inclined throughout its extent. The

other l 'cam' member 40055 has -a similar; inclinedy surface 44u. These two split '.ring members may be identical,- and one; atfdliag-ispositioned against the `shoulderI 541'? fon vthe Vouter lmember and the` r other 4Q' isinreversed position adjacent-a shoulder-5I on the end of the' controly member.v The grooves as shown which 'hold-them; against lon*n gitudin'aldisplacement;l Accordingly, it "will'be' seen-by referenceto' Figs. l and 2, that the outer control membery may shift axially within 'limits' determined' by the'key- 6 and `th'ecam surfaces-- Tl'iesplit ring member llllserves'to' close the slot v 'fso' that the key member islconined` therein It'will'be appreciated that byrotating the members 4l) and'lltt' that the extent-of axial move-- mentofthe outer orcontrol member is limited. As shown in Figs. 1 and' 2 A'the axial extent of movement is approximately maximum:

In the form` of device sho-wnvin Fig; 9, 'the parts' are essentially the same--asfthose alreadyv described but lthe device 4is Aincorporated directlyr inv the gun barrel construction.4 Accordingly, the

The sleeve or ring,rnem, bers 22. 24 and 26 are .united to the exteriorv parts have the same reference characters applied thereto with the addition of a prime, where the parts differ. In this form the gun barrel I has the slotted segmental structure I5 formed integrally thereon. The outer or control member 2li is made of one piece instead of an assembly of parts having the contact surface 23', the contact surface 25 for cooperation with the surfaces l'I and.l8. The othervv parts y.have the same reference characters applied thereto.

In using the construction, it may be adjusted to ,a position as shown in Figs. 3 or 9. In this position, the control member is shown shifted forwar.dly. vThis is .done by pressure upon the thumb piece .34. which lifts the ratchet teeth 33 from the ndetent 'I Vand by manually shifting the controltmember forwardly. In this position the rack engages the detent to hold the member 2li against longitudinal movement during normal handling of the gun. It will be noted that at this time the contactifacesz23 and 25-are 'spaced from the faces I'If andgfl8 loftthesegmented portion. However.'

the segmented portion is in its choked position. This is fthe-,fnormaL position Yfor-the segmented portion. AiVhen-a shotis red the internal pressure, which: may bepartiallydue Yto the gas presa;

sure; .orfthefforce'fioraction'of the;discharge of the-shotrand= its 'plug-fete.; causesA the segments Iitoexpand. Y There is knothing tov hold the segments :in\V :their chokedl 'position tso. they readily expand'intozthe.contact surfaces^23`and.25. N ow, this fextentof, expansion -may be controlled fby" the user.; gI1rother words, the expansion` dependsA upon. how far forwardy *.th'e control member Vis shifted-t This 'can be governed bythe rotary position-ofthexcontroliring III).I The substantially;

maximum .forward position is shown' iny Fig. 1.

In. this-position ,it is'preferable that theactionn is1comparab'lefto; a -cylinder borenwherein thereY is noychokingf action. If a slight :choking action1 is `desired for; :therst shot,the control member;

mayfbe;-shif-tedv=to the right from the position shown'in Fig. ..1 and-its position determined by the vrotatable-1adjustment of; the: member I as the element 5 'abuts the camusurface 44. This brings gthe;surfaces;23 and 251in closer relationship tothe'surfaces 'I7 and l8tolimitthe ex-` panding action of the segments I5; asthe rst shot is fmade Whenfthe gun is lred there is .a

reactionfor.'kickingiactiorr which tends .to throw thegunfbackwardly fas the charge is projected.

forwardlyxy This-is,met and overcome `by the shoulder fof-:the: user. .Immediately following the kickingofithe gun ithcusers shoulder rebounds.- Thisaction: causesxthe: outer control member to` shifzt,inwardly:relative tothe-gun barrel and the inclined1surface 44a.v of member 40a strikes ele# ment. Theextent:to'whichtthecontrol mem.-v

berth'usxshifts isdetermined by the rotary position.:of.ltheielement.4!la. This, then,'results in a choked action for 'the succeeding shot. Any timey the scontrolrmember shifts inwardly relative to the barreLas above described, the teeth 33 operate over the detent L In' order for the control "member to be shifted outwardly relative to the barrelythe rack mustbe manipulated to be releasedA from fthe detent. The member a can be adjusted to bring the most narrow portion thereof 'into' alignment with the element 6 so that movement of the controlmember inwardly of the barrel 'as the gun is fired for the first shot is such thatth'e surfaces 23 and 24 make contact with the surfaces -I'l and I8 and thus provide for a maximum choke.

