US3656434A

US3656434A - Shotgun shell with metal cap

Info

Publication number: US3656434A
Application number: US827819A
Authority: US
Inventors: Roger J Curran
Original assignee: Remington Arms Co LLC
Current assignee: Remington Arms Co LLC
Priority date: 1969-05-26
Filing date: 1969-05-26
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18
Also published as: DE2029989C3; GB1295897A; DE2029989A1; FR2048785A5; GB1251788A; DE2025478A1; DE2029989B2; FR2048781A5

Abstract

A shotgun shell having a metal cap made from sheet metal. The metal cap includes an annular fold which provides a strong cap to body attachment and an integrally formed primer pocket and anvil. The basewad can be eliminated in order to make extra volume available within the shell for additional propellant and/or projectile load.

Description

provides a e eliminated in order to make extra volume available within the shell for additional propellant and/or projectile load.

egrally formed [151 3,656,434 [451 Apr. 18, 1972 3,103,170 9/1963 Covington,Jr.etal.................. 3,157,121 ll/1964 Daubenspeck et al,.... 3,215,077 11/1965 Mayer et Inc.

FOREIGN PATENTS OR APPLICATIONS 11,079 1915 Great Britain..........................,

Primary Examiner-Robert F. Stahl Attorney-John H. Lewis, Jr. and Nicholas Skovran [57] ABSTRACT A shotgun shell having a metal cap made from sheet metal. The metal cap includes an annular fold which strong cap to body attachment and an int primer pocket and anvil. The basewad can b 12 Claims, 8 Drawing Figures MM U 00 11 Arms Company,

.102/43 P, 102/42, 102/44 ....F42b 5/30, F42b 7/06 102/38,42, 43,44, 43 P Bailey........................... Guignet.................... 7/1963 Daubenspeck et References Cited UNITED STATES PATENTS 3/1902 1,974,270 9/1934 3,099,958

Roger J. Curran, Stratford, Conn.

Remington Bridgeport, Conn.

May 26, 1969 Int. 694,713

Uited States Patent Curran I54] SHOTGUN SHELL WITH METAL CAP [72] Inventor:

[73] Assignee:

[22] Filed:

[21] Appl. No.:

[58] Field ofSearch.........................

SHEET 10F 2 PATENTEDAP 18|972 gall? Inventor 1 'Attornqg SHOTGUN SHELL WITH METAL CAP This invention relates to ammunition and in general to plastic bodied shotgun shells. More specifically, the invention relates to a shotgun shell having a plastic body and a metal cap in which the conventional basewad can be eliminated.

Shotshells are presently being designed and developed to take advantage of the cost and technical advantages which plastics offer. The present trend, therefore, is toward the use of less metal in shotshell designs. However, metals technology has also progressed beyond its present use in shotshell construction. Historically, the transition from paper to plastic body tubes was accomplished without much change in the function the metal portion served. Hence, differences between plastic and paper body tubes were not used to full advantage in these designs in consideration of the combination of metal with plastic. Likewise, primer design has not responded to changes in design and performance of the entire shotshell.

The concept of designing an entire shotshell rather than a series of shotshell components leads to useful designs which offers, at the expense of frugal compromises, certain degrees of freedom with respect to performance and cost.

To those shotshell users who do not reload (and it is believed that these are the great majority of shooters), there is some excess cost associated with any shotshell which may be reloaded. Linked with this cost is the requirement that any shotshell must fail safely no matter the number of reloadings. Because of the uncertainties of the reloading cycle, it should be possible to design a shotshell, with adequate safety factor for one firing, at a lower cost than one designed for more than one firing.

This invention deals with a shotshell design which combines safe performance, low cost of construction, and increased ballistic performance freedom and which may utilize a non-reloadable feature. Obviously, some of the elements of this design are not limited to the concept of a non-reloadable shotshell.

Shotshells have undergone various modifications through the years. Shotshell casings changed from metal, to paper, and finally to plastic. When the all-metal shell was used, a basewad was not necessary since the metal head portion was strong enough to absorb the shock of firing and the metal tubular body obturated sufficiently to provide an adequate gas seal. When the paper tubular body was introduced, it was found that some sort of reinforcing was necessary at the breech or head end of the shell. For example, U.S. Pat. No. 610,660, issued Sept. 13, 1898, shows an outer metal cap and an inner support cylinder to provide support for the boiler-room or cavity where the propellant means is ignited. Subsequently, a separate basewad was inserted at the breech end to provide necessary gas sealing and shock absorbing functions. The use of a basewad was carried over to plastic-bodied shotshells, first when oriented tubing was used for the cartridge bodies the later when an integrally formed basewad was provided for the cold-formed one-piece cartridge casings.

