IMPROVEMENTS IN ROCK DRILLING APPARATUS
Year: 1880

page_text: LETTERS PATENT to Henry Richmann and Uriah Kline Arnold, of the City
and County of San Francisco and State of California, United States of
America, Gentlemen, for an Invention of "IMPROVEMENTS IN ROCK DRILLING
APPARATUS."
COMPLETE SPECIFICATION filed by the said Henry Richmann and Uriah
Kline Arnold at the Office of the Commissioners of Patents on the 23rd July
1880.
HENRY RICHMANN and URIAH KLINE ARNOLD, of the City and County of San
Francisco and State of California, United States of America, Gentlemen. "IMPROVE-
MENTS IN ROCK DRILLING APPARATUS."
Our Invention relates to certain improvements in that class of direct acting
engines intended to actuate by air or steam a drill or tool for boring rock, the drill
being actuated directly from a piston moving within a cylinder, which cylinder is
in turn guided in a case or carriage suitably connected with a column or tripod for
holding it in any desired position.
Our Invention consists in a novel method of connecting the case or carriage
carrying the cylinder to the column, and in an improved clamp for holding it in
position on said column, and also in an improved means of protecting the feed
screw of the cylinder from the effects of the jar or wear.
.
It further consists in a peculiar means of arrangement of the extension column
or leg, whereby the screw of said leg is protected and the extension is firmly clamped
to the column at any desired point, to regulate the length of column, and in a
peculiar means of attaching the drill tool to the head or piston.
It also consists in a peculiar arrangement of the valve and ports of the drill
operating piston and its actuating valve, by which both drill and piston are
cushioned and a high speed can be attained, and by which the operating mechanism
is simplified; and further, it consists in an improved means for rotating the drill,

page_text: and in certain decans of Construction
accompanying Drawings, in which
WHICH
Fig. 1 is a longitudinal section of the case or carriage, with the the drilling
apparatus attached.
Fig. 2 is a transverse section of the same.
Fig. 3 is a longitudinal section of the drill column.
Fig. 4 is a transverse section of the same.
Fig. 5 is a longitudinal section through the cylinder and air chest.
Fig. 6 is a longitudinal section through the air chest, showing the passages r¹
and 7.
Figs. 7 and 8 are transverse sections of the cylinder and air chest.
Fig. 9 is a longitudinal section of the exhaust passage o.
Fig. 10 shows the ring W with its lug.
Fig. 11 shows the face of the ratchet.
Fig. 12 shows the face of the drill clamp.
Fig. 13 is an outside view of the mechanism.
Fig. 14 is an enlarged section of one end of the air chest.
Fig. 15 shows the under face of the air chest, with its ports and passages.
Fig. 16 shows the upper face of the cylinder, with its ports and passages.
Fig. 17 shows the face of the valve o.
Figs. 18 and 19 are enlarged sections of the air chest.
Fig. 20 is a section of a portion of the screw box in the case or carriage.
Letter A represents the semi-cylindrical case or carriage in which the cylinder
and the operating machanism of the drill are supported, this case or carriage having
formed upon its side a peculiarly shaped hollowed, bevel-edged trunnion B, by
means of which it is attached to the column or tripod, as hereinafter described. The
case or carriage is made of such a shape that the cylinder may slide back and forth
in it, but can only be removed at the ends.
On one side of the case or carriage is formed the feed-screw chamber or cover A¹,
this cover projecting up beyond the upper end of the case, as shown, and enclosing
or covering the feed screw C, at the upper end of which is the feed screw crank C¹.
On the side of the cylinder D is the carrier h¹ through which the screw C passes,
so that by turning the said screw the cylinder, with its drill, is moved back and
forth as desired.
