Improvements in Valves and Valve Gears for Engines, Compressors, and the like.
Year: 1898

page_text: Date of Application, 14th Oct., 1898-Accepted, 26th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Valves and Valve Gears for Engines, Compressors,
and the like.
I, FREDERICK WILLIAM GORDON, of Philadelphia, Philadelphia County, Penn-
sylvania, United States of America, Engineer, 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 pertains to valves and valve gears for engines, compressors and
the like. The valves are piston valves working in valve cylinders arranged in
the main cylinder-heads, the valve-cylinders opening directly into the main cylin-
der, and the valves, which have no passages through them, close the inner ends
of these valve cylinders and by their movements cover and uncover ports leading
to the main cylinder. The valves are thus brought extremely close to the cylinder
and the arangement secures a minimum of clearance and a minimum of exposure
of condensing surface to the steam within the cylinder. The valves are operated
by rockers whose motion is derived preferably from an eccentric. The valves
are in pairs, the valves of a pair balancing each other and opening by moving
in directions opposite to each other, one withdrawing away from the main cylinder
while the other moves toward and into the main cylinder, following up the main
piston. The steam valves of a steam engine may be operated through the medium
of release gear of the ordinary Corliss type. A steam engine may have a pair
of steam valves and a pair of exhaust valves in each cylinder head.
For compressors the inlet valves comprise a pair of the balanced piston valves
arranged in the head of the compressor cylinder and operated positively. The
discharge valves may be of similar character and positively operated, or the two
valves of the pair of discharge valves may be of dissimilar areas, and closed only
by positive mechanism, the valves automatically opening under the influence of
the pressure in the main cylinder. Or, instead of a pair of the discharge valves,
a single valve may be employed and closed positively by mechanism and opened
under the influence of the pressure. Or, in employing a single discharge valve,
a spring instead of positive mechanism may be employed to close it. In a com-
pressor arranged tandem to its driving engine, the operating motion of the air
valves may be derived from the same valve gear which operates the valves of the
engine.
In the following description the arrangement of valves with reference to a
steam engine will be first described, then following the description of the valves
applied to a compressor. In the drawings;-
Fig. 1 is a general side elevation of the main parts of an engine and compressor
arranged tandem to each other: Fig. 2 is a diagram illustrating the general
valve gear system between the eccentric and the wrist plates; Fig. 3 a vertical
longitudinal section of the steam engine cylinder, the left hand portion being
taken in the plane of line a of Fig. 5 and showing the steam valves at one end of
the main cylinder, while the right hand portion is taken in the plane of line b
and shows the exhaust valves at the other end of the main cylinder; Fig. 4 is a

page_text: side elevation of the steam cylinder; and Fig. 5 an end elevation of the steam
cylinder.
In Figs. 3, 4 and 5,
1 indicates the steam cylinder, 2 its piston, 3 the exhaust chambers in the
cylinder heads and 4 the steam chambers in the cylinder heads, and 5 and 6 the
steam valves. Each cylinder head is provided with its pair of steam valves and
its pair of exhaust valves. The valves 5 and 6 are piston valves working in valve
cylinders in the cylinder head. The valve cylinders open directly into the main
cylinder and have ports communicating with steam chamber 4. The valves
close the inner ends of the valve cylinders and in certain position are flush with
the inner face of the cylinder head, the arrangement being obviously such that
clearance and the exposure of the condensing surface to the steam within the main
cylinder is reduced to a minimum. Steam does not pass through the valves.
Valve 6 opens by moving to the left and uncovering the ports permitting steam
to pass from steam chamber 4 into the main cylinder. Steam constantly fills
the valve cylinder containing valve 5, and valve 5 opens by moving to the right
thus permitting steam to flow from its valve cylinder into the main cylinder.
Valve 6 opens by moving away from the main cylinder, while valve 5 opens by
moving toward and into the main cylinder, following up the main piston. Valves 5
and 6 are connected to and operated by rocker 7. The two valves being of equal
area balance each other in pressure, and they are balanced in current.
