Untitled record

No. 58,783.

J. M. CURRIE.

Projectile.

Patented Oct. 16, 1866.

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N.PETERS. PHOTO-LITHOGRAPHER. WASHINGTON. 0 C.

United States Patent Office.

J. M. CURRIE, OF WASHINGTON, IOWA.

IMPROVEMENT IN PROJECTILES FOR ORDNANCE.

Specification forming part of Letters Patent No. 58,783, elated October 16, 1866.

To all whom it may concern:

Be it known that I, James M. Currie, of Washington, in the county of Washington and State of Iowa, have invented certain new and useful Improvements in Projectiles for Ordnance; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification, and to the letters of reference marked thereon,like letters indicating like parts wherever they occur.

To enable others skilled in the art to construct and use the invention, I will proceed to describe it.

Figure 1 represents a side elevation, with a portion shown in section, to show the form of the projectile and the packing. Fig. 2 . is a .transverse section, taken on the line x x of Fig. 1.

My invention relates to elongated projectiles intended for use iu rifled ordnance.

In the drawings, A represents the projectile, which may be made of cast-iron. I make this projectile with a· conical point, as represented in Fig. 1, and at a point about onethird of its length from the front end I begin to decrease it in diameter, continuing the decrease toward the rear end for about one-third of its entire length, when it is again increased in size, as shown in Fig. 1. By this means I provide a cavity or recess around its central portion for the reception of a packing-ring, B, of soft metal.

From the rear end of the packing the projectile extends back to a point, the rear end thus forming a cone, as shown.

In the cavity formed around the central portion of the projectile I cast'a ring of lead, as represented by B, the rear end of which projects laterally beyond the sides of the body A, this packing-ring B forming a bearing-surface extending from a to e.

It will be observed that the surface of the body A where the packing is fitted upon it forms an incline, up which the packing B will be driven by the force of the gas acting against its rear shoulder, a, and that by this means the ring B will be expanded laterally, and thus forced into the grooves of the gun.

By thus forcing the ring B up the incline it will be expanded equally from front to rear, and thus the projectile will have a firm bearing along its entire cylindrical portion, by which means it will occupy a correct position in the bore of the gun, the axis of the projectile and that of the bore thus being made to coincide perfectly, and insuring its accurate passage along the bore and from the muzzle of the gun.

If in practice lead is found to upset at the rear,instead of driving up the incline,an alloy of lead and harder metal may be used-to form the packing-ring B.

One or more grooves, c, are formed along the surface of the inclined portion of A, as shown in Fig. 2, in which the lead or other metal forming the packing-ring will engage, and thus prevent the ring from becomingloose upon the projectile as the latter rotates in its flight. '

As the rear portion of the recess is the deepest, the shoulder-in rear of the recess will prevent the packing from slipping off at the rear, even if it becomes loose by being driven up the incline.

By these means I produce a projectile for rifled ordnance which has a true bearing along its entire cylindrical portion, which will take the rilling with regularity, evenness, and certainty, and which, while having a conical point, may be made solid and still have its center of gravity in front of its center of length.