IMPROVEMENTS IN PERCUSSIVE ROCK DRILLS
Year: 1874

page_text: LETTERS PATENT to Frederick Edward Blackett Beaumont, of No. 2,
Westminster Chambers, Victoria Street, Westminster, in the County
Sealed the 1st June 1875, and dated the 22nd December 1874.
PROVISIONAL SPECIFICATION left by the said Frederick Edward
Blackett Beaumont at the Office of the Commissioners of Patents,
with his Petition, on the 22nd December 1874.
I, FREDERICK EDWARD BLACKETT BEAUMONT, of No. 2, Westminster
Chambers, Victoria Street, Westminster, in the County of Middlesex, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
PERCUSSIVE ROCK DRILLS," to be as follows:-
.
This Invention relates to percussive rock drills of the kind in which a
piston on a drill spindle is caused to reciprocate in a cylinder by the
alternate admission and emission to and from the opposite ends of the
cylinder of compressed air or other fluid under pressure, the chief object
of my Invention being to effect the working of the slides or valves

page_text: which govern the admission and emission of the working fluid indepen-
dently of the movement of the drill piston, and to cause the working
fluid to advance the drill apparatus as the hole becomes deepened. For
this purpose I provide on the side of the drill cylinder a rotating slide
or a pair of slides, having passages or ways so arranged that during
rotation communications are alternately made between ports at each end
of the cylinder and a supply and exhaust port. Two separate tapering
slides may be employed, one for each end of the cylinder, fixed on one
shaft, with adjusting springs and nuts to set them to the desired degree
of tightness in their seatings. Or a single cylindrical slide may be used
with two sets of ways, a set for each end of the cylinder, and in such a
slide there may be external and internal annular passages for admission
and emission respectively. I cause the slide or slides to rotate by a
separate auxiliary engine worked by the fluid under pressure, so that the
motion of the slide or slides is in no way affected by the stroke of the
drill piston itself.
For advancing the apparatus, as the hole bored by the drill becomes
deeper, I form on the drill spindle, which is the extension of the piston
rod of the drill cylinder, a coned part, and I provide a lever with a pawl
working a ratchet wheel fixed on a screw. When from the deepening
of the hole the coned part of the drill spindle advances sufficiently far to
bear against the end of the pawl lever it moves the same, and thus
causes the pawl connected to it to take a fresh tooth of the ratchet wheel.
A small piston working in a cylindrical cavity on the drill cylinder, and
subject to the pressure of the working fluid, on the return stroke of the
drill moves the pawl lever so as to turn the ratchet.

page_text: of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Frederick Edward Blackett Beaumont, Her
special license that I, the said Frederick Edward Blackett Beaumont,
my exccutors, administrators, and assigns, or such others as I, the said
Frederick Edward Blackett Beaumont, 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 tho
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN PERCUSSIVE Rock
DRILLS," upon the condition (amongst others) that I, the said Frederick
Edward Blackett Beaumont, 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 Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Frederick Edward Blackett
Beaumont, 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, reference
being had to the accompanying Sheet of Drawings and to the figures
and letters marked thereon, that is to say: —
This Invention relates to percussive rock drills of the kind in which a
piston on a drill spindle is caused to reciprocate in a cylinder by the
alternate admission and emission to and from the opposite ends of the
cylinder of compressed air or other fluid under pressure, the chief object
of my Invention being to effect the working of the slides or valves
which govern the admission and emission of the working fluid indepen-
dently of the movement of the drill piston, and to cause the working
fluid to advance the drill apparatus as the hole becomes deepened. For
this purpose I provide on the side of the drill cylinder a rotating slide
or a pair of slides, having passages or ways so arranged that during
rotation communications are alternately made between ports at each end
of the cylinder and a supply and exhaust port. Two separate tapering
slides may be employed, one for each end of the cylinder, fixed on one

page_text: shaft, with adjusting springs and nuts to set them to the desired degree
of tightness in their seatings. Or a single cylindrical slide may be used
with two sets of ways, a set for each end of the cylinder, and in such a
slide there may be external and internal annular passages for admission
and emission respectively. I cause the slide or slides to rotate by a
separate auxiliary engine worked by the fluid under pressure, so that the
motion of the slide or slides is in no way affected by the stroke of the
drill piston itself.
For advancing the apparatus as the hole bored by the drill becomes
deeper I form on the drill spindle, which is the extension of the piston
rod of the drill cylinder, a coned part, and I provide a lever with a pawl
working a ratchet wheel fixed on a screw. When from the deepening of
the hole the coned part of the drill spindle advances sufficiently far to
bear against the end of the pawl lever it moves the same, and thus
causes the pawl connected to it to take a fresh tooth of the ratchet wheel.
A small piston working in a cylindrical cavity on the drill cylinder, and
subject to the pressure of the working fluid, on the return stroke of the
drill moves the pawl lover so as to turn the ratchet.

