US165255A - Improvement in projectiles for ordnance - Google Patents

Description

H. REILLY. Projectile for Ordnance.

Patented july 6, |875.

UNITED STATES PATENT CEEIGE.

HUGH REILLY, OF BROOKLYN, NEW YORK.

iMPRovEMENT 1N PRoJEcTlLEs Fou oRDNANcE.

Specification forming part of Letters Patent No. 165,255, dated July 6, 1875; application filed February 19, 1875.

To all whom 'it may concern:

Be it known that I, HUGH REILLY, of Brooklyn, New York, have invented Improvements in Projectiles, of which the following is a specification:

My invention consists in improvements in projectiles for ordnance.

The first of my improvements relates to the. form of the sabot or eXpansible ringat the base of the projectile, and in the method of attaching the same to the shot or shell. My second improvement relates to an arrangement of gas-escapes through the sabot in such a manner that by the sabots expansion the gas-escapes will not be closed, and the sabot will be lessliable to break.'

Reference being had'to the accompanying drawings-in which like letters represent like parts-- Figure I is a rear view of my improved sabot removed from the shot or shell. Fig. II is a section of a projectile cut in the plane of its axis, showing all my improvements. Fig. III is a rear view of the same.

In projectiles forordnance some arrangement has to be provided for enabling the shot to take the riding, and thus receive the desired rotation upon its longitudinal axis. This is usually accomplished by screwing to the projectile near its base a thick ring ot' brass, into which, from the rear, is cut a very'deep groove, thus making, as it were, a double ring, the outer part forming one side of thegroove being thin and tapered in section, the inner part being thicker, and tapered but slightly upon the side which forms the inner portion of the circular groove. Upon the inside surface 'of this annular ring is cut a screw by means of which it is attached to the rear por tion of the projectile.

When the gun is fired the outer thin edge is expanded by the force of the explosion, and is consequently driven into the grooves of the riding, thus enabling the shot or shell to receive the rotary motion due to the riin g. The female thread for the attachment of this kind of sabot to the projectile is cut upon the ring and the male thread upon the rear portion of the projectile, which has been previously reduced in diameter.

These threads are large and costly to cut,

both the projectiles and sabot having to be placed in a lathe for the purpose.` My improvement as shown in the drawings decreases the cost of the projectile, while an equally efficient arrangement is provided.

In Fig. II the sabot is shown at D, and in Fig. I it is shown detached from the shot or shell. The body of the projectile A, Fig. II, has at its rear end a projection, as seen at a', the shape of which is more clearly shown by reference to Fig. I, where a is the opening in the sabot corresponding in shape with the projection a. The distance which a', Fig. II, projects from the rear of the shot or shell is dependent upon the size of the projectile and the length of the sabot. The sabot D is made of brass or copper, or any other metal or cornbility. The rear part of the sabot D consists of a comparatively thin projecting edge or rim,whieh is to be expanded to lit'the grooves ot the riting when the gun is fired. The forward part of the sabot is'much' thicker, and an opening as at a', Fig.. I, is cast or cut through it centrally, which opening may have eight sides, as shown, or may be any other many-sided iigre. Into this opening a the projection a at the rear of the shot or shell closely ts, the projection being sufficient to entirely iill the opening in the thick part-'of the sabot, the length of the projection from that part of the shot where its diameter is rst diminished being equal to the length of the thick portion of the sabot.

A plate, B, Figs. II and III, smaller in diameter than the opening left by the rear projecting edges of the sabot D at their bottom, and equal in thickness to the length (measured in the axial line of the shot) of the cavity formed by the thin expansible edges of the sabot, is placed against the rear of the projection a' of the projectile, resting partly on the projection a', which is, in fact, the real base of the projectile A, and partly on the thicker portion of the sabot, where it fits around the projection a from the shots base. The plate B is a portion of a cone out at right diameter is the forward portion, which rests against the sabot and shot, the rear portion of the plate being of slightly less diameter.

pound may be used having the requisite plia-` angles to its axis. The part having the largest Thus the opening lcl't between the edges of' the plate l and the thin projecting edges of the sabot 1l) will bc a groove, in which the sides approach but do not meet, being a V with the sharp point cnt ofi.

This form of groove is adopted, as it is believed that a superior expansion of the thin edges of the sabot D is thus secured. This clamp-plate B thus serves to keep the sabot D iirmly attached to the projectile A, the plate being in this case held in position against the shot or shell by a bolt, C, but some other method may be adopted of holding the plate B against the projectile A. I prefer, however, t0 use the bolt G for this purpose, because all shot, after a certain size, are hollow, in the manufacture of which it is necessary to have a hole through the rear portion used for the support of the core to pass through while the shot is being cast. This hole is usually closed by a bolt, and when my improved sabot is used, the same bolt, only slightly larger, will serve to hold the clamp-plate B in position, saving the expense of cutting large screws, as already mentioned, or of forming other methods of attachment. I will mention, however, that the bolt (l can be a portion of the plate B, which virtually will form its head, though much enlarged, to serve this special purpose.

