US 2448343 A
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Description (OCR text may contain errors)
Au@ S, i948.
As. M. ZANDMER l PROJECTIL 4 Sheets-Sheet 2 Filed Dec. 14, 1942 Aug 33? 193484 s. M. ZANDMER l 2,448,343
PROJECTILE Filed Dec. 14, 1942 4 Sheets-Sheet 3 Aug., 3l, i948. s. M. ZANDMER 2,4489343 PROJECTILE Filed Deo. 14, 1942 .4 sheets-sheet 4 Y gm, In \\Y\\ \\\-k l alas ymrvamwner;
Patented Aug. 31, 1943 UNI TED S TA'ifES PATENT OFFICE PROJECTILE- v Solis Myron Zandmer, Los Angeles, Calif.
Application December 14, 1942, Serial No. 468,971
The invention relates to improvements in a projectile and barrel or bore of a gun or `cannon r other firearm.
An object of the invention is the provision of means. to reduce the friction and loss of energy in the passage of the projectile through the bore of the cannon while utilizing spiral tracks, grooves, or guides in the bore to impart a rotary motion or spin to the projectile Another object is to provide a positively interconnected friction reducing spirally disposed guiding means between the projectile and the barrel or cannon bore, positively constraining it to a rot'arymotion in its passage through the cannon,
Another object is to provide for a substantial reduction of recoil by reason of the provisiony of the friction-reducing means according to the inn vention, thereby permitting of lighter, simpler, and more mobile construction of guns or cannon and of recoil mechanism, especially desirable for tank or aircraft cannon, which can consequently be of'larger size.
A further object is the provision of means pro viding for friction reduci-ng bearings at more than one point along the yprojectile and also to provide mea-ns enabling change in the rate of the spiral of the r-iiiing in the barrel of the cannon to change the rate of spin or rotary motionof the projectile.
4Other objects will appearhereinafter.
2Enthe drawings which are diagrammatic Figure 1 is, a small scale view of a projectile according to the invention in which balls are mounted.
Fig. 2 is an enlarged fragmentary section on line 2 2 of the projectile of Fig-l, in place in the barrel of the firearm Aalso shown in section.
Fig. 3 is an enlarged view of a ball between the projectile and bore.
Fig. 4 is a view of a projectile embodying a preierredv modification of the'inventi-on, and Fig. 5 is an enlarged section on line 5-5 of Fig. 4, also showing the barrel of the lrearm in section.
Fig. 6 is -a view of a projectile embodying a further modication, and Fig. '7 is a section on line 1*-1 of Fig. 6, and also showing the barrel of the rearmin section.
Fig. 8V is a sectional View showing a detail.
Fig. 9 is an enlarged sectional view of a modificat-ion ofthe ball mounting in the projectile, and Fig;` 10 is another view of the same showing the balli received in and engaging the spiral groove or track in the bore of the cannon or firearm,
Fig.11 is a view similar to Fig. 9 showing the ball received in the spiral groove diagrammatie cal-ly shown.
Fig. i2 is a top plan View of the ball mounting of Fig. 9.
Fig. i3 is an enlarged sectional View of a iurtlier modification of; the ball mounting in the projectile, and Fig, 14 is another View of the same showing the ball received in the spiral groove or track in the `bore ofthe cannon or rearm.
Fig. 15 is a view similar to Fig- 13 showing the ball received in the spiralv groove. diagrammatically shoWn. y
Fig. 16 is a top plan view of the ball mounting of Fig. 13.
Fig.' 17 is a diagrammatic illustration of r`aportion of a irea'rm'bore laccording to the invention, provided with spirally disposed tracks, grooves, or guides for receiving the balls of the projectile and for imparting a rotary motion thereto.
Fig,e 18V is a diagrammatic illustration of an'- ot-her portion' of firearmA bore showing spiral tracks or grooves according to the invention, disposedin increased rate of spiral.
Fig. 119 -isareduced view similar to Fig. 8 of a desirable modification.
In the drawings i represents a projectile in which, according to the invention, spaced apart bal-ls 2v `are mounted in seats or sockets at fixed positions or locations in the body ofthe projectile, and are mounted to permit them to rotate in said seats or sockets 3 in the projectile. l
The balls may be mounted in the body of the projectile in the seats or sockets 3 provided in any suitable way and by any suitable means, and in the embodiment shown cages or insert members or plugs 4, having the sockets 3 formed thereon, are employed inserted in recesses 5 formed in the body of the projectile.
The cages providing sockets or seats 3 in the projectile are designed to receive a portion ofthe entire surface of the balls 2, While leaving a -portion of the balls exposed and protruding fromand beyond `the surface of the projectile. The portion off the sur-face of the ball received in the seat or socket, and the remaining portion protruding from the body ofthe projectile may be substantially half or more or any portion less than 4half of the surface vof theball, as may be desired. In the preferred embodiments exemplified in the drawings the ballsare disposed so that at least one hundred and twenty degree arcuate sections thereof engage in the riing groove and in the yprojectile body, respectively. In the form of Figs. l-3 approximately half the ball engages in each. The same is true in the form of Figs.
lief), and with respect to the balls 2 in the form of Figs. 6-8 (in which the balls 2a are primarily guiding or centering balls, rather than projectile rotating balls). In the. form of Figs. 9-12, an arcuate third of the ball is engaged in the projectile body and nearly two arcuate thirds of it in the rifling. In the form of Figs. 13-16 an arcuate third of the ball engages in the riiling and nearly two arcuate thirds in the projectile body. By this arrangement effective shear sections and load distribution are attained.
