IMPROVEMENTS IN MACHINERY FOR DRILLING OR BORING ROCKS AND OTHER HARD SUBSTANCES
Year: 1874

page_text: LETTERS PATENT to William Tregay, of Redruth, in the County of
Cornwall, for the Invention of "IMPROVEMENTS IN MACHINERY FOR
DRILLING OR BORING ROCKS AND OTHER HARD SUBSTANCES."
Scaled the 9th October 1874, and dated the 6th August 1874.
PROVISIONAL SPECIFICATION left by the said William Tregay at the
Office of the Commissioners of Patents, with his Petition, on the
6th August 1874.
I, WILLIAM TREGAY, of Redruth, in the County of Cornwall, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN-
MACHINERY FOR DRILLING OR BORING ROCKS AND OTHER HARD SUBSTANCES," to be
as follows:-
My Invention relate to improved machinery for drilling. or boring
rocks and other hard substances by the abrasive action of diamond or
other cutters made to rotate against the rock or other substance, the
object of the Invention being to render this means of drilling rock and
other hard substances available in mines and in other places where it.
"
:
:

page_text: could not hitherto be advantageously employed for want of machinery
sufficiently portable and effective.
The Invention relates mainly to the employment of a bore rod having
a plain exterior without an end-to-end screw, by which means the boro
rod can be rapidly run in and out by hand without any complicated
machinery, and can be readily changed for another, or lengthened as tho
boring progresses by screwing on additional peices at the rear end
without changing the position of the machine.
The Invention relates also to other parts, and to the general arrange-
ment of the machine. The machine is constructed as follows:-The
drill stem is smooth and even from end to end or nearly so without
external screw, except where the several lengths are screwed together,
and at its forc end the bit or drill head in which the cutters are set is
attached. This drill stem passes at one end through a tubular shaft to
which it is connected so as to be carried around therewith, and pressed
forward against the rock by a spring, clip, or latch on the tubular shaft
taking into a notch in the bore rod, the tubular rod being rotated by a
pinion, and having a longitudinal keyway to enable it to travel to and
fro through the pinion, carrying the bore rod with it. The remaining
portion of the tubular shaft is enlarged to receive a male screw turning
freely therein, the said shaft turning together with the bore rod inde-
pendantly of the screw, which is tubular, for the bore rod to pass through
it. This screw is prevented from moving longitudinally, and works
through a female screw which presses against the end of the tubular
shaft through the intervention of springs contained in a sleeve or tubular
extension of the female screw coupled loosely to said shaft by an internal
flange on the end enclosing an external flango on the end of the tubular
shaft. The female screw is prevented from turning by guides on tho
exterior, but is caused to traverse to and fro on turning the male screw
by means of a hand wheel.
14
The forward movement is modified and regulated by the springs above
mentioned, and when the pressure becomes excessive the springs aro
compressed, and the sleeve slides along the tubular shaft until it bears
against the end of a push rod extending along the tubular shaft, and
sliding in a longitudinal groove therein, and abutting at its other end g
against the spring clip, which it thus disengages from the bore rod,
throwing the latter out of gear until readjusted by the attendant,

page_text: The tubular shaft is mounted in bearings or guides, carried on a ring
or plate fitted to rotate in a circular clip fixed to the main frame; of the
machine, the said ring or plate having teeth cut in its periphery for
ä worm to gear with to rotate the ring or plate for the purpose of
clevating or depressing the point of the bore rod as required. Tho
tubular shaft is rotated by bevel gearing from a crank shaft driven by
an engine or pair of engines, the whole being mounted in a frame
carried on a telescopic strut or stand, the sections of which screw into
one another so as to be extended simultaneously, the two extremities of
the strut being provided with shoes for fixing against the rock, or it
may be mounted on a fixed pedestal or a trolley, according to circum-
stances. The main frame of the machine is fitted on said stand by a nut
or female screw working on a male scrow thereon, whereby the framo
may be raised or lowered.
The frame may also be turned around the
stand to hold the machinery in the required direction by means of a
worm gearing with a wheel keyed on the stand, but free to move up and
down thereon:
:
. A pump is provided worked by an eccentric on the crank shaft to
force water through the bore rod into the bore hole to wash out the grit,
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Tregay in the Great Seal Patent Office
on the 6th February 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
TREGAY, of Redruth, in the County of Cornwall, 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 seventy-four, in the thirty-
eighth year of Her reign, did, för Herself, Her heirs and successors,
give and grant unto me, the said William Tregay, Her special licence
that the said William Tregay, my executors, administrators, and
assigns, or such others as I, the said William Tregay, 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

