Improvements in Apparatus for Drilling or Boring Rock, Metals, or other Hard Substances.
Year: 1893

page_text: Date of Application, 12th Jan., 1893
Complete Specification Left, 12th Oct., 1893-Accepted, 18th Nov., 1893
PROVISIONAL SPECIFICAITON.
Improvements in Apparatus for Drilling or Boring Rock, Metals, or
other Hard Substances.
We, OLAF TERP, of Parkfield House, Forest Hill, in the County of Surrey,
Engineer, CHARLES BARRINGTON BROWN, Mining Engineer, and CHARLES
ARTHUR GODFREY, Gentleman, both of Finsbury Chambers, in the City of
London, do hereby declare the nature of this invention to be as follows:-
For boring holes in hard rocks, for blasting or tunnelling, it has heretofore been
customary to use either diamond drills, or steel drills. Diamond drills however,
are very expensive, whilst steel drills wear away so quickly that in drilling deep
holes they are of comparatively little practical use.
It is known that the hardness of diamond being taken at 10, the relative.
hardness of corundum or the best Naxos emery, is about 9, whilst that of the
different hard rocks which it is ordinarily required to drill is considerably less, so
that such emery forms the best material to use instead of diamond.
It is however necessary that the emery should be used in small pieces or grains,
and the difficulty of attaching such grains sufficiently firmly to an ordinary boring
bar or tool, has formed a great obstacle to its use for the required purpose.
An important part of the present invention relates to the composition of a novel
cement which we use for the purpose of carrying the emery, by means of which a
cutting mass is obtained which is very durable and economical, and is equally
effective in cutting stone or rock and metal.
The accompanying drawing illustrates a boring tool for boring holes in hard rock,
the cutting part being composed of grains of emery in combination with the
improved cement hereinafter described.
Figure 1 is a side view of a drilling tool, Figure 2 is a vertical section, and
Figure 3 a top view, and Figure 4 a horizontal section of the same.
a is a metal cylinder or tube (preferably iron or steel) which is screwed at its
upper part to connect it with the lower end of the revolving boring bar. The
lower end is open, and round it is cast a coating b consisting of a compound of the
corundum or emery in grains of suitable size with the cement hereinafter described.
This compound in a sufficiently fluid state, is cast round the end of the tube a in
the following way.
A hollow mould, preferably of iron, having an internal
diameter similar to the external diameter of the boring tool is prepared, and we
insert and hold centrally in it the lower end of the metal tube a, which has through
it a number of transverse perforations at c, c.
A core, which may also be of metal is also adjusted centrally in the mould, its
diameter being equal to the interior diameter of the cutting mass b. The fluid
composition of emery and cement is then poured into the mould until the latter is
filled, the transverse holes in the tube allowing the inner and outer coatings of the
compound to be united and thus ensuring greater stability.
When the compound has become hard, or after about 10 hours, the tube coated
inside and outside is removed from the mould and is allowed to dry for about ten
hours more, and is afterwards painted several times with linseed oil, and it is then,
after about two or three weeks further drying, ready for use, the cement containing
the emery adhering so firmly to the tube as practically to form a part of the
latter.
In order that passages for water may be left through the tube and the compound,
pieces of cork or other suitable material of sufficient length are fitted into some of
the transverse holes through the tube. These form cores round which the compound
is cast, and they are removed after the latter has become hard.