page_text: .
considerable weight serves to keep regular the rotation of the shaft e.
The cylinder C has ports c, c, at each end, which widen out so as to
present each two openings, one facing the grooves and the other facing
the groove &¹. The inlet pipe j also has its mouth within the slide jacket
widened out to include the two grooves 8, and the outlet pipes j',j¹, have
The
mouths within the jacket, facing respectively the grooves s'.
grooves 8, 8¹, are in such positions on the cylindrical surface of the
slide S that as the slide is caused to revolve continuously in one direction
the ports c, c, at the opposite ends of the cylinder are by means of the
grooves 8, 8¹, alternately put in communication with the inlet and the
outlet mouths, and thus the piston P being alternately pressed on by the
'working fluid on its opposite sides is made to reciprocato, causing the
drill D, which is secured in a socket at the end of the piston rod, to
make its strokes to and fro.
Fig. 5 represents a longitudinal, and Fig. 6 a transverse section of the
rotating slide made in two parts, cach slightly coned, with springs T to
press them into their seatings in their jackets, and adjusting nuts N to
prevent them from being seated too tightly.
Fig. 7 represents a longitudinal and Fig. 8 a transverse section of
another modified form of the rotating slide, an end view of which is
shewn in Fig. 9. In this case the working fluid is supplied by a pipe j
at the circumference of the casing in which the slide revolves, and the
exhaust is taken from a chamber at the end of the slide, which chamber
forms the middle cavity of the slide jacket, the two slides being employed,
one for each end of the cylinder, cach governing a port c leading to the
cylinder. When the slide is in the position shewn in Fig. 7 the port c is
in communication with the supply of the working fluid j.
Although I have represented the cylinder C as having the working
fluid alternately admitted to and discharged from both of its ends, it is
obvious that by suppressing the front half of the cylindrical slide in
Fig. 1, or the front conical slide in Fig. 5, or by employing a single slide,
such as is shewn in Fig. 7, and keeping the front part of the cylinder
permanently in communication with the supply pipe j, the forward
stroke of the piston would be effected on the pressure behind being
relieved.
Ton civing the drill nontial rotation at each stroke I fix an eccentric c

page_text: on the shaft e, which by means of a spring pawl works a ratchet wheel R
on the piston rod or drill spindle, another spring pawl n being applied to
prevent the ratchet from turning backwards.
As the hole is deepened the drill with its cylinder is advanced by
turning on a screw F a nut f, which is mounted in a boss attached to
the cylinder C. On this nut is fixed a ratchet wheel f¹, having a spring
pawl fengaging with its teeth to prevent it from turning backwards.
A plunger G fitted to work in a cylindrical cavity communicating with
the back end of the cylinder C has also a spring pawl engaging with the
ratchet wheel f¹, and the end of the plunger G rests on one arm of a
lever L, the other arm of which bears with its nose on the piston rod.
On the piston rod is formed a coned or taper part p¹, which at each
forward stroke of the piston (if the drill can sufficiently advance into the
hole) bearing against the nose 7, presses it downwards, and so elevates the
opposite arm of the lever L, raising the plunger G against the pressure
of the working fluid. On the return stroke of the piston, when the
coned part p' of its rod gets behind 7, that end of the lever L is free to
rise, and when the fluid pressure again acts on G at the beginning of
the next forward stroke of the piston G is depressed, its pawl turning
the ratchet wheel f¹ partly round, and thereby causing the drill to
advance. Should the feed of the drill be thus effected too rapidly, the
coned part p¹ of the piston rod being unable to advance sufficiently far
to act on the nose 1, the advance of drill ceases to take place until
the hole is sufficiently deepened to permit of the feed action as above
described. H is a winch for advancing or retracting the drill by
hand.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim,—
First. The method, substantially as herein described, of working
rotary slide valves of the cylinder of a percussive rock drill by means of
a separate auxiliary engine worked by a portion of the fluid which is
employed to work the drill, the said engine giving continuous rotation
to one or more such revolving slides mounted on the side of the drill
cylinder.
Second. The use for the cylinder of a percussive rock drill of one
or more revolving slides mounted in a jacket on the side of the
cylinder, the said slides having in them grooves, cavities, or passages so

page_text: arranged that during their rotation they alternately make and cut off
communication between the cylinder ports and the supply and discharge
pipes.
Third. The method, substantially as herein described, of proportioning
the advance of the cylinder of a percussive rock drill to the deepening
of the hole drilled by causing a coned part of the piston rod to move a
pawl in one direction, and the pressure of the working fluid to move it
back, and thereby to give partial revolution to a ratchet nut mounted on
the cylinder and working on a stationary screw.
Fourth. The combination of the coned part p¹ of the piston rod of a
percussive rock drill, the lever L, plunger G and its pawl, ratchet
wheel, and nut f on the screw F for effecting the forward feed of the
drill in proportion as the hole drilled by it is deepened, substantially as
herein described.
In witness whereof, I, the said Frederick Edward Blackett
Beaumont, have hereunto set my hand and seal, this Eleventh
day of June, in the year of our Lord One thousand eight hundred
and seventy-five.