US2915972A

US2915972A - Ammunition

Info

Publication number: US2915972A
Application number: US550570A
Authority: US
Inventors: Aaron L Hitchens; Czapek Emil
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1955-12-02
Filing date: 1955-12-02
Publication date: 1959-12-08
Anticipated expiration: 1976-12-08

Description

Unite 2,915,9'2 1C@ Patented Dees-,1959

AMMUNITIoN "Aaron L. Hitchens, North Ridge, Calif., and Emil Czapek,

Woodbridge, Conn., assignors to Olin Mathieson Chemical Corporation, East Alton, Ill., a corporation of Virginia Application December 2, 1955, Serial No. 550,570

lThis invention relates generally to ammunition and more particularly to gun cartridges and to a method for making the same.

In the manufacture of shotgun cartridges, it has been the custom, heretofore, to make the case from a relatively pliant and resilient convolute wound paper tube and a metallic head which closes one end of the tube. This type of cartridge is not entirely satisfactory, however, because the region of the tubular body adjacent the metallic head and particularly substantially adjacent to the ange or extraction rim of the head sometimes expands when the cartridge is fired rendering extraction thereof from the gun chamber extremely dicult. In fact, in some instances the head becomes detached from the tubular body by the guns extraction mechanism. In other instances, the friction between the cartridge case and the guns chamber is so great that none of the cartridge case can be removed by the average guns extracting mechanism. 'Ihese disadvantages of such a cartridge are hazardous as well as troublesome to the shooter for it sometimes happens that a cartridge is inserted and red in the chamber of a gun which contains the'tubular body of a preceding cartridge often with serious injury to the shooter.-

In view of these disadvantages of the paper shotgun cartridge having a metallic head, many attempts have been made to overcome this defective condition. It has been recognized that the expansion or bulging of the breech end of the cartridge case is due to the pressure of the gases developed by the explosion of the propellent charge and numerous expedients therefor have been proposed. Probably the most successful of these is the prov vision of an abturating basewad within the tubular body and adjacent the metallic head thereof,but even the best of these wads may fail to completely seal the breech portion of the cartridge against gas leakage. It has also been suggested, as for example, in U.S. Patent 1,171,313 issued to Bonham, February 8, 1916, that one end of the tubular body be folded about the end of the basewad and that the tube wall be forced into the extraction rim or ange of the metallic head by means of a metallic disk. This expedient has not been completely successful, however, as it involves a rather cumbersome manufactoring step and does not eliminate separation of theY head from the tubular body when the cartridge is red.

Numerous other shotgun cartridge cases have been proposed including cases molded from various plastic or synthetic resinous compositions or cases molded from paper pulp or papier mach but none have been foundv shotgun cartridge having the advantages of the usual paper cartridge but devoid of the disadvantagesrinherent with the prior construction. A further object of this invention is to provide a method for making a novel shotgun cartridge case having a paper tubular body. A still further object is to provide an improved case for shotgun cartridges.

Other objects will become apparent from the following description and accompanying drawing in which:

Figure 1 illustrates, in a vertical view in section, suitable apparatus for making an embodiment of this invention, and

Figure 2 is a vertical sectional View of a cartridge illustrating an embodiment of this invention made in apparatus such as illustrated in Figure 1.

Invaccordance \with this invention, generally stated, the foregoing objects as well as others are achieved by providing a shotgun cartridge with a plastic head and a paper tubular body havingione end thereof folded inwardly and embedded in the plastic head, thereby securely locking the tube and head together. This invention also provides a method for forming the plastic head about and in locking engagement with one end of the tubular body in such a way that the head isnot removed from the tubular body by the extraction mechanism of the gun. By plastic head or base as utilized herein and in the appended claims is meant a head formed from a resinous material which can be shaped in a softened state and hardened thereafter. Either a thermoplastic or a thermosetting type resin is suitable for the purpose provided that the required period of time at the molding or casting temperature thereof is below that point at which the properties of the paper tubewill be deleteriously alfected.

