US3405638A - Tracer vehicle wad structure - Google Patents

Description

United States Patent TRACER VEHICLE WAD STRUCTURE James A. Stoner, Jr., 1670 Broadhead St., Pittsburgh, Pa. 15206 Continuation-impart of application Ser. No. 536,865, Mar. 23, 1966. This application Jan. 22, 1968, Ser.

16 Claims. (Cl. 102-87) ABSTRACT OF THE DISCLOSURE A wad structure to carry a tracer projectile in a shotshell consisting of a resiliently yieldable cylindrical sleeve having a yieldable tube coaxially mounted therein to provide an axial tracer projectile guidance bore and mounted on an over powder wad which has a central projectile seat exposed by the bore and an axial ignition passage which passes through the over powder wad and communicates with the seat. A bullet shaped tracer projectile is positioned on the seat and extends into the bore in tight engagement. When the shotshell is fired the pyrotechnic mixture in the trailing end of the projectile is ignited via the passage and the cylindrical sleeve is axially compressed to eject the projectile under resilient resistance from the bore in a trajectory central of the shot cloud.

Cross references This application is a continuation-in-part of application Ser. No. 536,865, filed Mar. 23, 1966, now abandoned.

Background of the invention This invention relates generally to shotshells with single tracer projectiles and more particularly to shotshell tracer vehicles.

Shooting at moving clay targets with a shotgun, such as in the sports known as skeet and trap, is becoming an increasingly popular sport with the public. The required skill in mastering this sport is the ability of the shooter to properly lead the moving target with his shotgun so that the moving target will run into the shot cloud fired from the gun. Both the amateur and seasoned shooter find it difiicult, time consuming and expensive in the long run to determine and correct their faults in attempting to hit the clay targets. This is especially so when each successive target is propelled at a different angle relative to the shooter from the preceding target. In an attempt to determine exactly how the shooter is incorrectly placing his fired shot cloud relative to the moving target, many shot gun shell tracer devices have been developed in the past, however with very dissappointing results.

Heretofore, single tracer projectiles for shotgun shells have proved impractical and unrealiable because the tracer projectile has not given a true representation of the trajectory of the shot pattern or cloud. The tracer projectile traveled either faster or slower than the shot cloud or did not stay centered in the shot pattern thus giving a false picture. In an attempt to overcome these disadvantages a tracer projectile was developed which had the same ballistic coefiicient as each shot pellet of the shot column loaded in the shell with the vehicle. The tracer projectile was loaded in with the pellets and an ignition passage was provided in order to ignite the pyrotechnic mixture contained in the projectile upon firing of the shell. Such a structure is shown in the US. patent to R. I. Cowles et al., No. 3,262,390. This was a step in the right direction, however no means was provided to keep the projectile in the center of the shot pattern with the result that the tracer projectile fell wide of the center mark in the pattern. Also because of the odd shape and large size of the projectile and the propulsion effect of the burning pyrotechnic mix- Patented Oct. 15, 1968 ture on such a body, the projectile still traveled at an unpredictable rate and in an unpredictable manner giving an un-uniform trajectory not compatible with that of the shot cloud.

Summary of the invention The tracer shotshell of the present invention employs a tracer vehicle wad structure consisting of a cylindrical sleeve which is yieldable in the axial direction at least on firing the shotshell. A tube of resiliently yieldable material is coaxially mounted in the sleeve and provides a projectile guidance bore therethrough. This unit is then mounted on top of the lift off or over powder wad which closes one end of the sleeve. The lift off wad is provided with a projectile seat on the center of the inside face such that it is exposed through the bore of the yieldable tube. An ignition passage is provided through the lift off wad and communicates the projectile seat with the propellant which underlies the over powder or lift olf wad to permit ignition of the pyrotechnic mixture in the trailing end of the tracer projectile, which is seated on the projectile seat, upon firing the shotshell.

The tracer projectile extends from its projectile seat into the guidance bore. The diameter of the projectile guidance bore is preferably slightly smaller than the largest diameter of the tracer projectile. The tube consists of a resiliently yieldable material which permits the projectile to slightly expand the tube. When the shotshell is fired, the cylindrical sleeve and the coaxial resilient guidance tube are compressed or buckled in the axial direction which forcibly ejects the tracer projectile from the resilient guidance bore into the shot cloud.

