A Mechanical Fuze for Causing the Explosion of Shells and Indi- cating the Number of Revolutions Performed and Distances Traversed by Projectiles.
Year: 1888

page_text: Date of Application, 22nd Oct., 1888
Complete Specification Left, 22nd July, 1889-Accepted, 28th Sept., 1889
PROVISIONAL SPECIFICATION.
A Mechanical Fuze for Causing the Explosion of Shells and Indi-
cating the Number of Revolutions Performed and Distances
Traversed by Projectiles.
1, JAMES COULTHRED THOMPSON of Hazeldean Crescent Road Brockley S.E.
Gentleman, do hereby declare the nature of this invention to be as follows :-
It consists in fixing to a shell or projectile a case or instrument containing a set
or series of ordinary toothed wheels and also a central toothed pinion, or worm or
wheel gearing with the first wheel in the train of wheels used and to which central
pinion, worm or wheel a projecting vane is attached.
This vane will in flight be prevented by the force of the air through which it passes
from turning with the projectile. By this arrangement as the said case or instrument
is carried round by the revolutions of the shell or projectile to which it is applied
the said first wheel gearing with the central pinion, worm or wheel held from revolving
by the force of the air acting on the vane will be caused to turn on its axis and
transmit the action through the other wheels and a register of the revolutions can be
shown in the ordinary manner or an explosion can be caused at any desired revo-
lution by a detonating or friction charge being brought into play and fired by the
action of the train of wheels set in motion by the pinion, worm or wheel carrying
the vane, or the shell can be exploded on graze or impact by the detonating charge
being brought into contact with a pin or hammer set in position by the action of the
vane but held secure and safe until after the projectile has left the gun.
Oh 1000
J. C. THOMPSON.
COMPLETE SPECIFICATION,
A Mechanical Fuze for Causing the Explosion of Shells and Indi-
cating the Number of Revolutions Performed and Distances
Traversed by Projectiles..
I, JAMES COULTHRED THOMPSON of Hazeldean, Crescent Road, Brockley in the
County of Kent, Gentleman, 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 mechanical fuses for explosive projectiles or shells, and
comprises improvements which are applicable to both time or distance fuses and
percussion-fuses. My improvements moreover afford the means for ascertaining the
number of revolutions performed by a projectile or shell in its flight and the distance
traversed by the said projectile or shell.
An important feature of my said invention is the employment of one or more
blades or vanes which are to be applied to the fuse before the shell is inserted into
a gun, and which, by reason of the resistance of the atmosphere, will not participate
in the rotary motion imparted to the shell by the rifling of the gun. The motion of
the shell, relatively to the said vane or vanes is utilized for so adjusting parts of the
fuse that the bursting of the shell will take place either at any desired moment after
it has been fired from the gun, or when it strikes or grazes an object.
I am aware that attempts have been made to construct fuses with blades or vanes.
which in the flight of the shell, will rotate about the axis of the fuse for the purpose
above specified; but these attempts have all, as far as I am aware, been unsuccessful.
In my improved fuse, however, the blades or vanes are not intended to be rotated in
the flight of the shell, but are so formed and arranged that the resistance of the air
will avant their rotation.

