IMPROVEMENTS IN DRILLS AND APPARATUS FOR BORING HOLES IN COAL, HARD GROUND, SLATE, AND MINERALS
Year: 1869

page_text: LETTERS PATENT to Charles John Chubb, of No. 18, Endsleigh
Street, Tavistock Square, in the County of Middlesex, for the In-
vention of "IMPROVEMENTS IN DRILLS AND APPARATUS FOR BORING HOLES
IN COAL, HARD GROUND, SLATE, AND MINERALS."
Sealed the 18th January 1870, and dated the 6th August 1869.
PROVISIONAL SPECIFICATION left by the said Charles John Chubb at
the Office of the Commissioners of Patents, with his Petition, on
the 6th August 1869.
I, CHARLES JOHN CHUBB, of No. 18, Endsleigh Street, Tavistock
Square, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN DRILLS AND APPARATUS FOR BORING
HOLES IN COAL, HARD GROUND, SLATE, AND MINERALS," to be as follows:-
In the Specification of a former Patent granted to me and dated 21st
day of January 1869 (No. 195) was described the forming drills for
boring holes into coal or mineral in such manner that the drill should.

page_text: first cut an annular hole of the diameter of the hole to be bored, and
should afterwards break up the core left standing in the centre of such
hole.
According to my present Invention I form such drills with a central
drill point extending out to some distance in front of the other cutters
of the drill, and of a diameter to bore a comparatively small hole. By
thus forming the cutting end of the drill with a central leading drill
of small diameter it will not be necessary to cut away the face of the
coal or mineral to reduce it to a flat surface before commencing to
bore a hole, as however rough the face of the coal or mineral may be
the leading drill will enter into it, and then when the cutters which are
to cut the larger annular hole come into action they will be kept steady
even though they commence to act on one side only of the central
leading drill. The stem of the leading drill is twisted to a rapid spiral
so as to form a cylindrical stem with a groove running spirally around
it. The cutting point of the central drill is formed to cut a hole of
a diameter corresponding with its grooved cylindrical stem, so that the
stem as it revolves in- this hole shall form a steady pivot for the drill
to revolve around.
According to this Invention also in place of making the cutting end
of the drill in one piece with the twisted stem that carries it as
described in the before-mentioned Specification, I form the cutting
end of the drill separate from the twisted stem and affix it thereto by
bolts. For this purpose I form the back end of the cutter where it is
to be fixed to the end of the stem of the following transverse section
اشت
3. A slot is formed in the flat end of the twisted stem to
embrace the central part a and the two parts b, b, on each side of it
and which carry the cutters which are to cut the annular hole come one
on one side of the end of the stem and the other on the other side,
and are fixed thereto by bolts. The central part a may be prolonged so
as to extend out beyond the parts b, b, in order to carry the cutters
which are to break up the core left standing in the centre of the
annular hole cut by the outer cutters, or these cutters might be carried
by the parts b, b.
Also according to my Invention in place of the nut through which
the screw (employed to give a revolving and at the same time a forward
motion to the drill) works being connected to its pillar or support by

page_text: means of pins, as described in the Specification of the before-mentioned
Patent, I form each nut with pins or axes projecting out from its sides,
and I form slots or notches inclining downwards in the side plates of,
the pillars to receive these pins; several such slots are formed at different
heights on the pillar into either of which the axes of the nut can be
dropped; the nut can thus readily be set at any height on the pillar.
A hole may thus be bored at any height desired, and the nut being able
to turn with its pins or axes the drill can also be set to cut at any
angle desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles John Chubb in the Great Seal Patent
Office on the 5th February 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARlfs
JOHN CHUBB, of No. 18, Endsleigh Street, Tavistock Square, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of August, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Charles John Chubb, Her special licence that I,
the said Charles John Chubb, my executors, administrators, and assigns,
or such others as I, the said Charles John Chubb, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
DRILLS AND APPARATUS FOR BORING HOLES IN COAL, HARD GROUND, SLATE, AND
MINERALS," upon the condition (amongst others) that I, the said Charles
John Chubb, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters. Patent;