In the ordinary method of fitting feed screws to drills the screw is liable to
become loose by the continued back and forth motion of the drill, owing principally
to the defective means of securing the screw itself, the bearing of which becomes
worn by the jar. This defect we over come by forming on the lower end of the
screw Ċ two, three, four, or more annular V-shaped flanges or rings c, which fit in
corresponding grooves in a box a. This little box a is made in two parts, and fits
in the lower end of the chamber or screw cover A¹, between a shoulder a¹ and a
key b, a set screw b¹ keeping the two sides of the box together in position. By
having three or four V-shaped flanges on the lower end of the screw plenty of
bearing is given to hold it, and the key keeps the box ahead and prevents it or the
screw from jarring; the screw is not therefore liable to become loose, and the
cylinder and drill are held rigidly to their work.
In order to attach or connect the drill case or carriage to the column E we place
a ring El around the column loosely, upon each side of which are formed bolts e.
Upon these bolts is fixed the clamp F, which is formed in two halves, as shown, each
half having a hole through which one of the bolts e passes. Nuts c¹ are then screwed
on the ends of the bolts to keep the halves of the clamp in place. The socket or
journal F¹ into which the trunnion B of the case or carriage fits forms part of each half
of the clamp; its flange is inwardly beveled, as shown, to correspond with the bevel-
edged trunnion, so that when the said trunnion is placed between the halves of the
socket, and the nuts e¹ are screwed up, the clamp has a firm grip of said trunnion.
The central inner portion of each half of the clamp is grooved or channeled for

page_text: the reception of the ring E¹, so that while the ring will hold the clamp in place
when the nuts e' are screwed up the sides of the clamp will bind on the column,
but not on the ring, so the clamp will remain at any desired position. A slight
loosening of the nuts will allow the trunnion to revolve in the socket, to admit of
adjustment of the drill carriage and drill, and the tightening or loosening of the
clamp itself with relation to the column is regulated by the same nuts. The center
of the trunnion is hollowed, as shown, to allow space sufficient for the ring, and its
face fits close against the ring. By this construction we are enabled to keep the
drill very close to the column and overcome an objectionable feature which is
common to most rock drills, that of the drill standing too far from the column. In
a large drill we are now enabled to bring the drill carriage within one inch of the
column. The vertical and horizontal adjustment of the drill carriage and drill is
made by loosening the nuts e¹ and sliding the clamp, with its ring, up or down, and
moving the drill carriage by its trunnion in the socket. In this way the drill may
be moved or maintained in any position.
The adjustment of the drill column itself as to the decrease or increase of its
length to admit it to a shaft or tunnel and fix it in place is made in a peculiar
manner. The column itself is hollow, so that the extension column or leg G may
move up and down inside of the column. Inside of the column is a threaded
rod G', and the extension column or leg being itself hollow and threaded inside it
is screwed up or down on the rod G₁ by inserting a lever in the holes g at the
lower end of said leg. The lower end of the column E is split as shown, and
encircling this split portion is a spring clamp H controlled by a screw h. The
threaded rod G₁ is secured centrally in the hollow column by means of a key g'
passing through the sides of said column, and a slot in the head of said rod.
To increase the length of the column to fix it in place between the floor and roof
of a drift, for instance, a lever is inserted in the hole g, and the extension column or
leg screwed down on its rod, this being drawn out of the column. When the extension
column is drawn out sufficiently to fix the column, by forcing the pointed leg into
the floor, and the dogs at the upper end into the roof, the screw is turned, and the
spring clamp H tightened around the split end of the main column. This makes
the lower end of the main column bind firmly around the extension or leg, which
is thus prevented from turning, and is fixedly held in place.
Ordinarily a screw and nut is used to tighten up the extension column, and the
leg or extension column is externally threaded to screw up into the column. When,
therefore, this leg is screwed out the threads become exposed to injury. The screw
and nut also are apt to become injured by being knocked about. In our construction
the extension column or leg has its threads in a position where they are never
exposed to get injured, and we can, moreover, have a short column, and still extend
it quite a distance. When the clamp is tightened up the leg is kept from turning
round, and is better than a nut, since it will never jar loosc.
The method by which we secure our drilling tool to the drill head or piston rod
is peculiar, and is such that it is gripped securely, not at one point alone, but for all
of its length inside the drill head. In order to accomplish this the drill head I,
which is attached to or forms part of piston rod, has a tapering hole i formed in
its end, and its outer end has right hand threads upon it, as shown. The drill
clamp J is made in two or more pieces, and is tapered to correspond with
the tapered hole in the drill head. In this instance we have shown it in two
pieces.
