US2663961A

US2663961A - Choke for gun barrels

Info

Publication number: US2663961A
Application number: US172456A
Authority: US
Inventors: White Madge Burnam; Hartford National Bank A Compa
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-07-07
Filing date: 1950-07-07
Publication date: 1953-12-29
Anticipated expiration: 1970-12-29

Description

Dec. 29, 1953 E. F. WHITE 2,663,961

CHOKE FOR GUN BARRELS Filed July 7, 1950 Bnventor Patented Dec. 29, 1953 CHOKE FOR GUN BARRELS F. White, deceased Application July 7, 1950, Serial No. 172,456

10 Claims. 3

This invention relates to a choking device for firearms such as shot guns and more particularly to an adjustable choke device which may be automatically adjusted in response to the firing of the gun.

A choking device for a gun serves to control the shot pattern of the gun and more particulariy the s read a the shot at any given d stance from the muzzle. It is, of course, desirable to employ a choking device which is adjustable so that variations between an unchoked condition and a fully choked condition may be provided depending on the type of game for which the gun is being used. Moreover, it is sometimes desirable to vary the degree of choking action at to provide for automatic adjustment of the choking device to further constrict the muzzle upon the firing of the first shot so that the proper choking effect will be obtained for the second shot.

A choke device of the general type described above is illustrated in the patent to Egleson No.

2,453,747, granted November 16, 1948, and it is contemplated by the present invention to provide a gun choke which is an improvement upon that shown in this patent.

As illustrated the present device comprises an extension applied to the gun muzzle, the extension being provided with, longitudinal slots extending through its free end and a constricting sleeve is threadingly mounted upon the extension, the extension and sleeve being provided with cooperating means so that rotation of the sleeve serves to restrict the extension and thereby choke the gun. The amount of constriction or degree of choke depends upon the threaded adjustment of the sleeve in a clockwise direction (when facing the gun muzzle) on the muzzle extension. Suitable projections are provided in spaced relation on the rear end of the sleeve to extend rearwardly therefrom and a stop member is provided on the extension to extend between and be engaged by these projections. This sto member is spring pressed into position to engage the extension but may be drawn to dis-engaging position against th tension of the spring and, when moved to such a position, the sleeve may be manually adjusted to any desired position. In practice this would be the position desired for the first shot to be made with the gun and upon the firing of this h t the s e ve Woui be r tated by the explosion gases so that the next adjacent projection would be engaged by th stop member and thus the sleeve would be moved to a position to effect a greater degree of choke for the second shot.

The projections on the sleeve are spaced apart to a sufficient extent to allow rotation of the sleeve through a sufficient angle to efiect the degree of diiference in choking efiect which would normally be desired between the first and second shots fired by the gun. At the same time sulTi-' cient of the projections are provided so that the device may be set at the desired choking position for the first shot depending upon the desire of the user. Thus, the device may be manually set for any desired choking effect (except, of course, full choke position) and at each of such settings would give the user substantially the same service as that given by a double-barreled gun, one barrel of which is constricted more than the other.

Also at the same time the device may be set to any adjusted position and prevented from moving from that position if a constant and uniform choking elfect is desired.

One object of the present invention is to provid a new and improved adjustable gun choke.

A further object of the invention is to provide a gun choke which may readily set and retained in any desired adjusted position and which may be moved from this position to a different predetermined adjustable position by the firing of the gun.

A still further object of the invention is to provide an improved gun choke consisting of a gun barrel extension and a sleeve rotatably mounted thereon to efiect constriction of the extension and cooperating means on the extension and sleeve to permit adjustmentof the sleeve to any desired position in which it will be held against accidental movement in one direction, but which will be left free for movement in the opposite direction by the expanding gases upon discharge of the gun.

