US2939392A

US2939392A - Blank cartridge

Info

Publication number: US2939392A
Application number: US605267A
Authority: US
Inventors: Huck Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-08-31
Filing date: 1956-08-21
Publication date: 1960-06-07
Anticipated expiration: 1977-06-07
Also published as: GB791208A; BE550670A; FR1157250A

Description

June 7, 1960 R. HUcK 2,939,392

BLANK CARTRIDGE Filed Aug. 2l, 1956 2 Sheets-Sheet 2 June 7, 1960 Filed Aug. 2l, 1956 R. HUCK BLANK CARTRIDGE 2 Sheets-Sheet l /lV VEN TUR Raber HZ/[K BLANK cARrRmGE Robert Huck, *Gostenhofer-Hauptstrasse 61, Nurnberg, Germany Filed Aug. 21, 1956, Ser. No. 605,267

Claims priority, application Germany Aug. 31, 1955 8 Claims. (Cl. 102-39) This invention relates to a blank cartridge with a bullet-shaped head pushed on to the metal cartridge case but intended to be retained thereon when the cartridge is fired.

One object of the invention is to attach the bulletshaped head to the case in a simple way and in such a manner that it will not be blown off when the cartridge is red. t

A further object of the invention is to construct the blank cartridge in such a way that inaccurately sized cases produced in the manufacture of live ammunition (rejected cases) as well as spent cartridge cases of fired live ammunition can be used for making blank cartridges.

Another object of the invention is to enable fired blank cartridge cases to be re-used. This means that the bulletshaped head should not only be suitably attached to the cartridge case to prevent it from being blown olf when the cartridge is red but that its removal from the case after the latter has been fired and ejected from the rearm should be easily possible. At the same time there should be no difficulty in attaching a fresh bullet-shaped head to a red cartridge case without the case being deformed by the removal of the old head and its replacement by a new one. Any deformation that might occur in electing such a replacement could impair the mechanical strength of the cartridge case and hence also affect the reliability with which the new bullet-shaped head was retained.

VYet another object of the present invention consists in giving the blank cartridge a shape, powder charge, and performance that willl make it t for use in automatic fire-arms.

A further object of the invention consists in fashioning the blank cartridge in such a way that, apart from card-v board, the bullet-shaped head may be made of an elastic plastic material and be so designed that any reduction in its elasticity and mechanical strength under the influence of heat and cold will not inany way affect the reliability with which the head is held when the cartridge is red.

A further object of the invention consists in providing sqcient space inside the cartridge case for a powder charge that will produce the necessary volume of gas for the actuation of automatic fire-arms without however creating an undesirably high `gas pressure.

Another object of the invention is to provide a bulletshaped head that can be cheaply manufactured, a matter of particular importance when making the head of a plastic material.

Another object of the invention consists in ensuring that the tired and extracted blank cartridge in a machine gun or automatic lire-arm will be properly ejected and not cause the tire-arm to jam by being caught in front of the returning bolt after recoil. It is therefore a more particular object of the invention to provide a blank cartridge which in weight corresponds so far as possible with a live cartridge and in which the centre of gravity of the extracted part of the cartridge is located as nearly as end of the barrel 4. At the end of the tapering portion' Patented June?, 1960 possible in the same place as in the case of an extracted live cartridge case.

A further object of the invention is to make the blank cartridge resistant to deformation in the region of the shoulder and of the approximately cylindrical neck.

Other objects of the invention will be readily understood with reference to the following description and drawings.

The invention consists in that the bullet-shaped head which externally embraces the forward cylindrical neck of the cartridge case is provided with a cone-shaped annular skirt Which bears against the shoulder of the cartridge case and which in the loaded firearm tlls or is compressed within the space between the shoulder of the cartridge case and the wall of the chamber at the rear end of the barrel.

The specific advantage inherent in this arrangement is the fact that the said skirt in the loaded lire-arm is located in the gap between the shoulder of the cartridge case and the walls of the chamber.