In general,` in making the cartridge case of this invention, a paper tube is convolutely wound using a suitable adhesive such as casein or starch, Waterproofed and sized in accordance with known processes. The basewad is positioned within the tube so that it is spaced away from the end and that portion of the tube extending from the bottom of the basewad is subsequently folded rover and about the external edges of the bottom of the Wad; it being preferred that the angle of the bend be less than ninety degrees for the usual flat-bottomed wad illusl trated, i.e. that angle which leaves the folded end spaced from the wad as shown. A shotgun cartridge head or base is molded about the inwardly extending end of the tube by submerging it in a suitable molten resinous materialY confined in a die of suitable configuration and hardening the resinous material about the tube end.

It has been found that a shotgun cartridge having a case made in accordance with this invention is a vast Improvement over the various shotgun cartridges of the prior art because the advantageous characteristics of the laminated paper tube have been retained and, in addition, the breech end of the cartridge has been improved. In contradistinction to the paper shotgun cartridge having a metallic head, the shotgun cartridge of this invention is easily ejected from the gun chamber. In fact, it has been found .that basewads which do not provide sucient obturation to permit their use in the metallic headed prior art paper cartridge, as well as the better obturating wads, can be successfully utilized in a shotgun cartridge made in accordance with this invention because the breech end of the plastic'headed cartridge does not become perma` nently expanded by the gases developed by the explosion of the propellent charge. Cartridges having the breech structure provided by this invention have been successfully reloaded and again red without malfunctioning thereof. vThe plastic head also assists the basewad in providing rigidity to the breech end of the cartridge and thus assists in imparting the characteristic required for proper initiation of the 4priming charge. It is apparent,

therefore, that the cartridge provided by this invention has advantageous properties in addition to the important advantage of providing a substitute for the shotgun car- .Scrintion of ene embodiment of: this invention, 1a1 munie tubular-bodies nani be :cut therefrom is woundabout ai 1 1 l g 1 1 1 f 1 suitable mandrel from; papercoated 'with casein paste l 1 1 fand =isthen successively dried', sized, and cut to the; re- 1 1 1 i i quired length in accordance with. well knownpractice; 1 1 1 1 The .tube is then impregnated with paraffin or similar1wax= and .a i basewad `:is firstv compressed landA then positioned' 1 1 1 .therein =in accordance with fknown methodsr except the 1 f 1 f basewadfis positioned with the: bottom or: thatend there-1 i prdesignated -to .be :substantially f adjacent :the head ofi 1 z 1 1 1 the cartridge; spaced inwardly1 fromfone endoftheitubei l 1 iA .mandrel is :now inserted iin the tube' and .the end .of

the tube: is forced intov fa; diei having?, a concave zeavity ---1faround the iouterfed 1 1 against.: 1

about; c-

; tube .1, fol-ined; as .described hereinbefore is :placed on man rests on basewad 7 fandpressure eirerted through r'nan pressure exerted through mandrel 2 is maintained until the plastic has cooled and solidied. To facilitate removal of the cartridge case from the die, die cavity 5 is composed of two component parts, a cylindrical cavity 23 in die block 11 for forming the base of the head including the extraction rim and a cylindrical opening 22 through die block 9 for forming part of the base and the sidewalls of the cartridge head, as shown.

After the ethyl cellulose has cooled to below its melting point and preferably to 8O or 90 C., die blocks 91and 11 which are fastened together by

pins

10 and 12 forming a friction iit in corresponding cavities in each of these parts are separated by moving die block 9 and die 4 in a direction opposite to that designated by the arrow in Figure l. A primer assembly comprising a conventional battery cup 13, a primer cup, a priming composition and an anvil is inserted with conventional apparatus in the primer pocket in head or base 14 in the position shown in Figure 2 and the tubular body 1 is charged with propellant 1S,

filler wads

16 and 17 and projectiles 18. The end 19 of tube 1 is crimped over wad 20 to completely enclose the contents of the cartridge case.

