US1628527A - Projectile for smooth-bore guns - Google Patents

Description

Mgy 1o 19273 Filed Feb. 19, 1925 2 sheets-Sheet- 1 A .ofli w.

May Y1o. 1927.V 1,628,527

E. w. BRANDT -TROJECTILE FOR SMOOTH BORE GUNS 'Filed 1311.19; 1925 2 sheets-sheet 2 Fig. 3 Fig. 4'

7N/@mrow EWE/wwf Patented May 10, -192i?.

` UNITED STATES PATENT -'oI=1=-1C|a:. A

EDGAR WILLIAM BRANDT, or' PARIS, Fragancia.

PBOJECTILE FOB SMOOTH-ROBE GUNS.

Apgucation :nea rebraary 1a, 1925, serial No. 10,413, andan France January is, 1925.'

The invention relates to various improve` ments in projectiles of this class whereby their stability and range will be augmented as compared with the known types, said im.4 provements relating:

(a) To'the shapes and the relative dimensions of the several parts of projectiles which.

have a tapered form and maybe made cast iron, steel-pig, or steel;

l (b) To the arrangement of a set -of grooves at the largest part of .the projectile whichdoes not fit exactly into the bore of the gun, said grooves providing a pneumatic joint between the projectile and the cannon when the shot is fired; g

(c) To the disposition of the propulsive cartridge, in the tail part of -the projectile with the addition of strengthening sleeves; (d). To the construction of the fin device whereof the fins are 'longitudinally flanged at the outer edges in order to increase their total surface Without augmenting their general size, and also to provide for the holding of additional propulsi'vercharges employed in long-range firing.

The following description setsl forth the various features of the invention, with reference to the appended drawings which are given by way of example and in which:

. Fig. 1 is a`n elevational view of a projectile according to the. said invention.

Fig. 2 is a longitudinal section of the same.

Fig. 3 shows'the'profilel of the main body of the projectile together with` a modified -form of the band. and

Fig. 4 is a modification'of the same,

Fig. 5 shows4 various shapes which may be employed for the grooves provided in the band. i

Figs. 6, 7, 8 and 8EL are partial longitudinal sections showing various methods of attach,-

projectile.

. Fig. 9 is a .cross section of the tail piece and of the iin device on the line 9 9 of Figs- 10, 11 and 12 show various forms oftheV cases containing the additional charges. My said projectile essentially comprises a` vmain-body of cast.iron,p steelpig or steel into whose front end is screwed a fuse of the percussion, time, or combination type, and, toV whose rear end is secured a tail piece provided with a suitable n` device. The said main body comprises three parts; at the front, a part 1 having an ogival profile andA to which is secured the fuse 2, an intermediate part or band 3 whose largest diameter serves to determine the calibre of the projectile which is very -slightly below the diameter of the gun bore, and a tapered part 4 which is conical or substantially conical and preferably convex, it being joined tothe band portion 3.

The total length of the projectile with its fuse is comprised between threel or four calibres for initial velocities of -200V meters per second and between four and seven calibres for initial velocities above 200 meters per second. l

For initial velocities below 200 metres per second, the total length of the projectile is subdivided as follows: (1) the distance between the front end of the fuse, measured upon the centre line, and the middle plane M-N of the band, and which is taken as a unit or one part;` (2) the height of the tail fin device and which is also equal to said unit; (3) the height of the rear portion of the body between the said middle plane of the band and the top of-the tail is comprised between 1% and 2 parts(1:3 to 4 calibres or 3,5 tof4 parts). A

For initial velocities above 20() meters per second, the height of the fin portion is comprised between 1/2 part and 1 part. The other proportions will remain substantlally as above indicated, for projectiles which are constructed for small initial velocitiesy (11:4 to 7 calibres or 3 to 4 parts).

In the device'shown in Figs. 1 and 2,'the band ofthe projectile consists of a cylindrical portion extending outwardly of the front ogival portion 1 and of the rear portion 4, peripheral or circular grooves 5 being formed in the said cylindrical portion, the said grooves havingvherein a square crosssection. j p j In Fig. 3, the front part ofthesaid band' is directly joined to the front oival portion," and du@ to. the absage@ @i all r1 s extending `jectiles, thev trimming will be acilitatedif the .said belt extends somewhat outwardlf e from the vo 'val portion, anincreased'aerm' dynamic e ciency over what is afforded by the device shown in Figs. 1 and-2 will be obtained, at the same time facilitatingthe penetration into the layers of air as well as the iow of the air along the projectile without friction or eddies.