The skirt is compressed into this space more particularly when the cartridge is red. Its compression is due to the pressure created inside the cartridge case by the combustion of the powder forcing the metal walls of the case outwards on to the walls of the chamber and thereby lirmly wedging the skirt between the cartridge and the chamber walls. At the same time the pressure of the powder gases inside the cylindrical neck of the case acting in the direction of the barrel walls has the effect of compressing that section of the bullet-shaped head which adjoins the skirt, and of thereby assisting in retaining the bullet-shaped head on the case. The skirt which ernbraces the shoulder of the cartridge case and the section of the bullet-shaped head which bears against the cylindrical neck of the cartridge case are not directly exposed to the flash and the heat of the gases so that the firing of the blankI will not raise their temperature suciently to impair their mechanical strength.

` At the same time the cartridge can be readily inserted into the chamberiand the case can be easily extracted. Moreover, the bullet-shaped head can be easily removed from the tired case after extraction either by pulling or tearing it off. Plastic heads can be melted olf and cardf board heads or the like can be boiled off if required.

reference to the illustrative ings in which Fig. l is a blank cartridge according to the invention shown in side the chamber of a tire-arm and drawn on an enlarged scale;

Fig. 2 isv an enlarged representation of a detail of the blank cartridge according to Fig. 1;

- Fig; 3 is another form of construction `of a blank cartridge according to the invention, and

Fig. 4 is a detail of another form of construction similar to that shown in Fig. 3, the two latter drawings vbeing on a different scale to the rst.

The blank `cartridge 1 shown in Figs. 1 and 2, with which a tire-arm is assumed to have been loaded, comprises a metal case 2 with a tapering portion 2a which fits into the correspondingly shaped chamber 3 at the rear 2a facing the barrel is a shoulder 5. The cartridge case 2 then extends to form a cylindrical neck 6. An outwardly projecting ring 7 is worked into the cylindrical e neck 6. Two grooves 8 are recessed into the neck, 'one on either side of the projecting ring. Pushed over the cylindrical neck 6 is a bullet-shaped head 6 which is extended to form a slightly cone-shaped tubular skirt 10` bearing against the shoulder 5. That part of the bullet` shaped head 9 which embraces the roughly cylindrical neck 6 ofthe cartridge caseV 1 is internallylgrooved for" .serted intothe interior of the case.

engaging the annular projection 7 and itV also carries two projections which engage the grooves 8.

Further forward the bullet-shaped head is provided with a shoulder 11 which does not, however, kwhenlthe rearm is loaded make close contact with the shoulder 12 at the junction of the chamber and the barrel-4. Whenthe cartridge is inserted into the chamber the outerwall V13 of the 'lip v1.0 of the skirt bearing against'the ,shoulder of the case` 2 abuts the angle 14 in `the'corresponding part of the AYchamber. TheY bullet-shaped head has av suitably rounded nose 15 and is provided on its inside with a number of notches,` the disposition of for instance four such notches l16 Tbeing shown in the drawing Vofthe enlarged section illustrated in Fig. 2'. .Y

lThe bullet-shaped head 15 contains a plug 17 made .of felt or-the lke,..and a suitable quantity by weight'of powder topi-.Ovide a charge 18 is contained .in the powder chamber of the caseZ.

The blank cartridge functions as follows:

When the blank cartridge is fired the expanding powder gases enter the cavity v.inside the plastic bullet ,head 17 and vdrive thel plugll through .the nose whichv tears out towards the nozzle. The powder gasespress the cartridge case 1 radially youtwards on tothe walls-of the chamber. Consequently Atheplasticl part of the vbulletsshaped head which-embraces the .cartridge case is tightly compressed betweenzthe cartridge case andthe chamber walls. The bullet-shaped head :is thereby effectively prevented. from being blown out of the barrel. Y

