Improvements in Percussion Fuses for Explosive Projectiles.
Year: 1889

page_text: Date of Application, 1st Jan., 1889
Complete Specification Left, 1st Oct., 1889-Accepted, 2nd Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in Percussion Fuses for Explosive Projectiles.
L, ABRAHAM MARTIN, of 177 Aston Lane, Perry Barr, Birmingham in the County
of Warwick, Engineer, do hereby declare the nature of this invention to be as
follows:-
My Invention relates to percussion fuses of that kind in which the detonation of
the priming is brought about by the percussive action due to the inertia of a
weighted plunger capable of a short independent movement in the direction of the
axis of the projectile. This plunger carries a firing pin or striker whose point is
normally held retracted within the plunger, the striker being so connected to the
plunger that on the discharge of the gun the striker is brought into such relative
position to the plunger that on the projectile meeting an obstacle the striker will be
caused by the inertia of the plunger to strike upon and explode the priming.
My Invention relates to an improved mode of connecting the striker to the plunger,
and consists in coupling the plunger to the striking. pin by a buckled or conical disc
which is attached by its periphery to the rear end of the plunger and through which
the firing pin passes. This disc embraces the striking pin just in front of a slight
conical part of the pin of slightly greater diameter than the aperture in the disc
whereby the striking pin will be held with its point retracted within the front end of
the plunger and so prevented from coming in contact with the priming. This con-
nection between the plunger and pin is however, overcome when the rear end of the
fuse case in which the plunger works, strikes the pin and forces it forwards through
the plunger until the buckled or conical disc is struck by the rear end of the fuse
case and thereby collapsed or flattened. As the disc is prevented from expanding
at the periphery, the metal becomes crowded towards the centre whereby the size of
the aperture becomes contracted until its diameter is less than that of the pin. This
contraction takes place just in rear of the shoulder at the base end of the pin
whereby a firm connection is ensured between the plunger and striking pin in the
new position of the latter, the firing point of the striker then projecting in advanco
of the plunger, so that when the projectile meets an obstacle the striking pin will
be carried forward by the momentum of the plunger with sufficient force to explode
the priming.
I prefer to make the buckled or conical disc above referred to, in one piece with a
cylindrical casing of thin metal of which it forms the rear end. Within this casing
is enclosed an inner sheet metal casing of tubular or annular section, the annular
space being filled with tungsten, whereby I obtain great weight within a small
volume.
Dated this 1st dow of Ton 1000
COMPLETE SPECIFICATION.
Improvements in Percussion Fuses for Explosive Projectiles.
I, ABRAHAM MARTIN, of 177, Aston Lane, Perry Barr, Birmingham, in the County
of Warwick, Engineer, 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 percussion fuses of that kind in which the detonation of
the priming is brought about by percussive action due to the momentum of a plunger
P===

page_text: capable of limited motion, in the direction of the axis of the projectile, and carrying
a firing pin or striker. The point of the-firing pin or striker is normally held
retracted within the plunger, but the striker is so connected to the plunger that on
the discharge of the gun the striker. is, by virtue, of the inertia of the plunger,
brought into such relative position tbereto that, on the projectile meeting an obstacle,
the striker will be caused by, the momentum of the plunger, to strike upon, and
explode, the priming..
In order that my invention may be more readily understood, I have illustrated it
in the accompanying drawings forming part of this specification and will proceed to
describe it in detail with reference thereto. Figure 1 represents a central longitudinal.
section of the percussion fuse, the striking pin being in its normal or safe position.
Figure 2 is a similar view, shewing the striking pin in the position it is caused to
assume, with regard to the plunger, by the discharge of the gun. Figure 3 is a
view of the rear conical end of the striking pin, drawn to a larger scale. The same
letters of reference.indicate the same parts in all the figures, A being the part of the
base of the shell in which the percussion fuse is fixed; B the case of the fuze; C the
plunger; D.the striking pin; and E the detonating priming: The case B of the
fuse is cylindrical and is screwed or otherwise fixed in the base of the shell. A and
may be constructed in any suitable manner. It is closed at the inner end by screw
plugs e el holding the fulminate. Erbetween them, and having orifices for the passage
of the striker and of the flame.
or.
My Invention resides in the mode of connecting. the striking pin D to the weight
r.plunger C; and consists in coupling the plunger to the striking pin by a buckled
or conical disc c of metal which is attached by its periphery to the rear end of the
plunger and through which the pin D passes. This disc embraces the striking pin
just in front of a slight conical part d of the pin of slightly greater diameter than the
aperture in the disc whereby the striking pin will be held with its point d¹ retracted
within the front end of the plunger, as shewn in figure 1, and so prevented from
coming in contact with the priming. For further security. the front end of the
plunger is closed by a thin metal disc c¹ having a central orifice immediately opposite
to the point of the striker. The connection between the plunger C and pin D is,
however, overcome (when the gun is discharged) by the rear-end of the case B
striking the rear end of the pin D. The impact forces the pin forwards through the
disc cat the front end of the plunger, by virtue of the inertia of the plunger which
causes the plunger, when the shell is first set in motion; to remain practically
stationary until after the buckled or conical disc c is struck by the rear end of the fuse
case B and collapsed or flattened. As the disc c cannot expand peripherally, the
metal becomes crowded towards the centre thus contracting the aperture until its
diameter is less than that of the pin D. This contraction takes place just in rear of
the shoulder at the base end of the pin, whereby a firm connection is ensured between
the plunger and the striking pin in the new position of the latter in relation to the
plunger, the firing point of the striker then projectings in advance of the plunger,
as shewn in figure 2 which represents the position of the plunger during the flight of
the projectile. The plunger is now at the rearend of the case Bwith the pint pro-
jecting in front of it, so that when the projectile meets an obstacle the momentum
of the plunger will carry forward the striking pin with sufficient force to explode
the priming.
I prefer to make the buckled or conical disc c, above referred to, in one piece with
an annular casing ff of thin, metal, the annularespace being filled with tungsten,
whereby I obtain great weight within a small volume.
17
Having now particularly described a and, ascertained the nature of the, said
invention and in what manner the same is to be performed, I declarer that.what I
claim is;
1. In a percussion fuse for explosive projectiles, the herein described means of (con-
necting the striking pin to the weighted plunger by which it is shielded and actuated,
said. means consisting, in the combination, with the conical,,shouldered pin, and, with

page_text: the tubular plunger, of a buckled or conical disc carried by the plunger and adapted
to embrace the conical part of the pin and hold it retracted and to be collapsed by
impact and re-engage with the pin in the manner specified.
2. In a percussion fuse for explosive projectiles, the plunger constructed of a sheet
metal casing of annular section filled with tungsten, in combination with the herein
described buckled or conical disc and striking pin, substantially as specified.
Dated this 1st day of October 1880
A. MARTIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.