page_text: The exterior of the coating is provided with vertical grooves or flat sides with
which the transverse holes communicate, so that a stream of water forced down
the tubular drill from above, as in the ordinary diamond drill, passes through the
holes and through transverse notches at the bottom of the tool, and carries away the
débris.
The improved drill cuts freely in the rock exactly like the diamond drill, and
leaves a core in the tube which from time to time is brought up from the bore in
the rock, to ascertain its exact character.
Whilst the size of such a rock drill may be considerable, equally effective small
rock drills of from half an inch to two inches diameter for use in blasting, or large
ones of several feet diameter for tunnelling or shaft sinking may be used.
The cement or compound with which we mix the grains of emery as described,
is composed as follows:-
(1) Magnesium chloride crystals are mixed with water in the following
(2) Carbonate of magnesia is burned or calcined and is then reduced to powder.
It is then burned a second time at a temperature of about 1500° C., and is mixed
with about ten to fifteen per cent. of carbonate of magnesia less highly calcined,
the result being a nearly perfectly white powder.
The above materials are then mixed together in about the following
proportions
50 parts of the chloride of magnesium solution (No. 1),`
50 parts of the burned carbonate of magnesia (No. 2),
to which is added about 75 per cent. of large grained emery. Whilst liquid this
composition is poured into the mould as above described.
The drilling or boring apparatus described may be applied not only to the purpose
of drilling holes in rocks but also to that of boring and finishing metal cylinders
of any size.
Heretofore in boring cast iron cylinders of all kinds, such as steam cylinders,
pump cylinders, and the like, often of several feet diameter, it has been usual to.
place and fix the cylinder in a lathe and bore and finish it with steel cutters. This
process is very tedious and troublesome, as in the first place the heavy casting has
to be carefully adjusted and fixed in the lathe, and a rough first-cut must first be
taken off with the tool to remove the hard and rough surface of the casting, other
cuts following to complete and smooth the bore. In order to apply the improved
tool carrying emery mixed with cement as described, to the purpose of boring such
cylinders, instead of the ordinary heavy bar provided with steel cutters having a
screw feed motion, a cylindrical tool is substituted, of a kind similar to those
already described, consisting of a mixture of the cement above described and
emery, the front part of the cylinder being made somewhat conical and being.
provided with the largest pieces of emery, such conical part first entering the
cylinder which is to be bored and removing the hard skin of the casting, whilst
then by degrees the entire cylindrical surface of the tool comes into operation, the
grains of emery being of gradually increasing fineness, until the last or finest part.
serves to finish and polish the bore of the cylinder. Very great simplicity is also
thus obtained in the method of boring such a cylinder, as it is no longer necessary:
to adjust and fix the heavy cylinder upon a lathe, but it can be allowed to remain
upon the ground and is then bored and polished by means of a strong ordinary
boring bar and corundum tools as described acting automatically.
The tool, as in the drill first described and shewn, must have water supplied to.

page_text: it, in the first place to remove the borings, and in the second place to keep the tool
and the cylinder cool. This is effected by means of water supplied under pressure
into the hollow axle or bar, and through passages and openings in the cutting
surface of the tool.
Dated this 12th day of January 1893.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicants.
Improvements in Apparatus for Drilling or Boring Rock, Metals, or
other Hard Substances.
We, OLAF TERT, of Parkfield House, Forest Hill, in the County of Surrey,
Engineer, CHARLES BARRINGTON BROWN, Mining Engineer, and CHARLES
ARTHUR GODFREY, Gentleman, both of Finsbury Chambers, in the City of
London, do hereby declare the nature of the said invention and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement and accompanying drawing, that is to say :—
For boring holes in hard rocks for blasting or tunnelling, it has heretofore been
customary to use either diamond drills, or steel drills. Diamond drills however are
very expensive, whilst steel drills wear away so quickly that in drilling deep holes
they are of comparatively little practical use.
It is known that the hardness of diamond being taken at 10, the relative hardness
of corundum or the best Naxos emery, is about 9, whilst that of the different hard
rocks which it is ordinarily required to drill is considerably less, so that such emery
forms the best material to use instead of diamond.
It is however necessary that the emery should be used in small pieces or grains,
and the difficulty of attaching such grains sufficiently firmly to an ordinary boring
bar or tool, has formed a great obstacle to its use for the required purpose.
An important part of the present invention relates to the composition of a novel
cement which we use for the purpose of carrying the emery, by means of which a
cutting mass is obtained which is very durable and economical and is equally
effective in cutting stone or rock and metal.
In the drawing accompanying our Provisional Specification, a boring tool is
illustrated for boring holes in hard rock, the cutting part being composed of grains
of emery in combination with the improved cement hereinafter described.
Figure 1 is a side view of a drilling tool, Figure 2 is a vertical section, Figure 3
a top view, and Figure 4 a horizontal section of the same.
a is a metal cylinder or tube (preferably of iron or steel) which is screwed at its
upper part to connect it with the lower end of the revolving boring bar. The
lower end is open, and round it is cast a coating b consisting of a compound of the
corundum or emery in grains of suitable size with the cement hereinafter described.
This compound in a sufficiently fluid state, is cast round the end of the tube a in
the following way.
A hollow mould, preferably of iron, having an internal diameter similar to the
external diameter of the boring tool is prepared, and we insert and hold centrally
in it the lower end of the metal tube a, which has through it a number of transverse
perforations at c, c. A core which may also be of metal, is also adjusted centrally
in the mould, its diameter being equal to the interior diameter of the cutting
mass b. The fluid composition of emery and cement is then poured into the mould
until the latter is filled, the transverse holes in the tube allowing the inner and
outer coatings of the compound to be united and thus ensuring greater stability.
When the compound has become hard, or after about ten hours, the tube coated
inside and outside is removed from the mould and is allowed to dry for about ten
hours more, and is afterwards painted several times with linseed oil, and it is then