The fact that the resilient guidance tube is buckled or compressed upon ignition of the shotshell, does not effect the trajectory of the tracer vehicle. This is believed to be due to the fact that the resilient guidance tube springs back to its original form after firing. However if it is desired to reduce the amount by which the tube is axially compressed or buckled a clearance may be left between the inner face of the lift off wad and the adjacent end of the projectile guidance tube.

The tracer projectile may be fit in the guidance bore with a snug engagement with good results. However, it has been found that a tight fit is preferable whereby the resilient tube is slightly expanded by the tracer projectile. It is not completely understood what effect this resilient resistance of the guidance bore has on the tracer projectile as it is ejected therefrom. It is believed that this permits the projectile to be ejected from the guidance bore with greater initial velocity because a greater force would be required to move the projectile through the guidance bore than would be required with a mere snug bore fit.

The guidance tube is preferably mounted in the yieldable sleeve by an annular transverse wall which closes the opposite end of the sleeve from where the lift off wad engages the same. This annular wall provides a surface upon which the pellet column may rest.

A shot cup or receptacle consisting of a second cylindrical sleeve of flexible material, may be coaxially positioned in the shotshell adjacent the transverse annular wall to contain the pellets or shot column. This second cylindrical sleeve preferably consists of a plurality of arcuate sections or flaps formed by longitudinally extending slits which communicate with the open end of the second sleeve. Upon firing the shotshell these arcuate sections are permited to spread open by the resistance of the wind or air to permit the shot column to separate from the shot receptacle. It is another object of the present invention to provide a plurality of orifices of preselected number and size in the arcuate sections. Depending upon the size and number of these orifices, the air flow into the shot receptacle is metered through these orifices thereby providing a means to regulate the time required for the shot to' leave the shot receptacle. The advantage of this resides in the fact that the size of the shot cloud or pattern which reaches the target may be regulated. When employed with the tracer vehicle wad structure of the present invention, this insures that the tracer projectile will remain in the center of the shot column or cloudwhere very long shots or far off targets are encountered. However the shot receptacle of the present invention understandably has an application independent of the tracer shotshell described herein for the regulation of the shot pattern of any conventional shotshell.

Each of the combined elements of the tracer vehicle wad structure, with the exception of the lift off wad, may be integrally molded together as one unit from a resiliently yieldableamaterial suchas neoprene or any other suitable plastic. If it is desired to also integrally mold the lift off wad with the remainder of the wad structure as one complete unit, this may be accomplished by providing relatively large openings in the cylindrical wall of the yieldable cylindrical sleeve to permit the introduction and withdrawal of mold surfaces which would be necessary to provide the hollow interior between the yieldable cylindrical sleeve and the guidance tube when molding the wad structure.

It is another object of the present invention to provide a piston extension on the lift off wad which extends into engagement with the guidance bore of the guidance tube and which is also provided with the projectile seat on the end thereof to receive the trailing end of the tracer projectile. Such a piston provides stable projectile guidance and communication between the guidance bore and the lift off wad when relative movement is initiated therebetween upon firing the shotshell.

Another object of the present invention resides in the end face of the lift off wad, which engages the propellant or gun powder, having a frustoconical concave face which communicates with the axially positioned ignition passage adjacent the apex of the frustoconical surface. This frustoconical face is preferably provided with an apex angle of approximately 120 C. This frustoconical face permits the pellets to hit the target with greater impact; however, here again it is not understood why this surface in the lift off wad has such an effect or why greater velocity is imparted to the shot cloud.

The tracer projectile employed in the wad structure of the present invention is bullet shaped and therefore provides the added advantage of an undistorted trajectory path which is otherwise encountered by the spherical projectile normally employed with the Cowles et al. tracer vehicle which has a tail portion extending from the spherical main body of the projectile.

When the piston extension as described previously is not employed on the lift off wad, it is preferable to provide the projectile seat with a countersunk bore to receive the trailing portion of the projectile in snug engagement. This permits the projectile to be firmly maintained in an upright axial position upon firing the shotshell.

Other objects and advantages of this invention appear hereinafter in the following description and claims.

The accompanying drawings show for the purpose of exemplification without limiting this invention or the claims thereto, certain practical embodiments illustrating the principles of this invention wherein:

FIG. 1 is an axial longitudinal. sectional view in side elevation of the tracer vehicle Wad structure of the present invention.