A further object of the invention is to provide an adjustable choking device which may be moved from one position to another by the discharge of the gun and which shall be provided with improved means for releasably holding the parts in adjusted position.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of the muzzle end of a gun barrel having my improved choking device applied thereto;

Fig. 2 is a sectional view on line 2-2 of Fig. 1;

Fig. 3 is an elevational view of the muzzle extension of the device with the sleeve removed;

Figs. 4 and 5 are transverse sectional views on lines 4-d and 55 of Fig. 1, respectively;

Fig. 6 i a partial elevational view of the device showing the parts in one adjusted position; and

Fig. 7 is a view similar to Fig. 6 showing the parts in another position in which the sleeve is locked against movement responsive to the firing of the gun.

To illustrate a preferred embodiment of my invention, I have shown in Fig. 1 of the drawings the muzzle end of agun barrel ill to which is secured a shell or muzzle extension member II. This may be secured to the. barrel in any desired Way, such, for example, as by the screw threads It may be noted that the internal bore of the shell H as shown at i3 is slightly larger than the muzzle bore of the barrel IE] so as to permit a slight expansion of the explosion gases of the gun when this point is reached. At its forward portion the extension is provided with longitudinally extending slots it which open through the end of the extension and upon its exterior surface are provided annular cam surfaces It and i6 whereby, as will be hereinafter described, the extension may be constricted to effect various degrees of choking action.

A sleeve I6 is provided with internal screw threads 19 whereby it may be threadedly attached to the exterior screw threads 20 adjacent the rear portion of the shell or muzzle extension ll. Internally this sleeve is provided with annular cam surfaces 22 and which cooperate respectively with the cam surfaces l5 and 16 on the forward portion of the vmuzzle extension H so that as the sleeve is moved rearwardly by rotative engagement of the threads 19 and 2!) the forward portion of the muzzle extension may be constricted, the degree of constriction varying with the amount of rotation of the sleeve It in a clockwise direction when facing the muzzle of the gun, or in a direction to move the sleeve rearwardly upon the extension I I.- This constriction of the muzzle extension is permitted by the slots It as is well understood by those skilled in the art.

Upon the forward portion of the sleeve l8,is an enlarged chamber 24 which is constricted at its forward end to form an exit tube 25.

A plurality of longitudinally-extending slots 26 are provided in the chamber portion 24 of the sleeve. These slots extend through the wall of the sleeve at an angle to the radius of the chamber member, as shown in Fig. 5, so that when the explosion gases pass therethrough a torque will be imparted to the sleeve tending to rotate it in the direction of the arrow shown in Fig. 5 or in a direction tending to advance the sleeve upon the muzzle extension M. This rotation of the sleeve will be in a clockwise direction when looking toward the muzzle of the gun or in a direction tending to further constrict the sleeve member and thus provide a greater degree of choke.

Furthermore, it will be seen that the walls of the slots 25 are not parallel, but that the trailing wall is cut away or relieved as shown at 21 so that the expanding gases in passing through these slots will react with a greater force against the opposite edges and thus impart a greater turning torque to the sleeve topositively effect rotation thereof upon the muzzleextension in theproper direction to effect a greater degree of chokin action.

The non-radial direction of the slots provides vane-like segments 28 between adjacent slots and the direction of the arrow in Fig. 5 indicates the direction of rotation of the sleeve caused by the explosion gases issuing through the slots.

Upon the rear end of the sleeve l8 are provided nubs or projections 30 which project rearwardly from the sleeve along the exterior surface of the muzzle extension II. These projections are in spaced relation and while the number may be varied as desired, as shown six are employed and each is marked with a number or other indicia 3[ to indicate to the user the degree of choke provided by a particular setting of the sleeve.

Cooperating with these projections is a stop element secured to the muzzle extension as will now be described. The muzzle extension is provided with an arcuate recess or groove 32 shown more especially in Fig. 4 which extends around approximately three-fourths of the circumference of the extension. Within this slot is disposed a spring member 33 of arcuate shape. One end 34 of this spring member is turned inwardly in a radial direction and secured in an opening 35 in the body of the extension so that this end of the spring is anchored against movement. The other end of the spring is left free and is turned outwardly in a radial direction as shown at 3% and upon. this free end of. the spring is carried an adjusting button or fingerpiece 31.