A slot j is formed in the tapering portion, into which a small screw j¹ projects,
this screw passing through the drill head and setting in flush. The slot j is
extended or elongated to allow of the clamp being moved inwards or outwards for
a certain distance, but the screw j prevents the clamp coming out altogether. The
outer end of the clamp has left hand threads formed upon it inside the shoulder, as
shown. To cause the clamp to grip the drill we employ a sleeve K2, the inner
portion of which is threaded half right and half left with threads of different
pitch. That portion nearest the drill head is threaded to take the right hand

page_text: threads of the drill head, and that portion nearest the drill is threaded to take the
left hand threads of the clamp, which are of different pitch from the threads of the
drill head end.
To insert the drill in the clamp the clamp proper is slightly screwed out by
turning the sleeve K2, and opens enough to allow the drill but to enter, and is then
screwed back. To cause the clamp to grip the drill tightly the sleeve is screwed in,
thus drawing further into the beveled hole in the drill head the beveled clamp
carrying the drill tool. As this clamp comes in, the beveled sides squeeze the
clamp more tightly, and cause it to grip the drill tool for the whole length of
said clamp, but at no one point more than another.
The screw heads on the sleeve are so formed that the rotation of the drill with
its attendent jar tend to screw it tighter instead of loosening it, and being internally
threaded in two directions it also acts as a jam nut to hold the clamp to the drill
head. The tool is thus held rigidly in place, and has a long bearing, but is readily
removed by loosening the clamp, which cannot jam, owing to the peculiar con-
struction described. To tighten or remove the drill it is necessary to put a pin or
lever in one of the holes of the drill clamp and hold it, and by turning the sleeve
when the clamp is held still the drill can be either removed or tightened according
to the direction in which the sleeve is turned.
A novel feature in our device is the operation of the valve controlling the
admission and emission of steam or air to the piston, and the means by which the
piston itself is operated, and also in the method by which both valve and piston
are cushioned. The cylinder D has attached to it on one side the air-chest D¹, in
which the valve a moves. A valve chamber is formed in this air-chest, in which is
placed a steel bushing d', and the valve d fits inside of this steel bushing, which is
slotted to communicate with the ports, as hereinafter described. The valves or
bushings may be removed or examined at any time by taking out the hollowed
heads or screws fat the ends of the chamber.
The cylinder is not bored the same size all the way through, since we make our
piston of two diameters, to which the cylinder must be accommodated. Usually in
rock drills there is not as much force exerted on the piston on the back stroke as
on the forward stroke, since the presence of the piston rod at the front end reduces
the effective area of the piston at that end; drills sometimes therefore stick or move
slowly in being moved back, a defect which we remedy by making the front end L'
of the piston L larger than the rear. The increased diameter of the front end is
sufficient to account for the loss from the diameter of the rod, and the opposite ends
of the pistons are therefore of the same effective area. We have consequently the
same piston area at both ends, and the piston is given the same power in drawing
back as in going ahead.
Near the center of the piston is an annular groove for establishing connection
between two ports, as hereinafter described, in order to give motion to the air
valve. The air or steam for driving the drill is admitted to the valve through the
neck or opening H', and then fills the valve chamber between the inner heads of
pistons K of the valve. As the valve moves forward the head K passes by the
opening or inlet port M, allowing the air to pass into this port, but as the piston L
and the valve & move in the same direction at the same time this port or inlet M
is closed at its lower end by the piston itself. The air therefore cannot enter the
cylinder through the port, but goes through the longitudinal passage M', and through
the supplemental port m, m³, which is at the extreme end of the cylinder and
opens behind the piston. In passing through this port m, m³, the air goes around the
plate or valve o, which is so arranged as to admit air to the cylinder, but not to
allow it to pass out for the purpose hereinafter described.
