US2731754A - Adjustable choke for double barreled shotguns - Google Patents

Description

c. M. GIBSON 2,731,754

ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 1950 5 Sheets-Sheet l I II! 111 IIQ U Jan. 24, 1956 Filed Feb. 23,

Jan. 24. 1956 c. M. GIBSON 2,731,754

ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS Filed Feb. 25, 1950 5 Sheets-Sheet 2 b gwue/wbom CZ 705 M 6/550 C. M. GIBSON Jan. 24, 1956 ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 5 Sheets-Sheet 3 Filed Feb. 25, 1950 CL YDE r7. G/sso/v,

C. M. GIBSON Jan. 24, 1956 ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 5 Sheets-Sheet 4 Filed Feb. 25, 1950 Wow,

Jan. 24, 1956 c. M. GIBSON ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS 5 Sheets-Sheet 5 Filed Feb. 23, 1950 IN V EN TOR. CA 705 f7. a/aso/v,

United States Patent ADJUSTABLE CHOKE FOR DOUBLE BARRELED SHOTGUNS Clyde M. Gibson, Huntington, W. Va. Application February 23, 1950, Serial No. 145,818

2 Claims. (Cl. 42-79) Another object of this inventoin is to provide an ad justable choke device for use with double barreled shotguns, and including removable choke sleeve members for each shotgun barrel which may be readily removed and replaced independently of each other without removing the entire choke assembly from the muzzle end of the gun. This permits part of the assembly to be formed integrally with the gun barrels, if desired.

Further objects and advantages of this invention will be apparent upon reference to the following specification,

taken in conjunction with the accompanying drawings,

in which:

Fig. 1 is a top plan view of the muzzle end of a double barreled shotgun provided with the choke assembly of this invention;

Fig. 2 is a horizontal sectional view similar to Fig. 1, but showing in partial elevation the choke adjusting members and a key device adapted to actuate individually the choke adjusting members;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 1; i

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 1;

Fig. 5 is a front end elevational view of the muzzle end and choke assembly shown in Figures 14; a

Fig. 6 is a fragmentary bottom plan view ofthe muzzle end and choke assembly shown in the preceding figures;

Fig. 7 is a top plan view partly in section of a modified form of choke assembly, part of which is formed integral with the barrels of a double barreled shotgun;

Fig. 8 is a transverse sectional view taken on line 88 of Fig. 7; V

Fig. 9 is a bottom view of the gun barrel and choke assembly taken in the vicinity of line 8-8 of Fig. 7;

Fig. 10 is a fragmentary vertical sectional view taken on line 1010 of Fig. 7 to show the gun sight in the top of the choke assembly for removably securing the cam retainer pin of the choke adjusting members;

Fig. 11 is a top plan view of another modified adjustable choke arrangement;

Fig. 12 is a front elevational view of the construction shown in Fig. 11;

Fig. 13 is a longitudinal sectional view taken on line Iii-13 of Fig. 12;

Fig. 14 is a top plan view similar to Fig. 11 with a portion of the upper part of the housing for the choke adjusting members broken away; and

Fig. 15 is a front elevational View of the construction shown in Fig. 14.

Referring to Figures 1-6 of the drawings, the muzzle ends of the shotgun barrels are shown at 10 and 11 and are provided with a suitably shaped housing 12 which slides over the muzzle ends of the gun barrels, and has a pair of internal bores adapted to be aligned with and to form continuations of the gun barrel bores, but having larger internal diameters than said bores. The bores of the housing receive the adjustable and removable choke sleeves 13 and 14 for the respective gun barrels 10 and 11. The supporting sleeve 12 is secured to the muzzle end of the shotgun by a suitable number of pins 15 and 16 extending through the adjacent walls 17 and 18 of the shotgun. Instead of attaching the supporting sleeve 12 with the pins 15 and 16 as shown, the supporting sleeve section may be secured to the muzzle end of the shotgun by sweating on, by the use of solder, or by screws placed radially about the supporting sleeve 12 so as to grip the muzzle ends of the barrels. In another embodiment of the invention to be described, the sleeve section is formed integrally with the muzzle ends of the shotgun barrels.

The removable and adjustable choke sleeves 13 and 14 are received within the enlarged bores of the supporting sleeve member 12 with the rear end of each sleeve abutting the front end surface of one of the gun barrels 10 and 11. The choke sleeves are removably secured in place by a removable pin 20 extending centrally downwardly through the supporting sleeve section 12 and through correspondingly located slots or notches 21 and 22 in the central adjoining wall portions of the choke sleeves 13 and 14. The pin 29 is provided with a shouldered head 23 as more clearly shown in Figs. 3 and 4 and is cut away at 24 and 25 to conform to the inside shapes and diameters of the choke sleeves. The pin Zil may be retained in the choke sleeve securing position by a set screw 26 engaging a notch in the countersunk portion of head 23 and threaded into the fiat central upper portion 27 of sleeve 12.