FIG. 2 is a longitudinal sectional view in side elevation of a shotshell employing the tracer vehicle wad structure of FIG. 1 together with a tracer projectile.

'FIG. 3 is a longitudinal sectional view in side elevation of a tracer vehicle wad structure illustrating another embodiment of the present invention.

Referring to FIGS. 1 and 2, the outer enclosure of the shotshell 1 includes an elongated tubular casing 2 and a metal base 3 usually made of brass. The base 3 is secured to the'casing 2 by the'crimps 4'and 5 and by the outward pressure provided by the base wad 6. The primer cap 7 is provided in the axial center of the base 3 to ignite the gunpowder contained in the combustion chamber 8 when the primer cap 7 is. struck by a firing pin. The end of the shell 1 opposite the base 3 is closed by crimping over the end of the casing 2 as is indicated by the mouth 10.

This figure illustrates one structural form of the tracer vehicle wad structure 11 of the present" invention which primarily consists of a substantially cylindrical sleeve 12, an annular transverse wall .14, a projectile guidance tube 15 and a lift off or over powder wad 19 which has a perimetal expansion groove.17 and projectile seat 20 to seat the tracer projectile 21. The cylindrical perimetal wall of the lift off wad 19 is actually a separable extended portion of the member 12 with a snug perimetal tongue and groove or butt lap fitting indicated at 22.

The transverse wall 14 is shown here in the form of a disc and as an integral part of the sleeve 12. The projectile guidance tube 15 is mounted as an integral part of the wall 14 and provides a bore 23 to engage the projectile 21 when it is seated in the seat 20. The bore 23 also functions to guide the projectile 21 when it is ejected from the seat 20. Either bore 23 or the projectile 21 may be provided with rifling to impart a slight rifling to the projectile 21.

The chamber 26 defined by the sleeve 22, the wall 14, and lift off wad 19 functions as a cushion chamber. The outside diameter of the sleeve 12 decreases to a neck 27. At this point the sleeve 12 is thinner than the remaining outside walls of the chamber 26. The sleeve 12 and wall 14 are made of a strong flexible plastic material and thus, when pressure is applied from the combustion chamber 8 against the wad 19, the sleeve 12 which defines the chamber 26 will tend to yield or collapse because of the narrow neck 27. This has the effect of cushioning the recoil effect of the gun shooting the shell 1 and of forming a tight gas seal between the member 12 and the bore of the shotgun (not shown) when the Wad structure 11 is expelled from the casing 2.

The perimetral groove 17 in the lift off wad 19 also functions to form a tight gas seal within the casing 2 and the bore of the shotgun. The pressure of the expanding gas within the chamber 8 caused by the ignition of the gunpowder contained therein, has a tendency to expand the groove 17 by pushing the thin perimetral lip 28 of the groove 17 out against the casing 2 and the gun bore.

An ignition passage 31 passes through the wad 19 and comunicates with seat 20. This passage has two basic functions. First of all, it serves to ignite the pyrotechnic tracer mixture 32 contained in the hollowed out portion of projectile 21 as shown herein partial section. Seeondly, the pressure of the expanding gases from chamber 8 passing to seat 20 is regulated by the diameter of the passage 31. The pressurized gases forced through the passage 31, plus the effect of the collapsing cushion means on the seat 20, will force the projectile 21 through the bore 23 and into the middle of the shot column 34.

A control means comprising another aspect of the present invention may be employed with the aforementioned other five trajectory control means, namely, the pressure control passage 31, the propulsion effect of different pyrotechnic tracer mixtures such as illustrated at 32, the mass and ballistic coefficient of the projectile 21, the guidance bore 23, and rifling if provided, in order to maintain the projectile in the center of the shot cloud trajectory. This sixth control means is found in the shot receptacle 3 which is illustrated in FIGS. 1 and 2 as integrally connected to cylindrical sleeve 12, and the wall 14 which functions as a bottom to the receptacle 35. The receptacle 35 consists of a second sleeve 24 which has a plurality of longitudinal slits 36 communicating with the open end of sleeve 24 and forming the arcuate sections 37 which are also of a flexible material. The sections or flaps 37 remain secured together adjacent wall 14. Thus, when the receptacle 35 is propelled through the air, the drag friction of air flowing into the receptacle will tend to peel the outer ends of the sections 37 away from the shot column 34 permitting the vehicle 11 to fall away and the shot string to round out into a full pattern.

