US3342134A

US3342134A - Target practice ammunition

Info

Publication number: US3342134A
Application number: US580832A
Authority: US
Inventors: Stadler Hans; Schinnerer Thomas; Umbach Hans
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1964-04-30
Filing date: 1966-09-20
Publication date: 1967-09-19
Anticipated expiration: 1984-09-19
Also published as: BE663150A; NL6502837A; GB1109440A

Description

P 1967 H.STADLER ETAL TARGET PRACTICE AMMUNITION Original Filed April 19, 1965 4 FIG. 2

FIG. I

FIG. 2b

.FIG. 20

FIG. I0

INVENTORS. HANS STADLER THOMAS SCHINNERER HANS UMBACH United States Patent 3,342,134 TARGET PRACTICE AMMUNITION Hans Stadler, Numberg, Thomas Schinnerer, Furth, Ba-

varia, and Hans Umbach, Stadeln, Germany, assignors to Dynarnit Nobel Aktiengesellschaft, Troisdorf, Germany Continuation of application Ser. No. 449,003, Apr. 19, 1965. This application Sept. 20, 1966, Ser. No. 580,832 Claims priority, application Germany, Apr. 30, 1964, D 44,311 8 Claims. (Cl. 102-41) ABSTRACT OF THE DISCLOSURE A practice cartridge having a cartridge case and a projectile made in one piece and of thermoplastic material, and having an intentional breaking point between the projectile and the case. The breaking point consists of a radial connection between the rear portion of the projectile and the forward portion of the case, so that the cartridge case is stressed in shear by the propellant gases.

This application is a continuation of application Serial No. 449,003, filed April 19, 1965, now abandoned.

The present disclosure relates to practice ammunition, and more particularly to such practice ammunition in which the cartridge case and the shell are made in one piece of thermoplastic material and in which a well-defined and predetermined place of separation is provided between the case and the projectile. The projectile and case being connected solely by a substantially cylindrical breaking zone that will rupture substantially exclusively in shear.

Known in the prior :art is a target practice ammounition in which the cartridge case and the shell are made in one piece of thermoplastic material and in which an intended breaking or separating place is provided between the shell and the cartridge case. Apart from a relatively low overall weight, one obtains by the use of thermoplastic material with this known type of cartridge also a small weight of the shell part and therewith the desired small maximum flight distance. Therebeyond a safe eparation of the shell from the cartridge case is assured by the arrangement of the intended breaking place. Thus, the requirements made of this type of cartridge are fulfilled very satisfactorily by this prior art target practice cartridge 1 especially as it exhibits additionally the advantage of simple manufacture and low cost.

However, as has been found, it may happen with this type of prior art target practice cartridge that during the firing the separation between the shell and case at the intended breaking place takes place in such a manner that at some places of the end of the shell, parts projecting outwardly beyond the same of the mouth portion of the case remain stuck thereon. The cause of this sometimes not altogether clean separation between shell and case is r to be seen essentially in the arrangement and construction of the intended breaking place which have as a consequence that the plastic material at the connecting place between shell and case, that is, within the area of the intended breaking place, is stressed exclusively in tension during the separating operation. Since the firing image is falsified by parts adhering at the shell and influencing its flight and its weight, a completely satisfactory and smooth separation between shell and case at the intended breaking place is the more important the greater the required firing precision.

It is the aim of the present invention to eliminate the aforementioned disadvantage, that is, to create a target practice cartridge in which the separation between shell and case takes place with certainty in such a manner that after the separation, no parts of the case adhere any longer at the shell which influence the weight and the flight path of the shell in an undesirable manner, that is, which might render the same false. For a target practice cartridge in which the cartridge case and the shell are made in one piece of thermoplastic material and in which a defined intended breaking place is provided between the case and the shell, it is therefore proposed in accordance with the present invention to so construct and arrange the intended breaking place as radial connection between the rear end section of the shell part and the forward end section of the case part receiving the same that is stressed by the pressure of the propellant gases acting on the shell part exclusively in shear.

Customarily, the cartridge cases pass over by means of a part, the so-called case shoulder, tapering conically toward the forward end of the cartridge case, from a rearward wider part into a forward narrower part, the socalled neck of the cartridge case, whose forward end is referred to as case mouth. It has now been discovered that the construction in accordance with the present invention of the intended breaking place as radial transition between the end of the shell part and the case part may be realized in a particularly simple and appropriate manner if the shell part is extended about the usual cartridge case neck section and the also usual cartridge case shoulder section and the intentional breaking place is constructed as transition between the thus constructed shell part and the end of the powder space of the cartridge case.

