US3216356A

US3216356A - Projectile

Info

Publication number: US3216356A
Application number: US341463A
Authority: US
Inventors: Jr William F Kaufmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-01-30
Filing date: 1964-01-30
Publication date: 1965-11-09
Anticipated expiration: 1982-11-09

Description

Nov. 9, 1965 w. F. KAUFMANN, JR 3,216,356

PROJECTILE Filed Jan. 50, 1964 Fig! I INVENTOR. f WILLIAM F. KAUFMANN,JR

: I EY- /W% W [M1 21 ATTORNEY- United States Patent ()filice 3,216,356 Patented Nov. 9, 1965 3,216,356 PROJECTILE William F. Kaufmann, Jr., Philadelphia, Pa., assignor to the United States of America as represented by the Secretary of the Army Filed Jan. 30, 1964, Ser. No. 341,463 2 Claims. (Cl. 10238) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a caseless round such as is used in recoilless rifles and has for an object to provide an abutment or stop ring on a projectile for limiting loading movement of such a round into a gun in the absence of a base flange of the type found on customary metal cartridge cases. Another object is to provide such a stop ring capable of being sheared at a predetermined pressure such as propellant gas to give the projectile a shotstart effect with high acceleration and higher muzzle velocity.

Caseless rounds have long needed a satisfactory stop ring for accurate positioning of the round in the chamber of a gun, especially those having a firing pin for either percussion or electrically fired primers where moving the round too far into a gun may result in a misfire. Conversely, when a round is not moved far enough into a chamber there is danger of the primer cap being ruptured with a resulting rearward leakage of gas.

This invention has not only overcome these difficulties, but has enabled the present round to have a higher than usual acceleration and velocity. Specifically, a somewhat elastic ring is secured to the projectile and is fitted within a groove rearwardly of the projectile rotating band to extend radially outward far enough for engaging an inwardly extending ledge within the chamber of the gun. This ring is preferably of a plastic having an ultimate shear strength of about 20,000 pounds per square inch, so that on rupture of the ring, the projectile is given more rapid acceleration and velocity for a given propellant than it would have had with a metal cartridge case having a conventional base flange arrangement.

Referring to the drawing:

FIG. 1 is a longitudinal view partially broken away in section of a complete round of ammunition embodying the principles of the invention.

FIG. 2 is a partial longitudinal section through a portion of the projectile body containing the grooves for reception of the abut-ment ring and the rotating band.

FIG. 3 is a view corresponding to FIG. 2 but showing the abutment ring and rotating band in place.

FIG. 4 shows apparatus employed for applying the stop ring to its projectile groove.

The projectile body shown in FIG. 1 is provided with a nose 11 carrying any well known type fuze initia tor for an explosive charge. A boom 12 extends from the body 10 rearwardly and is provided at its rear end with a plurality of stabilizing fins 13. A frangible fiber glass case 14 encloses a well known type of propellant 14a, both encompassing the boom 12.

As shown in FIGS. 2 and 3 a rotating band 15 is secured within groove 18 on a rear portion of the projectile body 10. Rearwardly of and spaced from the band 15 a groove 19 is provided for reception of an abutment ring 16. Screw threads 17 on a rear inner surface of the projectile body 10 enable the threaded boom 12 to be secured firmly to the body 10. In FIG. 2 the

grooves

18 and 19 each have an appropriate width and depth for receiving the rotating band 15 and the abutment ring 16. The band 15 and ring 16 each is formed of a polyvinyl chloride plastic known as Geon having an ultimate strength in shear of about 20,000 pounds per square inch. The band 15 is sufiiciently deformable to be readily engraved by the rifiing when a low spin rate of around 15 to 20 revolutions per second is desired. In one size in which this invention was tested the diameter of the body portion of the projectile immediately in front and behind the

grooves

18 and 19 was 4.71 inches. The diameter of the radially outside surface of band 15 was 4.74 inches and that of the ring 16 was 4.84 inches, thus the projection of band 15 was .015 inch and that of the ring was .065 inch, making the ring project outwardly of surface 22a about 4 times the radial projection of the rotating band 15.

A short plug or mandrel 21 (FIG. 4) is slid into the rear open end of the body 10 when the boom 12 is disconnected from the projectile body 10 so that the abutment ring 16 may be secured to the projectile. For this purpose, expandable ring 16 is first pressed onto the tapered end 25 of mandrel 21 and moved gradually upward onto the portion 22 which has the same outside diameter as that of the body portion 22a immediately in front and in rear of the band 15 and ring 16. After mounting ring 16 on fixture or support 23 having three or more prongs equally angularly spaced, the projectile is forced downwardly upon spring 24, resulting in the ring 16 being moved upward along the mandrel outer surface. By pressing downward slightly on the body 10, ring 16 will be further moved upward along

flush members

22, 22a until ring 16 slips into groove 19. Its inherent elasticity holds ring 16 in place with-in groove 19. Since the rotating band 15 is of the same elastic material as ring 16 that band may also be slid into its groove in an even more easy manner because band 15 is relatively thinner and more easily stretched. The bottom of groove is of a size to maintain band 15 under slight tension and is also provided with fine knurling 20 to cause band 15 to dig into or be partially embedded in such knurling and thus oppose any tendency for the band to be shifted angularly by the rifling.

The term consumable case or caseless round includes not only those cases which are consumed by breakage or frangibility but also those consumed by being burned or consumed in any other manner as well as those without any case.

The reason the ring 16 and band 15 are separated is because at first they were made structurally integral, but such was found unsuitable because of an objectionable tilting of the unit. However their separation in the manner shown has proven satisfactory.

As shown in FIG. 1 the fiber glass case 14 should fit snugly against the rear side of ring 16 and snugly over the surface 22a of the same diameter on the projectile and forward edge of the tapered boom.

I claim:

1. A caseless round of ammunition including a projectile having a rotating band, a consumable case secured to said projectile, a propellant within said case, and means for guiding said round upon loading thereof into a gun and for providing a shot start effect to said projectile, said means including a plastic abutmentring on said projectile intermediate said case and rotating band, said ring projecting laterally of the projectile periphery substantially further than said rotating band.

2. In a caseless round of a fin stabilized projectile having a rotating band located on said projectile forwardly of the stabilizing fins and a propellant contained consumable case secured to said projectile, the combination therewith of means for accurately locating said round longitudinally in a gun and for providing the projectile with a shot-start effect, said means including an abutment ring on said projectile immediate said case and rotating band, said ring extending radially outward of the projectile pe riphery a substantially greater distance than does said rotating band for engaging a rear end portion of'a chamber in a recoilless gun, said ring being of a plastic material capable of being sheared when the propellant pressure has reach a predetermined value to increase the starting velocity of said projectile by a shot-start effect.

References Cited by the Examiner UNITED STATES PATENTS BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

Claims

1. A CASELESS ROUND OF AMMUNITION INCLUDING A PROJECTILE HAVING A ROTATING BAND, A CONSUMABLE CASE SECURED TO SAID PROJECTILE, A PROPELLANT WITHIN SAID CASE, AND MEANS FOR GUIDING SAID ROUND UPON LOADING THEREOF INTO A GUN AND FOR PROVIDING A SLOT START EFFECT TO SAID PROJECTILE, SAID MEANS INCLUDING A PLASTIC ABUTMENT RING ON SAID PROJECTILE INTERMEDIATE SAID CASE AND ROTATING BAND, SAID RING PROJECTING LATERALLY OF THE PROJECTILE PERIPHERY SUBSTANTIALLY FURTHER THAN SAID ROTATING BAND.