US2994273A

US2994273A - Projectile

Info

Publication number: US2994273A
Application number: US543001A
Authority: US
Inventors: Robert M Bleakney
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-06-30
Filing date: 1944-06-30
Publication date: 1961-08-01
Anticipated expiration: 1978-08-01

Description

Aug. 1, 1961 R. M. BLEAKNEY PRQJECTILE Filed June 50, 1944 l lllI/I S 2,994,273 PROJECTILE Robert M. Bleakney, Albuquerque, N. Mex., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed June '30, 1944, Ser. No; 543,001 6 Claims. (Cl. 10293) This invention relates to projectiles, and more particularly to sub-caliber sabot projectiles.

An object of this invention is to provide a sabot projectile comprising a sub-caliber core having a pair of releasable elements of substantially full caliber dimension mounted near the nose and near the rear of the core, respectively, for supporting and centering the core in a gun barrel, and a releasable light-weight spacer surrounding the core for maintaining the supporting and centering elements in spaced relation.

Another object of this invention is to provide a sabot projectile as described above in which the spacer also afiords lateral support to the supporting and centering elements.

Still another object is to provide a sabot projectile of the character described in which the spacer is partially segmented radially so as to disintegrate readily after the projectile leaves the gun barrel. Preferably, the supporting and centering elements also have weakened zones which cause them to disintegrate readily after leaving the gun barrel, under the influence of the centrifugal force set up by rotation of the projectile.

A further object of the invention resides in the provision of a sabot projectile comprising a sub-caliber core having a substantially full caliber discardable sabot, a substantially full caliber metal ring forming a bourrelet near the nose of the core, and a light-weight sub-caliber sleeve of plastic, fiber, or the like, surrounding the core between the sabot and the ring for supporting the ring latterally and maintaining it in spaced relation to the sa ot.

Another object of the invention is to provide a projectile as described above which is positive in operation and easy to manufacture and assemble, being adapted to large quantity production.

These and other objects of the invention will be obvious from the following specification and the accompanying drawing, in which:

FIG. 1 is a longitudinal sectional view, partly in elevation, showing the new projectile in a gun barrel; FIFIG. 2 is a front elevation of the projectile shown in FIG. 3 is a view similar to FIG. form of the bourrelet ring;

FIG. 4 is a cross-sectional view on line 4-4 of FIG. 1;

FIG. 5 is a view similar to FIG. 4 showing a modified form of the spacing element; and

FIG. 6 is a cross-sectional view taken on line 66 of FIG. 1.

The projectile comprises a sub-caliber steel core 10 having an ogive nose portion 10a. Near the ogive, a full caliber ring-shaped bourrelet 11 is mechanically connected with the core by means of threads 12 or other suitable means, such as a press fit. The ring is made of steel and is partially segmented by cutaway portions 13 of generally circular form extending to the inner edge of the ring, and by radial cuts 14 which extend outwardly from the cutaway portions 13 to within a short distance of the outer periphery of the ring. Thus, the recesses 13 and cuts 14 partially divide the ring into segments held together by weakened outer portions 13a, the widths of which are determined by the breaking strength of the material and by the dimensions and speed of rotation of the projectile, it being understood that the ring is adapt- 2 showing a modified ed to break apart at the weakened portions 13a under centrifugal force when the rotating projectile emerges from the gun barrel, as will be described in greater detail presently.

A modified form of the bourrelet ring is shown in FIG. 3. As there shown, the ring 11a has recesses .15 which do not extend into the inner edge of the ring, as do the cutaway portions shown in FIG. 2. Radial cuts 14a extend inwardly and outwardly from the recesses 15 leaving outer uncut portions 15a. The cutaway portions 13 and the recesses 15 serve both to lighten the weight of the ring and to weaken the ring so that it will break apart readily under centrifugal force on leaving the gun barrel.

To the rear of the ring 11, a partially segmented spacer 16 is mounted on the core, the spacer being of sleevelike form and made of light-weight material, such as wood, plastic, or the like. The spacer has radial cuts 17 extending outwardly from its inner surface, leaving uncut portions 18 adjacent its outer periphery, the radial dimension of the uncut portions being determined by the breaking strength of the material and by the dimensions and speed of rotation of the projectile.

In FIG. 5, I have shown a modified form of the spacer in which the sleeve 16a has radial cuts 17a extending inwardly from the outer periphery of the ring, leaving uncut portions 18a adjacent the inner surface of the ring. The

spacers

16, 16a are somewhat smaller in external diameter than the adjacent bourrelet ring 11.

The front end of the spacer 16 bears against the ring 11 while the rear end of the spacer bears against the front surface 21 of a sturdy full caliber steel sabot 19 fitted closely in an annular groove 20 by which it is well supported near the base of the core 10. The bourrelet ring 11 is driven firmly against the spacer 16, producing what may conveniently be termed an initially taut sub-caliber projectile. In other words, none of the components is loosely emplaced on the sub-caliber core 10. The sabot 19 is completely segmented radially and the segments are held in position in groove 20 by a turning band 22 of copper or other suitable material which is pressed or otherwise mounted on the sabot, the band having inwardly extending annular tongues 22a disposed in corresponding annular grooves in the periphery of the sabot. By thus mounting the turning band on the sabot, the band is prevented from being stripped from the sabot when the projectile is fired from the gun. A sealing disk 23, which may be made of copper, brass, or the like, is mounted on the base of the core and engages the rear face of the sabot so as to prevent the high pressure powder gases from leaking through the radial cuts in the sabot with a consequent loss of projectile velocity.

