Improvements in and relating to Tamping and other Places.
Year: 1886

page_text: Date of Application, 25th June, 1886.
Complete Left, 25th Mar., 1887.
Complete Accepted, 26th Apr., 1887,
Improvements in and relating to Tamping
and other Places.
I, GEORGE FRANCIS of Greenfields, Rhosddu Wrexham in the County of Denbigh
Mining Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in tamping blast holes in coal rock or other
substance where, explosives, lime, or other cartridges are used to loosen, force down,
or break up the material, its object being to produce a cheap, safe, and effective
tamping that can be secured in position with very little expenditure of time.
The blast hole may be prepared in the ordinary way, and a cartridge of any
suitable explosive material, or lime or other material used for the purpose inserted in
the hole. A tamping is then inserted consisting of a plug and sand or other loose or
granulated material, which when the plug moves or expands will cause it to be held
securely in the hole..
In carrying out the invention I prefer to form the tamping by enclosing a plug of
wood or other suitable material in a bag or case of textile or other flexible material.
The plug may be round, octagonal or of other required shape, and is say, about
3 or 4 inches long more or less according to the size of the hole, and of the charge
inserted therein. The plug or wedge may be made of any number of parts so cut or
divided that when the force of the explosion or expansion of the cartridge acts against
its rear end, it is expanded and wedged tightly against the sides of the hole. For use
with an explosive cartridge, a simpler form of plug or wedge will be found to answer
than when required for a lime or expanding cartridge. In its simpler form the
expanding plug may be formed wedge shaped or tapered in external contour, with a
wedge or tapered piece cut from the Hat or rear end, and the whole sawn longitudinally
nearly the entire length. Or it may be formed by cutting the plug diagonally, thus
forming two inclined planes, whose surfaces lie on each other. In this case it will be
preferable to insert a wedge shaped piece into the broad end of each part of the plug,
When pressure is brought to bear against the base of the expanding plug it is forced
outwards laterally in several directions. A wire may be attached to the expanding
plug, for the purpose of withdrawing it from the hole in case of misfire of the
cartridge, or for other reason.

page_text: The wedge is kept in position by a strip of tape carried across the base of the plug,
folded over and pasted to its wings. A groove to carry the fuse is made along the
length of the plug in line with the exposed part of the wedge, and the said slit before
mentioned. This plug is placed in a bag or case large enough in diameter to admit
it freely, the base being flush with the end of the bag or case, and the wire before
mentioned drawn through the other end. An india-rubber band is placed over the
bag and the plug, thus keeping both in position.
When required for use a fuse is to be passed up the groove (underneath the bag
case, and india rubber band) and drawn through to within about 2 inches from the end
of the fuse. The bag filled with sand or other material is tied tightly at the top with
the protruding wire, leaving a sufficient length of wire to reach outside the blast hole.
The tamping is now ready for use, and has simply to be inserted into the blast hole
until the cap end of the fuse touches the cartridge.
The action of this plug is to expand in diameter by the pressure at both ends,
namely the resistance of the sand or other material at the pointed end, and the force of
the explosion or expansion of the cartridge at the other, thus fixing it in the
blast hole.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Tamping Blast Holes in Mines
and other Places.
I, GEORGE FRANCIS, of Greenfields, Rhosddu, Wrexham, in the County of Denbigh,
Mining Engineer, 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 improvements in tamping blast holes in coal, rock or
other substances, where explosives, lime, or other cartridges are used to loosen, force
down, or break up material, its object being to produce a cheap, safe, and effective
tamping that can be secured in position with very little expenditure of time.
The invention consists essentially in complementary or compressed wedges or
wedging apparatus so placed or arranged in the blast hole, that the force of the
explosion shall itself drive, in the wedge or wedges between the complementary
wedges, or between the hole side and complementary wedge, thus tightly blocking
the hole.
In carrying out my invention the blast holo may lie prepared in the ordinary way,
and a cartridge of any suitable explosive material, or lime or other substance used for
the purpose, placed in the hole. A tamping is then inserted consisting of a plug and
a little ordinary tamping material or "stemming."
The action of the plug is to expand in diameter by the pressure at both ends
namely, the resistance of the stemming at the outer end, and the force of the
explosion, or the expansion of the cartridge at the other, thus fixing it in the
blast hole.
The plug may be made of wood, or metal or of wood and metal combined, or of any
other suitable material, and may be made of any number of parts, so cut or divided
that when the force of the explosion or expansion of the cartridge acts against its
rear end, the parts are forced in amongst each other and wedged tightly against the
sides of the hole.
The plug may be round, octagonal, or of other required shape, from four to six
inches long for ordinarily sized holes, and customary charges.
In order that my said invention may be more fully understood, I will now. refer to
the accompanying sheet of drawings which forms part of this specification representing
the said plug in some of the forms which it may assume.
Referring to the drawings-
Figure 1 is a sectional view of a bore hole with charge, fuse, and simple form of
improved tamping block placed ready for firing.
Figure 2 ideal view of same the moment after the charge is fired, and just as the
actual rupture is about to occur.
Figures 3 and 4, two views of a tamping block having a double wedge system.
Figure 5, a form useful in those cases where metal plugs are used, and it is desirable
to have few parts left in the hole on firing.

page_text: Referring first to Figures 1 and 2. A is the charge, B the lower wedge, C comple-
mentary wedge block formed with two slopes complementary to B, and a saw cut I,
each of these are preferably formed of wood with the grain parallel with the general
axis, D fuse passing up through a groove in the side of the block C. E stemming
of any suitable crushed or granular material. In actual operation the charge A. is
inserted with fuse, the block B C is then pressed down into place by a wooden stick,
and a charge of stemming thrown in, and lightly tamped, and the charge is ready.
On firing, the wedge B is driven into C, driving wedges on each side outward into
the sides of the hole, wedging them tight. The slight additional space left by the
retreat of wedge B allows for a little expansion of the charge and enables its full
power to be obtained and become ready to act in bursting the rock.
In figures 3 and 4, a second wedge G is placed in C, its edge being at right angles
to that of B. This block is useful where it is desirable to wedge the block tight before
exploding, the wedge G is forced down by a tamping bar or otherwise into wedge C
wedging this tight. The explosion by pressing wedge B in also still further tightens
the block in the hole.
Referring to Figure where only two siniple wedges are used B and C, a hole is
drilled through C and a little into B, and a rod H inserted to keep them in the same
relative position while being inserted into the hole, rod H after being pressed in tight
is withdrawn before igniting the fuse, and stemming is inserted, the force of the
explosion forces B to ascend the incline of Ctill it is absolutely wedged tight. This
form of wedge is preferably made of phosphor or aluminium-bronze, and in coal
mines is preferably chalked before use on each occasion to be more easily found after
the blasting.
The drawings show good examples as regards angle of wedge. The angle can be
considerably varied without injuring the result appreciably.
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. A tamping block consisting of a wedge B, and complementary wedge block C,
so arranged that when placed in the hole with the thick end of wedge B placed next
the charge, and sufficient stemming inserted into theghole to prevent the casy
ejectment of the block, the wedge B shall be forced by the expansion of the charge
into or along C wedging the latter tight in the hole.
2. A tamping block formed of two or more parts wedging into or on each other,
substantially as described and illustrated.
Dated this 24th day of March 1887.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Agents for the Applicant.