Improvements in and connected with Valves of Coal Cutting Machines and Direct Acting Engines.
Year: 1899

page_text: Date of Application, 4th Apr., 1899-Accepted, 2nd Sept.,
1899
[Communicated from abroad by HENRY CLARK SERGEANT, of Westfield, County
of Union, State of New Jersey, U.S.A., Engineer.]
Improvements in and connected with Valves of Coal Cutting Machines
and Direct Acting Engines.
I, VICTOR ISIDORE TEENY, of 60, Queen Victoria Street, in the City and
County of London, Consulting Engineer and Chartered Patent Agent, do hereby,
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to improvements in reciprocating direct acting engines
and more particularly to the class of machines in which a pick is attached to
an extension of the piston and used for undercutting coal; although the inven-
tion may be employed wherever applicable. The invention consists in applying
to a coal cutting or other similar machine a controlling valve in advance of the
main valve by which the motor fluid is distributed to operate the machine, and
providing means for operating the controlling valve to reduce the supply of
motor fluid, and thereby modify the action of the piston when its movement
exceeds that which is necessary to do work.
The invention is illustrated as applied to a coal cutting machine but is not
confined thereto, and the motor fluid will be hereinafter referred to as com-
pressed air, or air, although of course steam or other gas under suitable pressure
may be used.
In a coal cutting machine, the tool carried at the end of the piston rod strikes
the material operated upon, being moved, guided, and controlled, by the operator.
During its use, the machine is frequently moved while the piston continues to
reciprocate, so that at times the tool does not strike anything. Under these
conditions there is a tendency to acceleration of speed, or racing, accompanied
by much jar and vibration of the machine as well as danger of breakage. The
piston also makes a longer stroke than when cutting coal. Therefore when the
tool is in the coal the stroke is normal and when out of coal exceeds the normal.
By my invention when the stroke exceeds the normal, the controlling valve is
operated to partially shut off the air supply, thereby reducing the number and
force of the reciprocations of the piston, until the tool again strikes against some-
thing, (is in the coal) when, through reduction of the length of stroke, the
governor valve returns to its normal inactive position and the machine resumes
full speed and power.
In the accompanying drawings, Fig. 1 is a longitudinal sectional elevation of
a coal cutting machine embodying the invention, a portion of the front end
being broken away.
Fig. 2 is a sectional end elevation on the line 2, 2, of Fig. 1, the pistons and
valves being omitted.

page_text: Fig. 4 is an enlarged sectional elevation of the back end of the cylinder and
its head on line 4, 4, of Fig. 5.
Fig. 5 is an enlarged end elevation of the center plate.
Fig. 6 is a vertical sectional elevation of the cylinder and valve chests of the
engine showing another arrangement of the governing valve.
Fig. 7 is a vertical sectional end view on the line 7, 7, Fig. 6.
Similar letters indicate like parts throughout.
In the drawings, Figs. 1 and 7, A is the cylinder of a reciprocating engine.
B is the piston and 6 the piston rod to the outer extremity of which the tool or
pick, not shown, is ordinarily attached. The piston rod and piston are counter-
bored and rifled, forming a barrel C into which is fitted the rifle bar D).
The cylinder A is provided with the usual supply and exhaust passages F G
extending from the main valve chest H, and have an exhaust port E between
them. is the main valve which is reciprocated in the valve chest H to, operate
the slide valve i, which is of the usual form and travels over ports connected
with passages EFG which supply and exhaust the compressed air on the oppo-
site ends of the cylinder of the machine. J is the main supply pipe which
enters an additional chest, the controller valve chest K, from whence it passes
ordinarily through the controlling valve M into the main valve chest H to be
distributed by the main valve I.
The rear end of the cylinder A is closed by two parts, the back head N and
the center plate 0, which is between the back head and the open end of the
cylinder. These parts are shown on an enlarged scale in Figs. 4 and 5.
The rifle bar 1 is rotatably secured at its outer end in the center plate O
through which it projects far enough to carry the pinion P and the jamb nut p.
The back head N is formed with an internal cavity or cliamber Q of sufficient size
to leave space around the mechanism attached to the center plate so that an
equal pressure of air will exist at all points therein.
A number of passages are formed in the center plate O and covered by a
renewable flat ring of metat R the outer surface of which forms the seat for the
rotating annular auxiliary valve S. The inner face of the valve S forms a tight
working joint against the face of the valve seat R and has a central opening for
the pinion P and is also provided with projections 21 engaging the pinion by
which said valve is rotated in accordance with the movement of the rifle bar
in the piston.
His a port extending from the main valve chest supplying compressed air. to
the cavity Q at all times when the machine is in operation. hh are ports
placed symetrically in the valve seat R and communicating respectively with the
opposite ends of the main valve chest H to reciprocate the main valve I. e c¹ are
exhaust ports therefor. The auxiliary valve S is formed with two segmental
grooves ss at its underside and the upper part of the periphery of said valve is
cut away at S¹, as indicated.
The rifle bar is turned by the reciprocations of the piston, and through the
pinion P, imparts rotary movement to the auxiliary valve S, first in one direction
and then in the other. While making the working length of stroke the port h
will be uncovered on one side, while the exhaust grooves laps the exhaust
porte and the supply port h on the opposite side exhausting the end of the main
valve chest opposite to that which the port his supplying, and vice versa, with
the opposite movement of the piston B, rifle bar, its piston and the valve S.
The valve seat or ring R is held stationary against the center plate O, as in
the operation of the machine it is not required to move, but said ring is capable
of adjustment when necessary, being held in position by a crank pin r which
fits between two lugs extending from the ring R. The crank pin ris
attached to crank arm which is secured upon a shank which extends to the
outside of the machine through the back head N.
The controller valve M is located in the valve chest K where it is arranged
to be reciprocated, under certain conditions within a renewable bushing m¹.