The' rparts are nowIl in thev rposition shown in Fig. 4. When the gun is again red the segmented portions are held in choking position as the segments cannot expand. However, the position shown in Fig. 4 is for maximum choke. If it is desired that the parts assume a position short of maximum choke then the ring a is adjusted to limit the rearward motion of the -control element. By making this adjustment the desired clearance may be obtained for the expansion of the segmented portions before they come into contact with the holding surfaces 23 and 25 or 23 and 25 in the case of the modified construction. It is believed that probably the action which causes the telescoping action of the control member from the Fig. 1 position to or toward the Fig. 2 position is the rebound action of the physical structure or shoulder of the user of the gun. It all happens so quickly that as yet it is not known, what does cause this action, although it appears that the above explanation is plausible. The sudden gun movements incident to the firing of the gun in conjunction with the inertia of the control element provides the automatic adjusting action. As the control member shifts following the firing of the first charge, the teeth 33 slide along the detent l and the Vteeth latch upon the detent and hold the control member in its shifted position. In order to reset the structure it is only necessary to depress the finger piece 34 so that the rack releases the detent whereupon the control member may be shifted forwardly to the Fig. 1 position.

It will be observed that the segmented choking portion is always in a normal choking position and that the choke action is obtained by restraining the segments against outwardly flexing or expanding. It will also be observed that this restraining action can be regulated so that it comes into effect at any place between the maximum and minimum choke. In a twelve-gauge gun, for example, the diameter of a cylinder bored barrel is about .729 inch. A full choke may present a diameter of about .694 inch which would be measured at the ends of the segments when in their normal or collapsed position as shown in Fig. 3. These figures are, of course, variable insofar as this invention is concerned. The cam or flange portions 43 are preferably of such width that the two rings Ml and 4B@ can be relatively adjusted so as to grip the key 6 therebetween and thereby lock and hold the control member against axial movement. Thus the structure can be set or locked in elected positions from substantially no choke position to full choke position. A vent may be employed so that air or gas will not be trapped ahead of the shiftable part, to thus insure the automatic action.

In the full choke position there is a surface to surface contact of the surfaces I1 and I8 with the interior surfaces of the sleeve. If the sleeve be advanced forwardly a trifle, the surfaces are separated and then if the segments be expanded they engage the interior of the sleeve with only a line contact. However, in the full open position, as shown in Figs. 3 and 9, the angles are so preferably arranged that the intermediate portion I9 of the segments will have a surface contact with the interior of the sleeve for a considerable axial extent when the segments are expanded against the sleeve. An example of the angular disposition of the surfaces is as follows, the angularity being given with respect to the barrel axis: The angle of the surface 23, 4 2'; the normal angle of the surface l1 when the segments are contracted, 4 2'; the angle of the surface i9, 3 21'; the angle of the surface 25, 2 2'; the normal angle of sur- 6 faces I8', 2 2' when the contracted.

The construction of the segmented choking portion is considered to be of importance particularly as to the shape of the notches defining the segments to provide a line contact between the segments and the fact that the segments are normally in contact with each other. In a construction of this kind, there may be various particles of matter such as carbonndeposits or other extraneous material or substance which comes from the wadding or packing of the shells which may get in the slots between 4the segments and prevent their normal action of contraction. Any such material which gets into any one of the slots I0 can move freely into the widened V-portion so as to not block the slot in open position. Thus, under normal circumstances the segments will always come together at the line contact. This is advantageous also in the cleaning of the gun as the slots are normally closed and the cleaning cloth is not liable to be caught between the segments.