A modified form of construction of the blank cartridge isillustrated in Fig. 3 andi .shows the walls of the tapering ypart Sti-ofthe case which formsthe powder chamber thickened towards the base'of the cartridge. The base 20 of the cartridge is fitted with a cap, not shown, and is provided with channels V'which communicate with .the in. terior of the cartridge. VIt also has a lbevel edge y21. and an annular groove 22 above the'said edge, the bottom shoulder in the chamber wall and the outer .surfaceof the bullet-shaped head is in contact with the walls of the barrel up to the annularfzone 36. The powder gases released by the charge 40 when the cartridge is red drive the felt plug 29 through the cavity inside the cylindrical collar 25 of the case and into the interior of the bullet-shaped head 30. Owing to the pressure generated inside the -case the tapering portion 50, the shoulder 24,Hand thoroughly cylindrical neck'Ziare pushed outwards, and the wall of .the tapering portion 50 iS firmly pressed against the chamber walls. The shoulder 24 presses the skirt 31 intothecorresponding angle in the chamber wall fwhereas .the adjacent section of the bullet-shaped head between the mouth 35 of theV cartridge case and the shoulder 24is firmly wedged between the roughly cylindrical neck 25 and the corresponding part of the barrel wall. The beading26 is pushed into the cooperating groove in thebullet-shaped head. The cooperation of lthese parts produces a gastight joint and holds the bullet-shaped head suiciently tightly to prevent it from being blown off. The gas pressure inside the cartridge casefdrives the `plug y29. further upwardsjagainst the 1 notches 38 which .then tear open'roughly from the nose -:or groove is provided in the bullet-shaped head. 'The of the groove being perpendicular with reference to the base-,whereas the upper edge 23 of the sameis :likewise bevelled. The tapering portion 50 of the Vcartridgegcase is modified towards the head of the cartridge .to form a shoulder. 24 surmounted by a cylindrical neck'25. AnV

outwardly projecting annular beading 26 is embossed into the cylindrical neck 25, the lower lateral edge. 27 of which is perpendicular with reference to the ,longitudinal axis 4of .the cartridge. The edges i27 of the beading are rounded. Below `theshoulder 24 va felt plug 29 is..in Below thev felt lplug 29 is the powdercharge40. f Y

A bullet-shaped head 30 is pushed on to the Vcase shown in. Fig. 3. .The bullet-shaped head 30 is provided with a cone-shaped skirt 31 which ybears on the shoulder 24 whereas its lower extremity 32 is butt ended. The outer surface 33 of the tapering skirt 31 fits against a shoulder inside the chamber when the cartridgeis loaded into the breech. Above lthe skirt 31 the bullet-Vshapedhead has an annular step 34. The mouth 35 of they cartridge case is located beyond ythis step. Y

The bullet-shaped head 30 is of uniform wall thickness extending from the step 34 upwardly as far .as a zone 36. vAbove thisV annular zone 36 the bullet-shaped head is domed V3'7 and its Wall thickness decreases.V Notches 38 are cut into the Vinsidegof the dome 37. Thefpresencey of the notches 38 produces a very'thin wall section in -the nose 39 of the head.V .The bullet-shaped. head 30 is retained on the case, on thejone hand, by the 'beading'. 26 and on Vthe other handby the cone-shaped Iskirt which. is pressedv between the shoulder of the case Vand .the 'corresponding. angle in the chamber at Vthe end of the barrel rwhen thecartridge is ready for firing..

When a firearm is `loaded with fthe blank cartridge the tapering portion V50 .ofthe vcase is )in .contact withxthe chamberwalls and the base' 20x01? the Vcar.tri.dge.abuts the bolt -with' the extractor engaging thefgroove. 22. The outside surface 33 of the skirt 3.1 is in 'contact -withthe bullet-'shaped head 42v shown in Fig. 4 and Vits coneshaped skirt 43 are attached to the cartridge lcase 1 by means ofan adhesive between .the bullet-shaped head 42, the neck 41, `and the shoulder 24. Otherwise case and headare of similar shape to that shown in Fig. 3.

