IMPROVEMENTS IN ROCK DRILLS
Year: 1885

page_text: I ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents, 6 Bream's
Buildings Chancery Lane in the County of Middlesex Patent Agent, do hereby
declare the nature of the invention for IMPROVEMENTS IN ROCK DRILLS to be as
follows:-
This invention is applicable to those machines in which a piston, having
attached to it a drill or bit is reciprocated within a cylinder which is supported
upon a tripod or stand so that it may be swung in any direction in order to
properly direct the drill or bit against the work.
The invention relates to a valve mechanism of simple and novel construction
whereby the admission of steam or other motive fluid to the cylinder and its
exhaust from the cylinder are controlled. It also relates to a novel and simple
construction of the mechanism whereby the piston and its attached drill or bit are
rotated. It also relates to a novel construction of the piston and piston extension
whereby the pressure of the motive fluid is made available upon the whole area of
the piston to make its downward or working stroke, and it also relates to a novel
construction of the tripod or stand upon which the drilling machine is supported.
In drilling machines heretofore in common use the rotation of the piston and
attached drill or bit have, in many cases, been produced by means of a spiral bar,.
which extends downward axially into the cylinder and which fits a spirally
grooved nut in the piston. The upper end or head of the spirally grooved bar has
had a ratchet and pawl connection with the cylinder which permitted the spirally
grooved bar and its head to turn in one direction under the influence of the nut as
the piston makes its downward or working stroke, but prevents the spiral bar
from turning in the other direction as the piston makes its upward or return
stroke; and by holding the spiral bar against turning, causes the piston and bit to
turn relatively thereto. Such combination of parts has operated properly when
there was no unusual resistance to the turning of the piston and bit, but when a
greatly increased resistance has been opposed to such turning, as would be caused
by the bit sticking in a fissure in the rock, no provision has been afforded for the
D1131

page_text: yielding of the parts, and breakage of the machine was likely to ensue. In such
machines, as heretofore constructed no provision has been afforded for the free inlet
of steam or motive fluid to the cavity in the piston and piston extension which
receives the spiral bar, and hence the whole area of the piston has not been
subjected to equally effective pressure.
One object of this invention is to provide a valve mechanism for controlling the
supply of motive fluid to the cylinder which will be automatic and positive in its
operation and of very simple construction. To this end a cylindric valve chest or
cylinder having oppositely arranged valve seats is provided, from which passages
lead to the cylinder above and below the piston; and a valve is employed
consisting of a skeleton structure which is fitted to have a short reciprocating or
sliding motion in the chest or cylinder and which has at opposite ends heads or
discs which alternately close upon the valve seats and which are larger in diameter
than the said seats so that a considerable portion of a head or disc is exposed
beyond and around the seat when the valve is closed upon one or other of them,
and in the peripheries of the heads or discs which are exposed around the valve
scats when the valve is closed upon one or other of them are notches or recesses
which may be varied in size in order to regulate the operation of the valve. When
this valve is closed upon one seat that portion of one end of the valve which covers
the seat is free from pressure and the opposite end of the valve has the full
pressure upon it to hold the valve to its seat. As the piston moves to make its
stroke, motive fluid cannot pass through the open seat sufficiently fast to maintain
the maximum pressure, and consequently the pressure on the end of the valve
which tends to hold it to its seat will be decreased to such an extent that the
pressure on that portion of the opposite end of the valve which is exposed beyond
the seat will throw the valve over and cause it to close upon the opposite seat.
will be understood that the area of the valve which is exposed beyond and around
each seat, when the valve is closed thereon, may be varied by increasing or
diminishing the size of the notches or recesses in the peripheries of the heads or
discs, and it will be understood that by making these notches or recesses small in
size, the valve will be thrown over or shifted earlier in the stroke of the. piston
that it will be when the notches or recesses are larger in size and decrease to a
greater extent the area of the valve which is exposed around and beyond the
valve seats.
It
The valve above described serves only to control the admission of motive fluid
to the cylinder, and its exhaust therefrom is provided for by constructing the
cylinder with an annular exhaust channel or passage extending around it and
across which the piston travels in making its stroke. As the piston moves in
either direction this annular exhaust channel or passage affords free exhaust from
the opposite ends of the cylinder until the piston has covered the exhaust channel
or passage.
