US2512850A - Pattern control means for shotguns - Google Patents

Description

June 27, 1950 G, B, CRANDALL 2,512,850

PATTERN CONTROL MEANS FOR SHOTGUNS Filed sept. 5, 1947 Y INVENro @..CQANDLL Patented June 27, 1956 p 2,512,850. i PATTERN CONTROL MEAN-s Foitsrl*Po'rdn1\1sfv Gladstone Blakeorandan. vvqqdstoek. Ontario, Canada- Application September 5, 1947; Serialil Noz' '77254135 2 Glaims.V (Cl. 42h-i791) .invention relates.to.shot pattern control means'for-shotguns.

Knownpattern control devices for shotguns are obtainable: in @various sizes as attachments which maybathreaded onto the end of thebarrel of the rearm to control the -distribution of the shot andwimprovewthe` target pattern. A .full choke, which is anattachmen-t having a final restricted bore,:will vcause between.75% and 80% ofthe shot to be distributed. within a 30.3-inch. circle at a distance of 40 to 50 yards. A modied. choke ,will give =a 65% distribution and an improved cylinder, whichractually, has .nolrestrictionat all .but is merelya continuation ofthe true diameter of the boreof the; gun, .will give a 50% pattern. A serious.:disadvantage, however, attends the use :of chokesqinthat .a sharp muzzle blast is experi-y enced vwhich is annoying not only. to the iirer but to'fellow sportsmenstandingnearby.

Compensatorshave been. provided. which have ventggholesallowing some of the. gases to escape before thefshot leaves theY mouth .of thechoke, but,

inleveryjnstance., such vent holes` are for the purpose Q f reducingf recoil or kick and serve actually to aggravatethe annoyance to a by-stander due largelyto the directing of the gases to either sideaof .thefmuZZleQ Conventional compensators and-...chokesiareconsidered as very noisy .attache ments and although used widely in order ,to ob.- tain an improvedpattern with less. recoil, they are. `.used ispiteiof the, disadvantage of .discom-V fort not only ,toxthe iirerof theweapon butto by-standers;

It is the .particular object of the present inventionzto .provide improved. attachments for` shotgunscwhich includea vent piece in which the vents yarein .theform .of aY plurality. of axial slots of l considerable ,length :which are adapted. to allow escape of the. gases and dissipation of `the same to reducemuzzle blast.v

Anotheraobject-of the invention is to provide attachments. asrbefore including a vent piece in which the slots due-.to their ksubstantial length, allow the. gases to proceed in a forward direction due to their momentum so that blast noise will notfbe: directed either'b'ackvtowards the frer or tofeitherside. in the direction of by-standers.

A further-object: of ther invention is to .provide attachmentsrfor Shotguns including a vent piece in :which-the'. surfaces of the bore mate Withthe bore'surfaces of thegun barrel to conne-the shot in the desired manner` and yet allow escape of gases: through theventswhich are of such awidth that thezshot will -`notlpass therethrough.

A still Vfurther. object of the invention is to pro.

vide a lightbweightpattern control ydevice for-the muzzleof av shotgun barrel which'is formed-'substanti'all-y of a simpletubelhaving .longitudinalslcts .in parallelly spaced apart radial relation-extending longitudinally over a substantial-portion thereof to vallow the escape of .propellent'gases-in a forward direction*under` their ownv momentum without undu-lyrinipeding'the latter in their for- Ward-movement. I

. A still further objectof 4the-invention is to'pro-I vide attachmentsfor Shotguns comprising a vent pieceand a pattern tube designed to'be attached thereto forr Skeet shooting` .in particular in `which the entry dimensionsof the bore of the skeettube arein excess of the exit dimensions of-thefbore of the. .vent piece-and. the-barreloflthecguntto which the vent piece is attached;

A still further .object of the invention -is to =pro vide Aa vent piece and Apattern tubes. therefore which have'an entry bore lof the sameldiameter as the bore. of the gun to .which thevent pieeeais attachedythe. said `pattern tubes having constricted bores .to-l substantially. conform with:v chokes of various 4characteristics .and sizes.