Although in the foregoing, one embodiment of this invention is described in detail, this invention is not limited to such details as numerous variations can be made. Other suitably plasterized resinous materials such as, for example, melamine formaldehyde resins, urea formaldehyde resins, methyl methacrylate, ethyl methacrylate, polyamides, cellulose acetate and the like and molding compounds containing the same can be utilized for forming the cartridge head. Suitable plasticizers include dibutyl phthalate and the like. The laminated tube can be rolled with a water type adhesive such as described aboveA or the tube can be rolled with a resinous material such as ethyl cellulose, polystyrene, synthetic rubber, such as iride@ having. ainetallic'head whemshortages of metal:

' Referring .now to the accompanying drawing. fora: de-fy l 1 therein :to fold rthat fpo'rtioa extending from the' bottorln 1 1 f of the ibasewadinwardly at an :angieofiess than ninety I l f degrees.- Ehe .folded over 1 portion shoud- .be bent.

of' the, wad and dit :snuglythere 1 1 E E l :Die I4. sind .twopiece casting! die 9 =and=11f are assembled f as shown ini Figure il land. apretormed: disk'ot :a frnolding= 1 f 1 1cornpound; of: ethyl cellulose :having 1a mettingi point fof 1 .(11 is placed inciavity 15.; ''lie' ethyli cellulose 1 1its insertion; 'there-inf and assistsA mi secnrlng the pruning as'sembiywithin the; head.= .it has' alsobeen; found that the; l l iunction of pin Siz when acting: as a= guide; pin to property 1 position :the tubular body assembly; in? cavityi 5; is an :line y por-t'an't one Las the goed extracting iprop'ertresof the clara tridge having a plastic :head are ati least partially .due to@r 1 1 1 isi heated ite yabouti 1.185 toi 226C? 2C; l A laminated paper 1 drel 2 havinghandte 3 and isinserted in ydie v/ith the l ibend over iend; 6i 'o f tube extending beyond the bottom 1 .end of basewad 7 finito :the :plastic-rnaterial.v 1 :Mandrel 2 1 l 1thei erxaeti alignment of fthe :tnbuiar body with the; headl 1 ;asf is nade possitxle by .this invention.-y -This aligrurlen'iz 1 can be' accomplished much more accurately than is possr-l 135 f. the tubular body fand head; of :the cartridge :are not 1 drel 2 against:r basewad 17 1und1; :the :assembly Ior tube! :1 and basewad; 7; is rnnvedifn fthe direction indicated by they arrow in= Figure to a position in mold cavity 5 such; that at least; about one-half. eff the basewad :7 and that pon-1 tion of itube 1 l. thereabout is contained therein-.1 l Conicai ping t; :serves: to properly aligntube; f1 lwith1cavity5; Sto'y stopi tubef1 at the proper =level therein and, :tu form -a-y 1 v 1 :pocket: for; later insertion of :the .primer assernhiy; The 1 I neoprene; and? the like; dissolvedrinasuitablesolvent or. 1 L i 1 1 while molten; :in some-instances,1 whenla resnnius'adhei f 1 y 1 sive is utilized for rolling; the. tube, a; suitable wax such f mensionsof conical pin Si provision-can be made for cas 1 ing-aplastici tube-21; betweenpin-S-and theWallof-eylm-v 1 plastic ltube =211 is smaller= in diameter than the .external concentrici .with the axis et: the: head; the' cartridgebe asiparain is included ingthe adhesive. Ait-subsequent wax- 1 1 v either .the kadhesive orthe: wax irnpregnationA step; .itz de -1 1 1 1 1 2 sired.- vEvanescent f end closuressuch 1 as those formed s 1 from the tubular fbody for =a=r breakable top Wad can Lbe. i 1 1 1 1 util-ized infcriinping: theloadedeartridge and other Aknown i i 1 f 1 sequeneezof `'steps can be followedineprelpraing. thel lami- 1 inzatied ltubular bedje-if desired.; AIt particularly advan.-` 1 1 1 tageous -to1foid2 the tube' about; the outer edge of :they l basewad and to press it snugly against the. surfacel of thel g l l wadiat the: bend substantially as illustratedin the drawing. v i because isueh1a1 construction. results inf optimum strengthi 1 f and preventstheplastie iheadfrorn becoming severed from;

