US3812610A

US3812610A - Choke means

Info

Publication number: US3812610A
Application number: US00235498A
Authority: US
Inventors: J Kranz
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-17
Filing date: 1972-03-17
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28

Abstract

A tubular member having an arcuately diverging convex inner surface coaxially fitted over the arcuately diverging concave outer wall of a slotted portion of a gun barrel in longitudinal sliding engagement therewith for forcing the slotted portion of the gun barrel inwardly to vary the choke thereof and supporting the slotted portion of the gun barrel along substantially the entire length.

Description

0 United States Patent [191 [111 Kranz 1*May 28, 1974 CHOKE MEANS 1,508,605 9 1924 Legett et al 42/79 [76] Inventor: Jeremiah J. Kranz, 3620 Jefferson, et 42/79 Rapid y S. Dak. 57701 1 Notice: The portion of th te of thi Primary Examiner-Benjamin A. Borchelt patent subsequent to Sept. 20, Assistant Examiner-C. T. Jordan 1988, has been disclai i Attorney, Agent, or Firm-Merchant, Gould, Smith & 22 Filed: Mar. 17, 1972 Me N 2 ,498 [57] ABSTRACT A tubular member having an arcuately diverging con- [52] US. Cl. 42/79 Vex inner Surface coflxially fitted Over the arcuately [51] Int. Cl. F4lc 21/00 diverging Concave outer wall of a Slotted Portion of a 58 Field of Search 42/79 g barrel in longitudinal sliding engagement therewith for forcing the slotted portion of the gun barrel [56] R f r Cit d inwardly to vary the choke thereof and supporting the UNITED STATES PATENTS slotted portion of the gun barrel along substantially 653,613 7/1900 Brews... ..1 42 79 the enme h 685,669 10/1901 Broyles 42/79 4 Claims, 6 Drawing Figures 1 CHOKE MEANS 1. Field of the Invention This invention relates generally to shotguns and more particularly concerns those employing choke means.

2. Description of the Prior Art In the use of guns, such as shotguns and the like, it is often necessary to vary the choke or constrictuion of the muzzle to vary the shot pattern. It is especially desirable to be able to vary the choke of the muzzle when the gun is used for several different purposes, such as hunting'upland birds, small animals, ducks, trap and/or skeetshooting ete V 7 fi W i, if i g Many variable choke attachments have been devised in the prior art which are useful to alter the constriction of the muzzle of a gun barrel. In the most prominent of these an open-ended sleeve is provided with a tapered bore along a portion thereof, which taper extends in an even or straight line from the forward end of the sleeve to a mid-section thereof. Because the taper is angularly disposed with respect to the remainder of the sleeve and the outer diameter of the gun barrel, the sleeve does not support the gun barrel along the length of the sleeve during the use thereof. That is, only the muzzle of the gun barrel engages thertapered portion of the sleeve and portions of the gun barrel to the rear of the muzzle are unsupported by the sleeve. These unsupported portions of the gun barrel receive the initial shock of the shot passing through the barrel and, because they areunsupported, have a tendency to break after a relatively short period of usage, or develop a permanent constriction. My US. Pat. No. 3,605,313 solved this problem by providing means for supporting the slotted portion of the gun barrel along the length of the sleeve. The present invention also solves this problem but in a different manner.

SUMMARY OF THE INVENTION It is an object of of the present invention to provide a new and improved choke means for a gun barrel. The present invention pertains to improved choke means including a tubular member having a longitudinally extending arcuately diverging convex inner surface for slidably engaging a longitudinally extending arcuately diverging concave surface of a slotted portion at the end of a gun barrel for varying the choke thereof and supporting theentire constricted portion of the gun barrel. I

BRIEF DESCRIPTION OF THE DRAWINGS Referring tov the drawings, wherein like characters indicate like parts throughout the figures:

FIG. 1 is a view in side elevation of a portion of a 4 shotgun having the; present choke means installed FIG. 6 is an enlarged sectional view as seen from the line 6-6 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT -.stricting position and the slotted portion'of the barrel 11 will converge in a smooth are along the inside of the barrel.

