Improvements in or relating to Bits or Drills for Borers and the like, and in the Manufacture of the same.
Year: 1894

page_text: Date of Application, 17th Apr., 1894
Complete Specification Left, 17th Dec., 1894-Accepted, 2nd Feb., 1895
TRUVIDIONAL STUITIVATION.
Improvements in or relating to Bits or Drills for Borers and the
like, and in the Manufacture of the same.
A communication by CAMILLE BORNET, of 10, Rue St. Ferdinand, 'Paris, in the
Republic of France, Engineer.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this iuven-
tion to be as follows:
This invention consists of a new kind of hollow steel bit or drill for borers and
in the means for economically making these bits or drills. It is more particularly
intended to permit of their practical use in boring holes in mines by means of a
central injection of water for ensuring automatically a perfect and continuous
cleansing of these holes.
The invention, in fact, allows of hollow steel bars of variable length being
obtained at almost the same price as solid bars having the hardness and rigidity
necessary for making borers, jumpers, bits or other hollow tools intended for
attacking hard substances. In order to make these bars, hollow blocks of steel are
employed made directly by casting and having, for instance, an external diameter
of 60 millimetres, whilst the central hole, which is formed therein, is about
25 millimetres in diameter. This block is suitably heated and submitted to the
action of an ordinary rolling mill which draws it out, the grooves of said mill being
either semicircular, or of other form, but gradually diminishing in size. By this
means after it has been passed through the mill a certain number of times with
intermediate re-heatings, the external diameter of the hollow bar obtained is only
for instance 27 or 30 millimetres, the central bore then having a diameter of from
5 to 6 millimetres only, the length of the hollow bar obtained depending on that of
the block employed. It has been found easy in practice to obtain bars of two metres
and more in length.
The result of this special mode of treatment is that the central hole of the
hollow bar is not circular in form, but always more or less oblong, and it presents
sometimes angles or longitudinal folds. The process is therefore not suitable for
making metal tubes, but when it is a question of borers or hollow drills the form of
this tube is a matter of absolute indifference.
In forming the cutting head of the bit, care must be taken that its central bore
does not open out at the bottom of the boring hole, where it would run the risk of
being stopped up, and with this object after the end of the rod has been forged in
order to give it a more suitable cutting shape a hole is bored obliquely and a little
behind the cutting point into the said central bore and this oblique opening allows
the water injected to emerge there.
A method of making the cutting edge of the bit or drill is however preferably
employed which consists in cutting off a corner of the end of the hollow tubo
employed and then in bending or hammering over the tube end thus cut to the
ordinary shape of drill heads. By this operation the central bore of the rod.is
made to open a little behind the cutting point after it has been forged. By these

page_text: means the weakening of the end of the bit or drill by the central bore opening out
there is avoided.
It is evident that this mode of manufacture by drawing and forcibly compressing
hollow cast steel blocks by means of a rolling mill ensures the necessary hardness
and rigidity. Nevertheless solid steel forged blocks, if preferable, can also be
made use of in which is made a central hole or bore by operating on them whilst
hot by means of a punch which is caused to penetrate successively into the two
ends of the block and by then perfecting the bore, obtained by means of a
cylindrical rod. The boring of solid blocks may also be obtained by means
of a boring machine, or a lathe, but the punching process avoids any loss of metal.
In the foregoing, it has been mentioned that the hole or bore obtained in the rod
of steel was placed in the centre of this rod, but it must be understood that this
passage may, even with advantage, be placed eccentrically as regards the axis of
this rod, with a view to facilitate the making of the cutting edge, and the lateral
discharge opening of the said passage behind the point of the cutting edge. It is
sufficient in this case to employ blocks, the interior bore of which is eccentric, the
operation is then performed exactly the same as before, but the section of the
passage is a little more malformed by the action of the roller then when this hole
coincides with the axis of the block.
-
Taind this 16th dow of Ancil 1804
WM. P. THOMPSON & Co.,
Agents for the Applicant.
Improvements in or relating to Bits or Drills for Borers and the
like, and in the Manufacture of the same.
A communication by CAMILLE BORNET, of 10, Rue St. Ferdinand, Paris, in the
Republic of France, Engineer.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn, in the County
of Middlesex, Civil 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 consists of a new kind of hollow steel bit or drill for borers
and in. the means for economically making these bits or drills. They are more
particularly designed to permit of the practical use in boring holes in mines of a
ceutral injection of water for ensuring automatically a perfect and continuous
cleansing of these holes.
The invention, in fact, allows of hollow steel bars of variable length being
obtained at almost the same price as solid bars, such hollow bars having the
hardness and rigidity. necessary for making borers, jumpers, bits or other hollow
tools intended for attacking hard substances.
:
The invention will now be described in detail with reference to the accompanying
drawing, in which,
Figure 1 is a longitudinal section of the hollow steel block used for the
manufacture of these bits, borers or the like;
Figure 2 is a longitudinal section of the hollow bar obtained by drawing out the
block of steel in a rolling mill;
Figure 3 is a view in detail showing the irregular shapes of the hole or internal
passage of the extended rod;

