Year: 1889

page_text: Date of Application, 11th Dec., 1889
Complete Specification Left, 11th Oct., 1890-Accepted, 15th Nov., 1890
I, ABRAHAM MARTIN of 177, Aston Lane, Birmingham, in the County of Warwick,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in percussion fuses such as that forming the
subject of a previous application for Letters Patent dated November 22nd 1889,
No. 18,738.
The fuse therein described is designed to be fixed in the base of the projectile, the
striking or firing pin being movable relatively to the priming; and my present inven-
tion has for its object first to adapt the fuse to be fixed at the point or head of the
projectile instead of at the base and secondly to enable the relative positions of
the firing pin and priming to be reversed without in either case departing from the
principle upon which the action of the fuse depends for its operation.
In order to accomplish the first mentioned object, I provide a passage through or
past the striking pin, and, whilst preserving the same relative position and operation
of the parts of the fuse, considered with regard to the motion of the projectile, reverse
the position of the parts with regard to the projectile itself, that is to say, the fuse
being placed at the point of the projectile, the rear end of the fuse case (at. which is
situated the inwardly-projecting convex boss which acts on the case of the plunger as
described in my aforesaid Specification) is now the inner end whilst the priming is,
placed at the outer or front end and the plunger and striking pin are correspondingly
reversed in position in the fuse case.
In order to give passage to the gases developed in. the detonation of the priming,
the striking pin may be tubular or it may be of approximately triangular or such
other cross-section as (whilst being held within, and acted on by, the weighted plunger
in the manner previously described) to allow the gases to pass it.
The inner or rear end of the. plunger sheath also has orifices in it for the same
purpose, as likewise the convex boss of the fuse case, and provision is made by varying
the curvature of the said boss and of the concavity in the rear end of the plunger
itself, to prevent the passages past the striking pin being blocked by the rear end of
the plunger sheath when the latter is forced inwards.
In order to reverse the relative positions of the striking pin without varying the
operation of the fuse, whether it is fixed at the base or point of the projectile, I
substitute for the striking pin a tubular or hollow pin adapted to contain the priming
said tubular or hollow pin being fitted within, and acted on by, the weighted plunger,
in the manner described with regard to the striker in my aforesaid Specification; and
in the end of the fuse case or chamber I fix in place of the priming an inwardly-
projecting central pin against which, as an anvil, the priming is caused to strike by the
momentum of the weighted plunger on the projectile meeting an obstacle.
Dated this 11th day of December 1889.

page_text: COMPLETE SPECIFICATION.
Improvements in Percussion Fuses for Explosive Projectiles.
I, ABRAHAM MARTIN, of 177 Aston Lane, 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 improvements in. percussion fuses such as that forming the
subject of a previous application for Letters Patent dated November 22nd 1889,
No. 18738.
•
The fuse therein described is designed to be fixed in the base of the projectile, and
iny present invention has for its principal object to adapt the fuse to be fixed,at.the
point or head of the projectile instead of at the buse.
In order to accomplish this object I provide a passage through the rear end or past
the striking pin and through the rear end of the plunger sheath for the passage of the
gases developed by the detonation of the priming and otherwise adapt the fuse to be:
fixed at the point of the projectile whilst preserving the same relative position of the
operative parts of the fuse, considered with regard to the motion of the projectile upon
which the action of the fuse depends.
My invention has also for its object to enable the relative positions of the striking:
or firing pin and priming to be reversed without in either case departing. from the
principle upon which the action of the fuse depends for its operation.
Reference is to be had to the accompanying drawings, forming part of this Specifica-.
tion, wherein
Figures 1 and 2 are. longitudinal sections of the fuse as. fixed at the point of the
projectile and respectively shewing the normal form and position of the plunger and
the form and position assumed on the firing of the gun.
Figure 3 is a cross-section on line 1-1 Figure 1.
Figure 4 is a longitudinal section of the fuse in which the priming is carried by the
plunger-operated. pin.
The same letters of reference indicate the same parts in all the figures.
A is the fuse case screwed into the point of the projectile, B is the plunger, being a
cylinder preferably of compressed tungsten encased in a double sheath formed of solid
drawn thin brass capsules 6'62, the capsule 6 having a normally convex rear end. 6.
enclosing the concave rear end of the plunger. The plunger has an axial orifice
to receive the pin C, the rear end of said pin abutting against or being preferably
rivetted to the centre of the convex end b¹ of the plunger sheath. The inner sheath b²
is closed at the front end save that it has a central orifice smaller than the body of the
pin C and radial slits to enable the point of the pin, which is normally retracted within:
such front end, to force its way through; as shewn in Figure 2.
In order to give passage to the gases developed by the detonation of the fulminate
or priming g and enable them to reach the explosive charge of: the projectile,, the
striking pin may be tubular or it may be of approximately triangular, or such other,
form in cross-section as to leave thoroughfares d between it and the sides of.the: passage:
in the plunger in which it fits only just sufficiently to be guided and maintained: in its
central position. Or the pin might be cylindrical and the sides of: the passage longi-
tudinally grooved for the same purpose. For the same purpose, orifices e:are formed
in the front end of the sheath 62, said orifices communicating with a cavity el formed in
the front end of the body of the plunger and communicating with the said thorough:
fares d. Orifices f are also made in the domed rear end 6 of the plunger sheath and
the depth of the concavity in the rear end of the body B of the plunger is deeper than
the protuberance of the boss (by which the curvature of the end 61 is inverted, as
shewn in Figure 2 and as described.in my previous application on the discharge of the
gun) so that there will be a continuous thoroughfare for the priming gases from the
front to the rear of the plunger and through orifices h in the inner end of the fuse case
to the interior of the projectile. The priming g is fixed in place by the usual means.

page_text: In order to reverse the relative positions of the striking pin and priming without
varying the operation of the fuse, whether it be fixed at the base or point of the pro-
jectile, I substitute for the striking pin C above described, a tubular or hollow pin
adapted to contain the fulminate or priming, as shewn in Figure 4, and to be acted on
by the plunger, in the same way as the striking pin and in the front end of the fuse
case or chamber I fix, in place of the priming, an inwardly-projecting central auvil
against which the priming is caused to strike by the momentum of the plunger on the
projectile meeting an obstacle.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described percussion fuse provided with thoroughfares for the priming
gases leading from front to rear of the plunger and adapted to be fixed in the point of
the projectile, substantially as specified.
2. The modified form of the herein described percussion fuse having the plunger
operated pin adapted to carry the priming and provided with an anvil for the same to
strike against under the action of the plunger, as described.
Dated this 11th day of October 1890.
A. MARTIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.