US1384769A

US1384769A - Laren

Info

Publication number: US1384769A
Authority: US
Publication date: 1921-07-19
Anticipated expiration: 1938-07-19

Description

' F. B. MACLABEN.

ELECTRIC GUN. I APPLICATION FILED MAR. 18. 1916. 1,884,769. Patented July 19,1921.

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F. B.. 'MACLAREIL ELECTRIC GUNl V APPLICATION FlLE MAR. 16, 1916,

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' @nvm/woz I @MS04/Mur! Patented July 19, 1921.,

. F. B. MAcLAREN.

ELECTRIC GUN.

loN FILED MAR l1s 9| APPLlcAT .,1 s. 1,384,769. Patented July 19, 1921.

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eJen'c/ 7572:: anni UNITED STATES lEaEiJ'Emci: B. moLAEEN-,Q JERSEY criar, NEW JERSEY. AssIvGNoE To' ELEcfnriIc" or rm-LADELrHiA, PENNsjYLvANrA, A conronA'rzoN or GUN coEPoRATioN,

DELAWARE.

T o all whom t may` concern:

Be it known that I, FREDERICK" B. MAC- .LAREN, a citizen of the United States, resid.l ing at/Jersey City, countyfof Hudson, andv State of New Jersey, have invented certain new and useful Improvements in Electric Guns; and I do hereby declare the following to be a full, clear, and exact description.,

of the invention, such as will enable others skilled in thev art to which itv appertains', to

make and use the same.

The invention .relatesto electric guns, and

has for one obj ect to provide a novel method of discharging or propelling projectiles, which consists in generating traveling mag- .netic fields, annular in form, propagatedin the direction of the desired line'of flight of the projectile, by means of polyphase electric current developed and ldelivered by a generator ,so constructed as to be capable of storing up energy, as in a heavy rotating mass and delivering the same, when desired,

in the forni of current of high frequency Y prising a barrel surroundedby a series of the gun muzzle at .the attained velocity.'

annular coils so disposed and arranged that,

when they are connected to the leads'fromA the generator, they will produce -a series of traveling. annular magnetic fields progressing successively from the breech to themuz.- zle'of the gun, so that when a suitable projectile is placed in the breech, said projectile will be subject to the effect of current',

induced in it by said traveling magnetic fields andwill be moved throughjthe bore of the gun barrel toward the\muz-zle,'wi'tl1 an increasing velocity, which ultimately approximates that of the traveling magnetic fields', and vsaid projectile is discharged from These andv other objects and novel fea` tures of the invention will appear from'the annexed descriptiomin connection `with vthe accompanying drawings, in vvlilch:A 'l n' z 'inodeiand place of use;` 1

As illustrated in Figs. 1, 4^ and'5,the gun barrel preferably consists of--an inner tubu. larimember" 1 provided 'with a-clear unobstructed bore and open l,at both ends which QStaitially PATENT 5 OFFICE'.

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, specification of Leaersimen. Patented July 19, 1921, vApplication fleli March 16, 1916. Serial No. 84,674.A v

. Figure 1 is a side elevation of a gun and the means for operating the same.

Fig. 2 -isa side elevation, partly in section, 01:' a shell or projectile adapted for use with th gun.. A

' Fig. 3 1s a diagram ofthepower circuits'. y

Fig. 4. is a vertical -transverse section through the gun-taken on the Iine'4-4 ,of Fig. 5, with coils omitted.- l

Fig. 5 is a fragmentary longitudinalsection through-the gun taken on line 5-5 of Fig. 4.

Fig. 6 is a view similar to that shown inI Fig. 4, illustrating a modiication of the gun structure. v

Fig. 7 is a side-elevation of. ashell or j projectile adapted for use with ,a gun of the' type shown in Fig. '6. Figs. 8 and 9 "areY respectivelypa side. andan end4 view of a modified form of projectile, and Fig. 10 isfa. Vdiagrammatic view illustrating one way of changing 'pole' pitch.