The small plates or valves o, o¹, are made in a peculiar shape, being narrower at
the center than at the ends, as shown. They do not set down on the bottom of
the port in which they are placed, but rest on a ridge or shoulder X, which is
formed for it do drop upon. The air or steam may therefore enter the cylinder
pstt this valve when it is setting on the ridge or shoulder by passing by the narrow

page_text: central part of the plate or valve, but it cannot pass out of the cylinder since the
plate or valve o, o', when the exhaust air lifts it, shuts up against the port m or n,
as hereinafter described.
The air then as it crosses from the valve chamber through into the cylinder
through the passage m, m¹, starts the piston ahead, but as soon as it has moved a
short distance the whole force of the air will come in direct through the large port M
without having to pass through M², m, m!.
The air at the other end of the piston which has to be exhausted then passes up
out of the port N and out of the exhaust port Q¹. These exhaust ports Q, Q, one
near each end of the valve chamber, are so situated as to be nearer the ends of said
chamber than the inner pistons K ever reach. The said pistons K, K, are so placed
on the valve d with relation to the ports M, N, which form alternately inlet and
outlet passages, that for the admission of air the piston is partly over the inlet
port, so as to leave a comparatively small opening to admit the compressed air
through the passage M or N, as the case may be, while either of said passages
which is acting as the exhaust is left wide open by the piston K sliding far enough
by the opening to let the air escape freely. The exhaust ports Q. Q¹, at opposite
ends of the valve chamber are always between the two pistons K, K, and their
passages are carried across the valve chest to the common discharge O. These
exhaust ports being between the pistons K, K', the compressed air admitted between
the central pistons K, K, can only enter either of the passages M or N, as the case
may be, while the exbaust air issuing from either of these same ports M, N, is
directed behind the piston K, and between it and the piston K', so it may escape
by said exhaust ports Qor Q The ports M, N, therefore act both as inlet and
outlet ports alternately, the pistons K regulatingt heir functions in this respect, the
same piston also giving a larger opening for discharge of exhaust than for admission
of active air or steam at either end, as the case may be.
The air continues to exhaust out of the passage N, as described, until the end of
the piston passes by said passage N in the cylinder, and closes it when no more of
the exhaust air can escape. What air then remains in the cylinder beyond the
end of the piston in trying to escape through the small port n¹ shuts the plate or
valve o¹ up against the port n, thus closing said port so that the said air cannot
escape. An air cushion is thus formed in said cylinder, which prevents the piston
ever reaching the cylinder head. When the valve d is in the position to admit
air at this end the operation is repeated in the same manner, the air entering
through N, N, n, n¹, the valve o¹ dropping to admit it to the cylinder behind the
piston, and when the end of the piston passes N the air all comes in through that
port in the same manner as hereinbefore described, as occurring at the other end,
the exhaust also taking place at the opposite end in the same manner.
In order that the compressed air admitted to the valve chamber for working the
piston may also operate the valve suitably without the necessity of too many
valves or working parts we employ the following peculiar arrangement of
ports:
Let us suppose the valve to be at that end of the chamber where it is admitting
the air through the port M. to start the piston, the valve and piston being at the
same end at the same time. From the valve chamber in which the valve & moves
and between the inner heads K of said valve lead two ports t, ti, which are cut so
as to communicate with the cylinder in which the advancing piston moves in order
at the proper time, as hereinafter described, to allow some of the compressed air
entering the opening H³ to enter said cylinder near the center as well as at the
ends.
In the cylinder opposite those slots t, t¹, are cut corresponding slots r, r¹,
communicating with passages formed in the air chests, which cross each other and
ead to the extreme ends of the valve chamber, as shown, so as to open outside of
the outer piston K' of the valve d.
As has been before described the piston has an annular groove / formed at a
suitable point, the object of which is to connect these passages t, t¹, 1, 7, in order.