page_text: The valve M may assume a variety of forms but as here shown, it is of the
piston type and has its front end open towards the, chest, K. A number of
aligned slits n are formed in the side of the valve M near its open end, said slits
corresponding with similar slits m in the bushing m. These two sets of slits.
open into, a passage k formed in the wall of the valve chest K and communicating.
downward through the opening into the main valve chest H, so that in the
normal position indicated, the supply air passes from the pipe J through the
open end of the valve M, side slits n m and passages into the main valve
chest H. The bushing m¹ has a shoulder n' at its end opening into. the chest k.
The valve M has a partition across its middle portion and is hollow in its rear
part and contains a spring which normally holds said valve in the position
shown, in which the air passes freely therethrough.
From the space containing the spring which is in the rear of the controlling
valve M, although towards the front end of the machine as a whole, extends a
passage M, Figs. 1 and 2, and this passage is provided with a check valve M².
The passage M is continued through the walls of the cylinder and port plate g
and through the center plate to port m² in the back head N. The port m² is
located in the valve seat R in advance of the port h and at a point where it is
not lapped by the exhaust grooves when the piston is working at its normal
stroke. Said port is therefore open or uncovered part of the time, but com-
munication from the cavity or chest Q in the back head, with the space in the
rear of the controller valve M is prevented by the check valve M². When how-
ever, the piston travels further than the ordinary distance as is the case when
the pick is out of coal, then the traverse of the valve S is increased to such an
extent that the exhaust grooves will lap the port m² and also the exhaust port e
and permit the escape of the balancing air pressure which would otherwise exist
behind the controller valve M, whereupon the main air pressure in the chest -K
will immediately force said valve backward in the direction to close the open-..
ings n m compressing the spring j, the valve ultimately coming to rest against
an adjustable stop secured in the end of the valve chest which is set as may
be required to, produce the desired effect, reducing the supply of air to the main
valve and piston. So long as the piston continues to make an abnormally long
stroke, the exhaust grooves will continue to exhaust the port m² with each move-
ment, and the controlling valve will continue to be held against its stop j¹,
thereby diminishing the air passages to the valve chest H and decreasing the
speed of the piston and tool. When the tool again strikes the coal, the piston
and valve resume their normal length of stroke, the port m² will cease to be
exhausted the air pressure in the rear of the valve M will be restored by leakage
of air between the valve M and the renewable bushing, ml, and the spring will
push the valve M forward against the shoulder n' at the front end of the bush-
ing m opening the air ways n m to their full capacity and restoring. the free,
passage of the main air supply to the valve chest H.
"
Fig. 3 shows what I have termed a port plate g, it being a plate of metal
inserted between the valve chest H and upper side of the cylinder A and is used
as a means for continuing the air passages to the desired outlets. The groove h
in the plate g communicates with and is a continuation of the port hin the
valve seat R, groove h¹ a continuation of the port h and the groove M is a
continuation of the passage M¹ extending from the valve chest K in the rear of
the controlling valve M.
As indicated in Figs. 6 and 7 the controller valve T is similar in construction
to the valve M already described, except that as shown it moves in the opposite
direction and that the spring jis dispensed with. Instead of having lateral air
ways or slits, the said valve T is shown as slightly shorter than the valve. M. and,
when in its forward or normal position, which is towards the front end of the
machine, it uncovers the slits m in the bushing m¹ permitting free. passage of
the main air supply to the passage and thence, to the main valve chest H.
With this construction the valve T is normally held in its forward position by:

page_text: the pressure of the main air supply in which position the air passes freely there-
through to the main valve chest from whence it is distributed as stated.
Near the front end of the passage G is located a check valve G¹ which is so
arranged that the main air supply can pass therethrough in the direction to
return the piston towards the other end of the cylinder, but which closes auto-
matically to prevent the cylinder from exhausting from that end. A separate
exhaust port E is provided some little distance away from the front end of the
cylinder and through this the exhaust air escapes as the piston moves forward
on the power stroke. Ordinarily the piston does not move quite to the front end
of the cylinder, and only a slight air cushion is produced by the air confined by
the check valve G. When the pick is out of the coal however, the piston is
driven violently forward until stopped by the air cushion the pressure of which
is greatly increased by such additional forward movement of the piston.
As indicated in Figs. 6 and 7, I provide a small check valve t at the extreme
forward end of the cylinder A¹ and also a suitable passage t' extending from said
check valve to the valve chest K entering the same at 2, in advance of the forward
position of the valve T. When the pick is out of the coal and the piston makes
an additional forward movement by reason of the tool meeting with no resistance,
the air in the front end of the cylinder confined by the check valve G¹ in its
supply passage, becomes so highly compressed as to lift the check valve t, when
it traverses the passage t¹ and forces the valve T back against its adjustable
stop j, as indicated in Fig. 6, thereby closing the openings m to a greater or less
extent and throttling the air supply, reducing the speed of the piston as much
as may be desired, until the normal pressure is restored by the leakage of air
between the valve and the lining m¹.
While the tool meets with the usual resistance of the work and the piston
travels only the normal distance, the air confined in the front end of the
cylinder A will not be compressed sufficiently to raise the check valve, conse-
quently the valve T will be held in its extreme forward position by the supply
air in the chest K in which position the passages from the said chest to the main
valve chest H will be open, permitting the free flow of said air to operate the
machine at full power.
With either construction the operation of the controlling valve is entirely
automatic and its effect in reducing the flow of the main supply air to the main
valve of the engine will continue so long as the tool is away from the work and
the tendency to racing exists, but when the tool strikes the work and the piston
nakes only its ordinary stroke the controlling valves will immediately resume
their inactive positions and the machine will run at normal speed and full power.
The invention is not limited to the particular constructions set forth, and may
be embodied in various forms in accordance with the explanation of its nature
and purposes herein given.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a reciprocating engine, the combination with a cylinder having inlet
and exhaust ports, a main valve controlling the same, and a piston working in
said cylinder, of a normally inactive governing valve for reducing the speed of the
piston, and means for actuating the governing valve when the piston moves
beyond the normal working point and for rendering it inactive when the piston
resumes its normal stroke.
2. In a reciprocating engine, the combination with a cylinder having inlet
and exhaust ports, a main valve controlling the same and a piston working in
said cylinder, of a normally inactive governing valve for diminishing the main
air supply and means operated by the stroke of the piston for partially closing
the governing valve when the piston moves beyond the normal working point
and for opening said governing valve when the piston resumes its normal stroke.

page_text: 3. In a reciprocating engine, the combination with a cylinder having inlet
and exhaust ports, a main valve controlling the same, and a piston working in
said cylinder, of a normally inactive governing valve for diminishing the main air
supply to the main valve and means operated by the stroke of the piston for
operating the governing valve to diminish the main air supply when the piston
moves beyond the normal working point, and for restoring the same when the
piston resumes its normal stroke.
4. In a reciprocating engine, the combination with a cylinder having inlet
and exhaust ports and passages, a main valve controlling the same, and a piston
reciprocated in said cylinder, of a movable, normally inactive governing valve
controlling the main air supply, an adjustable stop for determining the active
position of said governing valve and means for moving said governing valve into
position to diminish said main air supply when the piston moves beyond the
normal working point.
5. In a reciprocating engine, the combination with a cylinder having inlet
and exhaust ports and passages, a main valve controlling the same and a piston
reciprocated in said cylinder, of a movable normally inactive governing valve
for diminishing the main air supply interposed between said main air supply
and the main valve, an adjustable stop for determining the active position of
said governing valve, and means operated by the stroke of the piston for moving
said governing valve into and holding the same in operative position to diminish
said main air supply when the piston moves beyond the normal working point.
A
1
P
1000
Dated this 4th day of April 1800.
For the Applicant,
GEDGE & FEENY,
Chartered Patent Agents, 60, Queen Victoria Street, London, E.C.