Referring tothe drawings, and more particularly to Fig. 1, A' lindicates the barrel offthe gun as a whole, which `in the'type shown is mounted by the usual form of trun.

nions F upon a swiveledbase B sup orted on a suitable sub-base or foundation` and is provided withany suitable type ofV re-'l coil mechanism C, traversing mechanism E,

elevating'l mechanism D, and' sighting de vices I. Obviously, any of lthe other usual or Well known types of'mountingand operating mechanism may be employed to suit the .particular character of "voJ the vgun and its v constitutes theA guidewayflfor the'projectile.V

Thisinner member lis preferably formed of a tube of metal possessing high specific resistance to electric currents,I such, forl ex'- ample, as silicon'steel, or, where practicable,

of a non-coiiductingy'material, such as indurated' ber or: a composite material possessing vsuliicient strength to withstand the the gun' vis .100' tressesv imposedfupon. it.- Bymaking the.

v sections 10 by means of sleeves and washers 13 of induratedl fiber or other good insulat-l ing medium. The splittingv of the jacket 10 is to prevent short circuit currents from iowing in it.

The annular space between the inner and outer tubular members 1 and -10 is subdi-v vided transversely by means of annular partitions 15, which in turn are provided at intervals with radial generally triangular ribs or fins 16, the partitions and ribs, 15 and 16, being preferably rigidly connected or formed integrally with the outer sections 10 of the jacket.

Arranged within the cellular structure formed by theinner tube 1 and the outer jacket 10 is a series of annular coils c', '02, c3., arranged is successive groups'andexten'ding from the breech to the' muzzle of the gun, each of said coils being so formed as to con form to the .annular space defined between the vertical wall of an adjacent partition 15 and the rearwardly inclined edges 4of the.

ribs 16 so thatV the partitions ,15 and the strengthening ribs 16 serve to take up thethrust produced in the gun by the passage of va projectile through the same and distribute such thrust uniformly throughout the gun barrel.

It will be understood that the innen tube 1 is rigidly locked to the other parts of the bar- Y. rel structure at the muzzle and breech, or, if

desired, at intermediate points Vvso as to pre vent any independent movement between the inner tube and the parts of the gun barrel.

The several sets of annular coils c', c2, 03 constitute the' means fory generating l'in the barrel or bore of the gun, traveling magnetic fields, which are propagated -longitudinally of the gun barrel from the breech toward the muzzle and which, when a projectile of' appropriate material is placed in the bore of the gunk at the breech, induce'currents in the projectile, thereby setting up aforce tending to move the projectile'through the gun to\v ward the muzzle. s

As'illustrated, fthe coils c', c2, c3 are supl plied with current of the alternating threephase type, but obviously current of any other polyphase type might be employed by proper selection and arrangement of the coils.

Each oup of coils, c', c2, and c3 is connected web the 16ms L', L2 and L3 Aof a threetions being made in accordance with the wir- -ing diagram illustrated in Fig. 3.

The\generator G, designed for high frequency and to deliver very large currents for relatively short periods of time, is provided with'a heavy iy wheel G', and is adapted to be coupled up with a steam engine or other prime mover. Theffly. Wheel G' serves as an agency for storing the energy developed by Athe prime mover and for delivering the stored energy to the gener-n ator. The necessity forsome energy-storingvmeans will be apparent when it is remembered that the power supplied by the.

generator is utilized only while the projectile is traveling through the gun barrel and witha gun barrel of the ordinary lengthand Ithe high velocity imparted to the projectile, each period of time, when power is demanded of the generator, is but a small fraction of a second. As the amount of power or'energy required'during this *briefv interval of time is very large, however, the reserve energy stored up in the flyl wheel becomes available. Y

In order to control'the supply of current from the generator to the coils o the gun barrel, there is interposed inthe circuit between the generator and .the coils a suitable switch S, which in turn is controlled by aA push button or other circuit controlling means S', preferably mounted Von the gun barrel and electrically connected with the switch S. Said switch S may be of any of the well known 'types used `in circuits of this general character.

The projectile P consists of either a solid or hollowk body of metal which may be of any `appropriate shape common to' shot or shell. Preferably the projectile ismade of metal having good electrical conductivity.

and suiiicient strength to stand the strains imposed upon it, such as steel, brass, cop, per, aluminum or similar metals. If de- 'sired, the projectilemay consist of laminated iron asshown at 101, Figs. 8` and 9, associated with insulated copperr conductors 102, the iron portions acting as. partof the magnetic circuit and the insulated copper as the-electric circuit for the induced currents. In the preferred form of the projectile,A however, the magnetic circuit is not especially provided for, but the good electrical conductivity of the projectile is a desideratum. lThe projectiles, as indicated, may bemade hollow to provide space fol` an explosive and adetonator, when the projectile takes the form of a high, explosive, or armor-piercing shell. or to provide space for powder,ifuse and balls when the projectile is used as a shrapnel. *In order to increase the efiiciency of the projectile as an element of the electrical system which'efi'ects `ner tubular member 1 and .thecoilsc c2v and c3, each of said coils fr", r'and ri being connected with the proper lead ofthe poly-'- phase circuit from the generator-.so that when the polyphase clrrentflows in theA s id coils, they set vup a rotary field within't e gun barrel which imparts a rotary motion to the projectile P. It is evident that the gun, as described, when operating to discharge a projectile therethrough, constitutes a polyphase motor of the induction type, of

very high power and relatively small size.