10 is a
wrist plate operated by rod 12 from an eccentric set, preferably, seventy-seven and
one-half degrees in advance of the crank, or the equivalent of such angle if rod 12
be connected above the axis of wrist-plate 10 instead of below it as illustrated.
8, indicates driving and releasing arms of ordinary Corliss type arranged to give
valves 5 and 6 their opening motion being driven through the medium of links 11,
9 indicating the rod through which the dash-pot closes the valves after being
released, and 13 indicating the usual cam of Corliss type by means of which the
governor determines the time of release.
14 and 15 indicate the exhaust valves, which are similar to the steam valves.
They are operated positively, both in opening and closing, by arms 16 and 17
actuated by wrist plate 18 through the medium of links 19. Wrist plates 10
and 1S are fast on the same rock-shaft both receiving motion from rod 12, wrist
plate 10 being on one side of the main cylinder to give motion to the steam valves
at each end of the main cylinder, while wrist plate 18 is on the opposite side of
the main cylinder to give motion to the exhaust valves. The distribution of steari
will or may be the same as derived from the use of Corliss valves and valve gear,
my improved arrangement yielding a preferable mechanical construction, greater
durability, a lessening of clearance, and a lessening of the exposure of metallic
surface to the steam within the main cylinder. The valves should be supplied
with suitable packing rings as will be explained later on in connection with the
similar valves as applied to compressors.
Referring to the compressor, Fig. 6 is a vertical longitudinal section of the com-
pressor cylinder, the left hand portion being taken in the plane of line c of Fig. 8
and showing the inlet valve system and the right hand portion being taken in
the plane of line d of Fig. 8 and showing the discharge valve system, it being
understood that each head of the compressor is provided with inlet and discharge
valves: Fig. 7 a side elevation of the compressor cylinder: Fig. 8 an end eleva-
tion of the compressor cylinder: and Fig. 9 an enlarged section of inlet valve 22,
the purpose of this figure being to illustrate the system of packing which may
properly be employed in all of the valves.
20, indicates the main compressor cylinder, 21 its piston, 22 and 23 the inlet
valves, 24 the rocker connecting these inlet valves, 25 an arm fast on the shaft of
rocker 24, and 26 the wrist plate for actuating all the compressor valves.
Inlet valves 22 and 23 are substantially like the steam and exhaust valves
heretofore described, and their ports communicate with inlet chamber 29 in the
cylinder head. Wrist plate 26 actuates the inlet valves through links 28, and

page_text: wrist plate 26 is actuated by rod 27 receiving motion from the eccentric of the
engine, the illustrated construction showing this rod as being coupled to the wrist
plate 10 of the steam engine. The opening and closing motion thus given to the
inlet valves is such that the valves are opened properly in the suction stroke
of the main piston by the time the fluid in the clearance space has expanded
down to suction pressure, the valves remaining open during the suction stroke
and closing properly at the end of the stroke and remaining closed during the.
compressive stroke.
30, indicates the discharge cylinder in the cylinder head, 31 the discharge valve,
32 the tappet rocker for closing the discharge valve, and 33 the links through
which wrist plate 26 actuates rockers 32.
Discharge valve 31 is provided with a cushioning piston to over-run cushioning
ports and serve in softening the closing and opening motion of the discharge valve.
This cushioning piston is preferably formed upon discharge valve 31 as in the
illustration.
In Fig. 6 the main piston 21 is beginning its compressing stroke, while dis-
charge valve 31 is at full lap and tappet 32 is moving away from the valve. The
discharge valve is held in its full lap position by the pressure in discharge
chamber 30. As piston 21 moves to the right, making its compressive stroke,
the pressure in front of it increases and finally reaches that of discharge cham-
ber 30. When the pressure in the cylinder shall exceed that in the discharge
chamber sufficiently to overcome the mechanical friction of discharge valve 31
then the valve will suddenly open and the compressed fluid in the main cylinder.
will be forced into the discharge chamber. As valve 31 makes its opening motion
it is cushioned by the action of its enlarged portion over-running the outer
cushion-ports.