In addition to the intended smooth and clean separation between the shell part and the case with which the usually present diametric differences of the cartridge are utilized advantageously, it is possible to achieve in connection therewith also an arrow-like shell, that is, a shell in which the center of gravity is disposed to a greater or lesser extent in front of the shell center if, according to a further proposal of the present invention, the extension is provided with a central axial aperture or recess starting from its rear end and extending over a more or less large part of the shell extension and possibly also of the shell, properly speaking. Not only the location of the center of gravity' of the 'shell but also its weight may be influenced by such a central aperture or recess whereby it is quite possible by a corresponding dimensioning of the aperture as regards its length and its cross section by reason of the larger shell weight conditioned by the shell extension to obtain a suitable and sufliciently heavy shell part for use also in automatic weapons.

Furthermore, an elastic yieldingness of the shell extension section is achieved by the arrangement and construction of such a central aperture or recess whereby the shell extension section is pressed under the pressure of the propellant gases penetrating into the aperture or recess around the entire circumference thereof securely into the barrel of the gun so that during passage of the shell part through the barrel, a particularly good seal with respect to the propellant gases is achieved. This seal can be further improved in that the shell extension section is constructed with an outer diameter increasing in the rearward direction, for example, of slight conical configuration which additionally also favors the achievement of an advantageous transition of shell to cartridge case shoulder.

Accordingly, it is an object of the present invention to provide a target practice ammunition of the type described above in which the shell part and cartridge case are made in one piece of plastic materialand which eliminates by extremely simple and operationally reliable means the aforementioned drawbacks and shortcomings encountered with the prior art constructions.

Another object of the present invention resides in the provision of a target practice cartridge of the type in which the shell andcartridg e case are made in one piece which assures a clean, smooth and completely satis- 1 factory separation ofv the shell from the cartridge; case under all operating conditions. i

A further'o-bject of the present invention resides :i-n-- the provision of atarget practice cartridge in which the shell is made in one piece with the cartridge case of the thermoplastic material and which is provided? with an intentional breaking place between the shell and .thc cartridge case ofsuch arrangement and constructionthat acompletcly clean separation occurs at the breaking place devoid of any parts adhering to the rear end of the shell that might impair or influence its flight characteristics. Still another object of the present invention re 2 I sides in the provision of a target practice cartridge. of

than attainable heretofore. I

'-unitary therrnoplastic construction as'rcgards shell and v v cartridge case which assures a greater firing accuracy scribed above which achieves all of the aforementioned provision of a unitary target practice cartridge consisting of thermoplastic :shell and cartridge case in which the i shell maybe made of relatively large: weight :notwith standing theuseofthermoplastic rnaterialso as to facili- I 'tate and irn pr'ove it's use with automatic weapons.

. I A. still. further object of the present: invention; resides 1 in the provision of a target practice ammunition of; "thermoplastic 'niaterialthat not. only achieves a com ,pletely. satisfactory and mean separation of the cartridge 7 y 1 case from the vintegrally formed shell, but which also E bears a particularly good seal of the shell duringv passage thereof through the barrel with respect to the propellant 1 ases." These and other objects,

features and advantages. of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which shows, for purposes of illustration only, several embodiments in accordance with the present invention and wherein:

FIGURE 1 is a partial axial cross-sectional view through a target practice cartridge in accordance with the present invention in which the intentional breaking place is arranged between the shell and the forward end of the cartridge case neck section,

FIGURE 1a is a partial cross-sectional View, on an enlarged scale, of the target practice cartridge of FIG- URE 1, illustrating a slightly modified construction,

FIGURE 2 is a partial axial cross-sectional view through a modified embodiment of a target practice cartridge in accordance with the present invention in which the intentional breaking place is displaced rearwardly by the length of the cartridge case neck section and shoulder section to the place of transition from the normally present cartridge case shoulder into the wider rear section of the cartridge case,

FIGURE 2a is a partial cross-sectional view, on an enlarged scale, of a modified construction of the conmeeting place between the shell and the case, with the target practice cartridge according to FIGURE 2, and

FIGURE 2b is a partial cross-sectional view, on an enlarged scale, similar to FIGURE 2a of a still further modified embodiment of the connecting place between the shell and cartridge case with the target practice cartridge of FIGURE 2.

