Double-action Fuzes for Shells.
Year: 1898

page_text: Date of Application, 23rd Aug., 1898-Accepted, 23rd Dec., 1898
COMPLETE SPECIFICATION.
Double-action Fuzes for Shells.
We, VICKERS, SONS & MAXIM, LIMITED, of The River Don Works, Sheffield,
in the County of York, Steel Manufacturers, do hereby declare the nature of this
invention. (as communicated to us from abroad by Friedrich Krupp, of Essen,
Germany, Engineer), and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement;
:-
This invention relates to a construction of double-acting fuze for shell, so
arranged as not only to insure the correct working of both the time fuze and the
percussion fuze but also according to one mode of construction, to enable the part
of the fuze containing the detonators for the time and percussion fuzes to be kept
separate from the body of the fuze until this is required to be used, so that shells
fitted with the new fuze can be transported and manipulated with perfect
security.
We will describe the construction of the fuze with reference to the accompany-
ing drawing in which Fig. 1 shews a vertical section of the new double acting
fuze, the various parts being in the position tliey occupy before the round is
fired; Figure 2 is a similar section shewing the parts in the position which they
assume after the round has been fired. Fig. 3 shews an exterior view of the fuze
from which the detonator has been removed, the exterior view of the latter being
shewn in Fig. 4. Fig. 5 shews in detail the elastic supporting disc used with
the fuse.
The double acting fuze (Fig. 2) consists of the fuze body A, the two com-
position rings B and C, the spring washer D (Fig. 5) the fuze cover E and the
detonator (Fig. 4). The latter which is generally, as advisable, kept separate
from the fuze and is not fitted to it till just before firing, contains the percussion
fuze and such parts of the fuze as cause the ignition of the time fuze when firing.
The fuze body A consists of the fuze plate w, the lower plug a and the upper
plug c The plug a which is fitted with exterior threads by means of which the
fuze is screwed into the shell, contains the explosive charge b from which a
channel filled with powder leads to the upper surface of the fuze plate w.
mouth of the channel is closed by means of a powder pellet . To the upper
surface of the fuze body is pasted a watertight cloth disc z which has an igniting
hole above the pellet. The explosive charge communicates by means of the
igniting holes and respectively with the recess in the upper plug c, and with
the bursting charge of the shell."
The
On to the smooth part of the upper plug c slide the two rings B and C con-
taining the fuze composition. The upper face of the composition ring B is
covered with a waterproof cloth disc The composition rings are kept in
position on the fuze body by means of the fuze cover E which is screwed on to
he plug and is then soldered or fixed to it, a spring washer 1) (Fig. 5) being
placed between the cover E and the upper composition ring C. The composition
ing B can be rotated on the plug whilst the composition ring C is prevented
from turning by a pin as shewn, or by a similar arrangement. Both composition
ings are provided with annular recesses d and e of well known arrangement,
illed with powder composition and interrupted by a solid bridge extending across

