Improvements in Percussion-fuses.
Year: 1890

page_text: Date of Application, 11th Apr., 1890
Complete Specification Left, 10th Jan., 1891-Accepted, 21st Feb., 1891 ·
PROVISIONAL SPECIFICATION.
Improvements in Percussion-fuses.
I, ROBERT LOW, of Eildon House, Macaulay Road, Clapham, in the County
of Surrey, Mechanical Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention relates to percussion-fuses wherein an annular or tubular piece or
guard is so fitted upon the needle, striker or pellet that it will keep the needle
and the cap or detonator out of contact with each other, until the projectile or
shell is discharged from a gun, when the said guard will be forced backward upon
the needle or pellet by the shock of the discharge, so that both the said needle or
pellet and the guard are free to move forward upon impact of the shell.
In my improved fuse, I make the needle, striker or pellet with an enlargement
or head, and between this head and the guard I arrange a spiral or other suitable
spring, which must be of such strength that it will withstand the usual dropping
or jolting test, but, in the discharge of the projectile or shell from a gun, will
yield to permit the required movement of the guard relatively to the needle or
pellet. I make the said guard and the needle or pellet of equal, or approximately
equal weight, so that the force which the spring has to exert to prevent relative
movement of the said needle or pellet and guard is the same whether the shell be
dropped with its base or its apex uppermost. I am thus enabled to minimize the
strength of the said spring in proportion to the entire weight available for exploding
the cap or detonator upon impact of the shell.
To provide for retaining the guard in place upon the needle or pellet after it
has been forced backward thereon, I make the needle or pellet with teeth and
provide the guard with movable segments having corresponding ieeth and acted
upon by a split ring or other suitable spring which moves or tends to move them
inward and thus causes their engagement with the needle or pellet when the guard
is driven backward thereon. Or I make the entire guard in segments having
suitable teeth to engage with those on the needle or pellet, and I combine with
the said segments one or more split rings or other suitable means for holding them
together and causing their engagement with the needle or pellet. Or I make the
guard itself in the form of a split ring.
My improvements are applicable to base-fuses and also to fuses for use in the
nose or apex of the shell.
In making a fuse for use in the nose or apex of the shell, I find it advantageous
to make the pellet with a central hole which is filled with mealed powder or
quickmatch and at the forward end of which is arranged the cap or detonating
composition the needle being fixed in the interior of the forward end of the
fuse-case or body. In the rear end of the said fuse-case or body I secure an
annular piece or disc in which is arranged a disc of compressed powder.
Dated this 11th day of April 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Percussion-fuses.
I, ROBERT LOW, of Eildon House, Macaulay Road, Clapham, in the County of
Surrey, Mechanical 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, and is designed to increase the efficiency
and safety of the same.
In my improved fuse, there is an annular or tubular piece or guard which is so
fitted upon the pellet that it will prevent contact of the needle with the cap, primer
or detonator, until the projectile or shell is discharged from a gun, when the said
guard will be forced backward upon the pellet by the shock of the discharge, so
that both the said pellet and the guard are then free to move forward upon impact
of the shell. The said guard, therefore, obviates the liability to premature action
of the fuse by accidental shock or concussion.
..I make the pellet with an enlargement, flange or head, and between this flange
or head and the said guard, I arrange a spiral or other suitable spring. This
spring must be of such strength that it will withstand the usual dropping or jolting
test, but, when the projectile or shell is fired from a gun, the said spring will, under
the shock due to the discharge of the gun, yield to permit the required movement
of the guard relatively to the pellet. I find it advantageous to make the said
guard and the pellet of equal, or approximately equal weight, so that, when the-
shell is subjected to the dropping test, the force which the spring has to exert to
prevent relative movement of the said pellet and guard, will be the same whether
the shell be dropped with its base or with its apex uppermost. I am thus enabled
to minimize the strength of the said spring in proportion to the entire weight
available for exploding the cap or detonator upon impact of the shell.
To provide for retaining the guard in place upon the pellet after it has been
forced backward thereon, 1 make the pellet with teeth, and provide the guard
with movable segments having corresponding teeth and acted upon by a split ring
or other suitable spring, which moves or tends to move them inward and thus
causes their engagement with the teeth on the pellet when the guard is driven
backward thereon. Or I make the entire guard in segments having suitable teeth
to engage with those on the pellet, and I combine with the said segments, one or
more split rings or other suitable means for holding them together and causing
their engagement with the pellet. Or I make the guard itself in the form of a
split ring provided with teeth to engage with those of the pellet.
My improvements are applicable to base-fuses and also to fuses for use in the
nose or apex of the shell.
In making a fuse for use in the nose or apex of the shell, I find it advantageous
to make the pellet with a central hole which is filled with mealed powder or
quick-match, and at the forward end of which is arranged the cap or detonating
composition, the needle being fixed in the interior of the forward end of the
fuse-case or body. In the rear end of the said fuse-case or body, I secure an
annular piece in which is arranged a disc of compressed powder, for communicating
the flame or flash to the powder-charge or bursting-charge of the shell.
In the accompanying drawing, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure is a longitudinal central section of one form of my improved fuse,
designed for use in the nose or apex of a shell.
Figure 2 is a transverse section on the line a, a, Figure 1.
Figure 3 is a longitudinal central section, showing another form or modification
of my improved fuse, designed for use in the base of a shell.
Figure 4 is a transverse section on the line ', ', Figure 3.