Promptly at the completion of the compressive stroke of the main piston, the
At this
tappet 32 pushes valve 31 to such position that the port will be closed.
time the valve will be in equilibrium of pressure and consequently the tappet,
will require to overcome only the mechanical friction of the valve. As the main
piston moves away from the valve, on its suction stroke, the pressure in the clear-
ance space of the cylinder expands and when the pressure in the cylinder has
fallen sufficiently below that in discharge chamber 30 to overcome the mechanical
friction of valve 31, the preponderating pressure in the discharge chamber will
quickly move valve 31 to full lap position, the motion of the valve being cushioned
by its enlarged portion over-running the left hand cushion-ports. The valve
remains in position of full lap until the main piston shall have started back on
its compressive stroke and compress the fluid in front of it to a degree in excess
of that in the discharge chamber, whereupon the discharge valve will fly open"
as before.
The motion of the compressor valves as derived from an eccentric is improved
by permitting a proper degree of lost motion between the eccentric and the wrist
plate 26. It is to be observed in Figs. 6 and 7 that rod 27 operates the main
wrist plate 26 through the medium of a slotted eye thus permitting plate 26 to
have a certain interval of rest during the stroke of rod 27 as produced by the
eccentric. Substantially the same result may be accomplished by connecting
rod 27 positively to the wrist plate 26 and introducing the lost motion in links 33.
The valve pistons, in order to insure their continued tightness, should be pro-
vided with packing rings. The system of packing rings illustrated in Fig. 9
may be applied to all of the valves. Ports which are to be uncovered by the valves
are provided with bridges 34. The valve piston is grooved and in this groove
is seated a packing ring 35, cut open so that it may expand, and dowelled to the
valve piston so that the cut will traverse one of the bridges 34. In the corner of
ring 35 is fitted a ring 36, also cut open, and arranged to have its cut traverse
another one of the bridges 34, the cuts in the two rings preferably traversing
two of the lower ones of the bridges.
Ring 36 is to be placed toward the minor pressure to which the valve is subjected,

page_text: the major pressure being thus at liberty to act against the major face of ring 35
and work inwardly through the cut in the ring and engage the inner surface of
the ring and expand both rings outwardly. The inlet valves 22 and 23 should
have similar packing at their outer ends in case the compressor takes fluid from
a source of pressure higher than that of the atmosphere. For instance, in Fig. 6,
if the compressor takes fluid from the atmosphere then the pressure in chamber 29
will correspond with that of the atmosphere and no packing will be needed at
the outer portion of the valves. But if the compressor takes fluid at a higher
pressure than that of the atmosphere, as in compound compressors, then the outer
portion of the inlet valves should have packing, and in such case, referring to
Fig. 9, packing rings of the kind described may be provided at point 37, ring 36
being disposed outwardly toward the lesser pressure.
In Fig. 10 I illustrate a pair of compressor discharge valves coupled together
similar to the inlet valves previously described, the valves in the present case,
however, having differential areas to bring about the automatic opening of them.
38 and 39 indicate the two discharge valves, 40 their connecting rocker, 41 a tappet
arm for actuating them, and 42 a rod for actuating the tappet arm in valve-
closing direction at proper time and from any suitable source of motion about
the machine. It is to be observed that valve 38 has the superior area.