The'blank cartridge shown in Fig. 4 functions as has been hereinabove already'described. The bullet-shaped head is retained in position on the cartridge case,rsub stantially as hasy been explained in connection with the preceding forms lof construction, Vby means of the conev 'hard synthetic plastic material suchasjpolythene, polyvinyl' chloride, or of cardboard, asbestos,plexiglass, vulcanised libre, or the like. An elastic synthetic `is preferj able as this easily tears when the cartridge lis fired and is readily deflected against the barrel Walls owing toits elasticity.

. The cartridge case may be brass, tombac (72-90%y copper, remainder Zinc), Vsteel, plated steel, copper, or-the like. l

'Itwill be readily -understood that the cartridge as well as 'the bullet-shaped head may also have some other shape to conform with the construction of the re-a-rm and that the vinvention must: not be deemed as being in anyfway limited by the illustrative examples that have .been described.

Moreover the felt plug maybe inserted -in -s'ome other Y position than that shown in'Figsfltol. "A preferred position is that 'illustrated in Fig. 3. Y

The bullet-shaped head, (9,. 30, l42) may also consist Ofmetal, especially lightjmetal such asaluminium -.or aluminium` alloy. InY this caseY the ldepth ofthegrooves 8 or the height of the annular beading -26 Vhas to .be smaller than shown in Fig. l and 3.

"What l claim is:

l. A-blank cartridge for a-fire-arm comprising a barrel,

a cartridge chamber located at .the rear end of theV barrel and' having.. a .frusto-conical shoulder portion .at the rear of said chamber; said cartridge comprising a metal cartridge case having a forward cylindrical neck, a frustoconical shoulder located immediately behind the neck, and a sleeve-like body located behind the shoulder, a charge of powder located within the sleeve-like body, a bullet-shaped head comprising a weakened closed end, a skirt covering the forward cylindrical neck of the cartridge case and a frusto-conical extension of the skirt covering the shoulder of the cartridge case, the skirt and extension being arranged when loaded into the lire-arm to substantially ll the space within the cartridge chamber and frusto-conical portion thereof and externalto the neck and shoulder of the cartridge respectively, while the bullet-shaped head projects into the barrel of the rearm, whereby upon discharge of the blank cartridge the pressure of the gases arising from the powder charge causes the shoulder and neck on the cartridge case to expand and to hold fast the extension of the skirt and the skirt itself against the frusto-conical shoulder portion of the cartridge chamber and the cartridge chamber respectively, while the closed end of the bullet-shaped head bursts and liberates the gases into the barrel of the firearm and hence into the atmosphere.

2. The combination claimed in claim 1, for use with a tire-arm having a second shoulder located at the entrance to the barrel forwardly of the frusto-conical shoulder portion, wherein the skirt of the bullet-shaped head is provided with a stepped portion adapted to substantially abut said second shoulder when the blank cartridge is loaded into the re-arm.

3. The combination claimed in claim 1, wherein the 6 i skirt of the bullet-shaped head and the extension thereof are secured respectively to the neck and frusto-conical shoulder of the cartridge case by adhesive means.

4. The combination claimed in claim 1 wherein the cylindrical neck of the cartridge case is provided with an external annular beading, and wherein the bulletshaped head is provided with an internal recessed groove corresponding and engaged with said beading.

5. The combination claimed in claim 1 wherein the lower end of said frusto-conical extension is provided with a butt-ended annular vertical surface.

6. The combination claimed in claim 1 further comprising a felt plug located forward of the charge in the sleeve-like body of the cartridge case.

7. The combination claimed in claim 4, wherein the surface of the beading which faces the base of the cartridge is normal to the axis of the sleeve-like body.

8. The combination claimed in claim 4, wherein the section of the annular beading has rounded corners.

References Cited in the le of this patent UNITED STATES PATENTS 726,579 Schutte Apr. 28, 1903 1,933,694 Allen et al Nov. 7, 1933 2,703,529 Tuckerman Mar. 8, 1955 FOREIGN PATENTS 71,249 Germany Oct. 2, 1893 1,081,764 France June 9, 1954 1,097,001 France Feb. 9, 1955 732,633 Great Britain June 29, 1955