The use of a basewad, however, requires sacrificing of valuable volume in the shotshell. This lack of shotshell volume becomes important in view of the present day search for a substitute for lead shot. Because of the problem caused be lead poisoning of wild fowl, iron shot appears to be the most promising candidate to replace lead, at least for field loads most often used by duck hunters. Having lesser density than lead, more volume of iron shot is needed to provide an equivalent load at the target.

The present invention is designed to provide a maximum volume load in permitting the elimination of the basewad but at the same time insuring that the sheet metal cap and plastic body construction are strong enough to perform. It must be recognized, however, that the unique cap to body attachment can also be used with a basewad, if for any reason this is deemed desirable.

It is an object of this invention to provide a plastic-bodied shotshell having a metal cap in which the cap and the cap to plastic body attachment are strong enough to eliminate the need for a basewad.

It is another object of this invention to to plastic body attachment.

It is another object of this invention to provide a novel sheet metal cap to which a primer pocket and anvil are integrally formed.

It is still another object of this invention to provide a shotshell design having a maximum volume thus increasing the capacity for shot loads.

Other objects and advantages will be apparent from the following description and accompanying drawings in which:

FIG. 1 shows a front elevational view of a loaded shotshell cartridge illustrating the invention;

FIG. 2 shows an expanded cross-sectional view of the breech end of the cartridge;

FIG. 3 shows an expanded cross-sectional view of the metal cap-body attachment;

FIG. 4 shows an expanded cross-sectional view of the primer pocket and anvil;

FIG. 5 shows a modification in which the metal cap has an integral primer pocket only and a conventional center-fire type primer is used;

FIG. 6 shows a modification in which the fold has a different configuration;

FIG. 7 shows another modified form of fold; and

FIG. 8 shows still another modified fold.

FIG. 1 shows a loaded shotshell 10 in which reference numeral l2 refers to a plastic body member and 14 refers to a metal cap member 14. Body member is preferably made of oriented plastic, e.g., polyethylene, polypropylene, etc., although obviously it may be made of any plastic material, such as polycarbonate, which can be deformed to form the body cap attachment and which has adequate physical characteristics to withstand firing conditions. FIG. 1 also shows a load of shot pellets 16, filler wad means 18, and propellant means 20. It can be seen that there is no basewad as such.

This invention is concerned mainly with the breech end of the plastic body member and its attachment with the metal cap and the details of the metal cap.

Plastic body member 12 is shown as a straight walled tube having an inner wall surface 22 and an outer wall surface 24. Obviously, either one or both of the wall surfaces can be tapered without affecting the invention. The breech end of the body member, which is closed off by the metal cap member, is deformed to form an enlarged shoe 26 which has an outwardly directed flange 28 which forms a rim and an inwardly directed gas-sealing flange 30, preferably, but not necessarily, of lesser thickness than the rim flange. The function of gas-sealing flange 30 will be explained later.

The metal cap member 14 has a tubular side portion 32 which extends forwardly from a transverse end wall 34 and is in close fitting relationship with the outer wall surface of at least a portion of the plastic body member. A portion of tubular side portion 32 can be tapered at 36 in order to provide a thickened portion adjacent the enlarged shoe portion and a thinner portion at the front end thereof. Conventional metal caps are of uniform thickness. The thickened rear end portion provides support for a gun extractor means (not shown) while the thinner portion at the front end of the metal cap provides a better fit between the metal cap and the plastic body member. The tapered forward end 36 also helps to prevent cutting off of the plastic body which sometimes happens with a thick, sharp-edged metal cap.

As can be seen in FIG. 2 the tapered tubular side portion 32 causes the lower end of the plastic body member 12 to be forced inwardly gradually so as to form a portion of lesser inside diameter than the remaining forward end of the plastic body. This lesser diameter becomes important when the lower skirt (not numbered) of the filler wad 18 (shown in FIG. 1) is forced down tightly so as to effect a water seal before firing and a gas seal upon ignition of the cartridge. It is noted that when the lower end of the plastic body is forced inwardly with a metal head having a uniform thickness, the point where the top of the metal head meets the plastic body is more sensitive to cutoff.

provide a novel cap The transverse end wall 34 of the metal cap extends outwardly past the outer wall surface of the plastic body member and then extends forwardly and inwardly to form an annular rim means 38 with the tubular side portion 32. End wall 34 also has an annular fold 40 integrally formed therein which projects forwardly and outwardly from the end wall 34 towards the tubular side portion 32 to end a predetermined distance 42 therefrom. It can be seen that the fold 40 defines a cavity 44 with the rim 38 and the tubular side portion 32 in which the enlarged shoe portion 26 of the plastic body is confined. It can also be seen that the enlarged shoe is substantially thicker than distance 42 so that unless the plastic shoe is substantially thicker than distance 42 so that unless the plastic shoe is reworked and levelled out, it cannot be pulled out of the cavity 44. The force necessary to pull the plastic body out of the metal cap obviously depends on several variables including distance 42, thickness of plastic body, etc. However, preliminary tests indicate the force required to be about 390 pounds as compared to a force of about 175 pounds required to pull a plastic tube out of a conventional metal cap-basewad design.