page_text: In one form of my improved fuse, Lemploy a train of wheels which is enclosed in
the fuse case and which when the shell is fired from a. gan, will rotate with the said
shell and case about the axis or spindle of the vane or vanes and thus cause the slow
rotation of a disc or wheel'; this disc or wheel is so formed and arranged that, when
turned or adjusted through any predetermined angle, it will permit the discharge of
the fuse and the consequent bursting of the shell.
In another form or modification of my said fuse, I fix the needle or striker on the
spindle of the vane or vanes and I form on the said spindle screw-threads adapted. to
engage with corresponding screw-threads in the fuse case, so that the rotation of the
shell and fuse-case relatively to the vane or vanes will cause the screwing in of the
said spindle and thus move the needle or striker towards the primer or detonator so
as to permit the explosion of the primer or detonator when the shell strikes or grazes
an object.
Figure 3 a longitudinal central section of a combined time or distance and per-
cussion fuse constructed according to my said invention, the parts being shown in
the positions which they occupy relatively to each other when the fuse is ready.
for use.
Figure 4 is also a longitudinal central section, some of the parts being removed
and the remaining parts being shown in the relative positions which they occupy
when the plunger carrying, the primer or detonator has been driven forward as
hereinafter described.
Figure 5 is a horizontal section on the line c, a. Figure 3.
Figure 6 is a plan, partly in horizontal section; showing the means hereinafter
described for connecting the two parts of the fuse-case.
Figure 7 is a plan, partly in horizontal section, illustrating a detail of
construction.
Figure 8 is a longitudinal' central section, illustrating another time or distance fuse
constructed according to my said invention.
Figure 9 is a side elevation illustrating my improved fuse provided with a single
blade or vane.
Figure 10 is a plan, and
Figure 11 a longitudinal central section of a percussion-fuse constructed according
to my said invention, the parts being shown in the relative positions which they
occupy when the fuse is ready for use.
Figure 12 is also a longitudinal central section of the said fuse, the parts being
shown in the positions which they occupy during the flight of the projectile or shell
in which the fuse is fitted.
Figure 13 is a similar view, illustrating another modification of my per-
cussion-fuse.
Like letters indicate corresponding parts throughout the drawings.
a is a chamber or casing, which is formed with a flange a¹ and with the usual
external screw-thread for securing the fuse in the point or apex of a shell. bisa tube
which is fitted. to slide to and. fro in a hole in one end of the said casing a, and which
is provided with a flange and is acted upon by a spring c enclosed in the said
casing. The said chamber or casing a, moreover, serves as the magazine of the fuse.
The tube has fitted to slide therein another tube or tubular plunger d provided at
one end with a flange d' which. bears against the corresponding end of the tube b.
In the upper end of the tube or plunger d is a cavity d² for the reception of a suitable
detonator or primer. A. toothed wheel e is fitted to rotate in a recess a² in the upper
or forward end of the casing a and is held in place by a plate a³. This wheele is formed
with a slot e for the purpose hereinafter explained. The tube is provided with a stud
or projection 6 which extends into a slot at in the casing a and which, when the parts
are in the position shown in Figure 3, bears against the underside of the wheel'e so
that the spring c is kept suitably compressed as shown.

page_text: The needle or striker is fixed in one end of a spindle g, the other end of which
extends through an adjustable casing h, in. which is firmly secured the aforesaid
plate a³. This casing is secured to the casing, a in. the following manner so that it
can be rotated relatively thereto, that is to say, the casing a is made with a circum-
ferential groove or recess a³ in which is inserted a split.or divided ring j the case h
is firmly secured to this ring by means of screws h¹ or in any other convenient
manner.
In the outer end of the spindle g is fitted a spindle on which are fixed the blades
or vanes & which are situated in the same plane as the axis of the fuse: The needle
or striker has formed therewith a pinion which is geared with a toothed wheel/
forming part of a train of gearing which also comprises a pinion m geared with the
toothed wheel e. The slot e¹ in the said toothed wheel is so arranged that, when the
said wheel is turned so as to bring this slot in line with the stud or projection 6? on
the tube b, the said stud or projection can enter the slot and the spring. c will then
react and drive the tubes b, d forward, thus causing the explosion of the primer or
detonator by striking it against the needle f
If the shell strikes an object before the tube is thus released the tube or plunger d
will be driven forward by its momentum and will cause. the explosion of the primer
or detonator and the consequent bursting of the shell. To prevent premature explosion
of the shell by means of the plunger d, I provide an arm e (Figure 7) which is
pivoted to the plate a³ and extends through the slot e¹ into. the space between the
plate and the plunger d. When the shell has in its flight made several revolutions,
the said arm will be moved aside so as to leave the plunger d free: to move forward
upon the impact of the shell.
By adjusting the wheel e by hand so as to bring the slot el a greater or less distance
from the stud or projection, the range of the shell or the time of discharge of the
fuse after the projectile leaves the gun can be regulated as required.
This adjustment is effected by rotating the adjustable casing relatively to the
casing a. The casing his provided with a graduated scale arranged to indicate
revolutions or yards as may be desired and a suitable arrow-head or pointer is pro-
vided upon the casing a for the purpose of indicating the time or distance for which
the fuse is adjusted.
When the fuse is properly adjusted and the shell is fired from a gun, the
casings a, h, and the train of wheels carried thereby will rotate with the said shell.
The spindle g and needle or strikerf will, however; be held or restrained from rotation
by the resistance of the air to rotary movement of the blades or vanes k. The afore-
said train of wheels will, therefore, be moved around the pinion. " and will thus be
caused to impart motion to the wheel e which will be rotated at a comparatively low
speed, thus bringing the slot el into line with the stud. or projection bat. the proper
moment to permit the discharge of the fuse and the consequent bursting, of
the shell.
By employing suitable registering mechanism in connection with. the aforesaid
train of wheels, I can provide for enabling the number of revolutions performed by
the shell to be ascertained after the recovery of the shell. The pitch of the rifling
of the gun being known it follows that the distance traversed. by the shell can also be
ascertained.
In the modification of my invention shown in Figure 8, the actuating spring c is
placed around the sliding tube or. plunger d and bears at one end against the flange d'
on the said tube and at. its other end against an internal flange a on the casing a.
The tube or plunger d is provided with a stud. or projection d³ which extends into
the slot a and bears against the underside of the wheel e so that when the said wheel
is turned into the proper position, the said stud or projection, will enter the slot.e
and the plunger d will be driven forward by the spring. c thus causing, the explosion
of the shell.
In some cases I use only one blade or vane k. as shown.in Figure 9, for the purpose
above specified.
In my improved percussion-fuse. shown in Figures 10 to 12,, the detonator:is carried

