Improvements in Projectiles.
Year: 1897

page_text: Date of Application, 20th Apr., 1897-Accepted, 5th June, 1897
Improvements in Projectiles.
1, ELIAS MATTISON JOHNSON, of Spuyten Duyvil, New York, in the County
and State of New York, United States of America, Manufacturer, 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 to that class of armor-piercing projectiles having a hardened
conoidal point and a soft metal cap attached to and surrounding said point, and its
object is to provide the projectile and cap with a lubricating compound or substance
whereby the efficiency of the projectile is increased.
The invention consists essentially in a projectile having a hard conoidal point, a
a soft metal cap fitting thereon, and a layer of lubricating material interposed
between the point of the projectile and the cap and surrounding said point, as
hereinafter fully described and claimed.
In the accompanying drawing :-
-
Figure 1 is a sectional elevation of a projectile with the soft metal cap
removed showing a layer of graphite or other lubricating material on the point
thereof.
Figure 2 is a longitudinal section of the projectile complete.
In the said drawing the reference numeral designates a projectile such as is
commonly used with rifled ordnance, and 2 a cap of soft, tough metal. The
numeral 3 designates a layer of graphite interposed between the point of the pro-
jectile and the soft metal cap. The inner end of the cap is provided with an
interior rib or flange which engages with a corresponding groove in the projectile
for holding the cap in place. The graphite is preferably applied in a pasty or
plastic condition which subsequently dries and hardens.
As before stated, the projectile is principally designed for piercing armor
plates, and, when the cap, which strikes the plate first, comes in contact there-
with, it will shatter or weaken the plate so as to prevent the crushing or breaking
of the point of the projectile. The point of the projectile is thus entirely
lubricated and a portion of the lubricating material will be carried into the
armor plate, which will reduce the friction of the projectile in penetrating the
plate.
As seen, the cap is made in a cylindro-conoidal form, so as to entirely surround
the point of the projectile, the line of juncture between the conoidal and cylindrical
portions being in rear of the point of the projectile, thereby giving resistance to
lateral deflection or longitudinal strain.
I am aware that projectiles have heretofore been fitted with thin caps of sheet
metal containing lubricant, the said caps being merely intended as sheaths to
retain the lubricant in place around the points of the projectiles, but experiments
have shown such a device to be ineffective. It is necessary for efficiency that the
cap shall have thick walls and be of suiticient strength not to be easily crushed in,
otherwise at the moment of impact it neither strengthens the projectile by
supporting its point, nor acts upon the plate by its own resistance to crushing.
In other words the caps containing lubricant heretofore known ceased to serve any
useful purpose at the moment of impact, whereas the function of my improved cap
is to prevent the crushing of the point of the projectile at that moment.
I am also aware that the use of solid metal caps for projectiles has been

page_text: proposed, but these caps did not contain a lubricant, and experience has shown
that they are greatly inferior to my invention in which a lubricating material is
interposed between the cap and the point of the projectile. My experiments have
shown that, when no lubricant is used, the surface of the head of the projectile is
torn and deeply furrowed in its passage through the cap and plate, thus adding
greatly to the resistance which it has to overcome. With a suitable lubricant, on
the contrary, the passage of the projectile through the cap and the armor plate is
facilitated, and both the hole through the plate and the head of the projectile are
usually found to be smooth, thus proving unmistakably the efficient action of the
-lubricant. While I have shown the lubricating material as being placed on the
point of the projectile and the cap then secured to the latter it is evident that
such lubricant may be applied to the inner wall of the cap instead of to the
projectile.
☐ 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
claim is
1. A projectile having a hard conoidal point, a soft metal supporting cap
having a correspondingly-formed recess secured to said point, and a lubricant
interposed between said point and cap, substantially as described.
2. A projectile having a hard conoidal point, a soft metal cap secured thereto
having a corresponding recess and fitting over said point, and a layer of graphite
interposed between said point and cap and surrounding the cap, substantially as
'described.
3. In an armor-piercing projectile, the combination of the pointed projectile, a
thick supporting cap entirely surrounding said point, and a lubricant interposed
between the cap and point, substantially as described.
4. The combination with an armor piercing projectile having a hardened point,
and a lubricant thereon, of the thick supporting cap entirely surrounding said point
and covering aid lubricant, substantially as described.
5. The combination with an armor piercing projectile of a recessed cap covering
the point of the projectile and containing a lubricant, the said cap being made with
thick walls so as not to be easily crushed in when the projectile strikes an armor
.plate.
6. In a projectile, the combination of a metal cap surrounding the point of the
projectile, and a lubricant interposed between the cap and projectile, the said cap
being made sufficiently strong to break in the hard face of an armor plate while it
is itself being crushed by the impact of the projectile on the said plate at high
velocity.
Dated this 20th day of Aumil 1007
BOULT & WADE,
Agents for the Applicant.