US1398229A - Armor-piercing projectile - Google Patents

Description

R. A. HADHELD AND-A. G. MCK'. IACK. ARMOR PIERCING PROJECTILE. APPLICATION FIL 6.17. I9|8 Patented Nov. 29,- 1921.

ROBERT ABBOTT HADFIELD, OF WESTMINSTER, AND ALEXANDER GEORGE IVICKENZIE JACK, 0F SI-IEFFIELD, ENGLAND.

ARMORf-PIERCING- PROJECTILE.

Application led December 17, 1918.

T0 all whom t may concern.'

Be it known that we, ROBERT ABBOTT I-IAD- FIELD' and ALEXANDER GEORGE MOKENZTE JACK, subjects of the King of Great Britain and Ireland, residing, respectively, at the city of Westminster, England, and Sheffield, in the county of York, England, have invented Improvements in or Relating to Armor-Piercing Projectiles, of which the following is a specification.

Heretofore armor piercing projectiles have been made with their ogival pointed heads in one piece of metal and integral with the bodies of the projectiles. When such a projectile strikes a hard faced armor plate, particularly when striking Vobliquely, there is a liability of the forward portion of its head being broken off or of a fracture being set up therein that will probably extend backward to the chamber or core of the projectile, with the result that although the projectile may perforate the plate, it is prevented from properly performing its required function of effective 'detonation Now this invention has for its obj ect so to construct an armor piercing projectile as to prevent any fracture that may occur in the forward portion of the head of such a projectile extending backward to the rearward portion thereof and thence to the detonating charge of the projectile, so that the projectile shall be better adapted than heretofore to successfully perforate a hard face armor plate and perform its proper function, even when striking the plate obliquely at a large angle. Y

For this purpose, the ogival pointed head of an armor piercing projectile is made in separate parts arranged one in front of the other, the rear or rearmost part being formed in one with the body of the projectile. Conveniently, the head may he made in two parts fitting oneV into the other and held together in any suitable way, it may be by the forward portion being inclosed in the metal cap with which the projectile is fitted for use and which is preferably secured in place by forcing portions of its rear end into notches, formed in the shoulder portion of the projectile in a known way. Means may be provided forv preventing the forward portion of the head turningon the rearportion thereof or projectile proper against which it bears. For this purpose two or more small dowel pins may be used arranged Specification of Letters Patent.

Serial No. 267,202.

to extend into each of the adjacent parts of the head. The forward pointed portion of the head of the projectile may be of ogival shape of any desired radius. The forward end of the projectile proper, constituting the rear part of the head, which is inclosed within the cap and retains in position the forward portion of the head, when the head is formed of two portions only, is of pointed form and may be of conical, or other shape and such as to form a blunt true head to the projectile ofsuch a shape that it will serve to prevent the forward portion, which rests upon it, being displaced laterally on impact against an armor plate, even at a considerable angle. The dividing surface between the two parts should terminate circumferentially in a line intermediate of the length of the ogival or equivalent shaped surface of the divided head and forward of the points of connection between the projectile and the cap fitted over the head. The axial thickness of the forward part of the head may be varied to suit requirement, but in the case where the head is made as described, good results have been obtained with an Patented Nov. 29, 1921.

axial thickness equal approximately to 40 to 50% of the caliber of the projectile.

The accompanying drawing shows partly in central longitudinal section and partly in side elevation and byway Of example only, an armor piercing projectile having its head made in two parts according to the invention and provided with a cap and with a hollow point or air deflector.

In this example, the head of the projectile is made in two parts a and al fitting one into the other, the separate forward part al being of ogival shape and the rear part a, which is in one piece with the body o of the projectile, and has a central forward end portion of conical shape closely fitting into a similar shaped recess in the rear side of the forward portion, c, c1 being the line of division between the two parts. The circumferential surface of the rear part a of the head of the projectile is of ogival shape flush with and forming a continuation of the ogiy place by forcing portions Z1 of its rear end into notches or recesses a2 in the shoulder portion of the projectile to the rear of the line of division c, c1 between the two parts a, al of the head of the projectile. e is a hollow point or air deflector of an ordinary kind secured over the forward end portion of the cap cl .and flush with the outer' surface thereof as usual. Means, such as dowel pins f may be fitted to the two parts of the head to prevent relative turning movement between such parts.

The separate forward part al and also the rear part a of the head of the projectile, as well as the cap cl that is fitted over the divided head of the projectile, are hardened and tempered. The hardening and tempering of the cap l in front of the head is or may be such that on impact of the cap against the hard faced armor plate it will partially break up the hard face of the plate and effect disintegration thereof of such a nature that the separate forward part al of the head of the projectile will complete the breaking up of t-he face to such a further extent that the rear part a of the head, that is of the projectile proper, will complete the perforation without fracture thereof occurring, even if the projectile strikes the plate at a large angle. To this end, the forward part al of the head may be hardened in such a way that it is composed wholly, or nearly so, of successive zones of steel of A and B ball hardness while the rear part kof the head is composed of successive zones of steel of A, B, C, D and E ball hardness, it being understood that A ball hardness corresponds to a hardness of 600 and above on the Brinell scale; B ball hardness to a hardness corresponding to 500 to 600; C ball hardness to a hardness corresponding to 300 to 400 and E ball hardness corresponding to a hardness of 300 and below. The volumes of steel of A and B ball hardness in the rear portion a of the head of the projectile may be small compared to the volumes of steel of similar hardness in the separate forward portion a1 of the head. The volumes of steel of C and D ball hardness in the rear part of the head, that is of the projectile proper, may also be comparatively smallwhile the volume of steel of E ball hardness, which extends to the base or rear end of the projectile, will be large.