With these and# other objectsvin view, the vin-H vention generally comprises a light :Weight vpattern control .device formed from. a 'thin .Wall tubular body having a continuous and uniform .innen-bore diameter vequal to the diameter of the muzzle-bore of the'shotgun barrelvto. which the device is designedtmbeattached. '.Vent meansin the form of longitudinally extending slots are provided in the` tubular body of such width that the smallest shot cannotpass therethrough exteriorly of the body. These .vents are of such length that shot or propellent gasesareallowed to exhaust underv their. own momentum vforwardly without'inate-I rially kvimpeding'their forward direction :of move# ment..

An alternative includes in the combination :a pattern tube which may be integrally formed with fthe .tubular body. and which determines initial shot distributiomvIn this connection the entry bore of the pattern tube must` be .of a di-i ameter equal` to .thesdiameter of the. borezoi Athe* tubularbody.

Another alternativeconcerns. the provision of an alternative form oi pattern tube particularly adapted for Skeet shooting and having a pattern controlling bore the diameter of which is greater than the diameter of thebore of the tubular body.y This modication includes enlarged vents insthe pattern tube designed to substantially completev the; exhaust of gases and being. ofa length less.

than the distancebetweenvthe entryof itsbore and the point of engagement of shot with the walls thereof.

Other objects of the invention will be apparent from a study of the following specification taken in conjunction with the accompanying drawings.

In the drawings,

Figure 1 is a sectional view of pattern control means according to my invention showing a Vent piece mounted on the muzzle end of a conventional shotgun barrel and in turn mounting a pattern tube in the form of a choke of improved type.

Figure 2 is an illustrative diagrammatic view of walls of the gun barrel and pattern control means of Figure 1 indicating gases escaping from the vents of the vent piece and further indicating the effect of the bore restriction of the pattern tube on shot moving through the bores and shown at two locations therein.

Figure 3 is a sectional view of a modified form f of pattern control means showing a vent piece as in Figure 1 by mounting a pattern tube of distinctive design, which I recommend for skeet shooting and the like being therefore known as a skeet tube and having vents of particular characteristics.

Figure 4 is a diagrammatic illustrative view of the walls of the bores of the pattern control means and gun barrel of Figure 3 showing gases escaping from the vents of the vent piece and the skeet tube, and showing the effect of the enlarged bore of the skeet tube on the distribution of shot by illustrating two positions of shot in the bores.

YFigure 5 is a' sectional view of pattern control means equivalen-t to that disclosed in Figure 1 by illustrating that the two components, that is to say, thevent piece and the pattern tube, may be formed in one piece if desired.

Referring tothe drawings and particularly to Figure 1, pattern control means according to my invention are shown, and comprise generally a vent ,piece IU and a pattern tube II. The vent piece I0 is threaded internally for mating with threads I2 on the muzzle end I3 of a conventional shotgun barrel I4. The other end of the'vent piece I0 is designed for mating with threads I5 on the entry end I6 of the pattern tube II.

The vent piece in the body portion I1 between its ends has a pluralitytof vents I8 (preferably 12 in number) which extend over a major portion of the muzzle I3 and entry end I6 of the pattern tube I I. Vents I8 according to my invention, must be'of a width which is less than the smallest diameter of shot for which it is to be used. Therefore, as a ball of shot passes through the bore I9 of the body I1, each ball of shot will not tend to pass through the slots I8, but the latter serveto provide a means of exhausting the gases before the shot enters into the pattern tube II. cordance with the invention, the walls of the body I1 are comparatively thin, that is to say, their thickness is comparable with the thickness of the walls of the muzzle end I3 of the shotgun barrel I4.r It will be noted that the bore I9 of the body I1 is continuous and uniform in diameter and equal to the diameter of the bore of the muzzle end I3 of the shotgun barrel I4 as illustrated in all forms, that is to say, the forms of Figure 1, Figure 3,-and Figure 5.