When the projectile is fired from a gun, the turning band 22 is engraved by the rifling in the gun bore and imparts rotation to the core through the sabot on which the band is mounted and through the spacer 16 and ring 11. As long as the projectile is in the gun barrel, the supporting and centering means comprising the ring 11 and the sabot 19 insure that the core is'axially centered in the barrel, this centering being necessary if the core is to be stable in flight after leaving the barrel. When the projecticle emerges from the gun barrel, the ring, spacer, sabot, and turning band are released from the core in order to decrease the air resistance on the projectile and permit higher velocity in flight. This release is accomplished by breaking of the bourrelet ring and the spacer at their weakened zones and by rupture of the rotating band, under the centrifugal force set up by the high speed rotation of the projectile. Thus, the projectile has the advantage of a large base area against which the propellant gases act, combined with the decreased weight and aerodynamic drag of the small caliber 3 core as compared with a full caliber projectile, which permits higher core velocity.

The spacer 16 supports the bourrelet ring 11 at its back, which ring is not strongly mounted on the core, by transmitting the thrust imparted to the ring by its contact with the bore of the gun, to the sabot which is well supported on the core in the groove 20. This permits the use of a relatively thin bourrelet ring .11, resulting in a saving in weight and a decrease in the hearing surface in contact with the gun bore.

It will be apparent that the new projectile is of simple construction, has relatively few parts, and may be easily assembled. The threads 12 are in such a direction that the bourrelet ring is driven backwardly and tightened against the spacer 16 by the rotation imparted to the core through the turning band. By thus tightening the bourrelet ring against the spacer 16, the sabot 19 may be prestressed laterally by the spacer so that the sabot is better adapted to withstand the turning or bending forward moments exerted on its segments by the powder pressure. Also, because of the wedging action imposed upon the spacer by the bourrelet ring and the sabot, the spacer and bourrelet ring are adapted to transmit torque from the turning band and sabot to the core.

In accordance withthe present invention, I have provided a sub-caliber sabot type projectile which is well supported and centered in the gun barrel and which discards the supporting and centering means immediately upon leaving the gun barrel, whereby the sub-caliber core may proceed toward the target at a high velocity and with potentially high striking power. It is to be understood that many possible embodiments of the invention may be made, and the matter described and illustrated herein is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. An initially taut sub-caliber projectile comprising a sub-caliber core, a sabot, means securely mounting said sabot on the rear end portion of the core, a full caliber metal ring having a screw thread connection with the core in front of the sabot, and an annular spacer of relatively light-weight material mounted on and extending around the core against which spacer the ring is tightened by the screw thread connection due to rotation of the core on acceleration, thereby transmitting a thrust to one side of the sabot in opposition to the powder pressure against the other ,side of the sabot.

2. A sub-caliber projectile comprising a sub-caliber core having a groove, a sabot mounted in the groove and having a turning band, a spacer extending around the core abutting the sabot, a full caliber ring abutting the spacer, and a thread course mechanically connecting the ring with the core, being of such direction that rotation imparted to the core by the turning band tightens the ring against the spacer with a wedging action to force the spacer against the sabot.

3. A sub-caliber projectile comprising a segmented sabot, a sub-caliber'core, which is grooved to receive the segments and retain the sabot, a full caliber ring which is thin relatively to the sabot, being mounted on the core in front of the sabot and having configurated openings extending endwise through the ring and spaced around the ring to reduce the weight thereof and provide weakened zones in the ring, a thread course connecting the ring with the core, and a spacer extending around the core between the ring and the sabot for supporting said ring at its back and at a predetermined distance from the sabot. l

4. A sabot projectile comprising a sub-caliber core having an annular groove in its rear end portion and a thread course in front of the groove, a plurality of segments mounted in the groove and projecting radially from the core a substantial distance to form a sabot, a spacer mounted on the core between the groove and said course, and a full caliber ring threaded on said course and screwed against the spacer to force the same against the sabot segments, the ring, spacer and sabot being releasable from the core during flight of the projectile.

5. A sabot projectile comprising a sub-caliber core having an annular groove in its rear end portion and a thread course in front of the groove, a plurality of segments mounted in the groove and projecting radially from the core a substantial distance to form a sabot, a turning band mounted on the sabot for holding the segments together in said groove, a spacer mounted on the core between the groove and said course and engageable with the front end of the turning band, and a full caliber ring threaded on said course and screwed against the spacer to force the same against the sabot segments and said band, the ring, spacer and sabot being releasable from the core during flight of the projectile.

6. A sabot projectile comprising a sub-caliber core having an annular groove in its rear end portion and a thread course in front of the groove, a plurality of segments mounted in the groove and projecting radially from the core a substantial distance to form'a sabot, a segmented spacer mounted on the core between the groove and said course, a full caliber segmented ring threaded on said course and screwed against the spacer to force the same against the sabot segments, the ring, spacer and sabot being releasable from the core during flight of the projectile, and a sealing disc on the core engaging the rear end of the sabot to resist the passage of high pressure gas between said segments.

References Cited in the file of this patent UNITED STATES PATENTS 36,773 Emry Oct. 28, 1862 132,903 Dana Nov. 12, 1872 FOREIGN PATENTS 131,034 Great Britain Aug. 21, 1919 46,057 Sweden 'Nov. 5, 1919 809,845 France Dec. 19, 1936