In a sport such as trap, many shots are made at traveling clay targets 40 yards or greater away from the shooter which is a considerable distance for a shotgun. Thus, in this type of shooting it is desirable to keep the shot column together for a longer period of time so that the shot pattern is not too large for the size of the target when the shot cloud reaches the target. To correct this, novel speed regulating orifices 38 are provided in the arcuate sections 3-7. The effect is that the air rushing into the receptacle 35 will be metered by or partially escape through the orifices 38, thus, decreasing the air drag on the sections 37. Therefore, by regulating the size, shape and number of the orifices 38, the time at which the wad structure will leave the shot may be regulated to vary the size of the shot pattern.

These regulating orifices 38 also comprise a sixth control means over the tracer projectile trajectory. By keeping the shot column 34 together over a longer period of time in its trajectory, the projectile 21 is also maintained in the center of the column giving greater assurance that the projectile 21 will remain in the center of the shot pattern. This control means is especially effective for long range shots. The shot receptacle 35 also serves to protect the shot column 34 and the gun bore.

By utilizing an effective cooperating combination of these six trajectory control means, the trajectory of the tracer projectile may obviously be regulated to that of the shot cloud or regulated such that the projectile stays in the approximate center of the shot cloud for a given anticipated shooting range of the shot cloud trajectory.

Since the projectile 21 fits tightly into the bore 23 and snugly into and against the seat the expanding gases in chamber 8 are prevented from escaping into the shot receptacle 35 before the projectile 21 and the shot column 34 have traveled a distance of 20* inches in the shotgun bore. In this distance the maximum effort of the expanding gases against the lift off wad 19 is expended and thus all of the expanding gas is effectively utilized.

Referring to FIG. 2, the projectile seat 20 is provided with a countersunk bore which snugly engages the trailing end of the tracer projectile 21. This permits the projectile 21 to be firmly held and maintained in its upright axial position upon firing the shotshell. The vertical or axial thrust imparted to the projectile 21 from the lift off wad 19 is communicated from seat 20 at the portion where the annular shoulder of the projectile 21 engages the lift off wad which is indicated at 41. If desired the trailing end of the projectile 21 may be extended to engage the bottom of seat 20 as indicated at 42 such that the vertical thrust imparted from the lift off wad 19 is applied to the trailing end of the projectile 21 rather than to the aforementioned annular shoulder.

It should also be noted in FIG. 2, that the diameter of the resilient guidance bore 23 is slightly smaller than the largest diameter of the projectile 21. This provides a tight fit between the projectile and the guidance bore causing the resilience tube 15 to slightly expand as indicated at 43. Although a mere snug fit between the projectile 21 and the guidance bore 23 has proved to be effective, the tight fit illustrated in FIG. 2 has been found to be preferable. However the exact reason for this is not entirely understood. It is believed that the resilient resistance of the guidance bore 23 retards the period of time in which the projectile 21 might normally be ejected from the tube 15. It is further believed that this relationship also has the effect of giving the projectile 21 a greater initial velocity than might normally otherwise be anticipated.

Like elements of the tracer vehicle wad structure shown in FIG. 3 are given the same reference numerals as the corresponding elements seen in FIGS. 1 and 2. In the embodiment of FIG. 3, the axially yieldable sleeve 12 is provided within a thin wall portion indicated at 44 which serves the same function as the annular neck 27 shown in FIGS. 1 and 2. These thin walled portions aid in permitting the yielda'ble sleeve 12 to collapse upon firing the shotshell. However, the sleeve 12, which is made of a strong flexible material such as neoprene, will collapse or buckle upon firing even in the absence of such thin wall portion. However, the effect of the thin wall portions is preferable.

The lift off wad 19 of FIG. 3 is provided with a piston extension 45 which extends into and engages bore 23 and has the projectile seat 20 on the end thereof to receive the trailing end of projectile 21. In this figure, projectile 21 is provided with a snug bore engagement with guidance bore 23. This bore fit should be tight enough to prevent leakage of expanding gases traveling through the ignition passage 31.

The resiliently yieldable tube 15 is provided with a clearance 30 between the inside face 46 of lift off wad 19 and the adjacent end 47 of tube 15. This clearance 30 reduces to some extend the initial distortion given to the resilient tube 15 upon firing the shotshell 1.