'For the manufacture of cast iron prothe ogival part, as shown in Figa'fl. y

1 v indicatin grooves shown 1n this figurejare analogousmain body of theprojectile has a'l diameter..

which is somewhat smaller than the diameter of the trimmed band,V so :as to. form .a

' -shoulderibi between these two' parts.'

l The gas which tends-to escape between-the projectile'and .the gun tubefwhen the shot ...1s fired will meet withv the shoulder b 'which will thus form arst obstacle. A The gas-twill howeverupass between the tube andthe rib ofthe band and will thus attain the firstgroove; this ,latter constitutes a region of `lt'lger4 cross 'section in which' the gas ex pands and losesf'its" velocity; by its impact Y n v against thev annular sur'facea ofthe" e oove gas is drivenfback, at least partial y,-'and' the vfirst eddy. is""thusproduced.` Slmilar eddies are produced in the samemanner in i el ' The genera-l cylindrical shapewithi ogrval obtained.. a AThe approveclaction of thefsaid pneumaticv the successive grooves, so-j-that .the discharge of the gas 1s checkedfin anenergetic man-- het. .A l, j Due to' the pneumatic joint whichis thus' formedA by-the groovedba'nd, the loss of gas' escaping between'theprojectile and the gun -tube will be therangewill be thereb augmented; at -the same time'g't'he propu sive action' of the charge is lmade regular in virtueof the diminution-in the variations of thisacti'onl between the suc' .cessive shots,lwhichare-duefto of se,

and a greater accuracyfiniiring willbe t us j ointis duetto the-pro er determination' of the height'of the V said and 'and'f the 'size and number 'ofthe grooves'formed therein saidY action augments with the'pressureof thev gases produced by the 'combustion of... the propulsive charge,

knownal'tillfer'y; projectiles. have a fram-Parts' 11H11@ fear.' the bnel'igsgfter'ni-f 'less than the diameter 'of the its vlateral walls are 'aperture '7. vThe sadzpiecemaybefsi l plys'crewed to 'the rear 'of the main-'bdd t of riveting, 6,'t`he ylixidtigliti-ifiytallic or oth-vr packing-member' oyeliplgf l.the projectile",` when"I leaving* the' mesma? nated by a plane transverse section, so that there will be vformed in the rear of the projectile when in Hight `a considerable vacuum which has a marked retarding action.

In my rojectile, the' rear part 4 of the 7o body whic 1 has thetapered form will'reduce the amount of the retardng action upon the projectile by obviating, or at, least greatly ',reducing, the eddiesat the rear; the streams 'of' air, `which are 'abruptly impelled and 75 pushed laterally yby the front ogival part 1 and the band 3, will slide along the parti 4 which moves forward in the reglon of the lvacuum produced 4atthe rear of the'ba'nd. f Due to the fact that the streams of air 'are 80.

,thus guided and brought' to the rear part of the projectile' without' the ,formatiolroff eddies, the projectile'v offer aless res@V 'ance to forward-'motign than the'known' artillery lprojectiles and f'will therefore 35.'

'possess a higherA aerodynamic etiiciencythair` the latter. n I l D By reason of the tapered shape. ofthe partf` 4', `the weighty of -this'portion wlllbe much reduced as compared with the weight "offf im pro'ectile of` like` calibre having theagr; A lindro-ogival profile'. For this reasonit ew 'centre of gravity of the lspindle-shaped body of .the projectile according to the Ainvention will be brought' mu'cl in front of the middle v95 A point on the mainjcentre line, whereby aerodynamic stability .of the ,projectile will be augmentedi; 4.A1-the .rear of the saiditapered portion 4.-, more. or' lessconveir, 'is-.mounted a'v tail piece 100 v6 having a tubular formandmade of -sem1 hard'steel or like aterial 0f great strength thexdiamcter of' the' saidpiece 1s considerably projectile, and 'as vshown t .105

' Vci er internally, j Fia-12, oriexternallyf. ig# "8% and'8` show by'WayP-ff eiiample various other 1 1 methods of ,securmg the same', 'res ectivelyzl? by-riveting, vseating orfsoldering or rweldff y- 'autogenous welding, bra'zing.A

l Between the body ,of 'the projectile .tllfgfti'l--f-p1e'tlfx may be augmentedbyfinterpo'smg mecharge #the cartridge j casef :will bei pressed laterally' in't'o thesaifd groore'orj grooves, a'nfd'-` the cartridge will. be drawn forward. with 5 Y adr amount of the propulsive charge.

