Improvements in Fuses for Projectiles.
Year: 1895

page_text: Improvements in Fuses for Projectiles.
1, HERBERT VIVIAN KEESON of 40 Loudoun Road, Saint John's Wood,
London, Gentleman, do hereby declare the nature of this invention to be as
follows:-
This invention relates to means for regulating the explosion of projectiles.
The chief object of this invention is to obtain a mechanical fuse which will
withstand shocks and centrifugal action and which by interlocking of the timing
and adjusting parts will exactly indicate the position of the exploding parts.
According to this invention, the works of the fuse are contained in an outer case,
which said case is screwed into the fuse-hole of the projectile. This case contains a
toothed wheel of a diameter slightly smaller than the internal diameter of the case.
This toothed wheel gears into a toothed pinion so as to multiply the revolutions of
this said pinion. This pinion protrudes through a plate which forms the wall of a
separate compartment of the fuse. The end of the pinion protruding into this
compartment carries an eccentric projection thus forming a crank. This crank fits
into a slot which is cut radially in a Hy-wheel which occupies the separate compart-
ment before-mentioned. Thus when the crank revolves it causes the fly-wheel to
oscillate backwards and forwards through part of a revolution. As the crank can
only revolve in accordance with the inertia and momentum of the fly-wheel the rate
of movement of all the works can be exactly determined.
The motive power is obtained by the action of a spring which tends to revolve
the toothed wheel before-described. When the projectile starts suddenly, a sliding
weight hangs back by its inertia and thus stretches a spring by pulling the rear end
of the said spring. When the sliding weight reaches the base of the fuse it is held
by a catch. The forward end of the motive spring then pulls a flexible wire or
cord which is wound around a pulley on the side of the toothed wheel. This pulley
is so shaped as to equalise the power of the spring by giving more leverage when
the spring is partly run down.
The operation of exploding performed by a striker fixed upon the side of the
before-mentioned toothed wheel. The toothed wheel is provided with teeth upon
When this
only about three-fourths of its periphery thus leaving a blank space.
blank space reaches the teeth of the before-mentioned pinion then the toothed wheel
being no longer checked moves suddenly onward bringing the striker into violent
contact with a percussion cap.
In order to adjust the moment of explosion, the toothed wheel protrudes slightly
through the outer case of the fuse. The edge of the toothed wheel is engraved
with figures upon a space beside the teeth. Each figure represents a movement of
the fly-wheel, and each such movement of the fly-wheel occupies one-eighth of a
second or such other fraction of time as may be determined upon at the time of
constructing the fuse. The instant of explosion is thus adjusted by turning the
toothed wheel.
In order to counteract centrifugal action the crank is counterpoised by a weight.
upon the pinion, such weight being diametrically opposite to the crank.
In order to prevent premature working of the fuse a check-pin is inserted through

page_text: the outer case so as to hinder the sliding weight from moving until the pin has
been removed.
Deted this Seventeenth dex of Mar 1805
Improvements in Fuses for Projectiles.
I, HERBERT VIVIAN KEESON of 40 Loudoun Road, St. John's Wood,
London, 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 means for regulating the explosion of projectiles.
The chief object of this invention is to obtain a mechanical fuse which will
withstand shock and centrifugal action and which by interlocking of the timing and
adjusting parts will exactly indicate the position of the exploding parts.
According to this invention the works of the fuse are contained in an outer case,
which said case is screwed into the fuse-hole of the projectile. This case contains
a toothed wheel of a diameter slightly smaller than the internal diameter of the
case. This toothed wheel gears into a toothed pinion so as to multiply the
revolutions of this said pinion. The axis of this pinion protrudes through a plate
which forms the wall. of a separate compartment of the fuse. The end of the axis
of the pinion protruding into this compartment carries an eccentric projection thus
forming a crank. This crank fits into a slot which is cut radially in a fly-wheel
which occupies the separate compartment before-mentioned. Thus when the crank
revolves it causes the fly-wheel to oscillate backwards and forwards through part of
a revolution. As the crank can only revolve in accordance with the inertia and
momentum of the fly-wheel the rate of movement of all the works can be exactly
determined.
The motive power is obtained by the action of a spring which tends to revolve
the toothed wheel before described. The following arrangement may be adopted.
When the projectile starts suddenly, a sliding weight hangs back by its inertia
and thus stretches a spring by pulling the rear end of the said spring. When the
sliding weight reaches the base of the fuse it is held by a catch. The forward end
of the motive spring then pulls a flexible wire or cord which is wound around a
pulley on the side of the toothed wheel. This pulley is so shaped as to equalise
the power of the spring by giving more leverage when the spring is partly run
down.
This arrangement however requires the fuse to be of considerable length and
therefore in order to economise space and increase the safety of the fuse it is
preferable to employ a spiral spring wound by the inertia of a weight free to revolve
axially in the fusé as is hereinafter described.
The operation of exploding is performed by a striker actuated by the before-
mentioned toothed wheel. The toothed wheel is provided with teeth upon only
about three fourths of its periphery thus leaving a blank space. When this blank
space reaches the teeth of the before-mentioned pinion then the toothed wheel
being no longer checked moves suddenly onward bringing the striker into violent
contact with a percussion cap.
In order to adjust the moment of explosion, the toothed wheel protrudes slightly
through the outer case of the fuse. The edge of the toothed wheel is engraved
with figures upon a space beside the teeth. Each figure represents a movement of
the fly-wheel, and each such movement of the fly-wheel occupies one-eighth of a
second or such other fraction of time as may be determined upon at the time