In order to provide for the exhaust from the lower end of the cylinder after the
exhaust channel or passage has been covered by the piston in its downward stroke,
an automatically operating and supplemental exhaust valve is arranged in the
cylinder structure, which valve controls communication between the main exhaust
and the supply passage leading to the lowermost end of the cylinder. This valve
is of such construction that when the live motive agent is acting upon the upper
end of the piston it will act upon the exhaust valve to hold it open and maintain
free communication between the passage leading to the lower end of the cylinder
and the main exhaust, but when motive fluid is admitted to the passage leading to
the lower end of the cylinder it will act upon this supplemental exhaust valve and
hold it closed so that no live motive agent can then escape.
In order to provide rotating devices which shall operate with the same certainty
as those heretofore used, but which in case the bit or drill should catch in a fissure
in the rock or in case any unusual resistance should be opposed to the turning of
the piston from any other cause, will allow the spiral bar to turn as the piston
makes its upward or return stroke and avoid breakage of parts, one member of

page_text: the rotating devices, either the ratchet or pawls, is clamped and held by friction
within the cylinder, instead of fixing such member immovable in the cylinder as
has heretofore been done. In what may be considered as the most approved form
of the invention a sleeve is provided which encircles the bead of the spiral bar and
is clamped and held within the cylinder by friction produced by spring pressure.
The internal circumference of this sleeve is provided with ratchet-shaped teeth
which extend lengthwise of the cylinder, and the head of the spiral bar is provided
with pawls which engage with these teeth.
In the normal operation of the machine the sleeve is held against turning in the
cylinder, and the spiral bar can turn in but one direction only, but in case any
unusual resistance is opposed to the turning of the piston the frictional resistance
to the turning of the sleeve will be overcome and the spiral bar will be permitted
to turn in the opposite direction.
Instead of providing the sleeve with ratchet-shaped teeth and the head of the
spiral bar with pawls, the arrangement of these parts might be reversed and
the teeth might be upon the head of of the spiral bar and the pawls held in the
sleeve. The same result can be attained by the use of two rings having ratchet-
shaped teeth upon their adjacent faces, and one of which is clamped and held by
friction in the cylinder, while the other is locked to the head of the spiral box so
as to turn there with.
As above stated it is an object of this invention to provide for the effective
action of the motive agent upon the whole area of the piston in making its down-
ward stroke.
The piston has a long piston-extension containing a cavity which receives the
spiral bar and in which is fixed a nut fitting the spiral bar. This piston extension
is constructed with longitudinal grooves in its outer surface, which serve to conduct
motive fluid to the upper end of the cylinder, and with holes leading to the internal
cavity which serve to admit the motive fluid to said cavity so that it may act upon
the bottom surface thereof and render that surface available to pressure in moving
the piston.
Another object of the invention is to provide a tripod or stand of simple con-
struction which will provide for swinging the drill cylinder into any desired
position and the legs of which are capable of of such adjustment as will enable
the drill to work close to the side of an upright wall as is often required in
tunnelling. The tripod or stand consists of two parallel hip-pieces which have
pivotted between them at their rear ends a back leg, capable of swinging in a
plane parallel with and between the hip pieces, and which have pivotted to their
forward ends front legs which are capable of swinging in a plane transverse to the
hip-pieces.
The drill back or frame in which the cylinder is capable of lengthwise adjust-
nent is constructed with a cylindric wrist or journal and the tripod has a split
collar or divided clamp which receives this wrist or cylindric journal and which is
itself fitted to trunnion bearings in the hip pieces so that it may be swung in a
plane parallel with and between the hip pieces.
Dal 11.
0012 1
Ր T

page_text: I ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents 6 Breams
Buildings Chancery Lane in the County of Middlesex Patent Agent, 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 is applicable to those machines in which a piston, having attached
to it a drill or bit, is reciprocated within a cylinder which is supported upon a
tripod or stand so that it may be swung in any direction in order to properly
direct the drill or bit against the rock.
The invention relates to valve mechanism of simple and novel construction,
whereby the admission of steam or other motive fluid to the cylinder and its
exhaust from the cylinder are controlled.-It also relates to a novel and simple
construction of the mechanism whereby the piston and its attached drill or bit are
rotated and by which the breakage of any parts of the machine is avoided, in case
there is any great or unusual resistance offered to the rotation of the piston and
drill or bit during their upward or return movement.-It also relates to a novel
construction of the tripod or stand on which the drilling machine is supported.
The accompanying drawing represents a complete machine. embodying the
several features of my invention.-Figure I is a vertical section of the machine;
Figure 2 is a front elevation including a partial section taken upon the plane of
the dotted line x x Figure 1; Figure 3 is a transverse section upon the plane
of the dotted line y y, Figure 1; Figure 4 is a transverse section upon the plane of
the dotted line zz Figure 1; Figure 5 is a plan of the upper portion of the tripod
or stand, the portion of the legs beyond their upper ends being omitted; Figure 6
is a vertical longitudinal section of the principal portion of the machine in the
same plane as Figure 1, and upon a larger scale; Figure 7 is a transverse section
upon the plane of the dotted line 11, Figure 6, of the parts whereby the piston
and drill or bit are rotated, showing these parts upon the same scale as Figure 6;
Figure 8 illustrates a partial transverse section upon the plane of the dotted
line zz, Figure 1 and upon the same scale as Figures 6 and 7; Figure 9 is a
sectional view of a portion of the machine similar to Figure 6, but showing rotating
devices of slightly modified form also embodying this invention; and Figure 10
and 11 are face views of two ratchets which are employed in the modification
illustrated in Figure 9 and which are hereinafter described, and Figures 12 and 13
are side and end views of the supply valve alone.
Similar letters of reference designate corresponding parts in all the figures.
A designates the drill cylinder to which is fitted a piston B, the rod B¹ of which
has at its lower end a suitable chuck B wherein a drill or bit B³ is secured.-The
cylinder is constructed with longitudinal flanges a which are fitted to a gibbed
slideway a' as shown in Figures 3 and 4, and this gibbed slideway is formed in
the drill-back A¹-The drill cylinder and all its appurtenances may be adjusted

page_text: longitudinally in the drill-back by means of a feed screw C, which is operated by
a handle or crank C', and which engages with a nut a secured to the cylinder,
and is fitted to a bearing a³ whereby its longitudinal movement is prevented.-By
turning the feed screw C, the drill cylinder and its appurtenances may be raised
and lowered or moved longitudinally in the back A¹.
The back A' has projecting from its rear side a journal or wrist A' which is fitted
to a divided clamp or collar A³ forming part of the tripod or stand.-The
construction of this tripod or stand is shown in Figures 1, 2 and 5.-It has at
opposite sides hip pieces A' between which the clamp or collar A³ extends, and
which are provided with trunnion bearings a' for the clamp or collar, as best shown
in Figure 5. The trunnion bearings a, which the clamp or collar A³ has in the
hip pieces A', permit of the clamp or collar, the drill-back and its attached cylinder
being swung backward and forward in a plane parallel with and between the
hip pieces.
The support of the drill back by a cylindric wrist or journal A³ in the divided
clamp or collar A³ permits the back and cylinder A¹ A to be swung to and fro in a
plane transverse to the hip pieces A-After being properly adjusted the machine
may be locked so as to operate the drill or bit in the proper direction by tightening
nuts a whereby the divided clamps or collars A³ are connected with the hip pieces,
and by tightening the clamp bolt a whereby the said clamp or collar may be
tightly contracted upon the cylindric journal or wrist A².
Between the hip pieces A at their rear ends is pivotted a back leg A³ which
may be adjusted or swung in a plane parallel with and between the hip pieces
and secured after adjustment by tightening the nuts a which connect it with the
hip pieces. At the opposite end of the hip pieces are front legs A° which may
be swung in planes transverse to the hip pieces and secured after adjustment by
tightening nuts as whereby they are connected with the hip pieces.-The legs have
at their lower ends points or spurs for engaging with the rock or bed upon
which the machine is placed, and are also provided with weights at for giving the
machine stability.-In Figure 2 one of the weights is removed in order to show a
square collar or projection all formed on the leg and with which the weight may
be engaged.
The lower end of the cylinder A is closed by a head A' and the upper end is
closed by a head A8 which consists simply of a cylindric piece of metal fitted
within a ring-shaped or annular frame A9 bolted to the upper end of the cylinder.
The heads are retained in place by bolts b which pass through the lower head
and through the annular ring or frame A' at the upper end of the cylinder,
and are there provided with nuts b'. Le designates a leaf or bent spring which
may be made in one or more thicknesses, through which the bolts pass, and
which bears at the middle of its length upon the upper head A8 of the cylinder.-
The tension of the spring 63 may be varied by adjusting the nuts b¹, and this
spring serves as cushion in order to prevent breakage by reason of the piston
striking the upper or lower heads of the cylinder.
The piston B is provided with any suitable packing to prevent leakage, and has
a long piston extension B which is made hollow to receive within it a spiral
bar D, forming a part of the mechanism for rotating the piston, and which is
hereinafter more fully described.-The piston extension B has screwed or other-
wise secured in it a spirally grooved nut 63 which is fitted to the spiral bar D.
The piston extension B is grooved longitudinally at s and has holes s¹ leading
inwards to the cavity which receives the bar D.-Steam passes upward through
the grooves 8 to act on the upper end of the piston extension and also passes
through the holes s¹ to act on the lower end of the internal cavity of the piston
extension to force the piston down.-The whole area of the piston is therefore
effective in making the down or working stroke.
The cylinder A is constructed with a valve chest A10 wherein is arranged a
valve E for controlling the supply of motive fluid to opposite ends of the

page_text: cylinder A. In the valve chest are formed seats c c¹ which communicate by ports
or passages c with the cylinder A on the opposite sides of the piston B.
The valve E consists of a skeleton-like structure which is best shown in
Figures 12 and 13, and has at opposite ends heads or flanges d -These heads
or flanges are of such diameter that they project outwards from and extend beyond
the seats c c¹, when closed thereon, and in the portions Bо projecting beyond the
seats are notches or recesses d*.-This valve E has but a very slight reciprocating
movement and closes alternately on the seats c c¹ in order to control the admission
of motive fluid above and below the piston.-The motive fluid, whether it be
steam or air, is conducted to the chest A10 by a supply pipe c*.
The cylinder A is provided between its ends with an exhaust channel or
passage e extending around it, and across which the piston passes in its
reciprocating movements.
In the position of parts shown in Figures 1 and 6 it will be observed that the
valve E is closed upon the seat c, thereby allowing a free opening through
the seat c' and passage c³ to the cylinder above the piston. At this time it will be
seen that the portion of the valve which corresponds to the area of the seat c is
free from pressure and the pressure acting upon the head or disk d outside of and
around the seat c tends to force the valve away from the seat, but the pressure in
the opposite direction against the full area of the head or disk d holds the valve
tightly to its seat c.-The motive fluid being thus admitted to the upper end of
the cylinder, the piston moves downward with a quickly increasing force and the
motive fluid cannot pass through the seat c¹ quick enough to maintain the maximum
pressure upon the pistón.-The pressure upon the head or disk d, of the valve,
which tends to hold it against the seat is thus reduced to such a degree that
pressure in an opposite direction on that portion of the head or disk d which is
exposed beyond the seat c will throw the valve over against the seat c¹, thereby
closing that seat and admitting steam or motive fluid through the seat c and
passage to the cylinder below the piston in order to make the return stroke of
the piston.
It will therefore be seen that the time, at which the valve is thrown over against
the seat c², is fixed by the amount of area of the head or disk d which is exposed
outside the seat c, and by increasing the size of the recesses or notches d✶ the
extent of this area may be so decreased as to cause the valve to remain longer
open, and the piston to complete the greater portion of its movement before the
valve is thrown over against the seat c¹.
When the piston commences its movement in a downward direction it will be
understood that there is a free exhaust through the annular passage or port e,
which is not cut off until such time as the piston reaches and covers this port: and
in order to prevent the accumulation of any pressure in the lower end of the
cylinder after the piston has passed the exhaust port e, and which would cushion
the force of the blow and impair the efficiency of the machine, an auxiliary or
supplemental valve is provided which controls the exhaust after the piston has
passed the port or passage e, and which will now be described with reference to
Figures 2, 4 and 8.
In the casting forming the cylinder is a small valve-chest or chamber e¹ which
is closed by a plug e and wherein is placed a valve e³ having a cylindric stem
which works in the bore or cylinder e-The outer portion of this stem is skeleton
or ribbed so as to allow for ample passage of steam, but the inner portion of said
stem is cylindric and snugly fits the bore or cylinder e-From the inner end of
the bore or small cylinder e' a passage e leads to the supply passage c³, which latter
is continued circumferentially around the cylinder, and the small valve chest e¹ is
in constant communication, by the passage or opening e, with the main supply
passage c², as shown in Figures 4 and 8.
When the valve E is closed upon the seat c, as shown in Figures 1 and 6, motive
fluid is admitted above the piston as before described, and a portion of this motive

page_text: fluid passing through the passage e³ bears against the end of the stem of the
valve e and forces the stem outwards so as to remove the valve from its seat and
thereby allow free communication from the passage c² through the passage e and
chest e¹, past the valves e³ and from the cylindric bore or cylinder et through the
passage or opening e' into the main exhaust e.-Consequently after the piston in
its downward movement has closed the exhaust passage e which extends around
the cylinder, the exhaust may still take place from the lower end of the cylinder
through the passage c³ and through the auxiliary valve e³ as above described.
After the piston has completed its down stroke and when the valve E is moved
to open the seat c, live steam or motive fluid passes through the seat cand
passage and thence through the passage e into the chest et, where it presses
upon the valve e³ and holds the latter tightly against its seat.-It will therefore be
seen that the valve e remains open during the time that the piston is making its
downward or working stroke and is held closed while the piston makes its upward
or return stroke.
The following is a description of the construction and operation of the devices
for rotating the piston and drill which are illustrated in Figures 1, 6 and 7.-The
spiral bar D, herein above referred to, has upon its upper end a head D¹ and this
head is encircled by a ring or sleeve F which fits snugly within the outer end of
the cylinder, and against which the upper cylinder head A bears by the pressure.
of the spring b².
f designates a ring or flange which fits loosely in the cylinder and which receives
through it the spiral bar D.-The inner circumference of the ring or sleeve F is
formed with ratchet shaped teeth f1, as shown in Figures 3 and 7, and the head D'
of the spiral bar carries pawls F1 which engage these teeth f-As here shown the
pawls consist of rectangular blocks of metal which are fitted in slide-ways f' in the
head D' of the spiral bar, and are formed with stems f³ which are pressed upon by
springs to throw the pawls F¹ outwards and into engagement with the ratchet-
shaped teeth f of the sleeve or ring F.
As the piston is traversed up and down in the cylinder, its nut b³, fitting the
spiral bar D, always tends to turn the latter during the downward or working
stroke of the piston, and when it is desirable that it should operate with as little
resistance as possible. The nut b³ acting upon the spiral bar D tends to turn it and
its head D¹ in the direction indicated by the arrows in Figs. 3 and 7.-This it can.
do because the pawls F, when turned in that direction, will play freely over the
ratchet-shaped teeth f¹, and hence the spiral bar, its head and the pawls all turn
with the piston.-When the piston makes its up-stroke, the nut b³ acting on the
spiral bar D tends to turn it in the opposite direction to that indicated by the
arrows in Figures 3 and 7, and now the pawls F¹ engage strongly with the teeth f¹
on the sleeve or ring F and prevent the spiral bar and its head D D' from turning,
and these parts being held stationary the piston and the drill or bit are made to
turn relatively to the spiral bar.
From the above description it will be understood that the sleeve or ring F is held
in place or clamped in the cylinder only by the force of the spring b³ pressing
the head A against it, and consequently if by reason of the drill catching in a
fissure in the rock, or from any other cause, there should be a great resistance to
the turning of the piston, the pressure of the spring 62 will be overcome and the
sleeve F will turn in the cylinder, thereby preventing breakage of parts.-This
important advantage results from having one member of the rotating devices, in
this case the ring or sleeve F, clamped and held by friction within the cylinder so
that it will be held stationary in the ordinary operation of the drill, and in case of
an emergency will turn by the application of a strong force to it.
If desired, the arrangement of the ratchet-teeth f₁ and the pawls F¹ might be
reversed, the pawls being located in and carried by the sleeve F, which is clamped
and held by friction in the cylinder, and the head D¹ of the spiral bar being
provided upon its exterior with the ratchet-shaped teeth f¹, the result of this

page_text: arrangement will be exactly the same as that due to the arrangement of parts
shown in the drawing.
Instead of making the rotating devices in the form of a sleeve having teeth
extending lengthwise of the cylinder and pawls engaging with said teeth there
may be employed rotating devices consisting of two rings which have ratchet
shaped teeth upon their adjacent faces, and one of which is clamped and held by
friction in the cylinder, while the other is locked to the head of the spiral bar and
forms pawls. Such a modification of this invention is shown in Figures 9, 10
and 11 In this example of the invention one of the rings F is clamped and held
by friction against the end of the cylinder by the pressure of the head A³ against
which the spring 62 bears, and the other ring F is locked fast to the head D¹ of the
spiral bar D by means of lugs or ears and notches ƒ ƒ formed respectively on the
ring F and the head of the spiral bar D', as shown in Figure 10.-In this case also
there is a flange f which is seated against a shoulder or rebate in the cylinder, and
an annular spring f' is interposed between the flange or ring f and the flange
or ring F, and serves to press and hold the ring F2 against the ring F.-The
rings F, F are provided upon their adjacent flat faces with ratchet-shaped teeth f1,
as best shown in Figures 10 and 11, and which permit the ring F to turn freely
relatively to the ring F in one direction and lock it against turning in the other
direction. When the piston makes its down or working stroke the nut b³ acting
on the spiral bar D turns the spiral bar, its head D¹ and the ring F which is locked
thereto, the spring f" permitting the ring F to yield in order that its teeth may
play or pass over the teeth of the ring F.
When the piston makes its up-stroke, or return stroke, the nut b³ tends to turn
the spiral bar and ring F in an opposite direction, but this is prevented by reason
of the teeth of the ring F' engaging with the teeth of the ring F, and therefore the
piston is compelled to turn relatively to the spiral bar.-If, however, any unusual
resistance is opposed to the turning of the piston, the force exerted through the
spiral bar by the ring F2 will be sufficient to overcome the clamping pressure by
which the ring F is held in the cylinder, and the ring F will turn with the spiral
bar thus avoiding breakage of any part or parts of the machine.
Having now particularly described and ascertained the nature of the said
Invention, 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. The combination with the cylinder and piston and oppositely arranged valve
seats, of an automatically operating supply valve, having heads or disks which.
alternately close upon said seats and are larger in diameter than the said seats, so
that a portion of the heads or disks is exposed beyond and around the seats, and
having in said heads or disks, notches or recesses which may be varied in size in
order to regulate the operation of the valve, substantially as herein described.
2. The combination with the cylinder and piston and the automatically-operating
su; ply valve, serving to alternately close the valve seats from which passages lead
to the cylinder above and below the piston, of an exhaust passage e between the
end of the cylinder and the supplemental exhaust valve e, which permits the
escape of exhaust through the passage leading to the lower end of the cylinder, and
is closed by the entrance of live motive fluid through said passage, substantially as
herein described.
3. In a rock drill, the combination with a cylinder and piston and a spiral bar
fitting a nut in the piston, of rotating devices consisting of the ratchet and pawls,
one member, either the ratchet or pawls, being clamped and held by friction within
the cylinder, and the other member, either the pawls or ratchet, being carried by
the spiral bar, substantially as herein described.
4. The combination with the cylinder and piston and the spiral bar, of rotating
devices consisting of the sleeve F provided with ratchet teeth f¹ and clamped and
held by friction within the cylinder, and pawls carried by the head of such spiral

page_text: bar and engaging with the ratchet teeth of the sleeve, substantially as herein
described.
5. The tripod or stand composed of the hip pieces A, the divided clamp or
sleeve A³ journalled between the hip pieces, the back leg A pivoted between the
bip pieces at their rear ends, and the front legs A6 pivoted to the front ends of the
hip pieces to swing in planes transverse thereto, substantially as herein described.
6. The combination with the cylinder and the spiral bar D projecting downwards
thereinto, of the piston and piston extension E, B', made hollow to receive the bar
and having holes a leading to its interior for the admission of motive fluid, sub-
stantially as herein described.