IMPROVEMENTS IN PERCUSSION FUZES FOR IGNITING THE CHARGES OP EXPLOSIVE PROJECTILES, MINES, TORPEDOES, AND OTHER CHARGES OF GUN- POWDER, OR OTHER EXPLOSIVE OR EASILY INFLAMMABLE SUBSTANCES OR COMPOUNDS
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of
the Commissioners of Patents, with his Petition, on the 23rd December
1863. A communication from abroad by John Jordan Eckel, of the
City of New York, in the United States of America.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer, and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PERCUSSION FUZES FOR IGNITING THE CHARGES
OP EXPLOSIVE PROJECTILES, MINES, TORPEDOES, AND OTHER CHARGES OF GUN-
POWDER, OR OTHER EXPLOSIVE OR EASILY INFLAMMABLE SUBSTANCES OR COMPOUNDS,"
to be as follows:-
This Invention consists, firstly, in the employment in a fuze of a ful.
minating capsule composed of glass or other frangible material containing a
quantity of sulphuric acid, and coated externally with a compound of sulphur
and potassa. On this capsule being broken by percussion or pressure the
sulphuric acid coming in contact with the compound of sulphur and potassa
forms a compound which takes fire instantly and burns slowly, and which is,
therefore, well adapted for igniting the charges of shells, band grenades, or
other explosive projectiles, or of mines, or torpedoes, or any charges of gun-
powder or other explosive or easily inflammable substances or compounds.
It also consists in various means of producing the fracture of this capsule in
its application to the firing of the bursting charges of hand grenades, sbells,
for ordnance, torpedoes, mines, and other charges of gunpowder, or other
explosive or inflammable substances or compounds used in military, naval, or
other operations. The best material for the fulminating capsule is glass. It

page_text: is filled about one-third full of sulphuric acid and hermetically sealed, then
dipped in or otherwise coated with a substance of shallac or other adhesive
material, and dipped in a mixture composed of equal parts by weight of pow-
dered sulphur and potassa, which adhere to the aforesaid coating. It is
afterwards dipped into the solution of shellac or a weak solution of india-
rubber, gutta percha, or other waterproof material to protect the mixture of
potassa and sulphur from the effects of moisture, and prevent it from being
rubbed off. This capsule is easily broken by percussion or pressure, and on
being broken the acid is allowed to come in contact with the mixture of
sulphur and potassa and form therewith a compound which at once takes
fire and burns slowly enough to insure its setting fire to gunpowder or any
other explosive or highly inflammable substance or compound which is placed
in contact with it. The quantity of potassium and sulphur on the exterior of
the capsule should be such that each will be in nearly the same quantity by
weight as the acid within.
In applying the Invention to a grenade I make it with two chambers, the
larger one to contain the bursting charge of gunpowder, and the smaller
one to contain the capsule and one, two, or more bullets, by the percussion of
which against the said capsule the fracture of the latter is produced. In the
partition betwen the chambers there is a small hole closed by a wooden plug
to prevent the gunpowder from interposing itself been the capsule and the
bullets, and so preventing the fracture of the capsule on the grenade striking
any body against which it is thrown or dropped. In the external shell of the
grenade there are two openings tapped with screw threads communicating
with each of the chambers. The one opening is for the introduction of the
bursting charge, and is closed by a solid screw plug after the said charge has
been put in, and the other opening is for the introduction of the bullets and
capsule and a small quantity of gunpowder to serve as priming, and is closed by
a hollow plug, which is screwed into it. This hollow plug consists of a small
hollow cylinder of brass or other metal made with a solid head at one end,
and having a screw thread cut on its periphery to enable it to be screwed
tightly into the grenade. The inner end of the plug has a screw thread cut
in its interior for the reception of a movable head or plate which screws into
it. In order to enable the loaded grenade to be transported safely the
capsule is placed in the cavity of the plug, surrounded with as much sawdust,
cotton wool, or other soft material as will fill up the said cavity, the head
screwed in by means of a screwdriver, and the plug being also screwed in
position. The loaded grenade may then be thrown about without any danger,
as the capsule is protected from the bullets confined by the above-mentioned

