fuzes
Year: 1895

page_text: Date of Application, 26th June, 1895
Complete Specification Left 28th Mar 1896 Accepted. 2nd May. 1898
I, JAMES COULTHRED THOMPSON, of Hazeldean, Crescent Road, Brockley, in
the County of Kent, Gentleman, do hereby declare the nature of this invention to
be as follows:-
This invention relates to improvements in fuzes for explosive projectiles or
shells.
According to one part of my invention I provide simple and efficient means for
securing the dome or movable portion of a fuze to the body thereof in such a
manner that while enabling the dome or movable portion to be readily turned to
set the fuze for bringing about the explosion it will not be possible under ordinary
circumstances for the dome to be removed from the body of the fuze.
For this purpose I form the interior surface of the dome or movable portion of
the fuze and the periphery of the body thereof, each with a circumferential
groove, these grooves being so situated that when the dome is in place upon the
body they will lie opposite each other. In the groove of the body I form an
aperture and through the wall of the dome form another aperture which
leads into the aforesaid groove. By turning the dome these two apertures can be
caused to coincide; I then pass through the aperture in the dome the end of a
copper or other metal wire or strip which enters the beforementioned aperture in
the body, the said wire or strip being preferably of the same shape in cross-section
as that of the grooves and of a length to correspond approximately with the cir-
cumference of the grooves. By then turning the dome about the body, the wire
or strip will be gradually drawn completely through the aperture in the dome and
be wound around the groove in the body, thereby filling up the space formed by
the two grooves. The head cannot now be detached from the body but can be
turned thereon. The aperture in the dome through which the wire or strip
entered, may be plugged with any suitable material. It will be evident that the
shape of the grooves and of the wire or ribbon in cross-section may be varied, and
if found necessary the end of the wire or ribbon and the aperture in the body may
be threaded or otherwise formed to ensure that the inner end of the wire or ribbon
shall not escape during the winding.
According to another part of my invention I provide improved means for
ensuring that the dome or other movable part employed for setting the fuze shall
not alter its position during flight.
For this purpose I form the body of the fuze with one or more radially disposed
pointed pins or long teeth which may be located within recesses of triangular form,
the apex of the triangle projecting inwardly and one side thereof being greater
than the other. The length of the pins or long teeth is approximately equal to the
greater side of the triangle and when in their normal position they lie in proximity
to the said greater side of the triangle. The triangular recesses are open at their
bases which are bounded by the surrounding dome so that the pointed ends of the
pins or teeth thus bear upon the inner surface of the dome. Springs may be
provided for tending to force the pins or teeth laterally towards the shorter side
of the triangular recess. By this construction the said pins or teeth will have the
effect of pawls, that is to say they will permit the dome to be turned freely in one
direction for setting it to the required position, but will prevent its movement in
the opposite direction, which is the direction the dome tends to take during the
flight and spin of the shell.

page_text: I may modify these means so that the dome will be locked by the shock of
discharge instead of by the spin of the shell. For this purpose I provide a weight
which is arranged to move in a longitudinal direction relatively to the shell, such
weight being notched for the reception of the inner ends of two or more pins whose
outer ends are pointed and come against the inner surface of the dome.
The
aforesaid pins lie in recesses and occupy an inclined position relatively to each
other when the dome is in place on the fuze and before firing. Upon discharge,
the weight moves towards the rear of the shell and said pins assume a straight or
approximately straight position relatively to each other which causes their pointed
ends to be driven into the metal of the dome and thereby locks it to the body of the
fuze. It will be found advantageous to so arrange the said pins that, when the
weight moves backward to its full extent, they will move slightly beyond their
position of alignment so as to avoid any chance of the weight again assuming its
normal position during the flight of the shell. The movement of the aforesaid
weight towards the front of the shell is limited by any suitable means.
Another part of my invention relates to improved means for enabling the
centrifugal force produced during the flight and spin of the shell to bring about
the explosion thereof. These means (which are more especially applicable to
fuzes in which a train of wheels operates during the flight of the shell) consist of
a pellet located within a cavity in the body of the fuze the said pellet being
provided with an arm carrying a neb. The pellet is situated eccentrically to the
longitudinal axis of the shell and the said arm is of such a length that its neb bears
upon the periphery of a disc forming part of the train of wheels. This disc has a
radial notch in its periphery which as the disc rotates comes into correspondence
with the aforesaid neb and allows the pellet to move towards the circumference of
the shell. The pellet is provided with a detonator, which, when the neb and the
notch coincide, strikes against a fixed pointed pin under the action of the centri-
fugal force, thereby exploding the shell. In order to avoid any chance of the
pellet being released except during the flight of the shell, I so arrange the moving
parts of the mechanism of the fuze that the said notch remains covered until the
shell has performed a number of revolutions during its flight.
As a further means of preventing the pellet prematurely approaching the said
pointed pin I may so arrange the parts that the arm or other suitable part of the
pellet will normally engage with the herein before mentioned longitudinally moving
weight or other suitable device and only become disengaged therefrom when the
longitudinally moving weight or other device is shifted on shock of discharge.
Dated this 26th day of June 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Fuzes for Explosive Projectiles or Shells.
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 :-
This invention relates to improvements in fuzes for explosive projectiles or
shells.
According to one of my present improvements I form the dome or movable
portion of the fuze and the body portion thereof, with circumferential grooves
which coincide when the dome is in place on the body and into these coinciding
grooves I insert a copper or other wire whose length is approximately equal to the
circumference of the grooves. By these means the dome, whilst being perfectly

