JPS6089699A - Casing cartridge made of plastic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This application is a continuation-in-part of US Pat. No. 514,245, filed July 15, 1983.

This application relates to cartridges, and in particular to cartridges suitable for pistols.

It is made with a traditional pistol cartridge and brass casing. The brass casing has an integrally formed head at one end having a detonator cup for igniting the charge;
with a bullet or other projectile crimped on the other end. Brass casings have the advantage of being reusable. However, brass casings have some drawbacks. Brass is expensive;
Special tooling is required to recrimp or reshape the bullet end of the casing over the bullet for a snug fit on the bullet.

Due to the high cost and disadvantages of using brass casings, aluminum casings have been developed that can be worn out. Although aluminum is cheaper than brass, it does not have sufficient elasticity to be reused. The final cost of a discarded aluminum casing is almost as high as the cost of a reusable brass casing. Owners prefer to reload their casings not only to reduce the cost of actual ammunition, but also to increase the accuracy of the powder charge, or to ensure quality control and more accurate bullet distance. do.

Several attempts have been made to develop reusable plastic casings for pistol cartridges. The use of plastic casings requires a tight fit between the casing and the bullet and between the casing and the end cap to prevent premature escape of gases generated when the charge is ignited. These gases quickly 703
Pressures in excess of kg/cJ (10,000 psi) are reached and thus the seal around the bullet and around the end camp of the casing must be sufficiently airtight to prevent gases from escaping until the bullet is fired. Sealing around the end camp is important because gas escaping from the rear end of the casing reduces the amount of force used to propel the bullet (and affects not only the bullet's trajectory but also its range and penetration power). Very important.

U.S. Patent Nos. 4,147,107 and 3,990,36
No. 6, No. 3,977.326, No. 3,842,739
No. 3,874,294 and German Patent No. 2,4
No. 19,881 is a known example of an application attempting to make a plastic casing. However, to be price competitive with aluminum or reusable brass, PlusDeck cartridges are inexpensive to manufacture, easy to reload, and have to withstand high explosive pressures for reasonable reusability. must be able to do so. In the previously mentioned patents, these goals were not achieved. All of these patents disclose plastic or composite metals and plastic casings that rely on multiple parts to create a seal around the end camp or to crimp or hold the casing around the bullet. The cost of producing and assembling multi-component casings is prohibitive, and thus these composite plastic casings have not been successfully marketed.

One object of this invention is to provide a plastic casing with a separate mounting end cap that is reusable and provides an airtight seal to the end cap and bullet to prevent uncontrolled escape of high pressure gases. That's true.

Another object of this invention is that it retains the bullet during transportation and handling, is easy to reload, is inexpensive to manufacture, and
Moreover, it is an object of the present invention to provide a cartridge that provides excellent sealing properties at the end cap and at the bullet end of the casing.

Essentially, these and other objectives are achieved by providing a hollow plastic casing made of a durable elastic plastic material, which extends the projectile end of the casing in a radial direction. inflates to release the bullet, but elastically returns to its original shape for reloading. Generally, the opposite end of the casing (for sealing around the end cap) includes an inwardly extending relatively axially thin flange or gasket that engages the sealing surface of the end cap. The flange or gasket is tightly fitted and sufficiently elastically deformed upon ignition of the gunpowder so that the flange or gasket forms an elastic seal on the sealing surface of the end gap to prevent escape of high pressure gases. By providing sufficient elastic deformability to the flange or gasket of the casing end cap, no additional parts are required to crimp or hold the casing snugly around the end cap. Similarly, by providing sufficient elasticity to the bullet end of the casing, the bullet will be released when the gunpowder is ignited, but the bullet end of the casing will not crack or deteriorate even after several repeated firings. The casing can therefore be reloaded. It is desirable to reach a reloadability of at least 4 to 5 times, and in some instances as many as 20 reloads can be achieved with the unique plastic casing.

As best shown in FIG. 2, the cartridge includes a casing 10, an end cap 14 containing a conventional primer cap 15, and a bullet 12. Details of the detonator cup are conventional and will not be disclosed.