page_text: of constructing the fuse.
the toothed wheel. In
counterpoised.
The instant of explosion is thus adjusted by turning
order to counteract centrifugal action the crank is
In order to prevent premature working of the fuse when a sliding weight
is employed a check-pin is inserted through the outer case so as to hinder
the sliding weight from moving until the pin has been removed.
is employed a check-pin is inserted through the outer case so as to hinder
the sliding weight from moving until the piu has been removed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is an external view of a fuse constructed according to this invention..
Figure 2 is a longitudinal section of the same,
Figures 3, 4 and 5 are transverse sections on the lines 3-3, 4-4 and 5-5
Figure 2.
Figure 6 is a left hand end elevation with the cover a¹ removed and
Figure 7 is a right hand end elevation of the spring box_c.
The external case of the fuse is made in three parts, a body a and covers a¹ a².
The cover a carrying a screw which fits the fuse hole of the projectile. b b¹ and 6ª
are three transverse plates dividing the fuse into compartments, the plate 6² forms
part of the body a, 61 is secured by screws 63 whilst b is carried from 61 by pillars b*.
c is a spring box mounted loosely on the spindle d which works in bearings in the
plates 6' and '6³. The box c contains a spiral spring (not shown) the outer end of
which is fixed to it whilst the inner end is fixed to the spindle d. On the right
hand end of the box c is a weighted pawl c' which is normally held by a spring c².
out of gear with a ratchet wheel 6 (Figure 4) on the plate b³.
The spindle d passes through the plate 62 and carries a hammer or striker d¹
which at the proper time explodes, as hereinafter described, a cap e on a nipple at
the end of a passage leading to a chamber containing priming composition f. The -
other end of the spindle d has fixed to it a pinion d gearing with a pinion g' on a
spindle g to which is fixed a wheel having a milled edge g² projecting through a slot
in the case a, a ring of graduations 93 and a partial ring of teeth g. 95 is a ring
slotted similarly to the case a, by turning it g² and g³ can be covered. The teeth g
gear with a pinion & fixed to a wheel gearing with a pinion j whose axis passes
through the plate and carries on the other side a disc to which is fixed a crank
pin working in a slot in the fly wheel k. The weight of the pin is compensated
for by cutting away the surrounding metal of the disc.
In order to give a certain amount of elasticity the slotted spoke is not connected
to the rim of the wheel.
Before firing, the train of clockwork is set to the proper initial position according
to the range desired by turning the milled edge g² until the proper graduation
comes opposite to an arrow on the case a, this can be done as the pawl c' is held out
of gear by the spring c².
When the projectile is fired its rotation causes the weighted tail of the pawl c¹ to
fly outwards overcoming the spring and putting the pawl into gear with the
ratchet wheel 6 on the plate 62 and it remains in gear as long as the rotation of the
projectile continues. At the commencement of the rotation the spring box c owing
to its inertia lags behind winding up the spring until it acquires the same speed of
rotation as the fuse but the pawl and ratchet prevent the reaction of the spring
from making the box turn faster than the fuse so that the spring in unwinding
drives the spindle d, its speed of rotation relatively to the fuse being governed
through the train of gearing by the inertia of the oscillating fly wheel k.
The spindle d and hammer d¹ therefore revolve comparatively slowly in the case
but after a certain time (dependent on the initial position of the wheel 92 93 9') the
blank space in the partial ring of teeth g comes to the pinion h and the wheel
getting out of gear with the pinion is no longer controlled and the spindle d being
Dow propelled by the full force of the spring revolves rapidly causing the hammer d
to strike a sharp blow on the cap e thus exploding the fuse.

page_text: 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. A fuse governed by clockwork which is started by firing the projectile.
2. The combination of a weight, a spring and clockwork so arranged that on
firing the projectile the inertia of the weight causes the spring to store up power
for driving the clockwork.
3. In the arrangements referred to in the preceding claims an escapement consisting
of an oscillating wheel slotted to receive a crank pin.
4. Exploding the fuse by the acceleration of the clockwork caused by the
absence of some of the teeth from one of the wheels.
5. Fuses substantially as described and shown in the drawings.
Dated this 11th dov of March 1806
HERBERT V. KEESON.