The removable and adjustable choke sleeves 13 and 14 are identical, since they are to be used with identical twin barrels of a shotgun. Each sleeve, as in the case of choke sleeve 14, is provided with a plurality of longitudinal slots 23 extending rearwardly from the forward end of the choke. A circumferential groove 29 may be provided on the outside periphery of the choke sleeve in a radial plane adjacent the ends of the slots 28 to provide a weakened zone so that the slotted ends of the choke sleeve will assume a relatively straight taper beginning at the plane of the groove 2?. The forward end of each choke sleeve 13, 14 is also provided with an external beveled cam surface 30 which is adapted to cooperate with a complementary beveled cam surface on the choke adjusting member to be described hereinafter in a manner to cause contraction or permit expansion of the choke.

The adjustable choke sleeves 13 and 14 each operate in conjunction with one of the choke adjusting cam members 35 and 36, which match sleeves 13 and 14 in their inner and outer diameters. Each choke adjusting cam member, as in the case of member 36, is provided with a beveled cam surface 37 to fit about and cooperate with the beveled cam surface 39 of the corresponding choke sleeve 13, 1d. The front end of each choke adjusting cam member 35, 36 is provided with a notch 38 to cooperate with the pin 39 of a removable choke adjusting key 40.

The choke adjusting cam members 35 and 36 are retained within the supporting housing 12 by a removable cam retaining pin 41 which may, if desired, be provided on its upper end with an integral front gunsight 42. The cam pin 41 is held in place by a set screw 45 and extends through upper portion 27 of sleeve 12 into cam grooves 43 and 44 in the adjoining walls of the choke adjusting members 35 and 36. These grooves are spirally arranged as shown, so that when one of the members 35 or 36 is rotated, it will bemoved forwardly or rearwardly, depending upon the direction of rotation, to contract or permit expansion of the forward end of the choke sleeve 13 or 14 with which it cooperates. It is desirable that one complete revolution of members 35 and 36 will move these members through the entire range of adjustments. It is clear that the engagement of the beveled cam surfaces 30 and 37 at the adjoining ends of the choke sleeves and choke adjusting members cause contraction of sleeves 13, 14 upon rearward movement of members 35, 36, while forward movement of these adjusting members permits the natural resilience of sleeves 13 and 14 to open the forward slotted ends of these sleeves.

In order to prevent accidental or unauthorized rotation of the choke adjusting cam members 35 and 36, they are provided with a plurality of peripheral detent receiving depressions 46 (Figs. and 6) adapted to cooperate with a pair of spring pressed detent balls 47 and 48. The detent balls 47 and 4-3 are held in place by a spring clip 49 mounted by a screw on the lower surface of sleeve 12.

Key 40 has a knurled grip 41a, a central portion 41b bearing markings, and a smaller rear end portion adapted to be inserted in either choke adjusting member 35 or 36. Projection 39 on the key 40 is dimensioned to engage slots 38 so as to rotate the choke member and adjust the choke of either gun barrel independently of the other.

In order to remove either of the choke sleeves 13 or 14 it is only necessary to unscrew the set screws 26 and 45 and withdraw the removable pins 20 and 41 which will thus permit the choke adjusting members 35 and 36, together with the choke sleeves 13 and 14 to be removed axially from the muzzle end of sleeve 12. The latter can be removed by taking out pins and 16.

Since the novel arrangement of removable choke sleeve as described above enables the ready removal of either or both chokes in a double barreled shotgun arrangement, it is also convenient to form the outer housing of the choke assembly integral with the shotgun barrels as shown in Figs. 7 through 10 of the drawings. The muzzle ends of the respective barrels 60 and 61 of a double barreled shotgun terminate at their forward ends in surfaces 59 and beyond these surfaces they are enlarged as at 62 to provide a supporting housing with twin enlarged cylindrical bores to receive removable adjustable choke sleeves 63 and 64, which are of similar construction to the choke sleeves 13 and 1 previously described. The choke sleeves 63 and 64 are retained in the sleeve supporting bores by a pin 65 passing through the upper and lower walls of the enlarged barrel portion 62 and through corresponding slots or notches in the adjoining walls of the choke sleeves. The central portion of the pin 65 is notched on each side to conform to the configurations of the choke bores in a manner similar to the pin previously described. In order to produce a more aesthetically desirable product, the pin 65 may be retained in place by a countersunk nut 66 at its lower end in the central bottom portion of the enlarged gun end section 62.

The choke sleeves 63 and 64 are adjusted by choke adjusting members 67 and 63 which are constructed and operate in the manner of the choke adjusting members 355 and 36 previously described. The adjusting members 67 and 63 are retained in place by the cam retaining pin 69 adapted to cooperate with spiral earn grooves in each adjusting member, such as the cam groove '76. The pin 69 may be countersunk in the top rib 7 2 and retained by the threaded gun sight member 73 which abuts the top shoulder surface of the pin 69.