page_text: .
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by a plunger arranged to slide to and fro within the casing a and acted upon.
by a spring p which is also enclosed in the said casing, and which holds, or
tends to hold the plunger n against the rear or lower end of the said casing. The
spindle on which the blades or vanes are mounted is provided with a screw-
threa led portion 2 and has formed with it the needle or striker f. The screw-
threaded portion of the said spindle fits into a correspondingly screw-threaded
hole in the casing a.
The spindle with the blades & thereon is partly screwed into the casing a as
shown in Figure 11, before the shell is inserted into the gun.
When the parts
are in the position shown, the detonator cannot come in contact with the needle
or striker. When, however, the shell is discharged from the gun, the rotation of
the shell and the fuse case relatively to the blades and spindle causes the
said spindle to enter the casing until it assumes the position therein shown in
Figure 12. Therefore when the shell strikes an object, the plungern will by its
momentum be driven forward and the detonator thus brought into impact with
the needle or striker.
The spring p may if desired be dispensed with as the screw-spindle is not to be
inserted in the fuse-case until the shell is about to be inserted in the gun conse-
quently the detonator cannot by any accident be caused to come in contact with
the striker.
To more effectually ensure the bursting of the shell upon the impact of the same
against an object or upon the grazing of an object by the said shell, I sometimes
make the spindle as in Figure 13 of such length that, when in the position
shown it will project beyond the forward end of the casing a.
In this case a
disc is provided for holding the striker away from the plunger-until the shell
strikes an object. It is obvious that when, in the flight of the shell, the blades or
vanes come in contact with any object, the spindle and needle or striker f
will be driven into the casing a, thus causing the explosion of the detonator. By
this means I ensure the bursting of the shell whether the plunger n is or is not
moved forward by its momentum.
It is obvious that the construction of my fuses can be further modified if desired
without departing from the nature of my said invention.
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. In or for a projectile or shell, a fuse provided with one or more blades
or vanes which, during the rotation of the projectile or shell in its flight, will be
held or restrained from rotation by the resistance of the air, for the purposes
above specified.
Second. A fuse provided with one or more removable blades or vanes and so
constructed that rotation of the fuse-case relatively to the said blades or vanes will
effect the adjustment of parts of the fuse for the purposes above specified.
Third. A time or distance fuse wherein a device for causing the explosion of
the primer or detonator is held out of action by a wheel or disc which, when turned
through a predetermined angle by the rotation of the projectile or shell in its flight,
will release the said device, for the purpose above specified.
Fourth. The combination, in a fuse, of a slotted toothed wheel for holding the
exploding device out of action, and a train of wheels connecting the said toothed
wheel with a spindle provided with one or more blades or vanes for preventing its
rotation during the flight of the shell, substantially as, and for the purpose, set
forth.
Fifth. A combination-fuse wherein the device for exploding the primer or detonator
at any predetermined distance, is held out of action by a wheel or disc connected
with one or more blades or vanes, and the device for exploding the said primer or
detonator upon impact is held out of action by an arm which, in the flight of the
shell, will be automatically withdrawn, for the purposes above specified.

page_text: Sixth. The improved fuse constructed substantially as described with reference to
Figures 1 to 7 or modified as described with reference to Figure 8 or to Figure 9
of the drawings and operating as above specified.
Seventh. A percussion-fuse wherein a screw-spindle fitting into a correspondingly
screw-threaded hole in the fuse-case and provided with one or more blades or vanes
is employed for relatively adjusting parts of the fuse in the flight of the projectile or
shell, for the purposes above specified.
Eighth. The improved percussion-fuse constructed substantially as described with
reference to Figures 10, 11 and 12 or modified as described with reference to
Figure 13 of the drawings and operating as above specified.
1000
Dated Gay of our 100.
J. C. THOMPSON.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.