Essentially the detonator cup has a small anvil.

The firing pin of the gun dents the detonator cup along the anvil and ignites a small charge, which in turn ignites the gunpowder 16 within the casing. As explained in more detail below, one unique advantage of this plastic casing is that due to the predetermined location of the interlocking rings and grooves,
The bullet is always seated exactly axially along the length of the casing, so that even after repeated firing the same volume of powder is created in the casing. By repeatedly using a precise charge, the same gas conditions exist in the casing, and the bullet always experiences approximately the same gas pressure during repeated firing. This feature makes the trajectory of the bullet very accurate when fired.

The bullet may be made of any material, preferably brass-coated lead, and includes a pair of axially spaced inwardly projecting a
19 with a radially smaller outer circumferential surface 18. Bullet end 10b of casing 10 includes a thin wall and a pair of axially spaced rings 20. The thin walls give greater flexibility to the bullet end of the casing, allowing the inherent elasticity of the plastic to allow the bullet end to expand radially upon firing, releasing the bullet and then reloading it. Return to original shape. As is well known in the prior art, the rifle chamber is cylindrical, as shown by phantom line C. The stepped end (FIGS. 2 and 5) or tapered end (FIG. 3) of the casing for the bullet is thus free to expand radially and release the bullet. The plastic used to ensure superior surface durability and elasticity is a high-density polyethylene plastic manufactured by DuPont, which has a Young's modulus of approximately 10” dynes/cJ;
It has a Poisson's ratio of about 0.3. Other plastics with suitable properties can also be used.

In the embodiment shown in FIG. 3, the bullet has an inwardly sloping groove 30. In this manner, the bullet end 40b of the casing is sloped radially inwardly and seats within the groove 30 of the bullet. One advantage of this type of bullet end of the casing is that
This end also expands upon firing, but does not have a sharp protrusion like ring 20 of FIG. 2, allowing the bullet to escape more smoothly. This increases the reloadability of the casing.

To increase the accuracy of the bullet, the rings may have different dimensions and shapes as shown in FIG. Therefore, the ring 22 near the end of the casing, and the ring 2 inside the casing.
4, so that when the bullet 12a disengages from these rings and the bullet exits the casing, the base 13 of the bullet does not contact the end rings 22. As shown in FIG. 5, rings 22 and 24 also have sloped sides, effectively making rings 22 and 24 annular trapezoidal bodies. The sloped sides strengthen the ring to withstand the loading of a bullet exiting the casing. in general,
The larger the facing angle opposing the bullet's ejection, the greater the pressure required to fire the bullet. Although two rings are shown and highly preferred, higher pressure, larger caliber cartridges may use more rings if desired. But those additional rings may make the bullet unstable.

In both the embodiments of FIGS. 2 and 3, the ends 10e and 40e of the end cap casing each include an inwardly extending flange 21 having an axial dimension indicated by the reference symbol X. The thickness in this axial dimension is important. This is because it is thick enough to withstand the penetration and shear forces of the high-pressure gas during ignition of the charge, but allows the flange to deflect rearward and compress, forming a resilient seal around the radial surface of the end cap. This is because it must be sufficiently thin. In a preferred embodiment for a specific cartridge gas pressure range of 0.38, this axial thickness is about 0.0508-0.1016
A small range of 0.0762 cm (0.0762 cm) has been successfully tested, although a small range of 0.0762 cm (0.0762 cm)
030 inches). Higher pressure ranges, such as larger diameter cartridges, may require thicker flanges. Although some sealing may also occur on the axially cylindrical inner surface of the end camp, it appears that the seal is primarily on the radial surface of the end cap in this configuration. The radial surface is designated with reference numeral 24 and the axially cylindrical surface is designated with reference numeral 25.

In the embodiment of FIG. 3, the flange 21 has a slightly axially inwardly thickened curved or straight larper to increase the gas pressure on the cylindrical end face 25 of the end camp, and has a metal end. A crimp surface for the camp 14 is formed. In both the embodiments of FIGS. 2 and 3, the end cap is held to the casing by slightly crimping the cylindrical surface of the end camp across the flange, as indicated by reference numeral 27. End cap 14 is a rigid material that engages the flange by any other suitable means, such as welding, gluing, or mechanical interlocking.