In this connection it is desirable to so mount each ball in its seat or socket, that there is-a minimum of bearing contact between the ballV and its seat or socket, so that there will be a minimum of contact pointsVV of sliding friction bespacing of the balls 2, Fig. 6.
I also provide by my invention for additional bearings on a projectile for use in a bore having variations in the rate of spiraling of its grooves. These additional bearings, additional to the single circular row of balls in xed spaced location, are provided by means of one or more rotary rings 8 carrying rotary balls, as indicated at 2a in Figs. 6, 7 and 8, the balls 2a having rolling contact on a surface 9 of the projectile. The rotary ring 8 is designed in any suitable manner to carry the balls 2a for rotation in fixed spaced locations in said ring corresponding to the The ring may, for example, be formed in two parts as seen in Fig. 8, comprising an inner ring portion and an outer Y ring portion and so shaped or formed at the tween the ball and its socket as the ball rotates therein.
Spiral grooves or guides 6 are provided in the,
barrel or bore 'l of the gun sor cannon and are of a suitable shape in cross-section, i, e,` arcuate or spherical, to receive and to positively guide and constrain ythe balls seated in the projectile, to the spiral path of the grooves to positively rotate the proj'ect'ne by means of the ball bearings moving in engagement with the spiral grooves, upon its being projected through the bore. The smooth portions la of the projectile between the spaced apart ball bearings are disposed adjacent and to pass over the corresponding smooth portions 'la of `the barrel between the spaced spiral grooves and are desirably spaced therefrom by a minimum of clearance sufficient to provide for expansion and contraction under temperature change While desirably maintaining the minimum of clearance at alltimes. The full load of the projectile in the bore lof the gun is then carried by the balls. However, the invention is not limited to this, as relative dimensions may be such that the load of the projectile may bepartially or Wholly carried by the smooth surfaces la of the projectile slidably engaging the smooth surface portions 'la of the barrel, th-e balls then bearing principally against the sides lof the spiral grooves to guide and impart rotation to the projectile.
Desirably the Iballs Zfmay be mounted in spaced apart relation in a circular row around the projectile, as seen in Fig. 1, the balls being disposed for rotation in the seats or sockets 3 which are spaced apart in said circular row so that the protruding part of each of the balls will :be in a position such that it will enter one of the spiral groovesV 6 of the bore 1 `of the cannon or gun. The balls, however, need not form a circular row, but may be disposed on or along the body of the projectile in any desired spaced arrangement so that they are in a position to be received in the spiral grooves in the bore of the gun, which grooves also need not be arranged in any fixed number or relation as to spacing so long as the grooves ,and balls are made and disposed to cooperate.
If the rate of spiraling of the grooves 6 in the bore is uniform throughout the length of the bore, the ball-s need not be in a circular row. Also, a second circular row of balls 2V may be provided as rseen in Fig. 4 to provide additional bearings and positive guiding means.
If, however, the rate of spiral is changed during the passage throughthe bore, only a single circular row or group of rotary balls in xed spaced location in the projectile surface may be used as in Fig. 1, which will be capable of conforming to any change in the rate of spiraling of the grooves.
ball recesses, as to conform to the spherical surface of and to retain the balls in the ring for rotation therein. The two parts of the divided ring S may be secured together by any suitable means, as rivets or other fastening means I0. The projectile surface or raceway 9 for the balls 2a of the rotary ring 3 may `be .provided in any suitable manner, and in the embodiment shown may desirably be disposed inwardly of the main surface I of the lprojectile thereby forming a shoulder at Il against which the rotary ring may have sliding contact. The connection of the nose la: of the projectile to the body thereof, may
e be by a screw threaded connection as indicated at I2 in Fig. 8. Desirably the rotary ring 8 may be initially fixed in position on the projectile by any temporary fastening and in the embodiment shown a small frangible spot Weld I3 or other fastening is formed between the rotary ring 8 and the shoulder ll, which will be broken upon any change in the rate ofv spiral of the grooves of the barrel in the passage of the projectile therethrough, to permit the rotary ring to change its rotary position in respect to the projectile to conform to the changed rate of spiral of the grooves, the projectile still being positively guided in the spiral grooves by the single circular row of balls 2 (Fig. 6) in xed location around the projectile whatever the rate of spiral `of the grooves may After the temporary seal or fastening i3 is broken, the balls 2a in the rotary ring 8 simply provide bearing for the projectile in its passage in the grooves of the .bore and do not serve to impart any rotary motion to the projectile, said rotary motion being imparted to the projectile by the xed rotary balls 2 in the spiral grooves of the bore. Upon discharge of the projectilefrom the barrel, there is no further function for the ring 8 and .balls 2a and whether or not the ring 8 -becomes separated from the projectile is immaterial. However, the nose la: may desirably be extended in diameter as shown at Ima: in Fig. 19 to hold the rotory ring 8 on the projectile.