page_text: NOW KNOW YE, that I, the said Charles John Chubb, 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 thereof, that is to say:-
In the Specification of a former Patent granted to me and dated the
21st day of January 1869 (No. 195) was described the forming drills for
boring holes into coal or mineral in such manner that the drill should
first cut an annular hole of the diameter of the hole to be bored, and
should afterwards break up the core left standing in the centre of such
hole.
According to my present Invention I form such drills with a central
drill point extending out to some distance in front of the other cutters
of the drill, and of a diameter to bore a comparatively small hole. By
thus forming the cutting end of the drill with a central leading drill of
small diameter it will not be necessary to cut away the face of the coal
or mineral to reduce it to a flat surface before commencing to bore a
hole, as however rough the face of the coal or mineral may be the
leading drill will enter into it, and then when the cutters which are to
cut the larger annular hole come into action they will be kept steady,
even though they commence to act on one side only of the central
leading drill. The stem of the leading drill is twisted to a rapid spiral
so as to form a cylindrical stem with a groove running spirally around
it. The cutting point of the central drill is formed to cut a hole of a
diameter corresponding with its grooved cylindrical stem, so that the
stem as it revolves in this hole shall form a steady pivot for the drill to
revolve around.
Figures 1 and 2 show a drill cutter constructed in the manner above
described. a is the central leading drill; the stem of this drill is
cylindrical, with a groove running spirally around it, as shewn, and it
forms a pivot for the other cutters of the drill to revolve around; b, b,
are the outer cutters for cutting the outer annular ring, and c, c, are the
cutters for breaking up the core left standing between the small central
hole and the outer annular hole; this cutter is shewn to be made
separate from the drill stem, as I prefer it should be; it might, however,
be formed in one piece with it, if preferred.
According to this Invention also in place of making the cutting end
of the drill in one piece with the twisted stem that carries it, as described

page_text: in the before-mentioned Specification, I form the cutting end of the drill
separate from the twisted stem and affix it thereto by bolts. For this
purpose I form the back end of the cutter, where it is to be fixed, to the
end of the stem of the following transverse section
; a slot
is formed in the flat end of the twisted stem to embrace the central
part a and the two parts b, b, on each side of it, and which carry the
cutters which are to cut the annular hole come one on one side of the
end of the stem and the other on the other side, and are fixed thereto
by bolts; the central part a may be prolonged so as to extend out
beyond the parts b, b, in order to carry the cutters, which are to break
up the core left standing in the centre of the annular hole-cut by the -
outer cutters; or these cutters might be carried by the parts b, b.
The Drawings, Figures 1 and 2, shew two forms of drill cutters, cachi
of them is made separate from its twisted stem, and is formed in the
manner above described, in such manner that it can be connected to it
by bolts and nuts. The way in which this is effected is so clearly shown
by the Drawings that it is unnecessary to give here any further descrip-
tion of it. In the drill cutter shewn at Figures 1, the cutters care carried
on the parts b, whilst in the cutter shewn at Figures 2 they are carried
on prolongations of the part a. I would remark that the arrangement
herein-before described for connecting the cutting end of a drill to its
stem is applicable when the cutting parts of the drill are formed
otherwise than is shown in the Drawing.
Also according to my Invention in place of the nut through which
the screw (employed to give a revolving and at the same time a forward
motion to the drill) works being connected to its pillar or support by
means of pins, as described in the Specification of the before-mentioned
Patent, I form each nut with pins or axes projecting out from its sides,
and I form slots or notches inclining downwards in the side plates of the
pillars to receive these pins; several such slots are formed at different
heights on the pillar, into either of which the axes of the nut can be
dropped; the nut can thus readily be set at any height on the pillar. A
hole may thus be bored at any height desired, and the nut being able to
turn with its pins or axes the drill can also be set to cut at any angle
desired.
At Figure 3 of the Drawings annexed is shewn a pillar suitable for
being fixed or wedged between the floor and roof of a mine; the side

page_text: plates of this pillar have inclined notches a formed in them, as above
described; b is the nut with pins 6' projecting from its sides to enter the
inclined slots a; c is the screw which works through the nut, and by
which a revolving and a slow forward motion is given to the drill.
In witness whereof, I, the said Charles John Chubb, have hereunto
set my hand and seal, this Second day of February, in the year
of our Lord One thousand eight hundred and seventy.
CHARLES JOHN CHUBB. (L.S.)