Referring now to the drawing, wherein like reference numerals are used in the various areas to designate like parts, the target practice cartridge according to FIGURE 1 is provided as usual with a cartridge case 1 having a large cylindrical rear portion 2, a forwardly conically aims and objects by extremely simple :rneansyet permits at the same time by extremely simple means i an :adjust.-=

:ment of the center of gravity of the. shell :in any desired mannerqv I A further object of the presentimventionresides inithe transition from the case :llor from the case shoulder 4 f to the shell 5, theradially extending, annularly shaped and'relatively narrow cut-i:n:or notch. 6 Whose depth: 7 corresponds in thiscase:exactlytothewell thickness of 1 i ,thecartridge case neck portion 4 so that in practice the. 1 1

shell 5 extends in effect withits extension 7 slightly into I the case neck-portion4 andthus is connected :with thel j case 1 exclusiyely'inthe radial direction by way of this extension 7. The' dash linesin FIGURE :1 indicate that the shell 5 may be provided. in its core with an aperture.

. or: recess open toward the bottom, vi.e., the shell need,

not necessarily be solid throughout.

As may readily be seen from. the. drawing,'the condi- =tions'are so chosenthat. the material has its weakest cross section at the transition: from; the shell. 5 to; the. vcase 1 so that defined intentional. breaking place. is

achievedpFurthermore, the. conditionsareialso so chosen 'that'duringfiringof the cartridge, the material is stressed 'at' this place :by the pressure of .the powder gases. ex-

clusively in shear and, therewith av smooth and cleanseparation of the; shell :5 from the case. 1 isachicvcd. I I 7 In order to achieve. a still .rnore clearly defined ini tended breaking place: and therewith a still more smooth I. I

and more clean separation between the shell 5 and the case 1; the construction of; this place may also be realized I approximately as shown in the enlarged cross section: of FIGURE la, thatii s', withianannular groove ornotch- 12 extending: :overthe entire. circumference or in a .similar.manner.v 1 1 I I In the, embodiment {of FIGURE? 2, the shellj .5, properly speaking, of solid. construction and. having an external surface slightly conically enlarged toward the i e'ar which-jas indicated by the dash lines in FIGURE 2-may :be I provided also in; this case within the core I v I thereof with a more or less large aperture or recess'open I toward the bottom, is provided in the rearward direction toward the rear end, which extension 8 corresponds to the usual cartridge case neck portion 4 and the cartridge case shoulder section 3, normally provided with such cartridges and indicated schematically in dash and dot lines. The rear end of the extension 8 projects slightly into the forward end of the wide rear section 2 of the cartridge case 1 having a cylindrical external surface and slightly conically tapering internal surfaces becoming wider in the direction toward the forward end so that the shell 5 with the extension 8 thereof is connected with the cartridge case 1 corresponding to the integral manufacture of the cartridge exclusively at this place and in the radial direction.

The arrangement is thereby made in such a manner that the annularly shaped area of slightest material crosssection coincides with the imaginary extension of the conical enlargement of the internal surfaces of the wide case section 2. It is achieved by this arrangement and construction that the area of smallest material cross-section defined as the intended breaking place is stressed during firing of the cartridge by the powder gases practically exclusively in shearing and a clean, smooth separation is achieved correspondingly between the

shell

5, 8 and the case 1.

Therebeyond it follows from this arrangement and construction that all places of the provided breaking cross section are disposed in a circularly shaped, conically tapered surface becoming smaller toward the rear so that after realized separation of the shell and case, the rear outer edge of the extension 8 is chamfered so to speak of, that is, the breaking surface is disposed practically in the aerodynamic shadow of the flying shell. Accordingly, in this case even with an eventually somewhat rough breaking surface, no parts thereof project beyond the largest diameter of the shell 5 or the extension 8 thereof so that the flight path is not impaired.

The extension 8 is provided in the illustrated embodiment with a central aperture or recess 9 extending over the entire length thereof and conically enlarged toward the rear whereby the conical incline or slope is chosen slightly larger than that of the external surface so that the wall thickness of the extension 8 is slightly reduced toward the rear. The advantage of a particularly good elastic adaptation of the extension 8 to the barrel of the gun during passage thereof through the same and correspondingly, a particularly good seal with respect to the propellant gases results therefrom. Of course, any other type of construction of the central aperture or recess may also be provided, for example, such an aperture or recess that a uniform wall thickness results or also especially such a construction that the aperture or recess extends in the longitudinal direction only over a more or less large part of the extension. It follows therefrom that one can at will readily influence the Weight and the center of gravity of the shell part in the desired or also necessary manner.