page_text: free to be rotated to set or adjust the fuze, cannot be detached. The manner
of inserting the wire into the grooves is an important feature in this part of my
invention.
According to another part of my invention I provide the fuze with improved
means for ensuring that the dome or other movable part employed for setting the
fuze, shall not alter its position during the flight of the shell. For this purpose. I
employ chisel pointed or other suitable pins of hard metal, which on shock of
discharge, or, when the shell commences to spin, embed themselves in the metal
composing the dome and thereby prevent its shifting.
Another part of my invention relates to the manner of producing the flash for
exploding the shell, by the employment of a pellet or weight which acts partly or
wholly under the influence of centrifugal force, and is so arranged that it remains
incapable of acting until after shock of discharge. This pellet or weight carries a
detonator which strikes a pin when the weight is released by mechanism controlled
by a train of wheels within the fuze.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings which illustrate the application of my improvements to a
distance fuze.
Figure 1 is a vertical section on the line 1. 1 of Figure 3, the dome being
indicated mainly in elevation;
Figure 2 is another vertical section of the fuze on the line 2. 2 of Figure 4, the
dome being mainly in elevation ;
Figure 3 is a plan of the fuze body.
Figure 4 is a horizontal section on the line 3, 3 of Figure 1.
Figure 5 is a fragmentary sectional view shewing a detail on an enlarged scale.
Figure 6 is a horizontal section of a fuze shewing a modified arrangement of the
pins for locking the dome to the body.
Like letters of reference indicate similar parts throughout the drawings.
A is the dome, and B is the body of the fuze; the latter is formed with the
ordinary screw threaded portion 6 for enabling it to be affixed to the shell. C is an
arbor whose upper end projects beyond the dome and is socketted to receive a
spindle D carrying vanes d. The inuer end of this spindle terminates inside the
dome where it is provided with a toothed wheel forming part of the train of wheels
within the dome. By means of the aforesaid vanes, the spindle D is prevented
from revolving during the flight and spin of the shell, by the resistance of the
air, and the said train of wheels is driven by the revolution of the shell in the
manner set forth in the Specification of my prior Patent No. 15159 of the year 1888
and thus motion is transmitted to the pinion c. This pinion gears with a toothed
wheel e which has connected to its lower face a disc E. The said disc is loosely
mounted on a fixed axis e¹ projecting from the body B and is provided with a radial
notch or slot e whose purpose will be hereinafter described.
The interior surface of the rim a of the dome or movable portion of the fuze, is
formed with a circumferential groove a¹ (Figure 5) preferably semi-circular in
cross-section, and the outer surface of the body B is formed near its upper or
outer portion with a corresponding circumferential groove b¹. The relative position
of these grooves is such that when the dome is in place on the body they will
come opposite each other and together form a groove of circular cross-section.
In the groove b¹ I form a lateral hole and through the rim a I form another
hole a² which leads into the groove a¹. These two holes can be caused to coincide
by turning the dome about its axis and I then pass through the hole a' in the
dome the end of a copper or other suitable wire a* which is of the same shape in
cross-section as that of the grooves and of a length corresponding approximately
to the circumference of the grooves. By then turning the dome about the body
in the direction of the arrow in Figure 5, the wire will be gradually drawn
completely through the hole a in the dome and be wound around the groove in the
body, thereby filling up the space existing between the two circumferential