page_text: to actuate the valve in the same direction as the piston. Now as the piston starts
forward impelled by the air entering through M the valve is at the same end as
that from which the piston starts. The passages t, t', are also both filled with
compressed air, which cannot however enter the cylinder on account of the face of
the piston closing said ports t, t, where they enter the cylinder. As soon however
as the annular groove in the piston comes opposite the slots t¹, 71, said passages
are connected, and the compressed air may pass out of the valve chamber through
the passage t¹ into the groove or channel 7, and thence into the passage 7 leading
in behind the valve-piston K. The valve d is then thrown forward so as to admit
air at the other end of the piston, the valve being actuated in the same direction as
the piston. The slots of the passages 7, 71, where they enter the cylinder are
somewhat elongated and are wider than the groove in the piston, so that as this
groove or channel is passing by said slots plenty of time is given for sufficient air
to enter the valve chamber to actuate the valve. In fact, these slots are made
about as wide as the length of travel of the valve.
In the reverse motion the operation is the same, that is, the air comes through t
and the channel connects this with the passage r, throwing the valve in the
direction of the piston travel. The passages 7, 71, are so formed in the air chest to
cross each other, as shown, without communicating with each other in order that
the valve may be moved in the proper direction.
l
It will be seen that in starting the piston from the end where the air enters
through M, as described, the groove in the piston connects the passages t and r
so that the air may enter the valve chamber and keep the valve at the saine end as
the piston. When the groove / reaches the slots t, ¹, then the air entering the
valve chamber throws the valve over to the other end to follow the piston. When
the piston therefore is at the end of the stroke the groove is in the proper position
to connect the slots, which will keep the valve at the same end which ever that
may be. By moving the the valve and piston in the same direction the admission and
exit of air is regulated, and the jar communicated to the parts does not effect it.
The gradual cushioning of the valve is accomplished by the hole p, p¹, through
the spindle of the valve. As soon as the neck of the valve stem begins to enter
the hollow or countersink f¹ in the valve chamber head f the air is compressed in
the hollow head, but some of this compressed air can escape gradually through the
small hole p, p, to the outside of the piston K'. There is some compression also
between the outside of the piston K' and the inside of the head f, but the opening
P. p, admits of enough air passing out to bring the valve up easily. A small disk,
of rubber or leather, is put on the inside of the hollow f¹, so the valve stem if it
strikes will do so without noise or jar.
A hole is made through the cylinder just at the off set in said cylinder, so
that there will be no vacuum and no compression behind the rear portion of the
enlargement L¹ of the piston L. As the piston travels back and forth free ingress
and egress of air is given behind this enlarged portion L' through this hole L',
otherwise the piston would not travel freely.
The method by which we impart a rotary motion to the drill is such that a very
small rotary movement can be made, while at the same time plenty of grip is given
to the ratchet by which it is accomplished. A ratcheted sleeve P having diagonal
slots P¹ is fitted over the drill head or spindle I inside of the cylinder extension K',
and lugs fit into these diagonal slots, as shown, the drill head or spindle itself
being attached to or forming part of the piston rod as hereinbefore described.
The head of the cylinder extension K³ is extended into said cylinder extension,
as shown at S, and on opposite sides of this are the pins or lugs St. Between these
lugs fitting in the head are springs 8 in which rest the ratchet sections V, these
sections encircling the extension S, as shown. The ratchet sections V are not made
in a complete circle, but the pius take up part of the circle, and as the ratchets on
the sleeve with which they engage are evenly cut on a circle, only half of the teeth
will engage at one time when two segments or ratchet sections are used, and only
one third when three are used. A very slight turn may therefore be given to the

page_text: drill, without having to have very small teeth to the ratchets, which are objectionable
in devices of this kind.
The teeth of the ratchets we make in a peculiar form to adapt them to take
upwear. Between each tooth v is a slot v¹ cut deeper than the tooth, as shown.
It is on the beveled faces of the teeth themselves that the wear occurs from
constant friction, but the faces of teeth formed in this manner may wear until
the lower edge of the tooth is worn down to the bottom of the slot, before the
point of the tooth will touch and be worn off. In the working of ratchets when
the teeth disengage the point of the upper tooth will not drop from the point of
the lower tooth in a vertical line on taking a new grip, but will jump slightly. In
doing this in our improved form of tooth, the point of the upper one will catch
on the back of the slot, and be directed against its disengaging tooth without
much slip. In this way all wear is taken up automatically, and the teeth are sure
to engage.
