An Improved Cap for Shells or Projectiles.
Year: 1895

page_text: Date of Application, 3rd July, 1895
Complete Specification Left, 17th Mar., 1896-Accepted, 18th Apr., 1896
PROVISIONAL SPECIFICATION.
An Improved Cap for Shells or Projectiles.
I, MARCEL HOLTZER, of "Acieries d'Unieux," Department of Loire, in the
Republic of France, Metallurgist do hereby declare the nature of this invention
to be as follows:-
The object of this invention is to provide, for use in connection with shells or
projectiles, a cap of steel, superficially tempered at its front part and secured in
position in a peculiar manner which enables the projectiles, especially when fired,
or projected, at an angle, to exercise their action upon armour plates and more
particularly upon plates with hardened surfaces.
The improved cap, when thus applied to a projectile, answers a double purpose,
viz.:
1. Surrounding, as it does, the point of the projectile, it serves to support it, and
to prevent it from breaking as easily as it would do if it were not provided with
such support, when it comes in contact with the hard surface of the plate which
the projectile is intended to pierce or traverse.
2. Its further object is to give to the hard surface of the plate fired at, a back-
ward "start" which, alone, may be sufficient to crack the said surface, and which,
at all events, assists in extending and dividing the perforative effect of the
projectile proper over an increased area (even though the increase or additional
extension may, in some cases, amount only to a few tenths of a millimetre).
The
flight of the projectile, at a considerable velocity, is thus interrupted less suddenly,
the consequence being a reduction of the strain to which the projectile is subjected,
so that such strain cannot exceed the limits of resistance presented by the different
points of the metal of which it is made.
In order to attain this double object in a wholly satisfactory manner, I make
use of the arrangement hereinafter described.
This cap may be either pointed, or rounded off, with, say, five centimetres
radius; or it may terminate in a blunt surface of suitable configuration; and it is
fixed on to the segmental or lanced point of the projectile by a setting or cupping
process hereinafter described.
The thickness of the metal in front of the point of the shell should be greater
than it has been hitherto, while it may vary according to the particular calibre or
"bore" for which the projectile is constructed. It should not, however, be less
than three centimetres, for sixteen centimetres bore.
As, moreover, in firing at an angle, or obliquely, the situation of the impact of
the point of the projectile proper is not the same as, or does not coincide with, the
point of impact of the cap, it is necessary, for oblique firing, to make the diameter
of the front part of the said cap sufficient to prevent the point of the projectile
itself from leaving the zone of action of the cap, when the point of the projectile
proper meets the plate fired at.
With this object in view, it is necessary that the cap should be of such thickness,
in a lateral direction at the point of the projectile that supposing it were bisected
at right angles to its axis, on the same level as the point of the projectile, the
radius thus obtained should be larger than, or at least equal to, the thickness' at
the point.
The portion of the cap, which is in direct contact with the point and the
segmental surface of the projectile, is, unlike this segmental surface, which is made
of hard and disruptive metal, constructed of comparatively soft and deformable

page_text: metal, so as not to break the said segmental surface. For this reason, the said cap
is not tempered, except at its front portion, which is hardened by a superficial
tempering process, so as to act with increased energy upon the hard surface of the
plate.
With a cap, the front part of which is hard, it may happen that, from the
moment of its first contact with the plate fired at, it will enter the plate to a
certain depth, which may reduce the extent of displacement or "sweep" of the cap
upon the plate, in oblique firing.
Now as it is essential that the point of the projectile proper should touch the
surface fired at, as near as possible to the point, already shaken by the cap, so as
the more readily and effectively to continue its perforating action, it may be
preferable, rather than terminating such cap simply by a rounded surface,-to
extend the same in the shape of an obtuse cone whereby the point of initial impact
will be made to coincide with the axis of the projectile proper, instead of being
placed in the rear of it.
The generatrix of such cone may be an arc of a circle tangential to the rounded
portion, its radius being sufficiently large for the apex of the cone to form an angle
of from 100 to 120 degrees.
To prevent any displacement of the cap upon the shell, particularly in oblique
firing, the said cap should be firmly secured to the segmental surface of the shell-
point. This result is attained by forming near the base of the pointer portion of
the shell, a circular groove, while leaving at the open end of the cap an internal
flange or shoulder, adapted to be driven into the groove provided round the
projectile as stated; the highest possible degree of pressure being applied for the
purpose.
Towards the point, the said groove should be cut practically at right angles to
the segmental surface of the shell, while towards the base of the shell-point, its
wall should be gently sloping, so as to fit in with, or join,. the segmental surface at
that part. This groove in the segmental part of the shell or projectile should be
made beforehand, that is to say, before the projectile is subjected to the tempering
operation, in order to enable the effect of the tempering to extend deeper in the
direction of the groove; whereas, if the said groove were cut in the projectile after
tempering, the resistance of the segmental portion of the said projectile would
thereby be materially reduced.
In order to prevent the cap from becoming disconnected from the shell
prematurely, at the time of the impact, in oblique firing, it is imperative to place
the groove, which, as has just been stated, serves to lock the cap in position, at the
greatest distance possible in the rear of the projectile-point. This distance, which
is limited only by the necessity of leaving the necessary room or "play" between
the inner walls of the gun and the largest external diameter of the cap, should
be greater than, or at least equal to, two thirds of the total length of the
mean arc of the segmental surface, measured from the point of the projectile to
the centre of the front zone or belt.
Dated this 3rd day of July 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
COMT DIE
DIECIEICATION.
An Improved Cap for Shells or Projectiles.
I, MARCEL HOLTZER, of "Acieries d'Unieux," Department of Loire, in the
Republic of France, 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 :-
The object of this invention is to provide, for use in connection with shells or