The projectile with its separate forward portion may advantageously be made of nickel chromium steel and of the composition set forth in the specification of a former application for Letters Patent filed October 4th, 1918. Serial No. 256,890. Also, the true head a and body of the projectile may be hardened' and tempered in the manner described in that specification so that the successive zones of steel of decreasing ball hardness are in the form of shallow or flattened cups arranged one behind the other and eX- tending more or less transversely. The sepa- As an example, it may be stated that. an armor piercing projectile made with a twopart head as described and suitably capped, the volume of steel of A and B ball hardness in the forward part of the head being in the proportions respectively of about 85 and 65 and the volumes of steel of A, B, C, D and E ball hardness, in the rear or true head and body of the projectile being respectively in the pro ortions of about 12, 7, 3, 4 and 74, successful y perforated a hard faced armor plate when striking at an angle of 30G.

By graduating the hardness of the separate forward and rearward portions of the divided head of the projectile in the manner described, each portion is adapted to perforate an armor plate so that if under very special conditions of attack, the forward portion of the'head should become broken off, the rear portion is nevertheless still available and capable of continuing the perforating action. In this way, a projectile having a divided head, made as described, iskbetter adapted to successfully perforate a hard faced armor plate and perform its proper function than a projectile having an undivided head made as heretofore, even when -striking the plate obliquely at a large angle.

It will be understood that an armor piercing projectile having a divided head constructed as described is designed to fulfil a different function to that of the cap with which it is fitted forruse, namely, to perforate and pass completely through a hard` faced armor plate, while the cap is designed to support the point of the projectile and break up the surface of the plate and then to itself become broken up to permit of the onward movement of the projectile in an intact condition through the prepared plate. Such a cap may thereforerbe said to be a frangible device, whereas thev divided head of theproj ectile is not.

What we claim is 1. An armor piercing projectile having a pointed ogival shaped head made in separate parts fitted together one in front of another, the rear part being formed in one piece with the body of the projectile and having its peripheral surface of ogival shape flush with and forming a continuation of the ogival surface of the remaining front portion of the head of the projectile. Y

2. An armor piercing projectile having a pointed ogival shaped head made in two parts arranged one 1n front of the other, the

iso

rear part being formed integral with the body of the projectile and having a pointed front end portion litting a correspondingly shaped cavity in the rear end of the front part and a peripheral surface of ogival shape flush with and forming a continuation of theogival surface of Jdie front part of the head. v

3. An armor piercing projectile having a pointed ogival shaped head made in separate parts tted together one in front of the other, the rear part being integral with the body of the projectile and having its peripheral surface of ogival shape flush with and forming a continuation of the ogival surface of the remaining front portion or head of the projectile and means located between the engaging parts of the divided head of the projectile to prevent relative turning movement between them.

4. An armor piercing projectile having a pointed ogival shaped head made in two parts, the rear part being integral with the body of the projectile and having a pointed front end portion fitting into a correspondingly shaped cavity in the rear end portion of the front part of the divided head and a peripheral surface of ogival shape flush with and forming a continuation of the ogival surface of the front part of the head, the axial thickness of the front part of the -head being of the order of about 40 to 50% of the caliber of the projectile.

5. An armor piercing projectile according to claim 2 made of hardened and tempered steel, the front part of the divided head being composed of successive zones of steel of A and B ball hardness and the rear part of said head bein composed of successive Zones of steel of A, 5B, C, D and E ball hardness.

6. An armor piercing projectile according to claim 2, made of hardened and tempered steel, the frontpart of the divided head being composed of successive zones of steel of A and B ball hardness in the proportions, by volume of the order of about 35 and 65.

7 An armor piercing projectile according to claim 2, made of hardened and tempered steel, the front part of the divided head being composed of successive zones of steel of of A and B ball hardness and the rear part of said head being composed of successive Zones of steel A, B, C, D and E ball hardness, the volumes of the successive zones of steel of A and B ball hardness in the rear part of the divided head of the projectile being small compared to the volumes of ythe successive zones of steel of A and B ball hardness in the front part of the head so that the remaining portion of the rear part of the head is of greater toughness than the other portions.

8. An armor piercing projectile according to claim 2 made of hardened and tempered steel, the front part of the divided head being composed of successive zones of steel of A and B ball hardness in the proportions, by volume, respectively of the order of about 35 and 65% and the rear part of the divided head and body of the projectile being composed of successive zones of steel of A, B, C, D and E ball hardness in the proportions, by volume, respectively of about 12, 7, 3, 4 and 74%.

9. An armor piercing projectile having a pointed ogival shaped head made in separate parts fitted together one in front of another, the rear part being formed in one piece with the body of the projectile and having its peripheral surface of ogival shape flush with and forming a continuation of the ogival surface of the remaining front portion of the head of the projectile, and a cap of hardened and tempered steel fitting over the divided head of the projectile and firmly Y engaged with the rear end part of the divided head of the projectile.

10. An armor piercing projectile having an ogival shaped head made in separate parts fitting one into the other and substantially flush with each other externally with the rear part in one piece with the body of the projectile, the forward end of the rear part being of obtuse conoidal shape and suoli as to prevent the forward portion, which rests upon it, from being-displaced laterally on impact against an armor plate.

Signed at London, England, this eighteenth day of November 1918.

REERT ABBOTT HADFELD. ALEXANDER GEORGE McKENZlE JACK.

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