Within the cartridge case 9 is disposed a `sleeve 11v of cardboard or analogous lnaterial which increase-s the strength as well as the fluidtightness of the said carlridge case. Due to the addition of the said reinforcing sleeve (or sleeves) the, said cartridge case will possess a suppleness and an elasticity, as regards punching e'l`ects,'which it would not have were it simply made with thicker walls. lVih this arrangement, I. am further enabled 'to provide'a waterproof coating between the cartridge case and the sleeve.

By the use of the said sleeve 11, I am enabled to 4accurately adjust the space provided for the powder constitutingl the propulsive charge, and this facilitates the manufacture of the cartridges and also provides for the folding down of the end of the saine in uniform conditions. Since the finished cartridges have a uniform length, the capacity of the expansion chamber at the rear part of the tail piece 7 will be the same for al1 the projectiles. By the said arrangements, I obtain theumform combustion of the propulsive charge and a uniform expansion of gases, whereby the firing is ren-v dered moreaccurate. It should be noed that the said important'advantages can behad by the use of one or more sleeves disposed at the exterior of the cartridges in-- serted within the said tail piece.

Upon firing the shot, when the charge is set off by means of the fixed or movable striker of the gun, the cartridge case and its strengthening sleeve or sleeves will be punched in coincidence with the holes 7 in the lateral wallof the tail piece, and the iga will escape laterally through the said 1o es. f

the support for a fin device which obviates the' use of a tail piece of great length which would be much affected by the win'd, and it thereby affords an approved longitudinal and transverse Istability and hence a great accuracy as to range and direction, as well as a most reliable functioning of the per-v cussion fuses. The fins are disposed at the cxtreme rear' of the projectile whereby they are enabled to travel in air which has resumed the normal state or Vat least iin which the streams are parallel forwardly of the vacuum region formed in the rear ot'` the said band. The several fins will thus act in conditions of maximum efficiency. The

length ot' the fins is either greater than,'.

equal to, or less than that the vlength of the tail piece 6, and is determined by experiment in view of obtaining the most approved stabilizing conditions.

The fins 12 are attached to the said tail piece 6 by rlvelng, soldering or welding,

The tail piece of the projectile serves as' or by like means, and have a relatively short length; the use of multiple fins compensates for theirshort length whereby'a sufficient total surface will be provided while obviating the use of a limited number of fins of 'considerable' length for the obt-ainment of an equivalent surface. According to the invention, the number of fins employed is always greater than four.

Fig. 9 shows a form of construction in which two adjacent fins are formed by a common sheet metal` member which is secured tothe said tail piece. The middle part of the said member has a suflicient width and has formed therein suitable holes 13 which register with the holes 7 in the lateral surface of the tail piece. In this torni of construction, the fins necessarily have .aneven number; but if they are cast integral with the tail piece, an odd number of tins may be provided, -for instance 5, 7, 9, 11` 13 or 15 fins.

In order to obviate unequal reactions upon the said fins when the gases under pressure which, after punching the cartridge .case and' the reinforcing sleeve or sleeves of the cartridge, proceed through the holes 7-13 and expand between the projectile and the tube ofthe said tail piece, the flow sections provided for the gases are substantially proportional to the volumes of the spaces comprised between the adjacent fins.v

If; as shown in Fig. 9, all the holes are of equal size and if there are two holes at A and three holes at B, the fins willi-be so disposed that the volumes at 'Af and at B will have substantially the ratio 2:3.

The fins 12 are flanged at 14 upon the ,whole or a part ofv their edge. The parts which are notthus flanged are rounded in such manner as to facilita-te the handling of the projectile. vThe flanged parts 14 serve to increase therigidity of the' said fins and will thus enable the sameto hold their shape during transportationl and handling. The flanged ,parts serve chiefly to increase the total guiding surface of the projectile when in flight, and the additional surfaces are advantageously situated at thevperiphery of theprojectifle, i. e. in the region in which the air has `become perfectlycalm by reason of" thege'n'eral shape of the projectile.

The flanged parts 14 also serve f or the'.

attaching of the v'cases containing the ,additional charges which are employed for longrange firing, said'cases being heldan elastic manner1 between the vsaid ns and in front of the holes 7-13 from which the jets of ignifed gas are to be discharged..

The said cases are made in two parts and are` constructed in various `forms `las shown by way 'of example in Figs. 10 to 12, and they are manufactured by casting or stampingof a plastic substance which is not su ject to ignition in the open air such as a l containing an amyl acetate varnish, for ex;

ample. j j When the shot is fired, the flames of the ignited gases will issue from the holes in the tail piece of the projectile, perforating the cases containing the additional charges, which are held by the flanges of the said fins. Due to the high temperature of the gases, the combustion 'of the said additional charges as well as their containing cases will be ensured, thus leaving nov unconsumed' residue. l

Obviously, the said invention is not limited to the onstructional forms hereinbefore described with reference to the appended drawings; the said forms are given solely by way of example and are susceptible of various modifications without departing from the spirit of the invention. In articular, it is evident that while the various improvements in projectiles above mentioned i will contribute in a general manner to the increase in the aerodynamic eiiiciency of the projectiles, to their stability in Hight, to the accuracy of/ the firing in range and direction, to the maximum range, and the like,

'A the said improvements need not be employed simultaneously, and a given projectile, provided it comprisesone or more of the said improvements,`may be considered as being within the scope of the invention.