page_text: grooves a b'. The dome cannot now be detached from the body although it is
free to be revolved thereon.
It is evident that the shape of the grooves and of the wire in cross-section may
be varied and if desired the hole 6 in the body may be screw threaded or otherwise
formed to ensure that the inner end of the wire shall not escape during the turning
of the dome in the act of drawing the wire into the said grooves. The hole a¹
may be made at au inclination as shown by the dotted lines in Figure 5 if found
more advantageous.. is a pin or stop which is situated near the inner end of the
hole 62 in order to prevent the wire from entering too far into the fuze and interfering
with the internal mechanism.
F is an elongated weight or plunger which is capable of moving freely lengthwise
in a longitudinal cavity in the body of the fuze. The upper end of this plunger
is formed with lateral notches which receive the inner ends of transversely arranged
pins or bars ff. These pins may be of hardened steel and are located in
recesses in the body B. The said recesses are formed with openings 6 which
extend through the marginal wall of the body, and through these openings the
outer pointed or chisel shaped ends of the pins f can project. When the dome A
is in place on the body B as shewn in Figure 1, these pins are retained in the
inclined position in which they are there represented by the full lines, and the
plunger F is then supported in its raised position, as shewn, by the outer ends of
the said pins lightly resting against the inner circumference of the rim a of the
dome. When the parts are in this position the dome can be readily rotated around
the body to set or adjust the fuze for exploding at the proper time. On shock of
discharge, however, the plunger is forcibly driven inwardly towards the bottom of
its longitudinal cavity b whereby the pins fare caused to come into alignment or
to assume a position somewhat beyond their alignment, as shewn by the dotted lines
in Figure 1, and in assuming this position their chisel shaped ends are driven into
the metal of the rim a of the dome, thereby firmly locking the latter to the body B.
No rotary movement or displacement can then take place between the dome and
the body during the flight of the shell.
Instead of employing pins whose operation depends upon the longitudinal move-
ment of the plunger F as above described, I may construct the body B with pins
or long teeth f₁ (Figure 6) which are located in recesses 6868 in the said body.
Each of these recesses is of triangular form, the apex of the triangle projecting
inwardly and one side 6x of each triangular recess being greater than the other.
The length of the aforesaid pins or long teeth f₁ is approximately equal to the
greater side of the triangle and when these pins are in their normal position, as
shewn by the full lines in Figure 6, they lie in proximity to the said greater side of
the triangle. The said triangular recesses are open at their outer parts or bases
where they are bounded by the surrounding portion or rim a of the dome, so that
the pointed ends of the long teeth f¹ thus bear upon the inner circumference
of the said rim. I may provide light springs f tending to force the pins or
teeth laterally away from the said greater side of the triangular recesses. By
this construction the said pins or teeth will act in the manner of pawls, that is to
say they will permit the dome to be freely turned in one direction for setting the
dome to the required position, but will prevent its movement in the opposite
direction which is the direction the dome tends to take during the flight and spin
of the shell. Therefore when the sudden twist that the shell receives on discharge
from a gun occurs, the relative positions of the dome and the fuze-body will remain
unchanged by reason of the entrance of the sharp outer ends of the pins into the
metal of the rim a of the dome.
G is the pellet or weight which is located within a cavity in the body B. This
weight is provided with an arm 9 having a projection g' at its free end and with a
recess to receive the primer. The weight G is situated eccentrically to the
longitudinal axis of the shell and the said arm 9 is of such a length that its
projection g' bears against, or is adjacent to, the external periphery of the aforesaid
disc E. As this disc rotates about its axis e' by the action of the revolving shell,

page_text: as already mentioned, the radial notch or slot e in its periphery eventually comes
opposite the aforesaid projection g', and the centrifugal force to which the weight
is subjected during the spin of the shell causes the said weight to immediately move
forcibly towards the circumference of the fuze. The primer carried by the weight
then strikes a fixed pointed pin 610 and the flash thus produced passes along the
passage (Figure 2) and thereby reaches the charge within the shell and effects
its explosion.
When the fuzes are made of comparatively small dimensions I prefer to employ
a small spring H for assisting the centrifugal force to drive the weight towards the
pointed pin 10 when the said weight is released. This makes the firing of the fuze
independent of the centrifugal force which in small fuzes might be insufficient to
ensure the explosion of the detonator.
The aforesaid arbor C is furnished with a safety pin c¹ which while in position
prevents the said arbor from being accidentally shifted. In order to avoid any
possibility of the weight G being released except during the flight and spin of the
shell, I so arrange the cock c' in which the pinion c is pivoted at its lower end, that
this cock normally lies immediately above the radial notch e in the disc E and by
coming in front of the projection g¹ prevents the latter from entering the said notch
and releasing the weight, even if by any means the weight should otherwise
become released.
As a further means of preventing the pellet or weight C prematurely approaching
the said pointed pin 610 prior to the discharge of the shell from a gun, and in the
event of the aforesaid cock accidentally moving from its position over the radial
notch e, I form the arm g with a recess 9*, (Figure 3) with which the cylindrical
surface of the plunger F engages so long as the said plunger is in the outward
position shewn in Figure 1. By these means it will be seen that the said weight
is incapable of shifting until the plunger has moved towards the end of its
longitudinal cavity, and this can only happen on shock of discharge.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A fuze wherein the dome connected to the body by a wire which is inserted
into an internal circumferential groove by revolving one portion of the fuze around
the other substantially as described.
2. A fuze in which the dome is locked to the body, on shock of discharge, by a
weight or plunger acting in conjunction with transversely arranged pins, substantially
as described.
3. A fuze in which pins situated in triangularly shaped recesses act to lock the
dome to the body when the shell suddenly commences to revolve about its axis
substantially as described.
4. A fuze wherein the detonator is carried by a weight which remains inactive
until the shock of discharge displaces Я retaining piece or plunger engaging with
the said weight substantially as described.
5. The combination with a weight carrying the detonator, of an arm extending
from the said weight and provided with a projection, and of a notched disc forming
part of the train of wheels within the fuze, the said notch being kept normally
covered by a portion of the mechanism substantially as described.
6. A fuze constructed and adapted to operate substantially as hereinbefore
described with reference to the accompanying drawing.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.