`I prefer tosupply at least three pattern tubes to the sportsman which would substantially correspond to conventional chokes. An improvement, however, will be evident in that the entry end I6 of the bore 20 of the patterntube` II has its surfaces meeting or in line with the surfaces arbore' I9 of the vent piece I0` The bore 28 is lio restricted towards the muzzle end 2| in accordance with the amount of choking required, that is, full choke, medium choke, or the improved cylinder type of bore which has no restriction whatever.

Referring to Figure 2, the effect of my pattern control means will readily be appreciated. The walls of the bores of the barrel I4, vent piece I0 and pattern tube I I are `represented by the lines 22, the chain lines 23 indicating that openings or vents I8 are located in this region which is vbounded by the right angular lines 24 and 25. u Terminal lines 26 indicate the muzzle end 2| of the pattern tube I I. The irregular hatched areas 21 and 21a illustrate the two positions of a charge of shot as it proceeds through the bores 21 indicating that the shot is relatively undisturbed by the exhaust of gases (indicated by lines 28) forwardly through the vents I8. It is important to note that due to the considerable length of the vents I8 that the gases are allowed to proceed substantially in the direction of their momentum, that is, forwardly. The shot will proceed through into the pattern tube and be restricted diametrically to distribute the charge in a more longitudinal manner as at 21a, so that it is Well packed and concentrated before it leaves the muzzle terminal points 26. The amount of restriction in the bore of the pattern tube I I will, of course, determine the nal distribution in the pattern of shot at a target. i In the sport of skeet shooting in particular, muzzle blast from conventional types of chokes is excessive and usually annoying to bystanders. I, therefore, provide a particular design of pattern tube 29 shown in Figure 3 which may be mounted on the vent piece I0. This specific embodiment of pattern tube hereinbefore referred to as a Skeet tube has an enlarged cylindrical bore 30 of a dimensi-on in excess of the diameter of the bore I9 of the vent piece I0. Enlarged ventsf3I (preferably six in number) are provided to allow a iinal exhaust of gases before the charge (not shown) leaves the muzzle end 32 of the skeet tube 29. The

skeet tube has an entry end 33 having a borev 34 designed for mating with the bore I9 of the vent piece I0. This entry end also carries threads 35 for mating fixture with the Vent piece substanmeansl corresponding to the elements shownin' Figure 1. vIn this case, however, it will be observed .that lines 36 represent the enlarged bore 30 of the skeettube 29 and then 'chain lines31 represent vents13I and terminal lines .38 the muzzle end 32. Here the shot. 21Y proceedstoward the skeet tube k29 confined as before-but upon reaching the enlarged bore of this'latt'er tube'it spreads out as indicated by lines 39 and engages Vthe walls of the bore 36 at a point more clearly indicatedby numeral 40 in Figure 3, the ball of the shot substantially following the path Y. Gases which have not been exhausted through the vents I8 of vvent piecel I0 willbe exhausted through vents 3I as indicatedby lines 4I, being moved forwardly as indicated by the I0. passed the vents 3l, showing its spreading to meet the walls 36 of the bore of the skeet tube and being substantially undisturbed insofar as the distribution of shot in the charge is concerned. As a result, therefore, the shot 2lb will be expelled from the muzzle 32 of the skeet tube 29v substantially by its own momentum, maximum control on the distribution of a shot being thereby accomplished by the muzzle end surfaces of the bore 30. A further advantage is that muzzle blast is substantially obviated as regards bystanders since the gases proceed forwardly as described, those gases which do pass out of the vents of the Skeet tube being of relatively small volume as compared with the volume of gases passing out the vents IS. Vents 3l are preferably very large and may be of a width greatly in excess of the balls of shot proceeding through the bore 30 in order to allow as quick an exhaustion of the remaining gases as possible so that the distribution in the charge 2lb will remain substantially in effect by these gases.