Having now described my invention, what 4I claim as` neu7 and desire to secure by Letters Patentis:

1. A'projectilevfr smooth-bore guns coniprising a. body havingy an.` ogival front part anda truncated conicalv rear part connected at their bases, a fuse secured to said front partvand av fin carrying tail part, the total length of said projectile-being comprised between 3.8 and 4 calibres the length of the rear part of the body being comprisedbetween 1.8 and 2 calibres and the length of the said tail part being less than 1 calibre.

2. A projectile for smooth-bore guns comprising a body having an ogival front part anda truncated conical rear part connected at their bases, a fuse secured to said' front part and a fin carrying tailpart, the total length of said projectile being comprised between 3.8 and 4 calibres, the length of the rear part of the body being comprisedl between 1.8 and 2 calibres and thel length of the said tail part being less than 1 calibre, the tins being secured on the tail in a region longitudinally separated from the rear part of the body of the projectile.

3. A projectile for smooth-bore uns comprising a body having an ogival front part and a truncated conical -rear part connected at their bases, a fuse secured to said front part and a fin carrying tail part, the total -length of said projectile being comprised between 3.8 and 4 calibres2 the length of the rear part of the body being comprised between 1.8 and 2 calibres and the length of the said tail part being less than 1 calibre, the diameter -of said fin arrangement being substantially equal to one calibre whereby a reliable guiding effect is obtained.

4. A projectile for smooth-bore guns an ogival front and a truncated conical rear part connected at their bases, a fuse secured to said front part and a short fin carrying tail part, a substantially cylindrical middle portion the diameter ofy which is equal to the calibre of the projectile and connecting said front and rearl parts with one another and circular grooves provided on thek periphery of said middle portion in planes at right angles to the axis of the projectile and adapted to create eddy currents o f thepropelling gases iowing around said middle portion each groove having an annular front wall `perpendicula'r to -the axis of the projectile, the lateral side of each groove tapering towards the rear end thereof.

5. In a projectile for smooth-bore guns, a body comprising an ogival front part and a tapered rear part, a tubular perforatedtail part secured to said rear part, fins provided on the outer periphery of said tail part, a cartridge Within saidtail 4part and one or more reinforcing sleeves concentric with said cartridge. v

6. In a projectile for smooth-bore guns, a body'comprising an ogival front part and a tapered rear part, a tubular perforated tail part secured 'to said rear part., fins provided on the outer periphery of said tail part, a cartridge within Said tail part and one or more reinforcing cardboard sleeves concentric with said cartridge.

7.,In a projectile for smooth-bore guns,

a body comprising an ogival front part and a tapered rear part, a tubular perforated tail part secured to said rear part, fins provided on the outer periphery of said tail part, a

of fins, greater than Wo, secured to the outer periphery of said tail part, the two fins of each pair being cut in one metal sheet and the outer edges of said fins being flanged longitudinally over one part of or all their length.

.9. In a projectile for smooth-bore guns a body comprising an ogival front part and a tapered rear part, a tubular perforated tail part secured to saidrear part, a cartridge within said tail part and a number of fins, greater than four, provided on, the outer peripher of said tail part, the outer edges of sai fins bein flanged longitudinally over' one part of or a l their length, and cases containlng additional charges carried by saidy tail part in front of the perforations therein, said cases being made of a material adapted to burn under the action of the combustion of said cartrid e.

10. In a projectile or smooth-bore guns a bod)T comprislng an ogival front part vand a tapered rear (part, a tubular perforated tail part secure Ato said rear part, a cartridge within said tail part and a number of ns", greater than four, provided on the outer a body comprising an ogival front part and 2" a .tapered rear (part, av tubular perforated tail part Secure to said rear part, a cal'- tridge within said tail part and a number of tins, greater than four, i'ovided on the outer periphery of said tall part, the outer edges of said fins being flanged-longitudina ly over one part ofor all their length and cases of a plastic cellulose compound containing additional char es carried by said tail therein.

In testimony whereof I have signed my name to this specification.

EDGAR WILLIAM BRANDT.

part in front of t e perforations l

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