An Improved Needle for Blasting Purposes.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improved Needle for Blasting Purposes.
HENRY WALKER Checkweighman Queen Street South Normanton Derbyshire
do hereby declare the nature of this invention to be as follows:-
--
An Improved Needle for Blasting Purposes. The said needle to be used in
preparing shots. The said needle to be made either of Copper, Brass, or Wood
which is to be hollow from end to end, so that the cap or detonator which is used
for the purpose of exploding the composition, or high explosive, may be passed
through the hollow needle into the cartridge of composition or explosive. After
the composition or high explosive has been tamped or stemmed ready for firing,
then the cap or detonator will be passed through the hollow needle which I do
wish to protect.
My invention is an improved Needle to be used in preparing shots for blasting
purposes so that the cap or detonator which is generally used for exploding the
composition or high explosive used in coal mines, quarries sinking shafts and
other places where the composition or high explosive has to be used for displacing
or getting material in the said coal mines, quarries or sinking shafts that the
said cap or detonator, shall not be placed in the hole which has been drilled for
the purpose, at the same time as the said composition or high explosive, but,
the detonator may be kept apart from the cartridge of composition or high
explosive is being placed in the hole. The said cap or detonator shall not be
placed to the cartridge of composition or high explosive previous to it being
tamped or stemmed. My method is to place the hollow needle to the cartridge
of composition or high explosive, and to place the said cartridge of composition
or high explosive in the hole which has been prepared. The said cartridge shall
be secured tamped or stemmed, & when the said cartridge has been secured then
the said cap or detonator shall be passed through the hollow needle which I do
protect into the said cartridge of composition. The said cap or detonator will
be secured in the high explosive. After the cap or detonator has been secured
in the cartridge or high explosive, the said needle which I do protect can be
withdrawn.
1011
J
1007

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows a side view of an improved needle, with part of it broken away,
and its right end in the paper tube of an explosive cartridge.
Figure 2 shows the ends of a pricker and placer rod employed.
The improved needle to be used in preparing shots for blasting purposes in
coal mines, quarries, for sinking shafts and for other purposes consists of a tube 1
of copper, brass, wood or paper, one end being provided with a handle 2, the
other end being reduced in thickness for a portion of its length to enter the usual
paper tube 3 projecting from an explosive cartridge 4. The cartridge is placed in
the bore hole 5 which has been drilled or otherwise formed in the coal, stone
or other material to be blasted by the needle 1 which may be about three feet
six inches long more or less. The cartridge is then secured by material being
tamped or stemmed round it and the needle for a sufficient length, the pricker
end 6 of a rod 7 about four feet six inches long more or less is then passed down
the hollow needle to break the closed end of the paper tube 3 as shown by the
dotted lines at the right end, the pricker is then withdrawn from the needle, and
the other end of the rod which is reduced in thickness and covered with paper 8,
is employed to place a cap or detonator 9 down the needle into the position shown
near the right end of Figure 1.
The rod 7 with its paper covered end is then withdrawn the detonator being
retained in the paper tube by the usual springs 10 within the tube, the two
wires 11 projecting from the detonator being of sufficient length to pass clear of
the outer end of the bore hole to enable them to be electrically connected in the
usual way when required.
By employing the improved needle as above described many accidents may be
avoided resulting from explosions caused by concussion when the bore hole is
being tamped or stemmed.
Having now particularly described and ascertained the nature of my said In-
vention and in what manner the same is to be performed I declare that what I
claim is:-
The improved needle for blasting purposes, substantially as described and
illustrated in the Drawings annexed.
Dated this Sixteenth day of August 1897.