The transverse end wall 34 also includes an integrally formed primer pocket 46 in which a primer cup 48 is positioned. Primer pocket 46 includes a forwardly extending cylindrical side portion 50 and an anvil portion 52 integrally formed with the front end of the cylindrical portion. Anvil 52 extends rearwardly toward the transverse end wall and has a conical side wall 54 which grades to a cylindrical impact end 56. The forward end of the conical side wall is thickened to provide additional rigidity for primer sensitivity. Formed in anvil 52 are a plurality of flash hole openings 58.

The specifics of the primer means and the method of forming the one-piece cup and anvil will be the subject matter ofa separate patent application and need not be detailed at this point.

Referring back to FIG. 3, it can be seen that upon firing of the cartridge, the explosive pressure generated will tend to cause the fold 40 to collapse toward air space 60. Explosive gases enter between the fold 40 and the enlarged shoe 26 caused by the metal head 14 moving outwardly towards the gun chamber and shown in an exaggerated way in FIG. 3. The explosive gases, however, will act against the thinned flange 30 and force the flange against the inside surface of the metal cap, thereby effecting a gas seal. In the absence of flange 30, e.g., in FIG. 3, the explosive gases can enter between the inside surface 22 of the plastic tube and the inside surface 62 of the metal cap to force the rim flange 28 against the inside surface of the metal rim at 64.

It should be obvious that with the elimination of the basewad there is more space or volume available within the cartridge shell. If the loaded cartridge is to be used in a conventional gun, i.e., with a chamber having a conventional length, the extra space either must be taken up by additional propellant, shot load, or filler wad means. An alternative, in which the ballistics could remain the same, and which would require modifications to the gun, could cut down the overall length of the cartridge so as to result in a mini-shell", e.g., 2 inches long instead of 2% or 3 inches, which are the conventional shotshell lengths. The modified gun to handle such a shortened shell would have many advantages, not only in functioning but in economics.

FIG. shows a modified metal head which does not include the integral battery cup and anvil assembly which is shown in FIGS. 1, 2, and 4. Primer pocket 46 is shown with a transverse end wall 66 having a flash hole opening 68 and a separate anvil element 70.

From FIGS. 2 and 5, it can be seen that the thickness of the transverse end wall 34 is not uniform but rather tapered toward the primer pocket 46 so as to have its maximum thickness near the central primer pocket. Inasmuch as the metal head is formed from sheet metal, which is of uniform thickness prior to being fed into the cap-making machine, it would be expected under conventional metal forming procedures that the transverse end wall 34 would be of constant thickness approximately equal to the original sheet metal thickness.

By providing maximum thickness of the transverse wall 34 adjacent the primer opening, the transverse end wall is strengthened in the manner of a truss in which the connecting end portion is free to hinge or pivot. The wall 34 acts as a three-dimensional plate supported or hinged on its annular edge. The thickened portion of the end wall adjacent the primer opening resists deformation under a central impact load such as would occur by a firing pin impacting against a primer. This resistance to deformation is important for primer sensitivity. In the absence of a back-up basewad means, the impact of the firing pin necessary to ignite the priming mix must be absorbed entirely by the primer means and the supporting metal head. For this reason, the tapered anvil and the tapered transverse end wall are more significant in this combination, i.e., without a base wad. However, it seems obvious that the body to cap attaching means can be utilized without the additional improvements to the primer anvil and the transverse end wall. It should also be obvious that the improvements to the primer anvil and the transverse end wall will also be important in other situations outside of the combination.

What is claimed is:

l. A shotgun shell comprising a tubular body member made of plastic material and a metal cap member which closes off one end of said plastic body member, said one end of said plastic body member having an enlarged foot means, said metal cap member having means integrally formed therewith to engage the inner and outer wall surfaces of said plastic body member at a point forwardly of said enlarged foot means to compress said plastic body member and to lock the metal cap member thereto, said enlarged foot means comprising an annular, flanged, rim portion which extends transversely outwardly from the outer wall of said tubular body member and a second annular, flanged, gas sealing portion extending transversely in a direction opposite to said rim portion.

2. A shotgun shell as recited in claim 1 wherein said gas sealing flanged portion is thinner than said flanged rim portron.

3. A shotgun shell as recited in Claim 1 in which said metal cap member comprises a cup-shaped sheet metal member, said sheet metal cap member comprising a tubular side portion, a transverse end wall to close off the breech end of the shell and an outwardly projecting rim portion interconnecting said tubular side portion and said transverse end wall, said tubular side portion extending forwardly in close fitting relationship with at least a portion of the outer wall surface of the plastic body member, said means locking the plastic body member to the metal cap member comprising an integrally formed annular loop means extending forwardly from said transverse end wall to define a cavity with said rim portion and said tubular side wall portion in which said enlarged foot means is compressingly held in place.

4. A shotgun shell as recited in claim 1 in which said metal cap member is made of sheet metal and comprises a tubular side portion which is in close fitting relationship with a part of the outer wall surface of the plastic tubular body member, an outwardly projecting rim portion, and a transverse end wall, said transverse end wall having a primer pocket formed centrally therein, said primer pocket being defined by an integrally formed battery cup portion, said battery cup portion having a cylindrical battery side portion integrally formed with an extending forwardly from said transverse end wall and a battery forward end wall portion connected thereto, said forward end wall portion having an anvil integrally formed therewith extending rearwardly toward said transverse end wall, and flash hole means formed in said forward end wall portion.

5. A shotgun shell as recited in claim 1 wherein said plastic body member is biaxially oriented.

6. A shotgun shell as recited in claim 1 wherein said sheet metal cap member includes a primer pocket and anvil integrally formed therein.

7. A shotgun shell comprising a deformable plastic body member and a sheet metal cap member, means attaching said metal cap member to said body member, said cap member comprising a tubular side portion and a transverse end wall, said transverse end wall having a primer pocket means formed integrally therein, said transverse end wall being tapered so as to provide a maximum wall thickness adjacent said primer pocket means thus providing desirable rigidity of the transverse end wall for required primer sensitivity.

8. A shotgun shell as recited in claim 7 in which said plastic body member has a permanently deformed annular, enlarged foot means at the breech end of the shell, said transverse end wall having an integrally formed, annular, fold means extending forwardly therefrom and spaced laterally a predetermined distance from said cap tubular side portion to abut said enlarged foot means without cutting into the plastic so as to form said cap to body attaching means and also to add rigidity to said transverse end wall.

9. A shotgun shell as recited in claim 7 in which an anvil means is integrally formed with said primer pocket means.

10. A shotgun shell as recited in claim 7 in which at least a portion of said tubular side portion of the metal cap member is tapered forwardly to provide a thinner section at the forward end of said tubular side portion.

11. A shotgun shell comprising a tubular body member made of deformable plastic material and a sheet metal cap member which closes off one end of said plastic body member, said one end of said plastic body member having a permanently deformed enlarged foot means integrally connected thereto by a connecting plastic portion which is thinner than said tubular body member, said sheet metal cap member having a tubular side portion and a transverse end wall to close off the breech end of the shell, said transverse end wall having an integrally formed, annular loop means extending forwardly therefrom, said annular loop means having a curved forward end which is located adjacent the tubular side portion of the sheet metal cap in close-fitting relationship to said thin connecting plastic portion of said plastic body member, the curved forward end of the loop means and the tubular side portion of the sheet metal cap acting in compression to lock the enlarged foot means and the plastic body to the sheet metal cap.

12. A shotgun shell as recited in claim 11, wherein said enlarged foot means comprises at least one annular flanged portiou integrally formed therewith and extending in a transverse direction to said tubular body member.

Claims

1. A shotgun shell comprising a tubular body member made of plastic material and a metal cap member which closes off one end of said plastic body member, said one end of said plastic body member having an enlarged foot means, said metal cap member having means integrally formed therewith to engage the inner and outer wall surfaces of said plastic body member at a point forwardly of said enlarged foot means to compress said plastic body member and to lock the metal cap member thereto, said enlarged foot means comprising an annular, flanged, rim portion which extends transversely outwardly from the outer wall of said tubular body member and a second annular, flanged, gas sealing portion extending transversely in a direction opposite to said rim portion.

2. A shotgun shell as recited in claim 1 wherein said gas sealing flanged portion is thinner than said flanged rim portion.

4. A shotgun shell as recited in claim 1 in which said metal cap member is made of sheet metal and comprises a tubular side portion which is in close fitting relationship with a part of the outer wall surface of the plastic tubular body member, an outwardly projecting rim portion, and a transverse end wall, said transverse end wall having a primer pocket formed centrally therein, said primer pocket being defined by an integrally formed battery cup portion, said battery cup portion having a cylindrical battery side portion integrally formed with and extending forwardly from said transverse end wall and a battery forward end wall portion connected thereto, said forward end wall portion having an anvil integrally formed therewith extending rearwardly toward said transverse end wall, and flash hole means formed in said forward end wall portion.

12. A shotgun shell as recited in claim 11, wherein said enlarged foot means comprises at least one annular flanged portion integrally formed therewith and extending in a transverse direction to said tubular body member.