The barrel 11 has an inner wall 15 with a uniform diameter and an outer wall 16 having a surface 17 which is diverging from a first location 18 longitudinally to the muzzle 14. The diverging surface 17 diverges arcuately over this distance in a generally concave configuration.

- The barrel 11 has a tubular member 19 slidably engaged thereover so that the tubular member 19 overlies the slots 13 in the muzzle 14. The tubular member 19 has an inner diameter at a first location 20 that is slightly larger than the outer diameter of the barrel 11 at the barrels location 18. The inner wall of the tubular member'l9 has a surface 21 which is arcuately'diverging from location 20 longitudinally to a second location 22 at the furthermost end of the tubuIar member 19. The arcuately diverging surface 21 forms a convex surface over this longitudinal distance. The distance from location 20 to the location 22 is approximately equal to the length ofthe slots 13.

The tubular member 19 is engageable over the barrel 11 and can be moved to a first position shown in FIG. 3 for providing no choking action to the muzzle 14. However, the inner diameter of the tubular member 19 at location 18 is sufficient to urge the slotted portion of the barrel 11 into a maximum desired choke or constricted position with the tubular member in a second position illustrated in FIG. 4.

When the tubular member 19 is positioned with respect to the barrel 11 so that the first location 20 on the inner wall of the tubular member is proximate the first location 18 on the outer wall of the gun barrel 11, the diverging inner surface 21 on the tubular member 19 blends smoothly with the diverging outer surface 17 on the gun barrel 11 to form a continuous, smooth surface. That is', the curve of the arcuate surface 21 is formed substantially similar to the curve of the arcuate surface 17 of the slotted portion of the barrel 1] when the muzzle 14 is in an unchoked or unconstricted position. As the tubular member l9 is moved outwardly intopositions of lesser overlying engagement with the barrel 1], and the-muzzle 14 is urged into more constricting positions, the slotted portion of the barrel l1 follows the curve of the arcuate surface 21 in the tubular member 19 so as to lie in juxtaposition to the surface of the inner wall of the tubular member l9 thus supporting the entire constricted portion 17 of'the gun barrel 11. Normally, slotting and bending the end of the barrel 11 greatly weakens the barrel 11 and causes eventual breaking thereof. However, since the slotted portion of the barrel 11 is supported along its entire length by the tubular member 19 the tendency toward eventual breakage is greatly reduced, if not eliminated. Also, there is little or no tendency for the slotted portion to develop a permanent choke or constriction.

The forwardmost end of a connecting member is affixed to the underside of the tubular member 19 and the rear end thereof is bifurcated with a part or branch thereof extending for a short distance on both sides of and parallel with the magazine 12. A handle 26 is affixed to the branches of the connecting member 25 so as to be slidably engaged over the magazine 12 adjacent the forward end thereof. In the present disclosure the shotgun 10 is a pump-action type having an action slide handle 27 slidably engaged over the magazine 12. The handle 26 must be engaged over the magazine 12 so as not to interfere with the operation of the action slide handle 27. In instances where the gun is a type having a stationary fore arm the handle 26 can be incorporated in the fore arm so as to form a portion thereof if desired while allowing the required amount of longitudinal movement. In the present embodiment six screws 28, three on either side, affix the handle 26 to the branches of the connecting member 25. A slot 29 is formed in the lower surface of the handle 26 and a stop member 30 is threadedly engaged in the magazine 12 so as to extend into the slot 29 and limit the longitudinal movement of the handle 26 and; consequently, the tubular member 19.