As the piston is moved back by the air or steam the drill head and drill are
rotated by the pins or lugs on said drill head, sliding in the diagonal slots in the
ratcheted sleeve, the sleeve itself being held by the ratchets of one of the sections V
engaging with the sleeve teeth. The drill head, piston rod, and piston, are
therefore turned slightly, so that at the forward stroke the cutting edge of the
tool in the drill head is presented in a new position in the drill hole. The springs
under the sections keep them engaged at all times with the teeth of the ratcheted
sleeves.
A good firm grip or engagement of the ratchet teeth is ensured by this
arrangement, and when the turn of the drill and head is only slight, there is
no danger of the teeth missing, since with two sections a turn of only half
the width of a tooth will admit of an engagement with one or another of the
sections.
Another difficulty experienced in rotating rock drills is that the drill head or
spindle will sometimes go back and forth, and be turned just as much as the
diagonal slot will admit, but will not turn clear around gradually. This is due to
the fact that the piston rod or clamp is loose in its packing and slides back and
forth too readily. In tightening them too much to overcome this, power is lost in
the increased effort to reciprocate and revolve the drill. This we obviate by
placing on the drill head or spindle a grooved ring W, through which the spindle
reciprocates freely. A channel w is cut longitudinally in the drill head or spindle,
and a key or lug W' on the ring W fits in this. A set screw W projects through
from the cylinder extension into the groove in the ring W, by which the friction
on this ring is regulated. We can therefore, while permitting a free reciprocating
motion to the drill, give friction enough to the drill head or spindle to cause the
drill to turn properly. The face of the ring may be made flat or grooved as desired,
the set screw fitting against it, and giving any desired friction. The friction ring
is preferable to a ratchet in the same position.
Having thus described our Invention, what we claim as new and desire to secure
by Letters Patent is,―
1st. In combination with the column E, the ring E'
column, and provided with the pin or lugs e and nuts e¹,
is connected to the column, and its position adjusted
described.
fitting loosely in said
whereby the clamp F
substantially as herein
2nd. The grooved clamp F formed in two parts, as shown, and provided with the
beveled socket F, said clamp being connected to the column by means of the ring E,
pins e, and nuts e' in combination with the cylinder case A with its bevel-edged
trunnion B, whereby the drill carriage is connected to the column, substantially as
herein described.
3rd. In a rock drill, the clamp formed in two parts and encircling a ring sliding
on the column, said clamp being secured to the ring by nuts, with its two parts
adapted to enclose the trunnion of the drill carriage, the same nuts regulating the

page_text: adjustment of the clamp with respect to the column and the carriage with respect to
the clamp, substantially as herein described.
4th. In a rock drill, a feed screw provided with two or more V-shaped flanges c,
as shown, fitting in corresponding grooves, whereby more than one bearing to over-
come longitudinal jar is obtained, substantially as herein described.
5th. In combination with the feed screws c provided with two or more V-shaped
flanges c, we claim the grooved box a fitting in the feed screw chamber A¹ against
the shoulder a¹, said box being provided with a key b, whereby wear is taken up
and jar of the screw is prevented, substantially as herein described:
6th. In combination with the case or carriage A adapted to carry the cylinder D
and drill operating mechanism, we claim the supplemental chamber or feed screw
cover A adapted to carry the screw c with its flange c, and the box a with its regu-
lating key b and set screw b', whereby said screw and its parts are protected from
accident, substantially as herein described.
7th. In a column for supporting a drill carriage, we claim the internally placed
threaded rod adapted to receive an extension leg which screws over said rod and
inside the column, whereby the screw rod is protected from injury, substantially as
herein described.
Sth. In combination with the drill column E, split at its lower end as shewn, and
the internally threaded extension leg G fitted to screw on to the centrally placed
rod.G', we claim the spring clamp H with its screw h, whereby the extension leg
and column are immovably joined and the leg prevented from turning, substantially
as and for the purpose herein described.