page_text: Figure 4 is a section of a completed hollow bit showing the cutting head;
Figure 5 is a side view of the cutting head;
Figure 6 is a detail view showing the method of making the above named cutting
head.
:
:
In order to make these bars, hollow blocks of steel such as A, Figure 1, are
employed made directly by casting and having, for instance, an external diameter
of 60 millimetres, whilst the central hole a which is formed therein, is about
25 millimetres in diameter. This block is suitably heated and submitted to the
action of an ordinary rolling mill which draws it out, the grooves of said mill being
either semicircular, or of other form, but gradually diminishing in size. By this
means after it has been passed through the mill a certain number of times with
intermediate re-heatings, the external diameter of the hollow bar B, Figure 2,
obtained is only for instance 27 or 30 millimetres, the central bore 6 then having a
diameter of from 5 to 6 millimetres only, the length of the hollow bar B obtained
depending on that of the block A employed. It has been found easy in practice to
obtain bars of two metres and more in length.
The result of this special mode of treatment is that the central hole 6 of the
hollow bar is not circular in form but always more or less oblong, and it presents
sometimes angles or longitudinal folds as shown in Figure 3. As however this
hole is only intended to form a passage for the water injected into the bore hole it
is obvious that the form of this tube is a matter of absolute indifference.
In forming the cutting head of the bit, care must be taken that its central bore
does not open out at the bottom of the boring hole where it would run the risk of
being stopped up, and with this object after the end of the rod has been forged in
order to give it a more suitable cutting shape, as shown in Figures 4 and 5, a hole d
is bored obliquely and a little behind the cutting point D. into the said central
bore band this oblique opening d allows the water injected to emerge there.
A method of making the cutting edge of the bit or drill is however preferably
employed, which consists in cutting off a corner of the end of the hollow tube B
employed, as shown at in Figure 6, and then in bending or hammering over
the tube end thus cut to the ordinary shape of drill heads. By this operation the
central bore of the rod is bent down and made to open at da little behind the
cutting point after it has been forged. By these means the weakening of the end
of the bit or drill by the central bore 6 opening out there is avoided.
It is evident that this mode of manufacture by drawing and forcibly compressing
hollow cast steel blocks by means of a rolling mill ensures the necessary hardness
and rigidity. Nevertheless solid steel forged blocks if preferable can also be made
use of in which is made a central hole or bore by operating on them whilst hot by
means of a punch which is caused to penetrate successively into the two ends of the
block and by then perfecting the bore obtained by means of a cylindrical rod. The
boring of solid blocks may also be obtained by means of a boring machine, or a
lathe, but the punching process avoids any loss of metal.
In the foregoing it has been mentioned that the hole or bore obtained in the
rod of steel B was placed in the centre of this rod, but it must be understood that
this passage may, even with advantage, be placed eccentrically as regards the axis
of this rod, with a view to facilitate the making of the cutting head and the lateral
discharge opening of the said passage behind the point of the cutting head. It is
sufficient in this case to employ blocks, the interior bore of which is eccentric, the
operation is then performed exactly the same as before, but the section of the
passage is a little more malformed by the action of the rolling mill than when
this hole coincides with the axis of the block.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. A hollow steel drill or bit for borers which is produced by drawing out in a
rolling mill blocks of hollow steel, cast or bored and which is characterised by the

page_text: irregular shape of its internal passage resulting from this mode of manufacture,
substantially as herein before described; and shown.
2. In combination with a hollow steel bar produced by drawing or rolling a
hollow steel block, a cutting head formed by cutting obliquely the end of the said
hollow bar and bending it down by hammering in such a way as to cause the
internal passage of the said bar to open out laterally and a little behind the point,
substantially as hereinbefore described and shown.
Dated this 15th day of December 1804
WM. P. THOMPSON & Co.,
Agents.