IMPROVE- MENTS IN THE MANUFACTURE OF DRILLS FOR BORING HOLES
Year: 1874

page_text: LETTERS PATENT to Charles Julius Ball, of New Bridge Street,
Blackfriars, in the City of London, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF DRILLS FOR BORING HOLES."
"IMPROVEMENTS IN THE MANUFACTURE OF DRILLS FOR BORING HOLES," to be as
follows:-
This Invention relates to drills of steel or other sufficiently hård
material used for the purpose of boring holes in rock or other hard
substances, and consists of improvements in the method of manu-
facturing such drills, by which improvements greater facilities are
obtained in forming, sharpening, and repairing the cutting points or
cutting edges of such drills than is the case in such drills manufactured
in the methods ordinarily used and practised. Such drills are ordinarily

page_text: formed of a bar of steel or other metal, circular, hexagonal, or poly-
gonal in cross section, having its extremity formed (in end view) either
of one cutting edge arranged transversely across the diameter of the
drill, or of two such cutting edges crossing one another at right angles,
or nearly at right angles, or of three or more such cutting edges; these
edges constituting a cutting face of somewhat greater diameter than
the body of the drill, and being formed by forging, hammering, or
pressing them out of the bar of which the drill is made. By this
method whenever a drill breaks or becomes blunted or worn by use
considerable time and labour have to be expended for its repair.
My improved method of manufacture consists in making (by rolling,
hammering, or in any suitable way) the bar which forms the body
of the drill of a transverse section similar in shape to that of the cutting.
face of the drill (in end view), but of somewhat less diameter. For
instance, if the cutting face of the drill is to consist of two cutting
edges crossing each other at right angles, I make the bar of a similar
shape in transverse section but of somewhat less diameter.
When it is required to form the cutting face of the drill it is only
necessary to hammer each of the four radial arms which are to form
the cutting edge of the drill until they have been sufficiently expanded
in diameter, and to sharpen and harden each such cutting edge if
necessary.
etimes I twist, for the whole or part of their length, the bars
ufactured as described.
By my improved method of manufacture great economy of the time
and labour required for sharpening and repairing such drills is effected.
I do not confine myself to any particular form of the cutting face
of the drill described, and of the corresponding section of the bar, which
may be varied to suit different circumstances and the different qualities
of the material which is being drilled.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Julius Ball in the Great Seal Patent
Office on the 16th July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
JULIUS BALL, of New Bridge Street, Blackfriars, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of January, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Julius Ball, Her special
licence that I, the said Charles Julius Ball, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Julius
Ball, 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 MANUFACTURE OF DRILLS FOR BORING HOLES," upon the
condition (amongst others) that I, the said Charles Julius Ball, 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.
NOW KNOW YE, that I, the said Charles Julius Ball, 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 and accompanying Drawing (that is to
say) :-
This Invention relates to the manufacture of drills of steel or other
sufficiently hard material used for the purpose of boring holes in rock
or other hard substances, and consists of improvements in the method
of manufacturing such drills, by which improvements greater facilities
are obtained in forming, sharpening, and repairing the cutting points

page_text: or edges of such drills than is the case when they are manufactured
in the methods ordinarily used and practised. In the ordinary method
of manufacturing such a drill it is formed of a bar of steel or other
metal, circular, hexagonal, or polygonal in cross section, and having
its end formed (in end view) either of one cutting edge arranged
transversely across the diameter of the drill, or of two such cutting
édges crossing one another at right angles, or nearly at right angles, or
of three or more such cutting edges; these edges constituting together a
cutting face of rather greater diameter than the body of the drill, and
being formed by forging, hammering, or pressing them out of the bar
of which the drill is made. By this method whenever a drill breaks
or becomes worn or blunted by use considerable time and labour have
to be expended for its repair.
My improved method of manufacturing such drills consists in making
(by, rolling, hammering, pressing, or other suitable way) the bar which
forms the body of the drill, so that its transverse section is similar,"
or nearly similar in shape to that of the cutting face of the drill (in
end view), but of somewhat less diameter. For example, if the cutting
face of the drill is to consist of two cutting edges crossing each other
at right angles I make the bar of a similar shape in cross section, though
of rather less diameter.
When it is required to form or repair the cutting face of the drill
it is only necessary to hammer each of the four radial arms which are
to form the cutting edges of the drill until they have been sufficiently
expanded in diameter, and then if necessary to sharpen and harden each
such cutting edge in the usual way.
Sometimes I twist helically, for the whole or a part of their length,
the bars manufactured as described which are to form the drills. Great
economy of time and labour in forming, sharpening, and repairing the
cutting edges of such drills is effected by my improved method of manu-
facture.
In carrying out my Invention I do not confine myself to any par-
ticular form of the cutting face of the drill described, and of the corre-
sponding section of the bar, which may be varied to suit different
circumstances and the different qualities of the material which is to be
drilled.
t
The accompanying Drawing is in illustration of my Invention:
:

page_text: CHARLES JULIUS BALL. (L.S.)