In the present shotgun 10 a ring is affixed to the under side of the barrel 11 in a spaced apart relationship, by means of webbing 36 welded to the barrel 11. The ring 35 receives the forward end of the magazine 12 therein and aids in maintaining the magazine 12 in the desired position beneath the barrel 11. For purposes of forming a detent, to maintain the tubular member 19 at the desired longitudinal position, a hole 38 is formed transversely through the webbing 36. The hole 38 is somewhat diminished in diameter adjacent one end 39 thereof and is provided with internal threads adjacent the other end 40 thereof. A ball 41, spring 42 and screw 43 are engaged in the hole 38, in the order set forth, to form the detent. The diameter of the ball 41 is such that it extends outwardly from the one end 39 of the hole 38 but cannot pass completely therethrough. The inner surface of one of the branches of the connecting member 25 isdimpled at 45 (see FIG. 6) to receive the outwardly projecting portion of the ball 41 therein and provide the detent action. Thus, the detent action maintains the tubular member 19 in substantially any desired longitudinal position.

The illustrated and described embodiment is utilized for its simplicity and it should be understood that many modifications and improvements can be incorporated in the desired choke means. Further, the device can be incorporated in many different types of guns in which choking or constricting of the barrel is desirable. Also;

the means for moving and holding the tubular member 19 in the desired position is only exemplary and many modifications and improvements can be incorporated therein. Thus, an improved choke means is disclosed which greatly increases the life and efficiency of the choke and greatly decreases the possibility of permanently damaging the barrel of the gun on which it is installed.

What is claimed is: 1. Improved chokemeans, comprising: a. a gun barrel having a plurality of circumferentially spaced, longitudinally extending slots forming a slotted portion therein adjacent the muzzle thereof;

b. said gun barrel having an inner wall with a uniform diameter and an outer wall having a longitudinally extending arcuately diverging concave surface from a first location to said muzzle;

c. a tubular member having an inner wall with a diameter at a first location slightly larger than the outer diameter of said gun barrel at said gun barrels first location;

d. said inner wall of said tubular member having a longitudinally extending arcuately diverging convex surface extending from said inner wall first location to a second location;

e. said tubular member slidably engaging said gun barrel in at least a partially overlying relationship; and

f. said tubular member being movable with respect to said gun barrel between a first position in which said first location at said inner wall of said tubular member is proximate said first location on said gun barrel and said second location is proximate said muzzle to support said muzzle in a substantially unconstricted position, and a second position in which said tubular member inner wall second location is outward of said muzzle so that said tubular member urges said slotted portion of said gun barrel radially inwardly to a constricted position while providing support for said gun barrel slotted portion along the length thereof.

2. Improved choke means as set forth in claim 1 including means attached to the tubular member for moving said tubular member between the constricting and unconstricting positions and for maintaining said tubular member in the desired one of said positions.

3. Improved choke means as set forth in claim 1 wherein the gun barrel arcuate surface extends longitudinally a distance approximately equal to the length of the longitudinal slots in the gun barrel.

4. Improved choke means as set forth in claim 1 including means for providing the tubular member with a plurality of positions relative to the gun barrel so as to render the choke means variable.

Claims

1. Improved choke means, comprising: a. a gun barrel having a plurality of circumferentially spaced, longitudinally extending slots forming a slotted portion therein adjacent the muzzle thereof; b. said gun barrel having an inner wall with a uniform diameter and an outer wall having a longitudinally extending arcuately diverging concave surface from a first location to said muzzle; c. a tubular member having an inner wall with a diameter at a first location slightly larger than the outer diameter of said gun barrel at said gun barrel''s first location; d. said inner wall of said tubular member having a longitudinally extending arcuately diverging convex surface extending from said inner wall first location to a second location; e. said tubular member slidably engaging said gun barrel in at least a partially overlying relationship; and f. said tubular member being movable with respect to said gun barrel between a first position in which said first location at said inner wall of said tubular member is proximate said first location on said gun barrel and said second location is proximate said muzzle to support said muzzle in a substantially unconstricted position, and a second position in which said tubular member inner wall second location is outward of said muzzle so that said tubulAr member urges said slotted portion of said gun barrel radially inwardly to a constricted position while providing support for said gun barrel slotted portion along the length thereof.