The rear wall of. the groove 32 is relieved or cut back as shown at 39 and 4D in Fig. 3, providing a shoulder 4| upon the rear side of the groove. This permitsthe spring member 33 to be moved rearwardly at its free end, the sprin fulcruming about the shoulder 4| as shown in dotted lines in this figure.- It will be seen from Fig. 1

of the drawings that the free end 36 of the spring normally stands between the projections or nubs 30 and is engaged by these projections so as to limit the rotation of the sleeve with respect to the extension member I I. The operator, however, by pressing against the fingerpiece 31 may move the end portion 36 of the spring rearwardly against the tension of the spring to the dottedline position shown in Fig 3-in which the end 36 of'the spring clears the projections 30 and permits free rotation of the sleeve 18.

The operation of the device is as follows. The user,- by moving the fingerpiece 31 rearwardly to dotted-line position shown in Fig. 3, may then rotate the sleeve to the proper position to obtain any degree of choking action desired. If, for example, he desires only a small degree of choke, the sleeve is moved to the position shown in Fig. 6 where the projection numbered 1 is engaged with the end 36 of the spring, the latter being on the right-hand side of .this projection as shown in the sectional view of Fig. 4. The sleeve is prevented from moving to. the right from this position, or from moving in a direction which will provide a more open muzzle. It may, however, be moved to the left or in a direction to provide a greater degree of choke until the spring 36 is engaged with the next of the spaced projections 30 or that one marked with the numeral 2.

In practice, the user sets the sleeve in the manner just described to provide the proper choking efiect for the first shot to be fired. -When this shot has been fired, the explosion gases issuing through the slots 2'6 of the sleeve will act on the vanes 28 to rotate the sleeve in a counterclockwise direction, as shown in Fig. 4, the rotation being limited, however, by the engagement -of the upstanding end 36 of the spring 33 with the next projection 30 upon the sleeve. Thus, there is provided the next degree of choke for the second shot to be fired by the gun. It will be apparent that as shown, six different positions of the choking sleeve are provided and in each 'one of these positions except the last or fullchoke position, the sleeve will be moved by the discharge of the gun to the next higher position to give the next greater degree of choke.

If, however, it is not desired that the settin of the sleeve l8 be changed by the firing of the gun, the sleeve when set is moved to the position shown in Fig. '7 in which the end portion 36 of the spring 33 lies on the opposite side of the projection 39. This will prevent rotation of the sleeve by the explosion gases and as the sleeve is held by friction against rotation in the opposite direction, the degree of choke will be unchanged until the sleeve is reset by the user.

While I have shown and described a preferred embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. Choke mechanism for firearms comprising a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rotation of the sleeve member, said last-mentioned means comprising a projection on one of said members and a stop element on the other member angularly fixed with respect thereto and movable longitudinally of said members, and spring pressed into engagement with said projection.

2. Choke mechanism for firearms comprising a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rotation of the sleeve member, said last-mentioned means comprising a plurality of spaced projections on one of said members and a stop element carried by the other member movable longitudinally of said members and spring pressed into the spaces between said projections to engage the latter.

3. Choke mechanism for firearms comprising a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rota- 'tion of the sleeve member, said last-mentioned means comprising a plurality of spaced projections on one of s'aid'members and a stop element carried by the other member movable longitudinally of said members and spring pressed into the spaces between said projections to engage the latter, said spaces being larger than said stop element to permit limited rotation of the sleeve member. I r

4. Choke mechanism for firearms comprisin a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rotation' of the sleeve member, said last-mentioned means comprising a plurality of spaced projections on one of said members and a spring of arcuate shape secured at one end to the other member, the free end of the spring carrying a stop element movable longitudinally of said members and normally standing between said projections.