9th. In combination with the hollow drill column E, we claim the centrally placed
threaded rod G', secured inside said column by the key g¹, and the internally
threaded extension column or leg G fitting on said rod inside the column, whereby
the length of the column is adjusted and the threads protected from injury, substan-
tially as and for the purpose herein described.
10th. In a rock drill, the method of attaching the drill tool to the head, con-
sisting in forming a tapering recess in said head and providing a tapering clamp
made in two or more pieces, and interposing between said clamp and head an
oppositely threaded sleeve, which connects the head and clamp, whereby a long
grip or bearing is obtained on the drill tool, substantially as herein described.
11th. In a rock drill, a clamp for holding the drill tool made in two or more
portions, and with a tapering end to fit into a corresponding socket in the drill
head, and adapted to be held in position by an internally threaded sleeve, which
shall draw said tapering clamp into the tapering drill head hole without a rotary
motion of the clamp itself, whereby the tool will be gripped tight but may readily
be released, substantially as herein described.
12th. In combination with the externally threaded drill head I, provided with a
tapering recess and the threaded drill clamp J, made in two or more parts tapered
as shown, and having a slot j for receiving the screw j¹, we claim the sleeve K2,
with its internal threads formed half right and half left, or of different pitch, said
sleeve being interposed between the clamp and head, whereby the clamp is connected
to the head without liability of jamming, and the sleeve acts as a jam nut as well,
substantially as herein described.
13th. In an engine having a piston and valve adapted to be moved in the same
direction by air, gas, or vapor under pressure, we claim the ports M, N, having the
supplemental ports m, n, m, n, and plates o, o¹, in combination with the main
piston L, L, and the valve d with its heads K, K¹, when combined, and arranged to
operate substantially as herein described.
14th. In combination with the piston L with its channel l, and the valve & with
its pistons K, K³, moving in an independent chamber, we claim the ports t, t', r, r¹,
whereby the valve is made to travel in the same direction as the piston, and operated
to admit or exhaust the air, substantially as herein described.
15th. The valve d with its double heads K, K¹, operating in an independent

page_text: chamber, having the inlet port H', double exhaust ports Q, Q', and inlet and dis-
charge passages M, N, in combination with the piston L, L, said valve having its
heads so arranged as to allow a smaller opening for the admission than the emission
of air or steam from the cylinder, substantially as herein described.
16th. In a rock drill having the drill tool connected direct to the piston rod, we
claim the piston L, provided with the groove l, for automatically connecting the
passages r, t, r, t, whereby the valve is operated in the same direction as the piston,
substantially as herein described.
17th. In combination with the valve d, provided with the opening p, p, the
chamber-head f, having the recess f¹, whereby the valve is cushioned and high
speed may be attained without the valve striking the head of its chamber, substan-
tially as herein described.
18th. The valve d, having the head K¹ with the extension provided with the
hole p', said valve moving in a chest having the chambered head f to receive the
valve extension and to cushion the valve at each end of the stroke, said chamber f¹
also serving to close the passage p, p', so that the air admitted through the passage
,, may act upon the head K¹ to start the valve, substantially as herein
described.
19th. In a rock drill having a piston actuated by air or steam admitted and
exhausted alternately at each end of the cylinder, we claim the valves or plates o, o¹,
placed in passages provided with shoulders X at opposite ends of the cylinders, and
so shaped as to allow the ingress but not the egress of air or steam, whereby
the starting and cushioning of the piston is accomplished, substantially as herein
described.
20th. In a rock drill having a piston L, L', actuated by air or steam admitted
alternately at cach end of the cylinder by means of ports and valves, as shown,
the valve d provided with double heads K, K', and moving in the chamber, having
the open ports Q, Q', situated between said heads, whereby said ports Q, Q, always
remain open for the exit of air, and exhaust valves are dispensed with, substantially
as herein described.
In witness whereof, we, the said Henry Richmann and Uriah Kline Arnold,
have hereunto set our hands and seals, this Fourth day of June, in the
year of our Lord One thousand eight hundred and eighty.
HENRY RICHMANN.
(L.S.)
Witnesses,
FRANK A. BROOKS,
S. H. NOURSE.
URIAH KLINE ARNOLD. (LS)