Improvements in Cartridges and in Detonators for Exploding the same.
Year: 1888

page_text: Date of Application, 8th May, 1888
Specification Accepted, 15th June, 1888
COMPLETE SPECIFICATION.
Improvements in Cartridges and in Detonators for Exploding the
same.
I, ARTHUR FAVIER of 15 rue de Richelieu, Paris, in the Republic of France,
Chemist, 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 cartridges formed of bygroscopic substances such as
nitrate of ammonia or nitrate of soda mixed with a body belonging to the fatty series
such as the natural or slightly nitrated hydro-carbons or the resins having waterproof
qualities all of which are fusible at a low temperature. These cartridges form the
subject matter of prior Letters Patent granted to me Arthur Favier and dated the
16th of February 1885 No. 2139 in the specification of which the manufacture of
the cartridges and the method of exploding the same by means of a central detonator
is fully described. One of the features of the present invention consists in employ-
ment of a detonator composed of the same kind of substance as that of which the
compressed cartridge consists in a pulverized or granulated form with the addition of
a small quantity of gun-cotton or nitro-glycerine.
The quantity of the latter substances may be reduced to 2 or 3
per
cent. of the
entire quantity of the detonator and its use presents no danger whatever as even
with 5 per cent. of gun cotton the pulverulent substance is capable of resisting the shock
of the discharge supposing the cartridge to be fired from a gun. The presence of the
nitrated composition nitro-glycerine or the like serves no other purpose than to permit
the use of ordinary fulmiuating caps and the quantity used may be reduced in pro-
portion to the increased power of the cap. The size of the detonator may be varied
in cartridges of uniform size and the power of the latter will vary accordingly. The
detonators formed of the same substance as the cartridge but in a pulverized state
with or without the addition of gun-cotton are much more sensible to atmospheric
influences than the same material in a compressed state and they therefore require to
be properly protected from such influences as hereinafter described and illustrated by
the accompanying drawings.
Fig. 1 is a longitudinal and transverse section of the cylinder or cartridge. A
provided with a central vacant space B and moulded in one piece.
Fig. 2 is a longitudinal section of the same cartridge charged, D being the
detonator, E the fulminating priming, F a cap of embossed paper which is traversed
centrally by a fuse; G is a paraffined or varnished paper case, and G' a small strip
of paraffined or varnished paper which serves as a joint cover..
Fig. 3 shows a longitudinal and transverse section of the compressed cylinder
moulded in two halves."

page_text: Fig. 4 shows a longitudinal section of the same cartridge charged.
Fig. 5 is another longitudinal section of one of these cartridges charged and
provided with an arrangement for detonating in water, J being the compressed
cylinder, K the detonator, M the cardboard piece carrying the tube H¹ resting thereon
by means of the top flange I, in this tube are placed the fulminating priming and the
fuse;
O is the embossed paper cap which covers the whole, and P is the envelope of
paraffined or varnished paper inade long enough to be fixed on the fuse.
Fig. 6 is a vertical section of the detonator separated from the compressed cylinder,
the explosion of which is to be determined by the said detonator.
Fig. 7 is a section and a plan of the cap F made of embossed paper C being the
central part which has to be pierced at the moment of using the cartridge.
Fig. 8 is a section and a plan of the cardboard washer which secures, under the
embossed paper cap, the tube which receives the fulminating priming.
Fig. 9 is a section and plan of this- tube, and
Fig. 10 represents the manner in which it is secured to the paper cap by means of
the card board washer.
After the compressed cylinder has been paraffined or varnished and charged with
the detonator it is covered with the cap of embossed cardboard which prevents the
moisture or damp from penetrating into the interior (see figure 7). It is then covered
with paraffined or varnished paper. When the cartridge is to be used it suffices to
pierce the cap and to introduce the fulminator cap into the centre of the pulverulent
substance.
When the cartridge is to be placed into a bore-hole full of water or when it has to
remain sometime in a damp place the following arrangement is adopted for fixing the
priming without introducing any water into the detonator. A little copper tube H.
(figure 9) is fixed to the embossed cap by means of the cardboard washer M (figure 10)
and the whole is placed on the loaded cartridge. The diameter of this tube is large
enough to permit the fulminating priming to enter and fit tightly therein. The length
of the tube is such that the whole of the part containing the priming penetrates the
middle of the detonator; this length varies with the power of the cartridge.
It is evident that the detonator may be separated from the compressed cartridge and
placed in a case of paper, glass or any suitable metal during the transport or storing
of the cartridges, so that the two parts are only put together at the moment when
they are to be used.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what I
claim is
1. The combination with a compressed cartridge such as described of a central
detonator composed of the same material as the cartridge but uncompressed and with
or without the addition of a nitrated explosive substantially as described.
2. The combination with a cartridge containing a detonator such as described of a
protective covering consisting of cardboard caps such as F and varnished or paraffined
paper cover G applied in manner substantially as described and illustrated. in the
accompanying drawings.
3. In a cartridge destined to be used under water the employment of a copper tube
such as
H secured to the embossed cap F by means of a cardboard washer M for the
purpose of receiving the fulminating cap or priming substantially as described and
illustrated in, the accompanying drawings.