Improvements in Detonators.
Year: 1894

page_text: Date of Application, 29th June, 1894
.
Complete Specification Left. 29th Mar.. 1895-Accepted, 4th May, 1895
Improvements in Detonators.
DANIEL HICKIE of No. 66 Basinghall Street, City of London Mining and
Machinery Expert and GEORGE FREDERICK BEUTNER of same address,
Merchant do hereby declare the nature of this invention to be as follows:-
:-
The sealing or enclosing of the fulminate and other sensitive compositions in the
shells or capsules containing same and which are known as "detonators," and
the improvements relate to the prevention of injury in packing, transit, storage and
use, hitherto common to detonators through damp arising from the absorbent saw-
dust covering or similar substances used, or loosened fulminate in removing such
substances prior to use of the detonator, or friction against the exposed fulminate
either through accident or placing the necessary fuses in the shells or detonators.
For the purposes of this invention a covering is placed on the fulminate in the
form of a "wad" of such a nature as to admit of the safety-fuse or the priming of
electrical fuse or other firing appliances, acting upon it so that the wad shall be
sufficiently flammable to act as a medium for conveying the necessary heat from the
fuse to the detonating composition at the proper time of using the detonator, the wad
or scaling material being sufficiently insensitive to friction and affording protection
against damp and the other risks referred to. The "wad or covering may be in
a dry form when placed on the fulminate or detonating composition, or it
a plastic or gelatinized form for which purposes celluloid or other substance of a
similar nature is used by preference.
Dated 9th Luna 1804
"
may be in
D. HICKIE.
G. F. BEUTNER.
DANIEL HICKIE of 66 Basinghall Street London E.C. Mining and Machinery
Expert and GEORGE FREDERICK BEUTNER of same address, Merchant 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 order to conserve the full exploding force of detonators it is essential to protect
their fulminating properties, from the time of their manufacture to that of their
application, against any possible counteracting influence having the slightest
tendency to weaken such force.
It is well known that the fulminating composition of detonators is liable to
deterioration through the action of damp, water, atmospheric and other influences
and that detonators which have been from any cause subjected to such influences are
a source of danger in mining and other operations as tending to cause misfires
or partial explosions at best, resulting in poisonous fumes and risks of secondary
explosions though unexploded portions of charges left in the ground or thrown out
amongst the debris. Official warnings of such risks have emphasised these

page_text: dangers, and workers have been from time to time cautioned on the subject of
unexploded portions of explosives thus left through incomplete detonation.
The system hitherto followed of covering the fulminate in detonators with sawdust
or other absorbent material afforded no protection against moisture and other
deteriorating influences beforementioned but on the contrary tended towards
bringing about the evils referred to inasmuch as such covering took in moisture at
once when exposed to moisture in transit or storage or injury to packages, and when
the boxes were opened in the mines or workings the absorbent covering became filled
with moisture from the surroundings and the fulminate, also absorbent in itself,
became moist and the detonators defective.
Before inserting the safety fuse or other igniting appliance in the mouth of the
detonator preparatory to using the latter, it was necessary to remove every particle
of sawdust from same as such covering prevented the fuse from acting on the
fulminate if allowed to remain over the latter. This also has caused accidents
owing to the sawdust having a tendency to adhere to the fulminate (especially
so through moisture) causing the users to pick out the obstructive covering with
some sharp pointed implement and thus run the risk of explosion through friction,
of which detonator composition is known to be sensitive.
There are other drawbacks attending the use of detonators as hitherto supplied as
for instance risk of explosion in placing the safety fuse in the open part of
the detonator shell and twisting the fuse down upon the fulminate which, in the old
form of detonator is exposed to friction. In wet ground also the detonator as
hitherto sent out from the factory had no protection against water and misfires beyond
the application of grease or clay, or, in some cases (when provided) a viscous
substance, applied to the mouth of the detonator and around the fuse. Such
protection often admits water and causes misfires or incomplete explosion with results
similar to those referred to.
By our invention the detonator is protected against the drawbacks referred
to through the use of a covering which in addition to being air tight and waterproof
possesses the properties of being sufficiently inflammable to allow the fuse to act
through it upon the fulminate and of being practically insensitive to friction.
This covering is in the form of a wad or disc composed of celluloid or other suitable
substance, resinous preparations or other substances, inflammable and easy of
application, in the form of dises or wads, and which may be conveniently applied in
a plastic or semi plastic form or cut out of thin sheets non plastic and may be
adhesive in themselves when placed in position, or made so by the application of an
adhesive substance applied to such wads or discs. These wads or discs are cut out
and pushed down upon the fulminate by any suitable means and in this position
protect the fulminate from the completion of the detonators to the moment of their
application upon the charge to be exploded. Unlike the old form of absorbent
covering the wads or discs through this invention are not removed from their
position. The safety fuse or other igniter is inserted in the ordinary manner, but
instead of going down upon the fulminate as heretofore the protecting wad stands
between and being free from the risk of ignition by friction caused by the fuse the
risk of explosion of the detonator by friction is eliminated. through the wad thus
placed which being ignited explodes the detonator.
In regard to the mechanical operations for cutting out and placing the wads or
discs in position as aforesaid we do not confine ourselves to any special appliances
inasmuch as various economical methods may be used for such purpose, or the
ordinary pressing machines and plungers or a modification of these may be so applied.
In this manner any convenient number of detonators may have the protecting wads
placed therein at one pressing after the detonator shells have been charged with
fulminate in the usual manner.
The wads or discs may be cut from sheets of celluloid softened by a solvent or
other means, or from thin non-plastic sheets of same material or other non-
hygroscopic substance sufficiently stable and inflammable for the carrying out of
the process and the purpose expressed.

page_text: The wads may be thus cut out in one operation for such number of detonators' as
may be conveniently placed to be completed at each operation.
The material to form the wads is laid upon the open top part of the detonator
shells and the plungers coming down carry each a wad to its position within the
tube or shell and upon the fulminate.
To facilitate the withdrawal of the plungers without displacing the wads, steatite.
chalk or similar substances may be rubbed on the points of the plungers to prevent
the latter from adhering to the wads or the wads to the plungers.
By this invention we are also enabled to use other cheaper and better fulminating
compositions which could not be used with the old form of detonator because of their
hygroscopic nature.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A detonator in which the fulminate is secured by covering it with an air-tight
disc or wad of a substance which is waterproof, practically insensitive to friction
yet sufficiently inflammable as described.
2. The use of celluloid or analogous substances for covering fulminate in
detonators as described.
0001
1
1005
D. HICKIE.
G. F. BEUTNER.