page_text: plate. When the grenade is to be used, the grenade is taken out, the plate
removed, the capsule taken out and put into the chamber with the bullets,
and the plug replaced in the hole. The dropping or throwing of the grenade
in this condition against any resisting substance or body causes the bullets to
break the capsule, and so produce the ignition of the priming powder in the
chamber. This powder on exploding blows the plug out of its hole, and.
ignites the bursting charge in the other chamber.
The mode of applying the fulminating capsule to projectiles used in
ordnance is as follows:-The capsule and a loose metal plunger for exploding
it are both inserted in a tube of brass or other metal, which is screwed into a
hole in the head of the projectile in the same manner as percussion fuze tubes
heretofore used. This tube is made with a solid head at its outer or front
end, and with a movable head screwing into its inner or rear end. The
capsule enveloped in cotton, gun cotton, or other soft material, is inserted
through the open rear end of the tube and pushed up to the front end, where
it is secured by a light wooden pin passing across the diameter of the tube,
suitable holes being provided therein for its reception. The plunger is
inserted at the rear part of the tube, where it is secured by one or more pins
of wood inserted through a hole or holes in the tube, and entering a groove,
hole, or holes in the plunger. The movable head, inserted after the plunger,
comes close up against the latter to prevent it from being detached by the
breakage of the wood pins by the sudden impact given to the projectile on the
ignition of the charge of the gun. The length of the tube and plunger should
be such as to leave a considerable space between the plunger and the capsule
when both are secured by their respective pins. In case the capsule is
enveloped with raw cotton or other soft packing material than gun cotton,
some priming powder should also be placed in the said packing material.
When the projectile is discharged from the gun the capsule and plunger
remain held apart by their pins until the projectile strikes any body and its
flight is arrested and retarded; when the momentum which the plunger has
acquired causes it to break the pins and continue moving forward, and makes
it strike and breaks the pin and crush the capsule, thereby causing the
ignition and explosion of the gun cotton or priming powder around it, which
blows out the portion of wood through pin left in the holes in the tubes and
fires the bursting charge. Instead of the tube screwing into the head of the
projectile as described, a tube screwing into the rear end may be used to
contain the capsule and tube; the capsule in such case being arranged in front
of the plunger, and the capsule and plunger being secured in the same
manner as in the tube.

page_text: Anohter application of the capsule is to the firing of torpedoes or charges of
gunpowder under water. A tube of brass or other metal is inserted into the
head of the barrel containing the charge of gunpowder, which tube contains
the capsule and a plunger by which it is to be fractured. This tube has no
opening at its inner end but a small vent, and has its outer end fitted with a
stuffing box, through which the plunger works perfectly water-tight. The tube
is so secured and packed in the head of the barrel that no water can enter
around it. The outer end of the plunger is connected with one end of a
lever, which is arranged on a fulcrum pin secured to the head of the barrel,
and the other end of which may be so arranged as to present itself in such
position as to be caught by an enemy's vessel passing over it, and thereby
drawn outward from the barrel in such manner as to cause the plunger to be
forced inward against the capsule which is placed in the tube between. its
inner end and the the inner end of the plunger, and thereby to produce the frac-
ture in the said capsule which is placed in the plunger, and thereby to produce
the fracture of the said capsule. Instead of the free end of the lever being
arranged for vessels to come in direct contact with it, it may have connected
with it one or more wires or cords, which may be so arranged as to be pulled
by persons stationed on shore or in a boat for the purpose of forcing in the
plunger and breaking the capsule, and thereby producing the explosion of the
charge at a time when an enemy's vessel is passing over it; or the said wires
or cords may be arranged to be operated in any other suitable manner for the
same purpose. The lever has applied to it a spring, which holds back the
plunger at some distance from the capsule until the lever is pulled at the proper
time to produce the explosion. The capsule, which is placed in the tube before
the introduction of the plunger, is enveloped with cotton or gun cotton, or
other soft material, to protect it from accidental fracture; and if cotton be
not used a small quantity of priming powder is introduced in the soft material.
The vent is closed by a wooden peg. When the capsule is crushed by the
plunger the gun cotton or priming powder is ignited and exploded, and the
peg blown out of the vent, when the ignition and explosion of the charge
takes place.
gun
Another application of the fulminating capsule is to the firing of the
charges of mines. A small pit is dug in the ground at a suitable point, and
this is lined with a wooden box to exclude the soil, the top of the said box
being a little below the surface of the earth, and fitted with a loose cover,
From the lower part
which is covered with a thin layer of soil to conceal it.
of the box there branches off one or more mines, the said pipes being filled
with gunpowder or other suitable combustible matter, and a small quantity of

page_text: gunpowder is placed at the entrance or entrances of this pipe or pipes.
On
the bottom of the box there is erected a hollow upright cylinder open at the
top, and this cylinder is fitted with a plunger having a broad head, which
occupies a position nearly close under the cover of the lever. In the lower
part of the cylinder there is a vent closed by a wooden peg. The capsule
enveloped in cotton or other soft protecting material is placed with some
priming powder in the cylinder below the plunger. On any person stepping
upon the cover his weight depresses the cover and the plunger, and causes
the fracture of the capsule, thereby producing the ignition and explosion of
the priming powder, and causing the vent peg to be blown out and the gun-
powder to be ignited. This powder ignites that in the pipe or pipes, which
conveys the fire to the mine or mines and produces the explosion of the
charge or charges therein.
Each of the several modes of applying, protecting, and producing the
fracture of the capsule may be applied to other purposes than that for which
it is herein represented.