Improvements in the Construction of Electric Fuzes and Detonators, and in the Method of and Appliances Employed for Manufacturing the same.
Year: 1889

page_text: Date of Application, 18th July, 1889
Complete Specification Left, 18th Apr., 1890-Accepted, 12th July, 1890
PROVISIONAL
SPECIFICATION.
Improvements in the Construction of Electric Fuzes and Detonators,
and in the Method of and Appliances Employed for Manufacturing
the same.
We, PAUL WARD, Electrician of 10 Hatton Garden, London, and EDWARD
MAMMATT GREGORY, Merchant of 61 Moorgate Street in the City of London do hereby
declare the nature of this invention to be as follows :—
In the Specification accompanying the application for a Patent (No. 3981) made by
us on the 26th day of February 1884, we described certain improvements in Electric
Fuzes and Detonators and in the priming material used therein.
The present invention relates to improvements in Fuzes and Detonators therein
described and has for its object to provide a means of more completely protecting the
same from the destructive influence of moisture, heat climatic and other influences.
In carrying out our invention we employ the safety armature (but composed of
either insulated or uninsulated wire of any suitable material such as copper or iron)
and preferably the same explosive compound or primary materials as set forth in the
above numbered Specification or we inay employ any other suitable priming material
but instead of inserting the armature into a quill or tube formed of glass or metal
coated internally containing the explosive compound or dipping the free ends of same
into a paste inade of the explosive compound as described in the said former Specifi-
tion, we form (in the manner to be presently described) the insulator, the wires,
and a receptacle for holding the priming composition all combined and so that an
absolute uniformn arrangement of the poles or wire terminal in the fuze is ensured
both in the surface exposed and in their separation from each other whereby the
article is much simplified and considerably cheapened and less likely to be acted upon
by various destructive influences.
For this purpose we employ a slab of metal or other material which is drilled
through from face to face, with holes about 1th in diameter or of such a diameter as
is suitable for the fuze required. This slab is supported by feet of such a height that
plugs of metal or other material inserted into the holes in the slab, rest on the table
supporting the whole so that the plugs do not reach the upper surface of the slab, by
say. These little plugs are dome shaped at their upper ends, and have two fine
holes drilled to a small depth (say ") in their domed ends as close together as is
practically convenient without their coalescing. Into these two holes in the said plug
are inserted the two free ends of a small hair pin-shaped wire loop (ie. the safety
arinature above referred to) so as to hold the said two free ends of the wire loop in a
certain definite position both as regards length and width apart in the hole in
which the plug of metal is contained. When all the holes in the slab and plugs are
occupied in the samer manner the remaining spaces above the domed shaped plugs
containing the wires are then filled up with a composition consisting, by choice, of an
intimate mixture of whitening and glue or whitening and gum or other suitable
insulating composition to which is added any suitable ingredient to render the said
composition waterproof and in order to make the said composition both heat and
damp proof we mix therewith a suitable quantity of the powder derived from the
calcination of "peat."
When the liquid part has evaporated or been driven off from the mass contained in
the said holes the plugs are pushed up from the bottom, and the wires surrounded by
the composition above mentioned, are taken out, the result being cup shaped cavities
with the two ends of the wires projecting in a certain definite width and length apart
thereinto, but completely insulated from each other. Any further moisture may be
driven off by a gentle heat.
A suitable quantity of explosive compound priming material is now placed into the

page_text: cup-shaped cavity and the same is laid aside to dry. A suitable quantity of the
composition of which the cup-shaped cavity is composed (before described) is then
inserted on to the top of the priming material and the whole may then, if considered
necessary, be protected by dipping into just melted paraffin or other wax, and
afterwards in Portland, Roman, or other hard cement as described in our said former
Specification or the insertion of the composition of which the cavity is composed may
be dispensed with and the fuze protected in the manner just before described. By
the above described method we form a complete fuze. The whole may then if
considered necessary, be coated over with a fusible alloy of low melting point, or even
with lead, by immersion in the molten inetal.
If we wish to make a combined fuze and detonator as mentioned in the said
previous specification we, previously to dipping the fuze into the cement, or other
protective coating as aforesaid, but subsequently to immersing it in the melted wax,
insert into the cup on the top of the wax, a quantity of the detonating paste described
in the former Specification or other detonating material. This combined fuze and
detonator is then protected in the manner above mentioned.
Dated this 18th July 1889
PAUL WARD.
E. MAMMATT GREGORY.
COMPLETE SPECIFICATION.
Improvements in the Construction of Electric Fuzes and Detonators,
and in the Method of and Appliances Employed for Manufacturing
the same.
We, PAUL WARD, Electrician, of 10 Hatton Garden, but now of 16, Crown
Terrace, Fulham and EDWARD MAMMATT GREGORY, Merchant, of 61 Moorgate Street,
in the City of 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:-
In the Specification accompanying the application for a Patent (No. 3981) made
by me the said Paul Ward on the 26th Feby. 1884 there were described certain
improvements in Electric Fuses and Detonators and in the priming material used
therein.
The present invention relates to improvements in Fuses and Detonators therein
described and has for its object to provide an improved fuse of special regularity and
cheapness of construction and means for more completely protecting the same from
the destructive influence of moisture, heat, climatic, and other influences.
In carrying out our invention we employ the safety "armature" (but composed of
either insulated or uninsulated wire of any suitable metal such as copper or iron) and
preferably the same explosive compound or priming materials as set forth in the above
numbered Specification or we may employ any other suitable priming material, but
instead of inserting the "armature" into a quill or tube formed of glass or metal
coated internally, containing the explosive compound or dipping the free ends of same
into a paste made of the explosive compound, as described in the said former Specifi-
cation, we form (in the manner to be presently described) the insulator, the wires,
and a receptacle for holding the priming composition all combined so that an
absolutely uniform arrangement of the holes or wire terminal in the fuse is ensured
both in the surface expored, and in their separation from each other, whereby the
article is much simplified and considerably cheapened, and less likely to be acted upon
by various destructive influences.
In order that our invention may be the better understood we now proceed to
describe the same in relation to the drawings hereunto annexed reference being
Like letters refer to like parts in the
had to the letters and figures marked thereon.
various figures.
Figure 1. shows in side, and end elevation and in plan the slab, or tool in which the
fuse plugs are manufactured,