.Regarding the mounting of the balls 2 in substantially fixed locations in the projectile surface, as seen in Fig. 3, the balls 2-may each be disposed in a `socket or seat 3 desirably of somewhat larger diameter than the segment of the spherical surface of the ball, at the plane of contact between the ball `and seat, which is substantially the ball diameter in the embodiment shown in Fig. 3 .(in which the ball is disposed substantially half in the socket and half protruding from the surface of -the projectile and engaged in the spiral grooveof the gun bore). Thus in Fig. 3, the seat 3 is desirably made of larger ldiameter than that of the ball. The ball preferably is temporarily fastened to the vbottom of the seat or socket 3.by
the'surface thereof, cages in said recesses for receiving said balls, said recesses being larger in area than said cages,.so th'at the cages .are laterally shiftable. therein, 'and resilient means disposed .in said recesses 'engaging the'cage members and the walls of the recesses vand retaining said cages ltherein in suchv manner that said cages may shift irisaid recesses to provide shift of :alignment of said balls to adapt them tothe spaced spiral groovesof the gun bore. 1 1' i.
3. A projectile having a plurality 'of recesses in Vthe surface thereof at spaced intervals around the projectile, a cage member in each of said recesses, each recess being of a greater dimension than the associated cage measured circumferenytiallyV of the projectile, a ball arranged in each cage member and projecting from the surface of the projectile a distance suiiicient to extend into spaced spiral grooves in the bore of a gun, and :spring means disposed in said recesses and engaging the cage members.
4. In a projectile, spaced proj ectile-rotating means comprising balls seated for rotation in the vsurface of the projectile and extending outwardly from the surface of the projectile suiiiciently for engaging spaced spiral grooves in th'e bore-of a gun, a ring member mounted for rotation on the projectile. during firing thereof, a second group of-balls mounted in said ring member and spaced Vtherearound corresponding to the spacing of the 5 In a projectile, spaced projectile-rotating means .comprising balls Seated for rotation in the surface of the projectile and extending outwardly -irom the surface of the projectile suiiicientlyI for engaging spaced spiral grooves in thebore of a gun, a ring member mounted for rotation on the projectile during the ring thereof, a second group of balls mounted in said ring member and spaced therearound corresponding to the spacing of the first balls, said-secondA group of balls extending outwardly from the surface of the projectile for a distancesufcient for engaging the 'spiral grooves in the bore of the gun whereby the second group of ballsserve asadditional .ball bearings, the rotative mounting of said-ringen the projectile providing compensation for any change in the rate of spiral in the grooves ofthe vgun bore, and a frangible connection between the ring, member and the projectile for freeing Asaid ring member to rotate during thering of the projectile when such compensation is required'.
6. In a projectile; a ring member embracing la viis reduced `diameter portion of the projectile and rotatable thereon, balls rotatably seated in said Vring -member at spaced intervals therearound,
said balls projecting outwardly from the vring member a distance suicient for engaging spaced spiral grooves inthe bore of a gun, said projectile having additional ball means arranged to engage `in such spaced spiral grooves, and having a frangible connection between the ring member and the projectile holding said ring member in xed position corresponding to a predetermined angle of lead of said grooves, and freeing said ring member to adapt said vprojectile for operation with a different angle of lead of such grooves,
- 7. In a projectile having a plurality of recesses in the surface thereof at spaced intervals around the projectile, a ball in each of said recesses, said balls extending outwardly from the surface of th'e projectile a distance sufficient for engaging spiral grooves in the bore of the gun, and a frangible means connecting each ball with the projectile and adapted to be broken upon insertion of the projectile in the gunbore with the balls yin said grooves.
8. A projectile having a plurality of recesses in the surface thereof at spaced intervals around the projectile, balls in said recesses, said balls having from approximately one-half to two- Vthirds of their diameter extending outwardly .from the surface of the projectile for engaging `spiral grooves in the bore of a gun, and frangible means securing said balls in said recesses and adapted to be brokenupon insertion of the projectile in. the gun bore withrthe balls in said grooves. SOLIS MYRON ZANDMER.
REFERENCES CITED UNITED STATES' PATENTSy Number Date 1 Name 791,679 Edmonds June 6, 1905 849,015 Ohl" Apr, 2, 1907 1,184,343 `Gruyer 1 May 23, 1916 1,227,889 Cox May 29, 1917 v1,602,037- f Mixsell Oct. 5, `1926 1,721,704 Mada-Schi July 23, 1929 2,264,791 Fries Dec. 2, 1941 u j FOREIGN APATENTS Number Country Date 184 Great Britain J an. 3,' 1896 6,940 Great Britain Apr. 12, 1900 20,336 Great Britain 1903 20,782 Great Britain Nov. 2, 1893 28,934 France Jan 22, 1925 (Addition to 495,517)