` It is a well known fact that motors of this .vtype generate heat during their` operation,

and in the present instance, special means is provided for rapidly dissipating the heat generated. This is preferably effected by providing the outer jacket 1Q of the gun with ribs or fins 2O to increase the convection and radiation surfaces. In addition to this cooling means, when necessary, the gun may be provided with means for circulatinge,rv a coollng medium, such as oil, around -the colls surrounding the inner tube 1, orV

by blowingair around the coils, or by providing the outer'jacket with double walls to constitute a water-jacket through which v water or 'other cooling medium ymay be forced. In the relatively small gun illusvtrated in the drawings, a` suiiicient cooling effect is produced by the ribs or-fins 20,

` associated with abody of oil confined'V in the spaces between the inner and outer tubular members, not occupied`by`the exciting coilsL the oil serving 'as a medium for conducting^the` heat from the coils to the outer jacket 10,-'whe`re Vit is 'dissipated by the ribs20. "j l ,Instead ofproviding the -gun with the longitudinal coils r', r?, r3, to produce a rotary field, to' impart V'the' desired rotaryf' motion to the projectile, the same result may fbe attained by providing the bore of the` t f inner tube 1 with suitable rifling 2, see Fig.

6, which are adapted to be engaged by complementary ribs d, formed on the projectile d', see Fig. 7 In this ,type of gun, it is nec- ,essary to prevent any relative rotary motion `between the innerA and cuter members 1 `and v Ainsulating -tube 3,- which is .located inthe 10 vof the gun barrel and'to effect this vob ject65V the inner memberl is'securely lockedto'the y outer member v10 by means of a keylt' which engages mating slots in the outer surface of the vmember 1 and the adjacent peripheral edges of the partitions 15. Preferably, in both types of the gun, as described, the inner -tubular member/.1` is' insulated -from the other .parts o fqth'e barrelby means of an interposed sheath 'or tube 3 of insulation, and. obviously the key 14 shouldbeof -in- 7 5 lsu'lating material or be properly insulated.

the projectile should be fas high as possible,`

and 'as the vvelocity 'of thel projectile cannot f exceed that of the traveling field, it is, therefore, necessary that the velocity of the-traveling fleld should be maintained as high "as practicable. The velocityof the traveling field is proportional' to thelpole lpitch and the frequency of .the inducing current so 95 that by varying or regulating either one or y both 'of thesepfactors, the velocity of the traveling field may' be correspondingly varied. Referring to Fig. '10, one way of varying the pole pitch is shown. In that figure a. series of coils 1O6 is` shown. The first threebeing connected to the polyphase system 107 `to form one pole, the following six coils being Aconnected tothe same system to form a pole of twice the length of the 10 first pole, and .byrepetitio-n the pole pitch maybe increased indefinitely. J

If the frequency of the currentsin the gun l coils is constant,-the. frequency of \the.cur p rent, induced in theprojectile is highest at 110 the breech'I and gradually decreases toward the muzzle asv the velocity vof the projectile increases. It 'is a well known fact that in polyphase induction motors of any type, the

forces-acting, on the part carrying the vinduced currents are a maximum for la certain i frequency of induced currents,` and if the frequency is descreased, the vforces fall off quickly, and if; increased, the forces decrease slowly from sald maximum. In consonance with'this principle, therefore, it is decidedly advantageous` to vmaintain the frequency of the inducedfcurrentsin the projectile con- ,V stant, and of such value as fwill maintain the forces vat a maximum.' This result;can"| 2 5i be approximated for practicalpurposes by making the velocitybf the traveling magv netic field comparatively-lowat theb'leec'l gun, an' outer housing,

and gradually increasing toward the muzzle of the gun. rent in the gun coils is constant, the resultl can be attained by varying the pole pitch, making it small at the breech and gradually increasingr toward the muzzle. In addition to this particular mode of varying the velocity of the traveling field, the same result may be effected by increasing the frequency of the impressed current during the time the projectile is traveling from the breech to the muzzle. of the gun, or by connecting the successive sets of coils on the gun to generators of different frequencies, which vary from a relatively low frequency near the breech and gradually increase to a maximum frequency at the muzzle. Obviously either of these two latter methods may be used in conjunction with the first method referred to, to wit, the variation of the pole pitch.