Moreover, when the segments are in their normal position, inclining toward each other, they substantially contact with each other throughout their length along the sharp knife edge meeting portions. When the segments fiex outwardly the slots between the segments open up more near the free ends of the segments than at the base of the segments. Therefore, the slots or spaces between the segments at any time when they are partially open present a diverging opening as distinguished from a converging opening. Accordingly, the structure minimizes or eliminates the shaving of shot which maysllde along the edges and materially reduces the' catching of wadding or the like.

I claim:

1. A choke structure for agun barrel comprising, a barrel member having a segmented end constituted by a plurality of circumferentially arranged segments defined-by intervening lengthwise extending slots, said segments converging toward their free ends and normally lying in choking position with the slots substantially closed and adapted to flex outwardly under pressure, means mounted on the barrel member for axial sliding movement and adapted to slide by forces caused in ring the gun, said means having surfaces for embracing the exterior of the segments when the said means slides to one position to hold the segments against outward nexing whereby to cause a choking action.

2. A choke structure for a gun barrel comprising, a barrel member having a segmented end constituted by a plurality of circumferentially arranged segments dened by intervening lengthwise extending slots, said segments converging toward their free ends and normally lying in choking position with the slots substantially closed and adapted to flex outwardly under pressure, and control means slidably mounted on the barrel member having internal surfaces spaced from the segments in one position and embracing the exterior of the segments in another position to hold the segments against outward flexing, said control means adapted to shift relative to the barrel member by forces incident to firing of the gun and detent means for holding the control means in an axial position and being neffective for so holding the control means when the control means is subjected to the forces incident to ring the gun.

3. A choke structure for afgun barrel comprissegments are normally ingnfa barrel, membeniihayingaa :segmented .endii constituted by a plurality of circumferentially means'fcrk limitingwthe sliding tv:stroke of the control meansx -4 -V Y 4.- A ,choker structureffor; a gun barrel comprising; a barrel -portion having a segmented end constitutedbyl a pluralityfgof -circumferentially ar-V rangedv lsegments defined by -jintervening length- WiseI extending .slots;:saidgsegments converging toward their free ends and normally lying in choking: positionand adaptedv to flex outwardly under pr essure,. andvecontroljmeans Aslidably mounted on the .portion-having internal surfaces spaced fromfvthe `segmentsdn one` position and Yembracing the `exterioimof the segments in another position-.to Ahold-the;segments against out-e Ward ex-ing, saidgcontrolrmeans adapted to shift relative to the vbarrel;-po rti: n"by-forces*incident to ringof the 'gunfadjustable means for limiting thesliding strokefofethecontrol means, said adjustable means beinggoperableto lock the control means inra selected-:position to hold the control means againstshifting.

5. A choke structureA for :av :gun barrel comprising, a barrel portion having a slotted end defining segments, said segments being yieldable'and normally converging` toward theend ofthe barrel portion so that the sides of the segments are normally in contact Wit-hieach' other and a sleeveV slidably mounted on-the barrel portion for axial sliding movement, the sleevean'd segments'having cooperating surfaces which are spaced'relatively WidelyJapart-When thesleeveY is at one. end of its movement zandvvhic-h ,approach each other as the sleeve moves Atoward `th'eother end of its movement, said sleeve-adapted to shift relative to' the barrel -portion by forces. incident to firing the faces move toward each other.

6. A choke structure for a gun barrel comprising, a barrel portionhaving a slotted .end defining segments, said segments beingyieldable and normally convergingtoward the .ven-d of the barrel portion so that the slotsare-normally substan. tially closed and a sleeve mountedl on thebarrelother end of its movement,said sleeve adapted toA shift relative to the barrel .130.1451011 by .forces incident to ring the. gun in a direction such that the cooperating surfacesmove toward each other, said surfaces on thevsegments .and sleeve being inclined relative to the barrel axis.