page_text: therein expressed, should and lawfully might make, use, excrcise, and
vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN MACHINERY FOR DRILLING OR BORING ROCKS AND OTHER HARD SUBSTANCES,"
upon the condition (amongst others) that I, the said William Tregay, 5
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 imme- 1
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Tregay, 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, reference being had to the three accompanying 1
Sheets of Drawings, and to the letters and figures marked thereon (that
is to say) :-
My Invention relates to improvements in that class of machinery in
which the drilling or boring of rocks and other hard substances is
effected by the abrasive action of diamonds or other hard cutters set in 2
a suitable drill head, and made to rotate against the rock or other
substance, the object of my Invention being to render this means of
drilling available in narrow workings in mines and other places where it
could not hitherto be advantageously employed for want of machinery
sufficiently compact and effective.
The Invention consists, firstly, in the employment of a bore rod
having a plain exterior, i.e., without the usual end-to-end screw or any
projection whatever except the cutters in the drill head whereby the
bore rod can be rapidly run in and out by hand without the aid of any
complicated machinery, and can also be readily changed for another, or {
lengthened as the boring progresses by screwing on additional lengths
at its rear end without disturbing the position of the machine.
The Invention also relates to an improved arrangement and con-
struction of parts of the rotary drill mechanism, whereby the drill,
which is fed forward by the attendant, shall be set loose or thrown out
of gear in the event of the feed or pressure being excessive, as hereafter
more fully described.

page_text: "
The Invention further relates to the combination and arrangement
of the mechanism for adjusting and holding the boring apparatus in
position.
:
In order that the construction of the machine may be more readily
understood I have illustrated it in the accompanying Drawings, in
which Figure 1 is a side elevation of the entire machine; Figure 2 is a
horizontal section on line 1-1, Figure 1, parts of the machine being
omitted.
Figure 3 is a longitudinal vertical section of the extensible screw,
stand, or support, on which the machine frame is mounted, and of
certain parts of the machine, the section being taken on line 2-2,
Figure 2.
Figure 4 is a longitudinal section of the bore rod and its accessories;
Figures 5 and 6 are cross sections respectively on lines 3-3, 4-4,
Figure 4.
A is the machine frame in which all the parts are carried, the said
frame being itself mounted on a telescopic or extensible screw stand or
strut B fixed either in the gallery or tunnel, or on a pedestal or a trolley,
according to the locality of the work. The frame A is fitted upon a nut
) or female screw C provided with a hand wheel C' and a shoulder C³,
upon which the frame A is free to be turned to point and hold the tool
in any direction. The stand is composed of a number of tubular screw
sections B, B¹, B³. The nut C travels on the outer section B to traverse
the machine up and down the stand. At one end of this section is fixed
5 the shoe b to fix in the rock; and at the other end is a nut or female
screw 6 to receive the section B'. This section has also at 6º a female
screw through which passes the section B³, having also a screw upon it,
but left handed. By turning the hand wheel B³ the sections B', B³, are
extended simultaneously; b³ is another shoe fixed to the end of the
) innermost section B², and provided with a handle to prevent the
section B turning with B'.
-
In quarrying at the surface, or in other cases, the shoe 6 may be
removed, and the stand screwed on a foot bolted to a pedestal or to a trolley,
the said foot piece being made of any length required, and with a screw
or smooth on its outer surface.
-
The frame is caused to turn around the stand B by a hand wheel D
on a spindle d turning in bearings in frame A, and carrying a worm

page_text: wheel D¹, which gears with a toothed collar d¹ fixed on the stand by an
internal tongue or key moving in a longitudinal keyway d³ in the outer
section B, so as to be free to move up and down thereon. E, E, aro a
pair of oscillating cylinders mounted on trunnions in frame A, and com-
municating with a steam boiler or other source of power, the distribution 5
being governed, as shown, or in any other suitable manner. These
cylinders drive a crank shaft F revolving in bearings in frame A, and
having keyed on it at one end a bevelled gear wheel F', which drives a
bevelled pinion F* keyed on a short shaft g at right angles to shaft F, and
turning in a bearing in the centre of a disc a forming part of frame A ; 1
G+ is another bevel gear wheel keyed on the other end of shaft g, and
driving another bevel pinion G¹ keyed on a tubular shaft H enclosing
the bore rod, to which rotary motion is imparted as hereafter described.
This tubular shaft H'is mounted in a guide frame I fixed at I', I', to a
ring K fitted to rotate in a circular clip K¹ bolted to disc a of frame A; 1
as shown in Figure 2; L, Figure 1, is a worm spindle turning in
bearings L'on frame A, and having a hand wheel L³, said worm gearing
with corresponding teeth cut on the periphery of ring K. By turning
worm L. the ring K may be rotated to elevate or depress the point of the
bore rod as required.
-
The construction of the bore rod is illustrated in Figures 4, 5, and 6.
M is the bore rod made tubular and plain, and smooth on its exterior
from end to end without any projection whatever, with which object the
several lengths of which it may be composed are fitted together by
screw joints, as shown at e. At its fore end is similarly attached the bit 2
or drill head in which the cutters are set. These cutters project a littlo
in order to make the bore hole a trifle larger than the bore rod, so that
the same may run freely, and protect said bore rod from abrasion. The
bore rod M passes through the tubular shaft H, which is bored out for a
short distance at one end to receive and guide the boro rod M, the 3
remainder of said shaft being of larger internal diameter to receive a
male screw O, made tubular, through which the bore rod also passes
freely.
The tubular shaft II is fitted to slide freely through its bearing in tho
end of frame I, as the tool is fed forward during the progress of the 3
work, the bevel pinion G¹ being fitted on said shaft with a key or feather
received in a keyway h, Figure 5, extending nearly the whole length of
shaft H to allow of this longitudinal movement of said shaft at the same

