IMPROVEMENTS IN THE CUTTING HEADS OF INSTRUMENTS USED DRILLING, BORING, TUNNELLING, OR OTHERWISE PENETRATING ROCK, STONE, OR OTHER HARD MATERIAL
Year: 1868

page_text: LETTERS PATENT to John Hosking, the younger, of Gateshead-on-
Tyne, in the County of Durham, Engineer, for the Invention
of "IMPROVEMENTS IN THE CUTTING HEADS OF INSTRUMENTS USED
DRILLING, BORING, TUNNELLING, OR OTHERWISE PENETRATING ROCK, STONE,
OR OTHER HARD MATERIAL."
Sealed the 14th July 1868, and dated the 17th January 1868.
PROVISIONAL SPECIFICATION left by the said John Hosking at the
Office of the Commissioners of Patents, with his Petition, on the
17th January 1868.
I, JOHN HOSKING, the younger, of Gateshead-on-Tyne, in the County.
of Durham, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CUTTING HEADS OF INSTRUMENTS USED
IN DRILLING BORING, TUNNELLING, OR OTHERWISE PENETRATING ROCK, STONE,
OR OTHER HARD MATERIAL," to be as follows:-
My Invention is intended to facilitate and expedite the operations
of drilling, boring, tunnelling or otherwise penetrating hard substances,
and consists in arranging the cutters upon the cutting head in a curved
line or lines, such curved line or lines not being circles or portions
of circles having the centre of the cutting head for their centre. The
form of the cutting head is hemi-spherical spheri-conical or so other-
wise "egg-ended" as that in longitudinal section the lines of the

page_text: face of the cutting head will be curved lines. But the form of the
cutting head may be varied. The form preferred however is spheri-
conical with the cutters arranged in spiral curved lines, the curve
commencing at the circumference and winding with more or less
pitch towards the centre; the number of lines of cutters, the proximity
of such lines, and of the separate cutters to each other, being adapted
to the nature of the material to be operated upon. The cutters may
be either formed of separate chisels or cutting edges, or made solid
by being formed upon the cutting head itself as being more applicable
to boring instruments of a small diameter.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Hosking in the Great Seal Patent Office
on the 17th July 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HOSKING, the younger, of Gateshead-on-Tyne, in the County of Durham,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of January in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Hosking, Her special licence
that I, the said John Hosking, my executors, administrators, and
assigns, or such others as I, the said John Hosking, 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 THE CUTTING HEADS OF INSTRUMENTS USED IN DRILLING, BORING, TUNNELLING,
OR OTHERWISE PENETRATING ROOK, STONE, OR OTHER HARD MATERIAL," upon
the condition (amongst others) that I, the said John Hosking, 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

page_text: the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Hosking, do hereby declare
the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon
(that is to say):
:-
My Invention of "Improvements in the Cutting Heads of Instruments
used in Drilling, Boring, Tunnelling, or otherwise Penetrating Rock,
Stone, or other Hard Material," is intended to facilitate and expedite
the operations of drilling, boring, tunnelling, or otherwise penetrating
hard substances, and consists in arranging the cutters upon the cutting
head in a curved line or lines, such curved line or lines not being
circles or portions of circles having the centre of the cutting head
for their centre. The form of the cutting head is by preference
hemi-spherical, spheri-conical or so otherwise "egg-ended" as that
in longitudinal section the lines of the face of the cutting head will
be curved lines. But the form of the cutting head may be varied.
The form preferred however is spheri-conical with the cutters arranged
in spiral or helical curved lines, the curve or curves commencing at
the circumference and winding with more or less pitch towards the
centre, the number of lines of cutters, the proximity of such lines
and of the separate cutters to each other being adapted to the nature
of the material to be operated upon. The cutters may either be
formed of separate chisels or cutting edges, or made solid by being
formed upon the cutting head itself, as being more applicable to
boring instruments of a small diameter.
Having thus stated the nature of the said Invention, I will proceed
to describe more particularly in what manner the same is to be per-
formed by reference to the accompanying Drawings.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a front elevation; and Fig. 2 a longitudinal section of
a cutting head of a spheri-conical form. The head as represented is
drawn to a scale of one inch and a half to one foot, and is five feet
in diameter, but the form and dimensions of the head may be varied.
Also it is represented as constructed of cast iron but it might, if

page_text: preferred, be made of brass, and for very small heads for boring
purposes the cutting head might be constructed of steel with the
cutting edges or points cut out of the solid metal.
A, A, is the frame of the head so formed as to admit of the chisels
or cutters being arranged in curved lines as required; B, B, are
the chisels or cutters arranged in spiral curved lines, the curve whereof
commences at the circumference and winds to the centre, but the
The
curve might terminate at any point on the head if preferred.
chisels or cutters are shewn separated, but they might be arranged
either in an unbroken line or further apart as required for the
particular material to be operated upon. It is also to be observed
that the chisels or cutters are shewn as fixed in their places by means
of keys, but this mode of fastening them may be varied. The dotted
lines C, C, Fig. 2 shew the lines of the cutting edges.
The arrows
shew the directions of motion of the cutting head.
Having thus described the nature of the said Invention and in
what manner the same is to be performed, I would remark that the
above described spiral arrangement of the cutters might be adapted
and applied to flat faced or other shaped cutting heads, but I hereby
declare that what I claim as of my Invention is, the construction
of cutting heads for the purposes referred to by preference of spheri-
conical or other "egg-ended form" or of other suitable form with
cutters or cutting edges arranged thereon in a curved line or lines
not being circles or portions of circles having the centre of the cutting
head for their centre as herein-before described.
In witness whereof, I, the said John Hosking, have hereunto
set my hand and seal, the Fifteenth day of July, in the year
of our Lord One thousand eight hundred and sixty-eight.
Witness,
HENRY CHARLTON,
Gateshead-on-Tyne,
Engineer.
JOHN HOSKING, JUN³. (L.S.)
Gateshead-on-Tyne.