page_text: after about two or three weeks further drying, ready for use, the cement containing
the emery adhering so firmly to the tube as practically to form a part of the latter.
In order that passages for water may be left through the tube and the compound,
pieces of cork or other suitable material of sufficient length are fitted into some of
the transverse holes through the tube.
These form cores round which the compound is cast, and they are removed after
the latter has become hard.
The exterior of the coating is provided with vertical grooves or flat sides with
which the transverse holes communicate, so that a stream of water forced down
the tubular drill from above, as in the ordinary diamond drill, passes through the
holes and through transverse notches at the bottom of the tool, and carries away
the débris.
The improved drill cuts freely in the rock, exactly like the diamond drill, and
leaves a core in the tube, which from time to time is brought up from the bore in
the rock to ascertain its exact character.
Whilst the size of such a rock drill may be considerable, equally effective
small rock drills of from half an inch to two inches diameter for use in blasting,
or large ones of several feet in diameter for tunnelling or shaft sinking, may
be used.
The cement or compound with which we mix the grains of emery as described, is
composed as follows:-
(1) Magnesium chloride crystals are mixed with water in the following
(2) Carbonate of magnesia is burned or calcined and is then reduced to powder.
It is then burned a second time at a temperature of about 1500° C., and is mixed with
about ten to fifteen per cent. of carbonate of magnesia less highly calcined, the result
being a nearly perfectly white powder.
The above materials are then mixed together in about the following pro-
portions:
-
50 parts of the chloride of magnesium solution (No. 1),
50 parts of the burned carbonate of magnesia (No. 2),
to which is added about 75 per cent. of large grained emery.
Whilst liquid this composition is poured into the mould as above described.
The drilling or boring apparatus described may be applied not only to the purpose
of drilling holes in rocks, but also to that of boring and finishing metal cylinders of
any size. Fragments of the composition of the cement and emery may be used
instead of diamonds in ordinary "diamond" drills.
Heretofore in boring cast iron cylinders of all kinds such as steam cylinders,
pump cylinders, and the like, often of several feet diameter, it has been usual to
place and fix the cylinder in a lathe and bore and finish it with steel cutters.
This process is very tedious and troublesome, as in the first place the heavy casting
has to be carefully adjusted and fixed in the lathe, and a rough cut must be first
taken off with the tool to remove the hard and rough surface of the casting, other
cuts following to complete and smooth the bore.
In order to apply the improved tool carrying emery mixed with cement as
described, to the purpose of boring such cylinders, instead of the ordinary heavy
bar provided with steel cutters having a screw feed motion, a cylindrical tool
is substituted, of a kind similar to those already described, consisting of a mixture
of cement above described and emery, the front part of the cylinder being made
somewhat conical and being provided with the largest pieces of emery, such conical

page_text: part first entering the cylinder which is to be bored and removing the hard skin of
the casting, whilst then by degrees the entire cylindrical surface of the tool comes
into operation, the grains of emery being of gradually increasing fineness, until the
last or finest part serves to finish and polish the bore of the cylinder. Very great
simplicity is also thus obtained in the method of boring such a cylinder, as it
is no longer necessary to adjust and fix the heavy cylinder upon a lathe, but
it can be allowed to remain upon the ground and is then bored and polished by
means of a strong ordinary boring bar and corundum tools as described acting
automatically.
The tool, as in the drill first described and shewn, imust have water supplied to
it, in the first place to remove the borings, and in the second place to keep the
tool and the cylinder cool. This is effected by means of water supplied under
pressure into the hollow axle or bar, and through passages and openings in the
cutting surface of the tool.
We do not confine ourselves to the precise form and details of construction, or to
the exact proportions of the composition described, which may be varied more or
less to suit different circumstances, but
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. The drilling or boring tool consisting of a metal tube a, coated inside and
outside at b with a mixture of grains of emery and the cement composed and
prepared as described, and having transverse holes c through the tube and through
the mixture, substantially as and for the purpose described and illustrated.
2. The boring tool consisting of a tubular bar, carrying a cylindrical coating
conical at its front end and consisting of a mixture of grains of emery of gradually.
increasing fineness with a cement composed and prepared substantially as described,
and having passages for water, such boring tool being arranged and operating
substantially in the manner and for the purpose described.
3. The cement for carrying the emery in drilling and boring tools of the kind
described, consisting of a mixture of (first) chloride of magnesium in water, and
(second) carbonate of magnesia burned and reduced to powder and reburned at a
high temperature and mixed with carbonate of magnesia less highly burned, the
several ingredients being prepared and mixed in or about in the proportions
specified, and substantially in the manner and for the purpose described.
Dated this 12th day of October 1893.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicants.