A communication from abroad by Friedrich PROVEMENTS IN ROCK DRILLS
Year: 1878

page_text: LETTERS PATENT to John Albert Reinhold Hildebrandt, of Bow Chambers,
Manchester, in the County of Lancaster, Engineer, for the Invention of "IM-
A communication from abroad by Friedrich
PROVEMENTS IN ROCK DRILLS."
Pelzer, of Dortmund, in Germany.
aled the 12th November 1878, and dated the 16th May 1878.
PROVISIONAL SPECIFICATION left by the said John Albert Reinhold
Hildebrandt at the Office of the Commissioners of Patents on the 16th May
1878.
JOHN ALBERT REINHOLD HILDEBRANDT, of Bow Chambers, Manchester, in the
County of Lancaster, Engineer. "IMPROVEMENTS IN ROCK DRILLS." (A communi-
cation from abroad by Friedrich Pelzer, of Dortmund, in Germany.
The Invention consists of improvements in rock drills having reciprocating or
percussive action, and relates to the slide valve motion, the automatic and gradual
turning of the tool, the automatic feed, the automatic and continuous removal of
debris or bore waste from the bore hole, and an adjustable stand for the machine.
The slide valve may be of the ordinary D or mushroom type, the valve rod being
actuated by two levers centred near the extremity of the piston rod when at the
ends of the stroke, one end of each moving freely in a slot of the rod, while the
other comes in contact with a nut or other projection on the piston rod, so that at
the end of the forward stroke the lever at the end is struck in the same direction,
and thus jerks the valve rod backward, the opposite taking place when the piston
rod is about to complete the return stroke. The violence of the action is checked
by buffers and springs placed at each end of the valve chest, the india-rubber or
other elastic material which is used for packing usually serving as a spring.
For the purpose of effecting the turning of the tool and the forward movement
of the machine or feed automatically a side lever is employed, which has a cranked
end working in a slide to which the clacks are attached which turn the ratchet
wheels. One of these sits on a square rod which works into the piston rod, the
other is fixed on the nut of the feed screw usually placed immediately below. Tho
0.11

page_text: cranked lever just mentioned is pressed by a spring on the same projection on the
piston rod which works the slide valve, and is so constructed that it slides on it.
Hence when the piston rod arrives nearly at the end of the stroke it comes in
contact with the said lever, and presses it outward against the pressure of the spring,
the lever moves the slide, and with that the clacks.
The ratchet wheels are so pitched that each stroke of the piston is sure to cause
the ratchet wheel at the end of the piston rod, and with it the rod itself, to turn
one tooth; but the wheel of the feed screw nut is pitched somewhat coarser, so that
it always works on the same tooth so long as the piston makes a stroke of normal
length, but whenever this length is exceeded the point of the clack, from the longer
movement of the lever and slide, gets over the point of the tooth, and consequently
moves the wheel one tooth.
For the purpose of automatically removing the bore dust or waste from the bore
hole, water or other fluid under pressure is employed and applied in the following
manner I form the cylinder cover into an annular casing of a little over the
length of the stroke, having a double gland, one to form a separation between this
chamber and the cylinder proper, and one to make a joint in the end or cover
proper. The double gland is so formed that both joints are screwed up simul-
taneously by the same screw, the two rings being connected by bars in the annular
space, which however do not touch the piston rod. The piston rod is provided with
an internal passage running from the socket, and opening into the annular space
just described. The tool or drill has also an internal passage opening near the
cutting edge, a joint being made in the socket by an india-rubber ring, and the
socket being screwed up by binding screws or bolts. The annular space or chamber
is supplied with water or other fluid under pressure through a pipe and tap on the
chamber, and connected by a flexible or other tube with the reservoir.
The internal passages may be formed in any convenient manner, but they are
most easily made in the drill by rolling.
The reservoir is a vessel of convenient form mounted on wheels, and provided
with air and water taps, also with funnel and valve for filling. The front has two
arms holding an upright screwed pillar, with ends adjustable against the floor and
ceiling of the workings by means of screws and nuts. This pillar carries as many
screwed cross bars on armed nuts as there are to be drills, and on these cross bars
are placed carriers or saddles to receive one end of the drills, the other ends being
supported on plain carriers fixed to cross bars formed of pipes with solid cores that
can be drawn out and fixed against the sides of the workings. These cross bars
are supported by simple upright rods and suitable brackets with set screws.
For single machines I use an adjustable stand or tripod, consisting of two bridges
provided with eyes for carrying the spindles of the drill, and rigidly connected by
a central bar shrunk into its place and piuned; it is prolonged at one end so as to
form a foot. The two other feet are attached to the opposite bridge, the end of which
are extended beyond the eyes provided to hold the machine. They are formed of
split halves, and pivots are inserted with a nut at the top, and carrying a plate with
a central pin and a quadrant slot below. Each of these two legs is centred at the
pin, and carries a bolt moving on the quadrant slot, and may be moved to any
angle the latter will allow. It is fixed in the desired position by screwing up the
nut on the bolt in the quadrant slot.
The legs consist of tubes carrying a solid sliding core at each end, one formning
the foot, the other beitig the portion centred and moveable on the quadrant plate.
The solid cores are adjustable in the tubes by means of collars and set screws.
The pivots of the quadrant plates can be turned in any direction and any angle,
and the quadrant plate allows a further angle of 90° with the centre of the pivot,
thus forming a universal joint.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Albert Reinhold Hildebrandt in the Great Seal Patent Office
on the 16th November 1878.
JOHN ALBERT REINHOLD HILDEBRANDT, Engincer, of 55, Cross Street, in the
City of Manchester, in the County of Lancaster. "IMPROVEMENTS IN ROCK
DRILLS." A communication from Friedrich Pelzer, Engineer, of Dortmund, in
Germany.
This Invention consists of improvements in rock drills having reciprocating or
percussivo action, and relates to the slide valve motion, the automatic and gradual
turning of the tool, tho automatic feed, the automatic and continuous removal of
debris or bore waste from the bore hole, and an adjustable stand for the machine.
The slide valve may be of the ordinary D or mushroom type, the valve rod being
actuated by two levers centred near the extremity of the piston rod when at the
ends of the stroke, one end of each moving freely in a slot of the rod while the
other comes in contact with a nut or other projection on the piston rod, so that at
the end of the forward stroke the lever at that end is struck in the same direction,
and thus jerks the valve rod backward, the opposite taking place when the
piston rod is about to complete the return stroke. The violence of the action is
checked by buffers and springs placed at each end of the valve chest, the indin-
rubber or other clastic material which is used for packing usually serving as a
spring.
For the purpose of effecting the turning of the tool and the forward movement
of the machine or feed automatically a sido lever is employed, which has a cranked
end working in a slide to which the clacks are attached which turn the ratchet
wheels. One of these sits on a square rod which works into the piston rod, the
other is fixed on the nut of the feed screw usually placed immediately below. The
cranked lever just mentioned is pressed by a spring on the same projection on the
piston rod which works the slide valve, and is so constructed that it slides on it.
Hence when the piston rod arrives nearly at the end of the stroke it comes in
contact with the said lever, and presses it outward against the pressure of the spring,
the lover moves the slide, and with that the clacks.
The ratchet wheels are so pitched that each stroke of the piston is sure to cause
the ratchet wheel at the end of the piston rod, and with it the rod itself, to turn
one tooth; but the wheel of the feed screw nut is pitched somewhat coarser, so that
it always works on the same tooth so long as the piston makes a stroke of normal
length, but whenever this length is exceeded the point of the clack, from the longer
movement of the lever and slide, gets over the point of the tooth, and consequently
moves the wheel one tooth.
For the purpose of automatically romoving the bore dust or waste from the bore
hole water or other fluid under pressure is employed, and applied in the following
manner :—I form the cylinder cover into an annular casing of a little over the
length of the stroke, having a double gland, one to form a separation between this
chamber and the cylinder proper, and one to make a joint in the end or cover
proper. The double gland is so formed that both joints are screwed up simul-
taneously by the same screw, the two rings being connected by bars in the annular
space, which however do not touch the piston rod. The piston rod is provided with
an internal passage running from the socket, and opening into the annular space
just described. The tool or drill has also an internal passage opening near the
cutting edge, a joint being made in the socket by an india-rubber ring, and the
socket being screwed up by binding screws or bolts. The annular space or chamber
is supplied with water or other fluid under pressure through a pipe and tap on the
chamber, and connected by a flexible or other tube with the reservoir.
The internal passages may be formed in any convenient manner, but they arọ
most easily made in the drill by rolling.

page_text: centred at P. On each return stroke of the piston the projection K presses the
lover h outwards against the spring f, and thus the finger i moves between the end
plates and d', a slido m, to which the clacks, hooks, or catches s° and s¹ are
hinged. These latter are pressed by springs into the teeth of the ratchet wheels R
and R. R is centred on a square rod t, which projects into a corresponding square
recess in the piston rod; hence the piston must follow the rotary movement of the
ratchet R, the teeth of which are so chosen that each ordinary stroke will cause
sufficient movement to the finger i and the slide m as to enable the catch s° to get
over the point of the tooth, and hence turn the wheel to that extent. The same
movement affects the ratchet R', the toeth of which however are pitched coarser,
so that an ordinary stroke will not cause the catch 8¹ to got over the point of the
tooth, but an unusually long stroke, such as is made if the drill has cleared the holo
sufficiently for a further advance, turns the wheel R', which is fixed to the nut R,
and hence moves the feed screw F¹, and thus propels the machine.
The arrangements for the automatic removal of the bore dust consist of a
passage p' in the drill T and the piston rod socket end, tho inlet p" to which is
encased in an annular space formed by a prolongation H of the cylinder cover and
an additional stuffing box M, a lantern with the bars u being employed to screw
up and hold the packing pieces S' and S2 in their respective places. This annular
chamber is in communication with a reservoir of water or other liquid under
pressure, which can be regulated by a stop-cock a. The liquid being forced through
the drill, and out at the working face or cutting edge, ejects the dust or debris from
the bore hole.
The passage in the drill T may be produced in any convenient manner, but I
prefer rolling it.
Fig. 3 shows the section of an unfinished tool T, the groove being gradually closed
by rolling, so as to be like Fig. 4 when finished. It is made tight in the piston rod
socket by an india-rubber or other packing S³. The feed screw F' and the spindle F"
serve to hold the drill G on its supports.
Figs. 15, 16, and 17 show several drills in their working position.
The principal parts besides the drills or machines proper are the reservoir E for
water under pressure, the screw pillar C, the drill holders Y and Y', and the
framing v, w, x.
The reservoir E is a cylindrical vessel on wheels furnished with a dome F, on
which the supply pipe D for the compressed air is fixed. 1, 1, 1, 1, are supply pipes
for the bore hole clearing apparatus for several machines. To the front of E a
frame is attached which holds the screw pillar C', which can be tightened against
the floor and ceiling of the workings by screws. The screw pillar carries nuts L
and collars with horizontal bars, cach carrying two arms L'. In each pair of arms
there is a screw N, on which the bracket Y, formed and acting like a nut, rests, and
this bracket holds the machine G by the spindles F, F, similar brackets or rests Y'
being placed at the opposite end, and supported by the stand composed of frame-
work v, w, x, while the two brackets Y and Y' are rigidly connected by means of
the bar Z. The bars O on Y¹ turn on the pin c, and rest with projections at y
against the shoulders y¹ to prevent them from turning too far. This bar O is then
laid on c, and fixed in its place with the screw clamp q
For supporting the working end of the machine a framework or stand is used,
which is composed of upright and cross bars w and a respectively, which are con-
nected and adjusted in any position by means of the bracket v. These frame bars
are largely composed of tubing with solid cores, which can be drawn in or out and
fixed with set screws.
Having now particularly described and ascertained the nature of my Invention,
and in what manner the same is to be performed or put in practice, I would have
it understood that what is shown in the Drawing is represented as an example
only, and that I do not limit myself to the exact details, forms, parts, dimensions,
and other particulars shown and described, but I claim particularly and sub-
stantially,

page_text: (1.) The construction and arrangement of valve motions for rock drills, substan-
tially as set forth.
(2.) The arrangement in rock drills for the rotary motion of the tool and the
automatic feed, substantially as set forth.
(3.) The application to rock drills of appliances by which the bore dust is ejected
from the bore holo automatically and continuously, similar to the one shown and
described, and the employment of hollow tools.
(4.) The construction and arrangement of the appliance by which the bore dust
is expelled from the bore hole, substantially as set forth, and the mode of producing
hollow tools by rolling.
(5.) The general arrangement of framing and other construction for the support
and adjustment of one or more rock drills simultaneously.
(6.) The application of all the parts combined, or the application of each sub-
stantial part singular and by itself or uncombined, with parts here described or
claimed.
In witness whereof, I, the said John Albert Reinhold Hildebrandt, have here-
unto set my hand and seal, this Fourteenth day of November, in the year
of our Lord One thousand eight hundred and seventy-eight.
Witness,
E. C. THOMPSON.
A. HILDEBRANDT. (L.S.)