The extension of the piston 45 into the bore 23 also aids the lateral stability of the wad structure 11.

The lift off wad 19 as shown in FIG. 3 is provided with a frustoconical concave face as indicated at 48. This frustoconical end face 48 has been found to give the pellets 34 greater target impact. It is not entirely understood why this frustoconical surface gives such a result. However, it is believed that this configuration causes the wad 19 of resilient material to spread outwardly and engage the gun bore with a greater seal than might be ordinarily provided by the groove 17 as shown in FIGS. 1 and 2. Furthermore, the frustoconical surface provides a concentration of the expanding gases toward the center of the lift off wad. The frustoconical surface is preferably provided with an apex angle of approximately Although this frustoconical surface 48 is both beneficial and effectual in controlling the trajectory of the projectile 21, it has also been found effective for use in the conventional shotshell.

I claim:

1. A tracer vehicle wad structure for use in a shotshell comprising a cylindrical sleeve yieldable in the axial direction at least on firing the shotshell, a tube of resiliently yieldable material coaxially mounted in said sleeve and providing a projectile guidance bore therethrough, a cylindrical lift off wad closing one end of said sleeve, a coaxially positioned projectile seat on said lift off wad and exposed through said bore, and an ignition passage commuiicating with said seat and passing through said lift off wa 2. The tracer vehicle wad structure of claim 1 charac terized in that said tube is coaxially mounted in said sleeve by an annular transverse wall closing the other end of said sleeve.

3. The tracer vehicle wad structure of claim 2 characterized by a second cylindrical sleeve of flexible material closed at one end by said annular wall and having a plurality of arcuate sections formed by longitudinally extending slits communicating with the open end of said second sleeve.

4. The tracer vehicle wad structure of claim 3 characterized by a plurality of orifices of preselected number and size in said arcuate sections.

5. The tracer vehicle wad structure of claim 2 characterized in that said sleeve and said tube and said wall are integrally molded as one unit.

6. The tracer vehicle wad structure of claim 3 characterized in that said sleeve and said tube and said annular wall and said second sleeve are integrally molded as one unit.

7. The tracer vehicle wad structure of claim 1 characterized by a butt-lap joint between said one end of said sleeve and said lift off wad.

8. The tracer vehicle wad structure of claim 1 characterized by a piston extension on said lift ofi Wad extending into engagement with said bore and providing said projectile seat on the end thereof.

9. The tracer vehicle wad structure of claim 1 characterized in that said ignition passage is coaxially aligned in said lift off wad and the exposed end face of said lift ofi wad is frustoconical concave.

10. The tracer vehicle wad structure of claim 9 characterized in that said frustoconical face has an apex angle of approximately 120.

11. A shot receptical for a shotshell consisting of a cylindrical sleeve of flexible material having a closure at one end and a plurality of arcuate sections formed by longitudinally extending slits communicating with the open end thereof, characterized by a plurality of orifices of preselected number and size to meter the airflow therethrough upon firing the shotshell.

12. A tracer shotshell comprising a cylindrical tubular casing having a base and a mouth, a primer positioned in said base, a propellant in said casing adjacent said base, a cylindrical lift off wad coaxially positioned in said tubular casing over said propellant, a projectile seat coaxially positioned on said wad and open to said month, an ignition passage in said Wad communicating said seat with said propellant, a cylindrical sleeve resiliently yieldable in the axial direction at least on firing the shotshell and coaxially p0si tioned in said casing on said wad, a resiliently yieldable tube coaxially mounted in said sleeve by an annular wall closing the open end of said sleeve, said tube providing a projectile guidance bore therethroughopen at both ends, a bullet shaped tracer projectile seated on said seat and extending into engagement With said bore and having a pyrotechnic mixture in the seated end thereof, and a shot column positioned in said casing over said annular Wall.

13. The tracer shotshell of claim 12 characterized in that the diameter of said 'bOre is slightly smaller than the largest diameter of said projectile.

14. The tracer shotshell of claim 13 characterized in that said projectile seat has a countersunk bore to receive the trailing portion of said projectile in snug engagement.

15. An over powder wad for a shotshell consisting of cylindrical body imperforate intermediate its ends and having a concave frustoconical end face.

16. The over powder wad of claim 15 characterized in that said concave frustoconical end face has an apex angle of approximately 120.

No references cited.

ROBERT F. STAHL, Primary Examiner.

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