;theztubefwhenthe -fshellistired= 1 1 1 1 1 1 1t is to lbeinoted,that bj1-properly iecmtrollingl di `drietal channel 24 through basewad i tapering 1 diameter of batters/1 cup E13 andis; expanded; thereby uponf ble `when assemblyinga metallic head with ai tubularibody.; 1

properly 'aligned and :the axis; oftheprimger: assembiyfnot;

ling thereof againlstthe chamber walls renders extractionl 1 i of the red cartridge case diflcult. Pin 8, while preferably nearly conical, can, of course, be made in other suitable shapes such as a truncated cone.

Having described the invention, what is claimed and desired to -secure by Letters Patent is:

1. In a gun cartridge, a case Vcomprising an oriticed basewad, a laminated paper tubular body compressibly' fitted over said wad and having one end thereof emd bedded at an open angle with said basewad ina set plastic head having a primer pocket, the plastic head comprising a base with an integral extraction rim thereabout, tubular sidewalls integrally projecting from the base about said tubular body and into said open angle, respectively, in the region of the basewad and a smaller substantially cylindrical tube integrally projecting from the base of the head as an extension for the primer pocket from said head into the orice of said basewad, the smaller tube and primer pocket being concentric with` the. projecting tubular side walls and extraction rim or the plastic head.

2. The cartridge case of claim l wherein the tubular primer pocket tapers from the pocket diameter of the opening in the base of the head to a diameter of less dimensions in the extension and a primer wedged into retention in said pocket.

3. A loaded gun cartridge having an oriced basewad, a powder charge, at least one overpowder wad and a projectile charge contained in a case comprising a ilexible laminated paper tubular body having one end thereof extending beyond said basewad and folded inwardly until pressed snugly about the outer edge of said basewad t0 form an angle therewith, said end being retainably embedded in a pressure molded and set plastic head extending into said angle and carrying a primer press-fitted therein for retention, said case having a crimped closure at the other end of 4said body.

4. In the manufacture of gun cartridges, the process for making cases therefor which comprises providing a paper tube, placing a compressed oriced basewad within the tube in a position intermediate its ends closer to one end than to the other such that a portion of the tube projects from the bottom end thereof, folding said projecting portion inwardly toward the bottom of said wad around the outer edge thereof to leave 4said bottom and portion in spaced relationship, and forming a plastic head in situ about the folded projecting portion of the tube embedded therein and at least said bottom of said basewad.

5. A shotshell cartridge case comprising a laminated paper tube, a substantially Hat-bottomed centrally orifced basewad compressed within said tube and disposed proximate one end of the tube, that end portion of the tube extending beyond the basewad being bent toward the center of the tube around the outer edge of said wad and forming an acute angle therewith, the bent portion of the tube being retainably embedded in a plastic head provided with a peripheral extension embracing an outer portion of the tube lateral to at least about half of the length of said basewad and with a centrally located extension embracing at least part of the interior surface of the basewad orice.

6. A method of making a shotshell case comprising providing a laminated paper tube, positioning a substantially flat-bottomed, oriiced basewad within said tube intermediate its ends with the bottom of said wad approximate one end of the tube with a portion ofthe tube projecting beyond said bottom of the basewad, folding the projecting portion of the tube inwardly thus forming a bent portion at an angle greater than and less than between the straight portion of the tube and the said bent portion of the tube, and molding and setting in situ a plastic head about at least half way up that end of the tube containing the basewad with a portion of the plastic head also being molded in the angle remaining between the basewad and the bent pro.

jecting portion of the tube.

References Cited in the le of this patent UNITED STATES PATENTS 1,330,144 Sherman Feb. 10, 1920 2,426,289 Wallace Aug. 26, 1947 FOREIGN PATENTS 10,760 Great Britain June 2, 1894 394,037 Great Britain June 22, 1933 914,780 France July 1, 1946 732,633 kGreat Britain June 29, 1955