5. Choke mechanism for firearms comprising a constrictable split muzzle extension, a sleeve rotatably connected to said extension, cooperating means on said extensionand sleeve to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve, and cooperating means on said extension and sleeve to limit rotation of the sleeve, said last-mentioned means comprising a plurality of spaced rearwardly extending projections on the rear end of the sleeve and'a spring member of arcuate shape having one end secured to said extension, the other endof said spring member being free and carrying a stop element normally standing between said projections but being movable longitudinally of said sleeve to clear said projections to permit rotation of the sleeve.

6. Choke mechanism for firearms comprising a constrictable split muzzle extension, a sleeve rotatably connected to said extension, cooperating means on said extension and sleeve to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve, and cooperating means on said extension and sleeve to limit rotation of the sleeve, said last-mentioned means comprising a plurality of spaced rearwardly extending projections on the rear end of the sleeve and a spring member of arcuate shape having one end secured to said extension, the other end of said spring member being free and carrying a stop element normally standing between said projections but being movable longitudinally of said sleeve to clear said projections to permit rotation of the sleeve, said extension having an exterior groove therein in which said spring member lies.

7. Choke mechanism for firearms comprising a constrictable split muzzle extension, a sleeve rotatably connected to said extension, cooperating means on said extension and sleeve to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve, and cooperating means on said extension and sleeve to limit rotation of the sleeve, said last-mentioned means comprising a plurality of spaced rearwardly extending projections on the rear end of the sleeve and a spring member of arcuate shape having one end secured to said extension, the other end of said spring membeer being free and carrying a stop element normally standing between said. projections but being movable longitudinally of said sleeve to clear said projections to permit rotation of the sleeve, said extension having an exterior groove therein in which said spring member lies and wall of said groove being cut away to permit movement of the free end of the spring member.

8. Choke mechanism for firearms comprising a constrictable split muzzle extension, a sleeve rotatably connected to said extension, cooperating means on said extension and sleeve to constrict the former upon rotation of the latter, means re.- sponsive to discharge of the firearm for rotating said sleeve, and cooperating means on said extension and sleeve to limit rotation of the sleeve, said last-mentioned means comprising a plurality of spaced rearwardly extending projections on the rear end of the sleeve and a spring member of arcuate shape having one end secured to said extension and the other end of said spring being free and being turned outwardly in radial direction to constitute a, stop element normally standing between said projections, said stop element being movable longitudinally of said sleeve against the tension of th spring to position to clear said projections and permit rotation of the sleeve.

9. Choke mechanism for firearms comprising a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rotation of the sleeve member, said last-mentioned means comprising a plurality of spaced projectio s n o e f s d mem e s and. a in o arcuate shape secured at on end to the other member, the free end of the spring carryin a stop element movable longitudinally of said members and normally standing between said projections and the spacing of said projections being such with relation to the width of said step element that limited rotation of said sleeve member is permitted by said stop element to substantially vary the amount of constriction of the muzzle extension member.

10. Choke mechanism for firearms comprising a constrictable split muzzle extension member, a sleeve member rotatably connected to said extension member, cooperating means on said extension and sleeve members to constrict the former upon rotation of the latter, means responsive to discharge of the firearm for rotating said sleeve member, and cooperating means on said extension and sleeve members to limit rotation of the sleeve member, said last-mentioned means comprising a plurality of spaced means on one of said members and a stop element on the other member movable longitudinally of said members and spring pressed into engagement with said spaced means.

EZEKIEL F.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,892,522 White Dec. 27, 1932 2,453,747 Egleson Nov. 1.6, 1948 2,490,829 N011 Dec. 13, 1949 2,567,826 Prache Sept. 11, 1951 FOREIGN PATENTS Number Country Date 296,553 Germany Feb. 15, 1917