7. A choke structurefor a gun barrel comprising, a barrel portion having a slotted end defining segments, saidsegments being. yieldable and normally converging toward the end of the barrelk portion and substantially contacting each other and a sleeve mounted'orr: the:fbarrel1,portion for gun in a direction suchthatthe cooperating suraxialvslidingmovement-the sleeve: andsegments: having;cooperating;Av surfaces fwhich are spacedl relatively Widelyy apartfwhenwthe-.sleeve is at one;- end. r'of .its movement' and. which approach each.: other whenithe sleeve ymoves toward theother-end; of its ',movement, said sleeve adapted -to-.shiftxrela-f, tive` to therbarrelyporton by yforces. incident to.:l ring -the 1 gun Ain a direction suchzgthatfthe :co-.1; operatingfsurfacesfmove toward each other, vreleasable meansror holdingy thesleeve in; :an axialx.v position-constructed and arranged so that the; sleevexvvill rmove fin -one `Vdirection, by reasonof-- forces-incident to ringithe'gun.

8. A choke structure for Va gun barrel compris-f, ing, a barrel portionhavinga slottedv end ,den-.l ing segments, said segments.bei-ngiyieldableand; normally converging toward .thaend of: thebarm; rel portionand substantially in contactwith each; otherY anda sleeve slidably mounted .on the bar-. relzgportion, the sleeve and segmentshaving cooperating surfaces-Which are spaced apartcwhen. the 1. sleevev iis-atene end of vitsV movement and which vare in substantial contact WhentheA sleeve is atv-the other end ofits movement, said sleeve adaptedy to shift relative tothe abarrel portion Joy: forces 4Aincident to .firing the gun from a .posi-` tion where `,thesurfaces fare; out of: contact' to a position-Where :the surfaces areen substantial@ contact, adjustable means :forlimiting the-stroke: of axial movement Lofithe sleeve, said. adjustable. means being operablef tolock the sleeve 'in :various axial positionsandltoholdthesame against sliding movement. 1

9. A .choke :structure forr-a gun barrelV comprising, a .barrel lportion having asegmented end constituted 'by a plurality of circumferentially arranged segmentsrdened by intervening length- Wise Aextending slots; said segments converging toward their free ends vand normally' lying in choking position and adapted to flex outwardly' under pressure, control `means slidably mounted for axial movement'on :the barrel -portion having internal surfaces spaced from the segments in one position-and embracing the exterior of thev segments'in another position to hold the segments against outward flexing, said control means adapted to shift axially relative to the barrel-portion by forces incident to ring the gun, ratchet meansl forholding the control meansin a SetA position and operable for slidingmovementof the control means upon firing of the gun and adjustable vlimit. means for .limiting the sliding stroke of the control means.

1 0; A choke structure for a gunbarrel compris-- ing, a barrel portionhaving a segmented end. constituted byq a ,plurality vof ,circumferentially arranged segments .defined by intervening lengths Wise extending slots, said.A segments converging.. toward their free ends and normally'lying. in

` chokingposition and adapted to l'ex` outwardly.

under pressure, .control means slidably. mounted for. axialmovement VYon Ythe vbarrel portion having. internal surfacesspaced from the lsegments in, one position land. .embracing the exterior ,of- .the segmentscin another .position to vhold the. seg ments againstoutward ilexing, said control means adapted ,to shift axially relative tothe barrel portion. vby ,forces incident to firing thegun, ratchetmeans for holding the control jmeans'in` a set position andy operable for sliding move-` mentbf .the control means Aupon firing -offthe gun. and adjustable limit means .-for limiting the slidingstroke of the-control. means, said adjust-p. able.` limit means. being,` adjustable 1. to; lock, the-f,

LEE H. WRIGHT.

REFERENCES CITED The following references are of record in the le of this patent:

Number i0 UNITED STATES' PATENTS Name Date Broyles July 10, 1900 Cory Dec. 10, 1901 Legett et al. L, Sept. 16, 1924 Pavek Aug. 31, 1926 Sedberry Oct. 25, 1938 Kitzmiller Jan. 20, 1942

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