Figure 5 is included merely to illustrate that the pattern control means of my invention may be incorporated in one unit if desired, in which case the device is comprised of a body 42 having a bore 43 of the same diameter as the bore of the gun barrel i4. A plurality of vents 44 are provided which substantially correspond to vents i8 of Figure l having the same characteristics. The muzzle end @5 of this device is formed integrally with the body 42 and has a restricted bore 16 substantially as indicated and corresponding to the restriction necessary for various choking eiects, one end of this combined Vent piece and pattern tube is designed for mating with threads I2 on the muzzle end i3 of barrel l. It will be appreciated, of course, that the skeet tube and vent piece of Figure 3 may be made in one piece in a similar manner. An example of an obvious additive feature is illustrated in Figure 1 Where a sighting bead 41 mounted in a sighting mount 48 is fastened into the body l1 of the vent piece I0 by the lug 49. Experiment with the pattern control means of Figure 1, in particular, has shown an improvement over the pattern distribution obtainable with standard chokes of a further ten per cent concentration with the different pattern tubes.

-The specific design of Skeet tube shown has proved capable of placing substantially ninety per cent of the shot within a thirty-inch circle at twenty-five yards as compared with roughly sixty per cent within the circle under similar conditions with former types of chokes normally used in skeet shooting. A particular advantage derives from confining the bores of the attachments described to an entry dimension which corresponds to the dimension of the bore of the gun barrel I4 since the shot will be conlned as it travels through these bores and the wadding or packing will not wobble to disturb the distribution of the shot on the iinal target. Many obvious modications will be apparent to gun makers apart from the specic embodiments described and, therefore, it is intended that the present disclosure should not be construed as limiting in any way other than that indicated by the scope of the following claims.

What I claim as my invention is:

1. A light weight shot pattern control device for the muzzle of a shotgun barrel, comprising, a vent piece in the form of a tubular body having a continuous and uniform bore of a diameter said tubular body having walls substantially equal in thickness to the thickness of the walls of the shotgun barrel at the muzzle end, and pattern controlling means comprising a pattern tube extending from the other end of said body designed to determine distribution of shot by controlling the latter as they pass therethrough substantially under the influence of their momentum alone, said pattern tube having a pattern controlling bore of a diameter greater than the diameter of the bore oi said tubular body and a plurality of radially positioned parallelly spaced apart longitudinally extending slots forming Vent means in said pattern tube.

Csi

2. A light Weight shot pattern control device for the muzzle of a shotgun barrel, comprising, a vent piece in the form of a tubular body having a continuous and uniform bore of a diameter equal to the diameter of a muzzle bore of the shotgun barrel, means for fastening one end of said tubular body to the muzzle of the shotgun barrel and providing alignment of the bore of said body with the bore of the muzzle of the shotgun barrel, said body having a plurality of radially positioned parallelly spaced apart longitudinally extending slots forming vent means for allowing the exhaust of propellent gases from the bore thereof exteriorly and forwardly of said body, said tubular body having walls substantially equal in thickness to the thickness of the walls of the shotgun barrel at the muzzle end, pattern controlling means comprising a pattern tube extending from the other end of said body designed to determine distribution of shot by .controlling the latter as they pass therethrough substantially under the influence of their momentum alone, said pattern tube having a pattern controlling bore of a diameter greater than the diameter of the bore of said tubular body, and a plurality of radially positioned parallelly spaced apart longitudinally extending slots forming vent means in said pattern tube, the vent slots of the latter being wider than the diameter of shot propelled through said pattern tube and extending in longitudinal dimension a distance less than the distance from the entry end of said pattern tube to the point of engagement of shot with the surfaces of the bore of said pattern tube.

GLADSTONE BLAKE CRANDALL.

REFERENCES CTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 85,949 McKenzie Jan. 19, 1869 618,901 Peterson Feb. '7, 1899 1,598,360 Pavek Aug. 31, 1926 2,098,617 Cutts Nov. 9, 1937 2,115,028 Logan Apr. 26, 1938 2,428,232 Limon Sept. 30, 1947 2,442,899 McAllister June 8, 1948

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