page_text: time that it is carried round by pinion G'. The connection between shaft H
and bore rod M. is made by means of a latch in received in a recess in
shaft H, and mounted to oscillate on a pin m³. This latch terminates
in a cross piece or blade m³, which is by the action of a spring m
5 pressed into a corresponding recess in the bore rod M, whereby the latter
is carried round with the shaft H, and held up to its work. The shaft H
and bore rod M turn independently of the screw O, which is turned by
hand wheel O' to feed the bore rod forward as required. For this
purpose the screw O has formed upon it a shoulder at o, bearing against
the end of frame I, and works through a corresponding nut P, which is
caused to travel along the screw when the latter is turned. This nut is
fixed in a sleove P', which is coupled loosely to the shaft H by an
internal flange. p on the former, enclosing an external flange h³ on the
end of the latter, whereby to withdraw the shaft or bore rod on reversing
the motion of screw. The nut and sleeve P, P', are prevented from
turning by the longitudinal guide frame I, which is received in corro-
sponding grooves in the exterior of said sleeve, as shown in Figure 6. The
forward movement of the nut and sleeve P, P', is transmitted to the
shaft H by the intervention of rings of of india-rubber R, R, R, (or by
other means), which rings acting as springs become compressed between
the nut P and the end of shaft H. S, S, S, are loose washers of hard
metal, and T are friction balls introduced between the stationary
springs R and the rapidly rotating shaft H. These springs serve. to
modify and regulate the pressure or feed of the boring tool; but I do
not lay any claim to the exclusive use or application of these springs to
a rotary drill, as such have been used before for a similar purpose.
It will be seen that the pressure of the boring tool against the rock can
never become excessive, the boro rod being automatically thrown out of
gear whenever the compression of the springs allows the sleeve P' to
slip forward so far over shaft H that it bears against the end of a push
rod U extending along the shaft H, and sliding in a. longitudinal groove
therein. This push rod terminates at its other end in a bevelled surface
abutting against the spring latch m, which is thereby disengaged from
the bore rod, throwing the latter out of gear until readjusted by the
attendant. The bore rod can then be passed freely forward or backward
by hand, and may be changed for another, or have an additional length
screwed on at the rear end o². The sleeve P: is cut away on one
as shown in Figure 6, to avoid coming in contact with the bevel gear G
when pressed forward as the boring progresses, V, Figure 3, is a pump

page_text: mounted in frame A, and operated by an eccentric on shaft F, for
drawing water from any convenient supply, and forcing it through the
pipe coupled at vi to the rear end of the bore rod (or at o' if not desired
to pass the water through the whole length of the bore rod) to wash out
the grit and keep the bore hole clear.
'
Having described the nature of the Invention, and the manner of
performing the same, I declare that without limiting myself-to-tho-
precise details of arrangement of the machinery herein-before described,
what I claim as my Invention to be protected by the hercin-before in
part recited Letters Patent is,-
.1st. In a rotary rock drill the employment of a bore rod fitted in and
connected to a tubular shaft, substantially as shown. and described, the
said bore rod being made plain on its exterior, and capable of being
lengthened by screwing on additional longths at the rear end,.substan-
tially as and for the purpose specified.
2ndly. In combination with a bore rod constructed as above specified
the mechanism constructed, arranged, and operating substantially as
described, and shown in Figures 4, 5, 6, whereby the drill is fed forward,
and is set loose on the pressure becoming excessive until readjusted by
the attendant, as specified.
3rdly. The combination and arrangement of mechanism for adjusting
and holding the drilling apparatus in position, substantially as shown
and described.
i
1
In witness whereof, I, the said William Tregay, have hereunto set
my hand and seal, this Second day of February, in the year 2
of our Lord One thousand eight-hundred and seventy-five.