page_text: projectiles, a cap of steel, superficially tempered at its front part and secured in
position in a peculiar manner which enables the projectiles, especially when fired,
or projected, at an angle, to exercise their action upon armour plates and more
particularly upon plates with hardened surfaces.
The improved cap when thus applied to a projectile, answers a double purpose,
viz.:
1. Surrounding, as it does, the point of the projectile, it serves to support it, and
to prevent it from breaking as easily as it would do if it were not provided with
such support, when it comes in contact with the hard surface of the plate which
the projectile is intended to pierce or traverse.
2. Its further object is to give to the hard surface of the plate fired at a back-
ward "start" which, alone, may be sufficient to crack the said surface, and which,
at all events, assists in extending and dividing the perforative effect of the
projectile proper over an increased area (even though the increase or additional
extension may, in some cases, amount only to a few tenths of a millimetre). The
flight of the projectile, at a considerable velocity, is thus interrupted less suddenly,
the consequence being a reduction of the strain to which the projectile is subjected,
so that such strain cannot exceed the limits of resistance presented by the different
points of the metal of which it is made.
In order to attain this double object in a wholly satisfactory manner, I make use
of the arrangement hereinafter described, and illustrated in the accompanying
drawing, in which
Figure 1 is a section of a shell provided with a rounded cap, and
Figure 2 a similar section of a shell fitted with a pointed cap.
This cap a may, be either pointed, or rounded off, with, say, five centimetres
radius; or it may terminate in a blunt surface of suitable configuration; and it is
fixed on to the segmental or lanced point of the projectile b by a setting or cupping
process hereinafter described.
The thickness of the metal in front of the point of the shell, at c, should be
greater than it has been hitherto, while it may vary according to the particular
calibre or "bore" for which the projectile is constructed. It should not, however,
be less than three centimetres, for sixteen centimetres bore.
As, moreover, in firing at an angle, or obliquely, the situation of the impact of
the point of the projectile proper is not the same as, or does not coincide with, the
point of impact of the cap, it is necessary, for oblique firing, to make the diameter
of the front part of the said cap sufficient to prevent the point of the projectile
itself from leaving the zone of action of the cap, when the point of the projectile
proper meets the plate fired at.
With this object in view,
is necessary that the cap should be of such thickness,
at d, that supposing it were bisected at right angles to its axis, on the same level as
the point of the projectile, the radius thus obtained should be larger than, or at
least equal to, the thickness at c.
The portion of the cap, which is in direct contact with the point and the
segmental surface of the projectile, is, unlike this segmental surface, which is made
of hard and disruptive metal, constructed of comparatively soft. and deformable
metal, so as not to break the said segmental surface. For this reason, the said cap
is not tempered, except at its front portion, which is hardened by a superficial
tempering process, so as to act with increased energy upon the hard surface of the
plate.
With a cap, the front part of which is hard, it may happen that, from the
moment of its first contact with the plate fired at, it will enter the plate to a
certain depth, which may reduce the extent of displacement or "sweep" of the cap
upon the plate, in oblique firing.
Now as it is essential that the point of the projectile proper should touch the
surface fired at, as near as possible to the point, already shaken by the cap, so as
the more readily and effectively to continue its perforating action, it may be
preferable, rather than terminating such cap simply by a rounded surface, as

page_text: :
shewn in Figure 1, to extend the same in the shape of an obtuse cone (Figure 2,)
whereby the point of initial impact will be made to coincide with the axis of the
projectile proper, instead of being placed in the rear of it.
The generatrix of such cone may be an arc of a circle tangential to the rounded
portion, its radius being sufficiently large for the apex of the cone to form an
angle of from 10 to 120 degrees.
To prevent any displacement of the cap upon the shell, particularly in oblique
firing, the said cap should be firmly secured to the segmental surface of the shell-
point. This result is attained by forming near the base of the pointed portion of
the shell, a circular groove e, while leaving at the open end of the cap an internal
flange or shoulder, adapted to be driven into the groove provided round the
projectile as stated; the highest possible degree of pressure being applied for the
purpose.
Towards the point, the said groove should be cut practically at right angles to
the segmental surface of the shell, while towards the base of the shell-point, its
wall should be gently sloping, so as to fit in with, or join, the segmental surface at
that part. This groove in the segmental part of the shell or projectile should be
made beforehand, that is to say, before the projectile is subjected to the tempering.
operation, in order to enable the effect of the tempering to extend deeper in the
direction of the groove; whereas, if the said groove were cut in the projectile after
tempering, the resistance of the segmental portion of the said projectile would
thereby be materially reduced.
In order to prevent the cap from becoming disconnected from the shell
prematurely, at the time of the impact, in oblique firing, it is imperative to place
the groove, which, as has just been stated, serves to lock the cap in position, at the
greatest distance possible in the rear of the projectile-point. This distance, which
is limited only by the necessity of leaving the necessary room or "play" between
the inner walls of the gun and the largest external diameter of the cap, should be
greater than, or at least equal to, two thirds of the total length of the mean arc of
the segmental surface, measured from the point of the projectile to the centre of
the front zone or belt.
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 I
-claim is :-
1. Providing shells or other similar projectiles with
a cap or calotte of
comparatively soft and deformable, non-tempered, metal, the front portion only of
which is hardened by superficial tempering, for the purpose of enabling the
projectile to act with increased energy upon the hard or hardened surface of the
plate fired at.
2. The method of fixing the cap or calotte in position upon the shell or pro-
jectile by a cupping or inter-locking operation, the projectile being provided, for
the purpose, with a groove, and the cap, with a shoulder, bead or flange of
corresponding section; the said groove being cut in the body of the projectile
before the same is tempered, all substantially as and for the purpose specified and
as illustrated in the drawing.
Dated this 17th day of March 1896
HASELTINE, LAKE & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.