In order to remove or replace either choke sleeve 63 or 64, it is only necessary to withdraw the pins 65 and 69 and slide the choke adjusting members 67 and 68 together with the choke sleeves 63 and 64 out of the enlarged bores at the front ends of the gun barrels. The adjustment of the choke sleeves .63 and .64, one at a time, is effected by an adjusting key similar to the key 40 pre viously described, the members 67 and 68 having notches 67 and 68' corresponding to notches 38 in the embodiment of Figs. 1-6. Spring detents, not shown, may also be provided to prevent accidental rotation of the choke adjusting members 67 and 68 in a manner similar to that shown in Figs. 4 and 6.

Figs. 11-13 show a modification of the invention in which sleeves 83, slotted at their forward ends at 86, are supported in supporting sleeve bores 87 by screw threads 88. This modification also differs in that the choke adjusting members 89 and 90 have a plurality of cam grooves 91 and the cam element 92, corresponding in function to elements 41 and 69, has a plurality of teeth 93 which lie in the grooves 91. The element 92 also is of different construction in that it has a rearwardly extending tongue 92a which fits into a depression 94, and through which passes a screw 95 having an enlarged head to serve as a sight.

In the embodiment shown in Figs. 14 and 15, the choke sleeves may be of any of the various types shown in the above described embodiments, and the choke of these sleeves is controlled by choke adjusting members 101, the forward portions of which have external square type threads 102. The forward end of the housing 103 surrounding the sleeves 100 and members 101 has matching internal threads 104 which are approximately half as deep as the height of threads 102. The threads 102 of the members 101 intermesh as shown in the drawings. Top and bottom ribs 105 and 106 are attached to housing 103 as by welding, soldering or other suitable means for reinforcement.

The embodiments which I have described thus provide constructions which are readily assembled and disassembled, and which, by a simple construction, permit the use of different choke settings on each barrel of a double barrelled shotgun. In this way, if desired, one barrel is ready for close in shooting, while the other is ready for longer range work. Or, if desired, both barrels may be set to the same choke setting, or to only slightly different settings.

I am fully aware that variations may be made in the devices which I have described and shown withou departing from the inventive concept, and it is my intention to cover all such variations falling within the scopes of the appended claims I claim:

1. A choke device for a double barreled shotgun, comprising a housing carried by the muzzle ends of the barrels, said housing having a pair of bores axially aligned with and forming continuations of the gun barrel bores, but having larger diameters than said gun barrel bores, a. pair of tubular choke sleeves mounted one in each bore of said housing, said choke sleeves having axially slotted forward wall portions and cam shaped forward end portions, means for retaining said choke sleeves in said housing, a pair of tubular cam members positioned one in each of said housing bores forwardly of said choke sleeves, said cam members having rear cam surfiaces cooperating with the cam shaped forward ends of said choke sleeves-so as to cause contraction of the forward portions of said choke sleeves on rearward movement of said cam members, a helical groove in each cam member, and an element located between said cam members and cooperating with .said helical grooves and with said housing for holding said cam members in said housing and for causing axial movement of the cam members when they are rotated.

2. An adjustable choke device for double barreled shotguns in which the barrels terminate at their muzzles in forward end surfaces, said device comprising a supporting housing carried by the barrels and extending beyond said forward end surfaces of the gun barrels, said supporting housing having a pair of bores aligned with 5 and forming continuations of the gun barrels, but of greater diameter than said gun barrels, said housing having at least one transverse wall, a pair of choke sleeves having longitudinally slotted forward end portions terminating in forward cam surfaces, said choke sleeve members being movably positioned one within each of the bores of said housing with the rear ends of the choke sleeves abutting the forward end surfaces of the respective gun barrels, said choke sleeves each having at least one opening in their side walls, at least one removable retaining pin passing between said choke sleeves to retain the choke sleeves in their respective supporting housing bores, said retaining pin extending through said transverse wall of said supporting housing and into said openings in the adjacent wall portions of said choke sleeves, and a pair of cam members positioned one in the muzzle end of each bore of said housing and cooperating with said cam surfaces to control the bore diameters of the longitudinally slotted ends of the choke sleeves, said cam members being tubular and each having a helical groove therein, and a cam member retaining pin extending through a transverse wall of said housing and into the cam grooves of said cam members, whereby said last mentioned retaining pin serves to hold said cam members in said housing and also serves, in (:0- operation with said cam grooves, to translate rotary movement of said cam members into axial movement of said cam members to cause changes in the choke of the corresponding choke sleeves References Cited in the file of this patent UNITED STATES PATENTS

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