IVhat I .claim is 1. The method of discharging or propelling projectiles, which consists in generating traveling magnetic fields propagated in the direction of the desired flight of the projectile by means of polyphase electric current, and subjecting the projectile to the inductive accelerating influence of said traveling fields.

2. The method of discharging or propelling proj ectiles` which consists in generating annular traveling magnetic elds propagated in the direction of the desired flight of the projectile by means of polyphase electricA current land Yinterposing the projectile within said annular fields to subject th'e same to the. inductive influence of the latter.

3. The method of shooting projectiles which consists in establishing a field travelin in the direction of flight by means of polyphasev currents` and applying the accelerating motor effect of that field to" the projectile to shoot it through theV air.

4. The methodV of shooting projectiles by electricity which consists in producing a traveling magnetic flux flowing crosswise of the direction of flight and establishing acur- `rent flow in the projectile in directions at right angles to both the flux and Iflight paths and thereby causing the resultant motor effeet to accelerate and shoot the projectile through the* air.

5. An electric gun for discharging projectiles` comprising a tubular barrel,projectil'e revolvlng means. a series of annular coils surrounding the barrel and arranged to produce a traveling magnetic field progressing from the breech to the muzzle of the barrel, and means for 4simultaneously supplying 4polyphase electric currents to all of said coils to produce such field.

6. An electric gun for discharging proj ectiles, comprising a barrel having V an inner tubular member constituting the bore of the If the frequency of the cura series of annular coils interposed between the inner and .outer members arranged to produce a traveling magnetic Held progressing from the breech to the muzzle of the barrel, and means-for supplying polyphase electric currents to'j said coils.

. 7 An electric gun for discharging projectiles, comprising a barrel, including a series of annular coils. surrounding the barrel arranged to produce a traveling magnetic field progressing from the breech to the muzzle of the barrel, a series of coils arranged longitudinally of the barrel ,to produce a rotary magnetic field within they barrel, and means for supplying polyphase'electric current tov the respectlve sets of colls.

8. An electric gun for discharging p'rojectiles, comprising a barrel including an'inner tubular member of high electrical resistance to effect a substantially equal distribution of "flux around the tubular member, a series of annular coils surrounding the tubular mem- .ber and arranged to produce a travelin magnetic xfield pro ressing from the breec to the muzzle of t e barrel, and means for supplying polyphase electric current to said coils.

9. An electric gun for discharging proj ectiles, comprising a barrel including an inner tubular member of high electrical resistance, an outer tubular member provided with heat dissipating means, and a series of coils interposed between the tubular members and arran ed to produce, Awhen supplied with' polyp ase electric current, a traveling magnetic field progressing from the breech to the muzzle of the barrel.

11. In an electric gun for discharging projectiles, a 'barrel comprising an inner tubular member, aspaced outer tubular member, an-

nular partitions having ribs extending longitudinally of thel barrel, and annular coils: interposed between said members and bej tween said partitions, said coils being ar--" ranged to produce, when supplied with poly-1 phase electric current, a traveling magnetic field progressing from the breech to the muz' I zle of the barrel.

.12.v In an electric gun for discharging projectiles, a barrel comprising an outer tubular 'member split longitudinally, with insulation between thej'adjacent edges, an in ner tubular member possessing high electrlcal resistance, and a plurality of sets of annuto said generator to store up energy applied lar coils interposed between the inner and to said generator, and a gun com rising a outer members and arranged to produce, barrel surrounded by a series o annular Whensupplied with polyphase electric curcoils adapted to be simultaneously connected 5' rent, a traveling magnetic field progressing to said generator to produce a traveling inag- 15 from the breech to the muzzle of the barrel. netic lield progressing from the breech to the 13. An ordnance system propelling projecmuzzle of the gun.l tiles 'at high velocity, comprising a genera- In testimony whereof I ailix my signature. tor of polyphase alternating currents of high 1Q frequency and power, ally Wheel connected FREDERICK B. MAOLAREN.