page_text: Figure 5 is a longitudinal central section, and
Figure 6 a transverse section on the line, x2, Figure 5, showing a further
modification of my invention.
Like letters indicate corresponding parts throughout the drawing.
a is the fuse-case or body which is adapted to be secured in the apex or in the
base of a shell; is the pellet; c is the annular piece or guard for preventing
premature action of the fuse by accidental shock or concussion.
The pellet is formed with an enlargement, flange or head b', and between this
flange or head and the guard c is placed a spiral spring. d for the purpose above
specified.
In the fuse shown in Figures 1 and 2, the guard c consists of three segments,
which are formed with annular recesses or grooves c', and are held together and
pressed firmly against the pellet b by means of springs or split rings e fitted in the
said recesses or grooves c'. The segments composing the guard c are formed with
teeth c² adapted to engage with corresponding teeth 2 on the pellet & when the said
guard is moved backward on the pellet. The needle is fixed in the forward end
of the fuse-case or body a, and the primer or detonator g is secured in the forward
end of the pellet b. A hole or passage b³ is formed longitudinally through the
centre of the pellet b, and is filled with mealed powder or quick-match, and a disc h
of compressed gunpowder is secured in the rear end of the fuse-case or body a.
The action of the fuse shown in Figures 1 and 2 is as follows, viz. :-When the
shell containing the said fuse is discharged from a gun, the guard c, by reason of
its inertia, is held back while the pellet moves forward with body of the fuse,
thus compressing the spring d, until the forward end of the said guard is flush, or
nearly flush with the forward end of the pellet b. The teeth c² of the guard c then
engage with the teeth 2 of the pellet b and retain the said guard in place upon the
pellet. The pellet b is thus released and the guard c then forms virtually a part
of the said pellet. Upon impact of the shell, the said guard, the spring and the
pellet are, by their momentum, driven forward, so that the primer or detonator g
strikes the needle f, which causes the explosion of the said primer or detonator; the
flame is transmitted by the quick-match in the passage to the disc of compressed
powder, whereby it is communicated to the bursting-charge of the shell.
In the fuse shown in Figures 3 and 4, the needle f is formed on (or fixed in) the
forward end of the pellet b, and the primer or detonator g is secured in the forward
end of the fuse-case or body a. The pellet b is, in this case, made solid, as the flame
is transmitted directly from the primer or detonator g to the bursting-charge of the
shell. The guard c and spring d are constructed and arranged substantially as
above described with reference to Figures 1 and 2.
The fuse shown in Figures 5 and 6 is similar in construction to that shown in
Figures 3 and 4, with the exception that the guard c is made in the form of a tube
having radial slots in which are fitted to slide locking-pieces c³. These locking
pieces are provided with teeth c to engage with the teeth on the pellet for the
purpose above specified. The said locking-pieces are pressed against the pellet
by means of a spring or split ring e fitted in an annular recess or groove c¹ in the
guard c.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I wish it understood that
I claim :-
First. A percussion-fuse wherein a guard for preventing premature action of the
fuse is fitted upon the pellet in combination with one or more suitable springs, for
the purposes above specified.
Second. A percussion-fuse such as I have hereinabove described, wherein the
pellet and the guard for preventing premature action of the fuse are made of equal,
or approximately equal weight for the purpose above specified.
Third. A percussion-fuse such as I have hereinabove described, wherein the
guard for preventing premature action of the fuse consists of a split ring or of a

page_text: series of segments pressed together by means of one or more split rings or other
suitable springs, and is adapted to engage with projections or teeth on the pellet,
for the purposes above specified.
Fourth. The modification of my invention wherein I provide the guard with
locking-pieces which are caused to engage with the projections or teeth on the
pellet by one or more suitable springs, substantially as, and for the purpose, above
specified.
Sixth. The improved percussion-fuse constructed substantially as described with
reference to Figures 1 and 2, or to Figures 3 and 4, or to Figures 5 and 6 of the
accompanying drawings and operating as above specified.
ROBERT LOW.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.