Improvements in Time and Percussion Fuses.
Year: 1897

page_text: Date of Application, 17th Nov., 1897
Complete Specification Left, 16th Aug., 1898-Accepted, 22nd Oct., 1898
PROVISIONAL SPECIFICATION.
Improvements in Time and Percussion Fuses.
I, CHARLES AMBROSE McEvoy, of 69, Victoria Street, Westminster, in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
The outer case or body of the fuse is formed to be screwed into the nose of a
shell projectile. In its rear end is a hollow chamber the rear end of which is closed
by a screw plug having a passage formed through it by which flame can pass from
the chamber to fire the charge in the body of the shell."
a
In the front end of the chamber is placed a loose weight or striker having
projecting point on its rear end-a coiled spring tends to throw the striker
rearwards.
Two short metal tubes one fitting within the other are also placed within the
chamber-the outer one fitting the interior of the chamber loosely and the inner
one being filled with powder and carrying fulminate at its forward end to be
exploded when the point of the striker is brought against it.
The outer tube is made to project for a distance beyond the front end of the
inner tube so that when the rear end of the inner tube is resting against the rear
end of the chamber the front of the outer tube is against the striker and keeps
the striker from being brought into contact with the fulminate and preferably also at
the same time holds the striker up to the front end of the chamber-thin metal
pins connect the two tubes together in this position.
The striker is also held to the forward end of the chamber by a rod screwing
into it and extending out through the front end of the outer case or body of the
fuse. The end of the rod where it extends beyond the outer case or body is made
to carry wings or vanes which may be parallel with or at an angle to it so as
either to impede the rod from being turned or to give to it a turning movement
as the shell passes through the air on being fired from a gun.
The rod may either be carried by the front end of the outer case or body in
such a way that it can turn freely but not move endwise or the rod may
have a second screw thread cut around it and be screwed into the front end of
the case.
When a shell carrying a fuse constructed in the above manner is fired from a
gun the pins coupling the two tubes above mentioned are sheared and the outer
tube moves back away from the striker leaving the striker free to be thrown
backward by the coiled spring so soon as it is liberated from the screw which
holds it. As the shell passes through the air and the screw rod is either turned
or impeded from turning by the air-this in conjunction with the rotation of the
shell causes the screw rod to unscrew from the striker and liberate it. So soon
as the striker is liberated it is thrown backwards by the coiled spring against the
fulminate and the shell is fired. Should the shell strike before the shell is thus
fired the two tubes and the fulminate carried by the inner one are thrown forwards
against the striker and the shell is fired as with an ordinary percussion fuse.

page_text: By giving a greater or less number of turns to the screw rod and thereby more
or less unscrewing it from the striker before the shell is fired from a gun-the
number of turns the projectile must make before the striker is liberated can be
varied to any extent desired and the time of firing can so be accurately adjusted.
Dated this 16th day of November 1897
1
Improvements in Time and Percussion Fuses.
I, CHARLES AMBROSE McEvoy, of 69, Victoria Street, Westminster, in the
County of Middlesex, Civil 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:-
The drawings hereunto annexed shew views of two examples of time and per-
cussion fuses constructed according to my invention.
Figure 1 is a side elevation, Figures 2 and 3 end views and Figure 4 a
longitudinal section of one form and Figure 5 a longitudinal section and Figure 6
an end view of a modified form.
In these figures A is the outer case or body of the fuse-it is formed to be
screwed into the nose of a shell projectile. In its rear end is a hollow chamber
closed by a screw plug A¹ having a passage formed through it by which flame can
pass from the chamber to fire the charge in the body of the shell. B is a striker
which can be thrown rearwards by the action of the coiled spring C. D and E are
metal tubes one fitting within the other and secured together by thin metal pins F.
The outer tube D projects for a distance beyond the front end of the inner tube
and comes against the rear end of the striker whilst the rear end of the inner
tube E rests against the screw plug A¹. E is a small recess in the forward end
of the tube E for carrying fulminate. E are small holes by which when the fulminate
is exploded the flash can pass to powder or other explosive in the interior of
the tube E.
G is a screw rod screwing into the forward end of the striker. To its forward end
is secured a cap H which has a screw thread cut within it having a pitch corre-
sponding to the pitch of the screw thread on the rod G. The screw thread in the
cap H screws on to a corresponding screw thread cut around the front end of the
case A.
In this way the striker B is restrained from being thrown rearwards not only
by the tubes E F but also by the screw rod G. I, I are blades projecting out from
the exterior of the cap H. In Figures 1 to 4 the blades are shewn to be fixed
rigidly to the exterior of the cap and to be inclined to its axis in such way that
when carried through the air by a shell fired from a gun the pressure of air upon
the blades causes the cap to rotate in the same direction as the shell is made to
rotate by the rifling of the gun but at a slightly different speed so that the cap
gradually unscrews itself from off the end of the case A.
In Figures 5 and 6 the blades I are shewn to be carried on the exterior of the
cap H in such a way that the angle at which they are set relatively to the axis
of the case A can be varied as may be desired.
The forward end of each blade has a pin I¹ projecting from it which screws into
a coresponding radial hole in a ring K which can be turned around the forward
end of the case A or can be clamped and locked to it by a nut L screwed onto a
screw thread on the forward end of the rod G.
The rear end of each blade has a pin I2 projecting from it to enter a correspond-
ing hole in a flange which surrounds the rear end of the cap.

page_text: In this way when the nut L is slackened a partial turn can be given to the
ring K and the blades can be thereby inclined more or less to the longitudinal axis
of the case A-and by then again screwing up the nut L the blades can be locked
securely in the inclined position to which they had been set.
When a shell carrying a fuse constructed in the above manner is fired from a gun
the small metal pins which couple together the tubes D E are sheared as the
shell is projected forwards and the outer tube 1) moves back away from the striker
and the striker is then only restrained from being thrown rearwards by the
screw rod G which screws into it.
The fuse is now ready to be fired should the shell strike any obstacle. In this
case the two tubes D E would fly forwards and the fulminate carried by the inner
tube E be brought against the striker and the shell would thereby be exploded as
with an ordinary percussion fuse.
As the shell passes through the air the screw rod G gradually becomes unscrewed
from the striker B and finally ceases to hold it in its forward position the coiled
spring C then throws the striker rearwards and its point coming against the
fulminate carried on the forward end of the tube fires the fuse and explodes the
shell.
In the construction shewn at Figures 1 to 4 the time at which the fuse is set to
fire the shell can be adjusted by more or less unscrewing the cap H from the front
end of the case A before inserting the projectile into the gun. To facilitate the
adjustment the cap may carry an indicator point H' and a scale be marked upon
the exterior of the case A as indicated at M Figure 1.
In the construction shewn at Figures 5 and 6 the time can be adjusted by
varying the angle at which the blades I are inclined or partly in this way and
partly by more or less unscrewing the cap from the end of the case.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In a time and percussion fuse the combination of the striker, the spring for
throwing it rearwards the two tubes fitting one within the other for restraining
the striker from being thrown rearwards until the shell carrying the fuse has
been fired from a gun-the screw rod also restraining the striker from being
thrown rearwards and the wings or vanes carried by this rod which as the shell
passes through the air impede the rod from being turned or give to it a turning
movement substantially as described.
2. The construction of time and percussion fuses substantially as herein before
described and illustrated in the drawing annexed.
Dated this 15th day of August 1898