As shown in FIGURES 2a and 2b, a still more clear definition of the intended breaking place, that is, a still more sudden cross-sectional change at this place may be achieved if the connection between the extension 8 and the case part 2 does not take place directly at the mutually overlapping ends but slightly displaced toward the rear into the case part 2 (FIGURE 2a) and possibly also slightly displaced in the forward direction from the end of the extension 8 (FIG. 2b), that is, this connection takes place in such a manner that the extension 8 and the case part 2 are efiectively slightly further slipped one into the other and annularly shaped

notches

10 or 10 and 11 result or are provided.

While we have shown and described several embodimen in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art. For example, the illustrated embodiments are not limited to a certain calibre of the target practice cartridge and accordingly the illustrated dimensions are therefore to be understood only as exemplary which, of course, is also true insofar as the shape of the shell is concerned.

Thus, it is obvious that the present invention is not limited to the details described and illustrated herein but is susceptible of numerous changes and modifications as known to any person skilled in the art and we therefore do not wish to be limited to these details but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A cartridge having a firing axis of symmetry, comprising: a plastic bullet portion having a forward free end and a rearward substantially cylindrical portion: a plastic tubular cartridge case for enclosing propellant powder and having a forward substantially cylindrical tubular portion only partially encircling said bullet rearward cylindrical portion to define overlapping cylindrical portions; the inside diameter of said overlapping portion of said forward substantially cylindrical tubular case portion equalling the external diameter of said overlapping portion of said bullet rearward cylindrical portion; and said overlapping portions being homogeneously integrally connected along their entire adjacent peripheries to form a one piece plastic bullet and case structure to form the sole connection between said bullet portion and said cartridge case, and to constitute means for forming an intentional cylindrical breaking zone between said bullet portion and said cartridge case that is stressed substantially exclusively in shear by the pressure of the propellant gases during the firing of the cartridge.

2. The cartridge according to claim 1, wherein said cartridge case includes a rearward case portion, a forward neck portion and a shoulder portion connecting said neck portion and said rearward case portion.

3. The cartridge according to claim 1, wherein said bullet portion is provided with a central axial recess opening in the rearward direction.

4. The cartridge according to claim 3, wherein the walls forming said axial recess decrease in thickness toward the rearward end in a uniform manner.

5. The cartridge according to claim 1, wherein said cartridge case has a uniformly increasing internal diameter toward its forward end.

6. The cartridge according to claim 1, including an annular wedge shaped notch in at least one of said cylindrical portions immediately adjacent said overlapping portions.

7. The cartridge according to claim 6, including an additional wedge-shaped annular notch in the other of said cylindrical portions substantially identical to and opening in the opposite axial direction from said first-mentioned wedge-shaped annular notch.

8. The cartridge according to claim 1, wherein said cartridge is constructed of a thermoplastic material.

References Cited FOREIGN PATENTS 4/1961 Austria. 4/ 1960 Great Britain.

Claims

1. A CARTRIDGE HAVING A FIRING AXIS OF SYMMETRY, COMPRISING: A PLASTIC BULLET PORTION HAVING A FORWARD FREE END AND A REARWARD SUBSTANTIALLY CYLINDRICAL PORTION: A PLASTIC TUBULAR CARTRIDGE CASE FOR ENCLOSING PROPELLANT POWER AND HAVING A FORWARD SUBSTANTIALLY CYLINDRICAL TUBULAR PORTION ONLY PARTIALLY ENCIRCLING SAID BULLET REARWARD CYLINDRICAL PORTION TO DEFINE OVERLAPPING CYLINDRICAL PORTIONS; THE INSIDE DIAMETER OF SAID OVERLAPPING PORTION OF SAID FORWARD SUBSTANTIALLY CYLINDRICAL TUBULAR CASE PORTION EQUALLING THE EXTERNAL DIAMETER OF SAID OVERLAPPING PORTION OF SAID BULLET REARWARD CYLINDRICAL PORTION; AND SAID OVERLAPPING PORTIONS BEING HOMOGENEOUSLY INTEGRALLY CONNECTED ALONG THEIR ENTIRE ADJACENT PERIPHERIES TO FORM A ONE PIECE PLASTIC BULLET AND CASE STRUCTURE TO FORM THE SOLE CONNECTION BETWEEN SAID BULLET PORTION AND SAID CARTRIDGE CASE, AND TO CONSTITUTE MEANS FOR FORMING AN INTENTIONAL CYLINDRICAL BREAKING ZONE BETWEEN SAID BULLET PORTION AND SAID CARTRIDGE CASE THAT IS STRESSED SUBSTANTIALLY EXCLUSIVELY IN SHEAR BY THE PRESSURE OF THE PROPELLANT GASES DURING THE FIRING OF THE CARTRIDGE.