page_text: Figure 1 is a side and end view of the plug used in conjunction with the above
able.
Figure 2 shows the wire armature in position ready for the formation of the
insulating plug.
Figure 3 shows the wire armature with the insulating plug formed thereon.
Figure 4 shows the completed fuse covered by protective coatings.
For this purpose we employ a slab of metal A Figure 1, (shown in side & end
elevation & plan,) or other material which is drilled through from face to face with
holes about th" in diameter, or of such diameter as is suitable for the fuse required.
This slab is supported by feet F of such a height that plugs of metal or other material
inserted into the holes in the slab, rest on the table supporting the whole, so that the
plugs do not reach the upper surface of the slab A by say ". These little plugs as
shown at G Fig. 1 are domed shaped at their upper ends and have two fine holes
drilled to a small depth (say ") in their domed ends, as close together as is practically
convenient without their coalescing.
Into these two holes in the said plug are inserted the two free ends of a small hair
pin shaped wire loop E (i.e. the safety armature above referred to) so as to hold the
two free ends of the wire loop in a certain definite position both as regards length
and width apart in the hole in which the plug of metal is contained. When all the
holes in the slab and plug are occupied, in a similar manner, the remaining spaces
above the domed shaped plugs containing the wires are then filled up with a com-
position, consisting, by choice, of an intimate mixture of whitening and glue or
whitening and gum or other suitable insulating composition to which is added any
suitable ingredient to render the said composition waterproof and in order to make the
said composition both heat and damp proof we mix therewith a suitable quantity of
the powder derived from the calcination of "peat."
When the liquid part has evaporated or been driven from the mass contained in the
said holes the plugs are pushed up from the bottom and the wires surrounded by the
composition above mentioned are taken out, the result being cup-shaped cavities as
shown at B Fig. 3 with the two ends of the wires projecting a certain definite width
and length apart thereinto but completely insulated from each other. Any further
moisture may be driven off by a gentle heat.
A suitable quantity of explosive compound (priming material) is now placed into
the cup-shaped cavity and the same is laid aside to dry. A suitable quantity D,
Fig. 4 of the composition of which the piece in which the cup shaped cavity is formed
(before described) is caused to surround the plug B and the priming material, or to
cover the priming only, and the whole may then (if considered necessary) be protected
by dipping into just melted paraffin or other wax and afterwards in Portland Roman
or other hard cement as described in Wards said former specification and shewn at C
Fig. 4. Or the insertion of a second layer D of the same composition as that of the
plug in which the cavity is formed, may be dispensed with, and the fuse protected
with the paraffin or other wax or cement.
By the above described method we form a complete fuse. The whole may then
(if considered necessary) be coated over with a fusible allow of low melting tempera-
ture or even with lead by inmersion in the molten metal.
If we wish to make a combined fuse and detonator as mentioned in the said
previous specification, we, previously to dipping the fuse into the cement or other
protective coating as aforesaid but subsequently to immersing it in the inelted wax,
insert into the cup on the top of the wax, a quantity of the detonating paste
described in the former specification, or other detonating material. This combined
fuse and detonator is then protected in the manner above mentioned.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
Lot The formation of a matrix of wire and insulating substance providing a cavity

page_text: into which a sensitive priming composition is placed for the purpose, substantially as
above described.
2nd. The construction of a tool as before described for the formation of the
matrixes of electric fuses, substantially us described.
3rd. An electrical fuse in which the ends of the wire or wires are embraced in a
non-conducting plug carrying the priming charge and the whole protected by dipping
in paraffin, cement or melted metals, substantially as described.
Dated this 18th day of April 1890.
FELL & WILDING,
1, Queen Victoria Street, Agents for the Applicants.