The forward part of the sabot rests against the shoulder left when the rear projection a was formed, and this shoulder is so formed by being beveled inward (the forward part of the sabot D having a corresponding bevel) that, after the sabot D is in position and firmly held by the. clamp-plate B, no danger will exist of the sabots expanding at any part ex cept the thin rear portion, it being sometimes considered undesirable to allow the sabot to expand through its whole length, but cases may arise in which the expansion of the sabot through its whole length will b e advantageous, and in such cases the beveled shoulder may be changed in the construction of the shot or shell, and the shoulder be made at right angles with the axial line of the projectile. When it is desired to increase the expansion ot the sabot D through its entire length the shoulder of the shot or shell, and the front portion ot sabot resting on it, may both be beveled outward.

In either case, whether the shoulder and sabot are beveled outward or inward, the amount of bevel required will be very slight; about ten degrees will, in most cases, be suiiicient, the angle being measured from a line running at right angles to the axial line ofthe projectile.

My second improvement consists in so ar ranging gasescapes that the expansion of the sabot will not close them, and will vnot tend to break the sabot itself. In starting a heavy shot more powder has to be burned than can safelybe absolutely confined, and a portion of the gases of combustion must be allowed to escape; an intentional windage must, in other Words, be formed. This object has usually been attained by cutting slots in the outside surface ot' the sabot, and at times into the body of the shot itself, through which slots or grooves the might pass. These are liable to be, and usually are, entirely closed up by the expansion of the sabot.

In Figs. I, II, and III, at b, are seen the gas-escapes as arranged in my plan. The holes (eight, as shown in the drawing, or any greater or less number) are bored through the thickened forward part of the sabot, commencing at that part of the thick forward portion not covered by the edges of the clampplate B, and continuing tlirougl'i the sabot to its forward surface. These holes d would be closed, when the sabot D was in position, by the shoulder against which the sabot rests, were it not that either7 just where these holes meet the shoulder, the metal of the body of the projectile is cut away, or the entire shoulder is cham fered off, thus permitting the gases in certain quantities to find, through d, a free escape from the base of the .shot to a point in -front of the expanded sabot.

It will be observed that the thin rear edge of the sabot may be expanded, or the sabot' may expand through its whole length, and the gas-escapes d will not be closed, my method of boring them through a part ot' the sabot, which is not materially affected by the explo sion or expansion attendant thereon, securing this beneficial result.

At E I show an expansible ring attached to the forward part of my projectile, which ring may be expanded by the passage of a portion of the gases ot' combustion through the gas-escapes d. This ring, when expanded, will keep the projectile truly centered during its passage along the bore of the gun, and may or may not be sufliciently expanded to take the grooves of the riding. I have shown this ring as screwed to the metal of the pro jectile, the forward part of the body A having been sufficiently reduced in diameter to per mit of this ring being placed upon the shot from the forward end. This is no part of my invention, but I have thus figured the device as a portion of a well-made projectile. The gasescapes c1, as described, are well adapted to be used with such a forward expansible ring, for, by their construction, they are less liable to be closed by explosion, and thus make the expansion of the ring E more c er tain.

In describing the clampplate B I have omitted to state that some arrangement must be made to keep the gas from introducing itself between the plate B and the thick part of the sabot D directly in contact with it, for should this happenthe clamp-plate would be forced from its position, and the sabot would separate itself from the shot. To avoid any such accident, I make a small groove in the part .of the plate B which rests upon the sabot D, and I make a corresponding groove upon the sabot D. In one ot' these circular grooves I place a ring of soft metal, which may be circular in section, as seen at F, Fig. II, which will, when the plate B is attached to the projectile, be crushed into the groove between the sabot D and the plate B, making an effectual gas-cheek, and preventing the penetration ofthe products of combustion under the plate B. Other forms of gaschecks may be adopted. The parts of the plate B and sabot D which come in contact could be accurately faced in a lathe or other mechanism, such faced surfaces forming a close and gastight joint. If the clamp-plate B is at tached to the projectile, as shown by a bolt, C, similar methods may be followed in malring a 'gas-tight joint between the head of the bolt c and the rear portion of the plate B.

'Other methods of attaching the plate B to the projectile A may be adopted which do not require the use of a bolt, C, and dispense with any necessity of gas-checks excepting the one shown at f. The clamp-plate B may be of iron or of almost any material having suiicient strength.

My improved method of forming and fast ening the sabot D to the projectile may be used by itself, or my improvement inthe arrangement of gas-escapes may be used in a sabot as at present constructed. My improvements may be used together to produce a pro- HUGH REILLY.

Vitnesses:

PHILLIP ABBOTT,

WILLIAM SooTT.

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