For example, in the modification shown in FIG.
are provided at the end of the cylindrical surface of the end cap so that the end cap knob can be removed from the casing by simply snap-fitting the casing onto the end cap without the need for crimping tools. It will be appreciated that in all embodiments, the flaps or dimples do not create a seal, but rather are simply a mechanical release mechanism. Sealing to prevent gas leakage is important for accurate firing, and this is due to the flexibility and compressibility of the flange 21-2. The flange is made flush so that the flange seats snugly against the edge camp surface.

To reload the bullet into the casing, the bullet end of the casing is forced apart by the bullet and the bullet is pushed rearward until it snaps into place. The old end cap is then pushed out and replaced with a new end cap, which is crimped and seated in place by the dimples 28. A suitable charge of gunpowder is, of course, placed in the casing prior to placement of the bullet.

As shown in FIG. 6, the seal between the end can knob and the casing may be provided by a gasket 34.

The thicker flange 32 then extends radially inwardly and lies next to the flexible gasket 34. When the bullet is fired, the high pressure inside the casing (usually about 843.6-L532.54 kg/cd (1
2,000 to 21,800 psi) is the flange 32
A seal is achieved by pressing the soft gasket 34 against the end cap, compressing the soft gasket 34 into the end cap.

Plastics are highly preferred for sealing flanges and gaskets because of their high compressibility (K) and inherent flexibility, which is much higher than metals. High compressibility (K) is inversely proportional to the Young's modulus of elasticity of the material according to the following formula:

Here ■ is Poisson's ratio (a measure of the property of a material that maintains a constant volume when stretched). non-oriented polymer,
For example, high density polyethylene has a Young's modulus (E) approximately one to two orders of magnitude lower than metals such as steel and aluminum. Poisson's ratio of polymers is usually about o, a -6
, 4, while metals such as steel and aluminum are about 0.4-0.5. Thus, the high compressibility (K) (ie, softness or sponginess) of polymers is much greater than that of metals. Under pressure, the polymer attempts to seal the end cap by elastically deforming.

Obviously, if the flange is too thick, the flange will absorb pressure towards the interior of the flange material and will not undergo the desired elastic deformation for sealing at the end camps.

In the embodiment of FIG. 6, flange 32 must be able to transmit pressure pulses to gasket 34 to achieve the desired sealing effect. Usually the flange is about 0.1
It is 6 centimeters (1/16 inch) thick.

Generally the end cap has a pillbox shape, but
As shown, it is possible to construct the end cap with a slightly flared cylindrical section 36. In this embodiment, the plastic flange 38 of the casing
is located on the inner sealing surface 39 of section 36 and creates a seal on this surface when the cartridge is ignited. Once again, the flange 38 can be elastically deformed as described with reference to FIGS. 2 and 3. Of course, a gasket seal (not shown) may be provided as a variant.

While the preferred embodiment has been illustrated and described, it will be appreciated that variations will be apparent to those skilled in the art. Therefore, the invention is not limited to the particular embodiments shown in the drawings.

[Brief explanation of the drawing]

FIG. 1 shows a cartridge employing the principles of the present invention. FIG. 2 is an axial cross-sectional view of one embodiment of the invention. FIG. 3 is an axial cross-sectional view of another preferred embodiment of the invention. FIG. 4 is a detailed partial sectional view in the axial direction of a modified example of the embodiment shown in FIG. 2. FIG. 5 is an axial cross-sectional view of another preferred embodiment of the bullet end of the casing. The sixth section is an axial cross-sectional view of another preferred embodiment of the end cap end of the casing. FIG. 7 is an axial cross-sectional view of another preferred embodiment of the end cap end of the casing. <Part names> 10...Casing 12...Bullet 1
4... End camp 16... Loading gunpowder 18... Outer surface 19.30... Groove 20.22.24... Ring 21 .32.38...Flange 24...
- Radial surface 25...Cylindrical surfaces 10b, 40b in the axial direction
・・・・・・Ends for bullets 10e, 40e・・・Ends for end caps (N Procedural amendment (method) December 12, 1939 Commissioner of the Japan Patent Office Mr. Manabu Shiga 3 Person making the amendment Relationship to the case Date of correction order for applicant 4 and agent 5 October 30, 1980 6. Subject of amendment All drawings Contents of amendment As shown in the attached sheet, engraving of the drawings (no change in content)