The tappet
arm having put the valves to position of complete closure at the beginning of the
suction stroke, the lowering of the pressure behind the retreating piston, by
expansion of the fluid in the clearance space, causes the pressure in discharge
chamber 30, acting on valve 38, to move the valves to position of full lap, the
movement being cushioned at the cushioning ports of the lower valve. The main
piston having completed its suction stroke and started upon its compressive stroke
toward the discharge valves under consideration the fluid in advance of the main
piston will by compression reach a pressure in excess of that in discharge cham-
ber 30, whereupon this excessive pressure, acting on valve 38, will quickly move
the valves to open position, the movement being cushioned at the cushioning
ports of the upper valve. This quick opening movement of the valves will take
place when the excessive pressure in the main cylinder shall be sufficient to over-
come the mechanical resistance of the valves. The difference in diameters of the two
valve pistons will be arranged with reference to the working pressures and the friction
of the valves, and, if desired, the relative areas may be such that the valves will
open somewhat before the pressure in the main cylinder reaches that of the dis-
charge chamber. The size of the valve stems may be varied to effect minor
differences in effective area of the two valve pistons.
In Fig. 11 is illustrated a discharge valve whose closing movement is effected
by a spring of sufficient power to overcome the mechanical friction of the valve,
the opening motion being effected by the pressure.
When the fluid being com-
pressed in the main cylinder reaches a pressure sufficiently in excess of that in
discharge chamber 30 then the valve will be forced open and held open till the
completion of the compressive stroke. As the piston starts to return on its suction
stroke, the expansion of the fluid in the clearance space of the cylinder will lower
the cylinder pressure and the spring will push the valve to position of full lap.
The sudden movement of the valve in each direction is cushioned by the action
of the outer enlarged portion co-operating with the cushion ports.
Having now particularly ascertained the nature of my said invention, and in what
manner the same to be performed, I declare that what I claim is:-
1. In valves for engines, compressors and the like, the combination, substan-
tially as set forth, of a main cylinder-head having a valve-cylinder open at the
inner face of the cylinder-head and provided with ports near such face, and a closed
valve-piston closing the inner end of the valve-cylinder and co-operating with
said ports.

page_text: 2. In valves for engines, compressors and the like, the combination, substan-
tially as set forth, of a main cylinder-head having a valve-cylinder open at the
inner face of the cylinder-head and provided with ports near such face and a
closed valve-piston closing the inner end of the valve-cylinder and co-operating
with said ports, in conjunction with devices for moving the valve-piston in closing
direction and permitting it to be moved in opening direction by the action of the
pressure within the main cylinder.
3. In valves for engines, compressors and the like, the combination, substan-
tially as set forth, of a main cylinder-head having a valve-cylinder open at the
inner face of the cylinder-head and provided with ports near such face, and a
closed valve-piston closing the inner end of the valve-cylinder and co-operating
with said ports, the same being duplicated and having the two valve-pistons con-
nected by a double rocking arm arranged to move the two valve pistons simul-
taneously in opposite directions and to give them their opening and closing
motions.
4. In valves for engines, compressors and the like, the combination, substan-
tially as set forth, of a main cylinder-head having a valve-cylinder open at the
inner face of the cylinder-head and provided with ports near such face, and a
closed valve-piston closing the inner end of the valve-cylinder and co-operating
with said ports, the same being duplicated and the two valve-pistons being con-
nected to a double rocking arm provided with mechanism for moving the two
valve-pistons simultaneously in closing direction only, the two valve-pistons of
the system having dissimilar effective areas.
5. In steam valves for engines, the combination, substantially as set forth, of
a main cylinder-head having a pair of valve-cylinders open at the inner face
of the cylinder-head and provided with ports, closed valve-pistons closing the
inner ends of said valve-cylinders and co-operating with said ports, a rocking
arm connected with both said valve-pistons and arranged to move them simul-
taneously in opposite directions, an actuating rocker arranged to move the valves
in opening direction and then be released from them, and a dash-pot rod connected
with the valves to effect their sudden closure.
6. A compressor and engine arranged tandem to each other each being provided
with suitable valves, wrist-plates for actuating the valves, an eccentric for actuat-
ing the wrist-plates, and a slotted eye or equivalent lost motion device introduced
between the eccentric and the discharge valves of the compressor.
Dated this 14th day of October 1898.
ALLISON BROS.,
Agents for the Applicant.