Year: 1897

page_text: Date of Application, 21st Apr., 1897-Accented, 12th June, 1897
I, JAMES HENRY CARPENTER, Steel Manufacturer, residing at Reading in
the County of Berks State of Pennsylvania, United States of America do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My invention relates more particularly to projectiles which are adapted for such
work as the piercing of armor plates.
This class of projectiles is ordinarily of cylindrical form with a conical or
"ogival" head the surface metal of which is hardened by chilling so as to greatly
increase its crushing strength. The advantage of this increasing the crushing
strength of the surface metal at the front of the projectile, carries with it a
resulting disadvantage due to the tendency of the chilled metal to flake off when
subjected to the strain of impact with the hardened surface of armor plate; and
also by the further tendency of the head of the projectile to break off entirely
from the cylindrical body, the line of fracture tending to start at and approximately
follow the junction line between the chilled and unchilled surface metal.
The object of my invention is to overcome or at least minimize these bad effects.
resulting from the chilling of the metal, and 1 accomplish this in the chilling
operation by causing the chilled metal to be so blended with the unchilled metal as
to give to the combination great tenacity as well as hardness, and so as to avoid
any weak junction line such as would naturally become a line of fracture. The
invention is fully described in connection with the accompanying drawing and is
specifically pointed out in the claims.
Figures 1 and 2 are respectively an end view and an elevation of a projectile in
which the approximate lines of junction of hardened and unhardened metal are
indicated in a form which embodies my invention.
A represents the cylindrical body, B the conical or "ogival" head, and C the
extreme pointed end of the projectile. The band d, represents the "shoulder" or
"bourillet of the projectile, being the portion of its surface which is accurately
fitted to the bore of the gun and a' indicates the ordinary copper band, near
the base.
The present approved method of manufacturing these projectiles involves the
use of a fine grade of steel which after having been roughly formed to shape is
completed by first accurately turning and boring it to size, second, subjecting the
head portion to the chilling or hardening operation, and third, grinding the hardened
shoulder to an accurate fit in the bore of the gun. The hardening operation
consists ordinarily in subjecting the whole head and shoulder while properly heated
to the action of a cooling medium, such as cold water or other liquid, while
allowing the connected body portion of the projectile to cool slowly; the chilled
surface metal being joined with the unchilled on a plane at right angles to the axis
of the projectile. One feature of my invention consists in avoiding this plane of
connection, which as previously stated is apt to become a line of fracture and
I accomplish this by providing a protecting cover of asbestos or other suitable
material, for the body of the projectile, which will protect portions a a of the
surface from contact with the cooling medium, while exposing adjacent portion b b
also lying within the band d, thus causing the latter to be made up of alternating

page_text: hardened and unhardened surfaces and breaking up the line of connection so that it
shall not be liable to become a line of fracture as heretofore.
The further difficulty referred to as experienced with these chilled head
projectiles is the breaking off of the point C of hardened metal. This I overcome
by also protecting the point in the chilling operation so as to leave it relatively
soft; preferably though not necessarily extending the unhardened or partially
hardened surface metal as at cc into the hardened portion of the heut so as to form
a broken or uneven connecting line-similar to that at shoulder d.
The protection afforded the point C by the asbestos covering during the
hardening operation, is so complete as to prevent any appreciable chilling or
hardening of such point except immediately adjacent to the exposed surface when
the heat is carried off somewhat by conduction; and the effect of impact of the
soft metal point against a hardened armor plate, is to cause a spreading of the soft
metal, instead of a fracturing of the projectile as has been commonly the case
heretofore, and to considerably increase the penetration.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. A chilled head projectile having alternating sections of hardened and
unhardened surface metal at the band of junction, substantially as and for the
purpose set forth.
2. A chilled head projectile having the hardened surface metal thereof blended
into the adjacent unhardened surface metal on a jagged or wave-like junction line,
substantially as and for the purpose set forth.
3. A chilled head projectile having a relatively soft point formed integral
therewith, substantially as set forth.
4. A chilled head projectile, having the metal forming the point thereof relatively
soft, and points or sections of said softer metal extended into the hardened surface
metal of the head, substantially as and for the purpose set forth.
5. A chilled head projectile having the metal forming the point relatively soft,
and projections a of unhardened body metal blended into the hardened surface
metal, substantially as and for the purpose set forth.
Dated this 21st day of April 1897.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.