page_text: the groove. At the one end of the recess c is formed a channel e¹ which_com-
municates by means of an igniting hole y with the interior of the plug c. There
is also a channel leading from the one end of the recess d in the upwards
direction. Where the latter opens out in the upper face of the composition
ring B, the cloth disc ¹ is formed with a hole for transmitting the fire from
recess e to recess d. It must be noted that the channel is made at that end of
the recess d which is opposite to the part of the recess e containing the channel el.
It follows that the recesses on being ignited do not burn in the same, but in
opposite directions. The gases generated during the combustion of the powder
in the composition rings are allowed to pass out through the igniting holes. The
igniting hole in question for the lower composition ring B is shewn at 2 in
Figs. 1 and 3 of the drawing. The lower composition ring B has a transverse
bridge or partition and the fuze plate is engraved at a on its face. According
to the setting of the composition ring B opposite the mark of the fuze
plate w,
the time fuze, as will be further explained below, is either put out of
action so that the shell can only explode by means of the percussion fuze, or it
causes the shell to explode shortly before reaching the muzzle of the gun (case
shot action) or it explodes the shell after a shorter or longer space of time so
that the shell bursts during its flight (shrapnel action). Into the interior of
the plug.c is fitted the detonator F (Fig. 4) which consists of the head f and the
tubular stem g screwed onto the former. The latter has exterior threads by
means of which the detonator is screwed into the threads of the plug e, and it
contains in its interior two chambers separated by the partition . The upper
of these chambers receives the parts intended for igniting the time fuze and the
lower one contains all the parts of the percussion fuze.
From
The parts of the time fuze in the upper chamber consist of the bolt h, the safety
spring supporting it, and the needle 7 fixed in the partition k. To strengthen
the action of the igniter, the needle is surrounded by a powder ring m.
the chamber igniting holes n lead to an annular fire groove o formed on the
exterior of the stem of the detonator which, when the detonator is in position,
faces the igniting hole y.
The percussion fuze contained in the lower chamber of the stem g consists of
the bolt p, the safety spring q, the abutment ring r, the helical spring s and the
needle t. The bolt P is bored out vertically forming a channel u so that the flash
coming from the igniting pellet passes through the hole in the bottom of the
detonator and through the hole in the fuze body to the explosive charge. The
ring keeps the bolt away from the needle t in the partition (Figure 1) by
means of the safety spring while the helical spring s is intended to prevent the
striking bolt p which will be released by the spring 9 and ring r after the round
has been fired as at Fig. 2, from striking too soon against the needle t.
As has been mentioned before, the detonator F is kept separate from the fuze
during transport of the shell and is not screwed on to the fuze till the firing is
to take place; but there is nothing to prevent the detonator from being always
fixed to the fuze.
In the latter case, it would however be preferable to dispense with the stem g
of the detonator which forms a separate piece and to insert the percussion and
time fuze parts directly into the hollow plug of the fuze body A.
The action of the new double acting fuze is as follows:-When, on firing, the
shell begins to move, the bolt h on account of its inertia overcomes the strength
of the safety spring i and flies back against the needle 7, (Figure 2) so that the
composition pellet of the bolt becomes ignited. The flash caused by this, in-
creased by the ignition of the powder ring m passes through the holes n into the
groove o and thence through the hole y into the powder contained in the recess e.
According to the setting of the composition ring B the explosion of the bursting
charge of the shell caused by the time fuze will take place sooner or later. If
for instance the ring B is adjusted to the zero position shewn at Fig. 1 in which the
zero line of the ring B will be exactly over the mark of the fuze plate w

page_text: the hole in the fuze plate w is below that of the ring B and this is also below
the end of the recess e which contains the channel el. The flash coming from the
bolt will therefore pass straight through to the charge 6 and will explode the
bursting charge of the shell shortly before reaching the muzzle (case shot action).
If however the ring B is adjusted to the position shewn in Figure 3, in which the
cross on the ring is over the mark wl of fuze plate w, the hole of the ring B is
exactly below the solid transverse bridge of the composition ring C and also the
pellet is exactly under the solid bridge of the ring B. Consequently the
powder in recess e of the ring C will burn without the possibility of passing on
the flash to ring B and to the charge b. In this case therefore the time fuze is
entirely out of action and the explosion of the bursting charge of the shell can
only be caused by the percussion fuze (shell action). If the ring be adjusted so
that any other mark of its division is brought over the mark w of the fuze
plate w, the powder in e will first burn and then, after a certain time depending
upon the position of the igniting hole in ring B, the powder in d will be ignited.
Here the flash will pass through the part of the recess d lying between the hole
in the composition ring B and the powder pellet of the fuze plate w, and on
igniting the pellet the flash will pass to the explosive charge b. The explosion
of the charge will consequently now take place after a space of time during the
flight of the shell (shrapnel action) determined by the setting of the composition
ring.
On the starting of the shell the ring r will also have slid backward owing to
its inertia, overcoming the resistance of the spring q and occupying the position
shewn at Firure 2; the bolt p will consequently now only be held back by the
spring s, so that (assuming the time fuze to be put out of action as first described)
when the shell strikes an object, the bolt, in flying forward together with the
parts and r and overcoming the resistance of the spring s will strike with its
igniting charge against the needle t, and in firing the charge b will effect the
explosion of the shell.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A double acting fuze combined and operating substantially as herein
described with reference to the accompanying drawing.
2. In a double acting fuze, the combination with a fuze body such as A con-
taining the rings B and C with composition charges for the time fuze, and the
firing charge b, of a separate detonator such as f g containing the detonating
devices both for the time fuze and for the percussion fuze, such detonator being
adapted to be kept separate from the fuze body until required for use, sub-
stantially as described with reference to the drawings.
Dated this 23rd day of August 1898.
ABEL & IMRAY,
Agents for the Applicants.