Claims (1)

Claims: (11) a plastic casing having a separate end cap, a bullet end and an end cap end, a charge, and a bullet seated in the bullet end of the casing; The projectile end has a gripping device for engaging and retaining the projectile, and the end cap end has a surface that abuts the mating surface of the end cap, and the end cap has a surface that abuts the mating surface of the end cap, and the end cap has a surface that abuts the mating surface of the end cap, and the end cap has a surface that abuts the mating surface of the end cap. sealing the end cap and having a thickness sufficient to transmit gas pressure to the mating surface of the end cap by compressing a portion of the end cap end more toward the end camp surface with the pressurized gas; (2) the device for sealing comprises a radially inwardly extending, axially thin flange for engaging a mating surface of the end cap; A cartridge according to claim 1, characterized in that the flange forms a seal with the face of the end cap when subjected to pressure from the fired cartridge. (3) The flange has an axial thickness. is about 0.050
8-o, i o i 6 centimeters (0,020-0,0
40 inches). (4) the bullet end of the casing has a pair of axially spaced, radially inwardly extending rings, and the bullet has a pair of axially spaced grooves; a rear radial four-part circumferential surface, the ring seating within the groove to retain the bullet within the casing;
The projectile end of the casing has an outer wall that is radially straighter and smaller in diameter than the end camp end of the casing, so that the projectile end of the casing has a smaller diameter outer wall in the radial direction during firing. 2. A cartridge according to claim 1, wherein the cartridge can be expanded to release the bullet and its end can be returned to the contracted state for loading. (5) A patent characterized in that rings closer to the distal end of the bullet end of the casing have a larger inner diameter than rings farther from the distal end of the bullet end of the casing in order to more accurately fire the bullet from the casing. The cartridge according to claim 4. (6) The bullet has a peripheral surface inclined inwardly in the axial and radial directions at the rear to form a casing seating surface, and the bullet end of the casing is seated on the casing seating surface of the bullet. The projectile end of the casing has four radially inclined walls, so that the projectile end of the casing can expand elastically to release the projectile upon firing, and then return the end to its beveled condition for refilling. The cartridge according to claim 1, characterized in that the cartridge can be (7) the end camp face is a radial face, the end camp also has an axially cylindrical face, and the flange abuts both the radial face and the cylindrical face; The cartridge according to claim 2, characterized in that the cartridge is fitted together. (8) In a remanufacturable hollow plastic casing for use with a remanufacturable pistol cartridge to be ignited within a cylindrical pistol chamber, an end cap knob for accommodating a powder ignition device. an end for a bullet, an end for a bullet, and a central portion for joining both ends,
the bullet end is elastically expandable in a radial direction;
Thus, the bullet end can expand to receive the bullet during remanufacturing and release the bullet during firing, and the bullet end can return its end to its original shape following release of the bullet, thereby remanufacturing the bullet. The tip of the bullet end has a smaller outer diameter than the central part of the casing, and this smaller diameter allows for radial expansion relative to the cylindrical chamber of the rib pistol in which the cartridge fires. A remanufacturable hollow plastic casing featuring: (9) The wall thickness of the bullet end is thinner than that of the central portion, increasing the outward radial expansion of the bullet end upon firing. Casing as described in section. (10) The casing according to claim 9, wherein the bullet end portion is provided with two circumferential rings on the inside for engaging with mating grooves provided in the bullet. (11) The inner diameters of the rings are different, with the ring closer to the discharge end of the projectile end having a larger inner diameter than the other ring.
Casing as described in section. (12) The inner and outer diameters of the bullet end gradually decrease;
9. A casing as claimed in claim 8, characterized in that the casing is therefore inclined inwardly towards the discharge end of the casing.