Improvements in and relating to the Valves and Valve-gear of Steam Engines.
Year: 1885

page_text: Improvements in and relating to the Valves and Valve-gear of
Steam Engines.
I, JEROME WHEELOCK, of Worcester, Massachusetts, United States of America,
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
AND RELATING TO THE VALVES AND VALVE GEAR OF STEAM ENGINES," and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to the valves and valve gear of steam-engines, and
comprises improvements in the apparatus described in the specification of Letters
Patent dated July 25, 1878 No 2965.
An important feature of my said invention is the employment, at each end of
the cylinder, of a semi-rotary or oscillating steam-valve in combination with a
sliding exhaust-valve, which valves operate in conjunction with one cylinder-port,
and both pairs of which valves are arranged to be actuated by one excentric
through the medium of suitable valve-gear.
In
Another important feature of my said invention is the construction and arrange-
ment of the valve-gear in such a manner that each exhaust-valve will rest, or
remain stationary, during a portion of the movement of the excentric rod, and the
extent of movement of the said valve will thus be reduced to a minimum.
some cases, I use a gridiron slide-valve and thus provide for an extensive area of
exhaust-port, which can be thoroughly controlled by the valve, notwithstanding its
limited range of movement.
My improved engine is not only as serviceable for ordinary purposes as those
heretofore used, but, in cases where high speed is required, it will work much more
effectively and with as great economy as, or greater economy than, other types of
high speed engines heretofore employed.
In some instances, I combine a semi-rotating or oscillating steam-valve and any
exhaust-valve possessing the general characteristics of a gridiron-valve, and which
is, or may be, so operated from a rock-shaft as to enable the said valve to,rest, or
remain stationary, during a portion of the movement of the said shaft. I prefer to
use a rock-shaft and a gridiron slide-valve connected therewith by means of a
link and so arranged that, although the movement of the said shaft is regular, the
speed of movement of the valve will vary in each stroke, and the valve will be at
rest during a portion of the rocking movement of the shaft.
>

page_text: I will now proceed to describe my improvements, which are illustrated, by way
of example, in the accompanying drawings, in which:
Figure 1 illustrates, partly in side elevation and partly in longitudinal vertical
central section, a steam-engine cylinder embodying some of my present improve-
ments.
Figure 2 is a transverse section of the same on the line x, x, Figure 1.
Figure 3 is a vertical longitudinal central section, drawn to an enlarged scale,
showing the valves and other parts shown in Figure 1.
Figure 4 is an enlarged view of the lower left hand portion of Figure 2.
Figure 5 illustrates the manner of applying sliding exhaust-valves, according to
my present invention, in place of the semi-rotating valves employed in some
engines heretofore constructed.
The remaining figures of the drawings are hereinafter described.
In Figures 1 to 4, A indicates the engine-cylinder, which has, at each end of its
lower side, a port a which serves for both the induction and eduction of steam.
These ports are very near the ends of the cylinder, and the cylinder-heads A¹ are
recessed internally at their lower sides, as at a¹, to afford inclined or curved upper
walls to the said ports. The semi-rotating steam-valve B and its cylindrical
chamber B¹, the steam-chest B' and the throttle-valve and its hand-wheel C are
substantially such as are in practical use, and they may be varied if deemed
necessary.
D is a gridiron-valve having bars and webs d and openings d. The said valve
constitutes the chief novel element in the combination of parts shown in Figures 1
to 4. D¹ is the valve-seat which has numerous openings 6 and suitable bars
and webs b¹ corresponding with those of the valve. The valve-seat D¹ is most
advantageously made by casting it in one piece having sides and ends, so that it
has the form of a rectangular hollow structure with flanges 6 at its outer end,
whereby, when it is inserted into an opening provided for it in the cylinder
casting, it can be secured in position by means of the bolts or screws which secure
the exhaust pipe elbow c to the cylinder. This exhaust pipe elbow is substantially
rectangular in transverse section at its upper end and circular in transverse section
at its lower end. The openings b in the valve-seat afford an aggregate area of
exhaust-port of such proportions as to be more than ample for exhausting steam from
the cylinder, while the steam-valves are operating independently of the cut-off.
For operating the valve D, I employ a rock-shaft E which is loosely coupled to
the said valve as hereinafter described. The said rock-shaft fits, at one end, into
a bush or bearing e which is enclosed within a tight cap el bolted to the cylinder-
casting. At its other end, the said shaft occupies a similar bush or bearing fin
the double bonnet F, within which one end of the spindle of the semi-rotating
steam-valve B is similarly mounted. Within the valve-chamber, the rock-shaft is
provided with two disc-cranks g, which serve as arms, and each of which is
connected by a link k with the valve D; the said valve is thus coupled to the
rock-shaft. The disc g next the outer or protruding end of the rock-shaft,
moreover, ensures, or assists in ensuring, a steam-tight joint at the inner end of the
bearing or bush f; therefore I prefer to employ the said discs, although simple arms
may be employed without departing from the nature of my invention.
Each link h has a wrist-pin h¹ at each end thereof; these pins project in
opposite directions, so that one of the said pins occupies a hole or bearing therefor
in the disc-crank or arm g and the other occupies a similar hole or bearing in a
lug on the valve D.
It will be seen that half a turn of the rock-shaft will cause a sliding movement
of the valve D upon its seat, and the said rock-shaft has a similar rocking move-
ment to that of the spindles of semi-rotating exhaust valves heretofore employed,
the said rock-shaft being coupled to the steam-valve by the cut-off gear
and vibrated by the excentric rod G, which is coupled to the rock-shaft arm i
It will be seen, moreover, that the disc or arm g and link h form a knuckle-joint or
toggle-joint between the rock-shaft and the valve; therefore, after the valve has
E

page_text: completely closed its port, the rock-shaft can be somewhat further rocked without
causing a further movement of the said valve. Furthermore the slide valve D
opens slowly, then moves rapidly, then stops, and then closes rapidly.
By providing, in the manner above described for a rest or cessation of motion of
the exhaust-valve and for variation of speed in its movement, and by employing a
gridiron valve, I am enabled to reduce the extent of movement of the said valve
to a minimum, and to ensure its being completely closed before the steam-valve
uncovers its port, and also to prevent its being opened until after the engine has
passed its "dead centre" during its proper stroke; the engine will, therefore, work
effectively and economically at a high speed.
Figure 5 of the drawings is intended to illustrate how engines which have a
Bemi-rotary or oscillating exhaust-valve can be economically provided with a
sliding exhaust-valve, in accordance with my present invention, in place of the
said semi-rotary valve. In such engines the said semi-rotary exhaust-valve
occupies a taper cylindrical chamber. In this chamber I fit a correspondingly
tapered shell having disc-shaped heads and a flat gridiron valve-seat D' similar
to the seat D¹ herein before described. The gridiron valve D is also substantially
as hereinbefore described. Above the said valve, a rock-shaft E is introduced so
that its ends fit into the bearings or bushes which were previously occupied by the
ends of the valve-spindle; the said shaft is coupled to the valve by arms or discs g
and links has herein before described. The two rock-shaft arms i are coupled
together by the rod K, and the excentric rod G is coupled to the arm i nearest to
the excentric, as heretofore. Although the hook-connection by which the excentric
rod is coupled to the said arm is of novel construction, it has no special relation to
the invention herein described. The arms i, the steam-valve arms 1, the latch
links m, the cam-levers n, and the rod o, which connects both cam-levers with the
governor, are arranged substantially as shown in Figure 1, the difference being
only in such matters of relative arrangement as are incident to the location of the
slide-valve rock-shaft in a plane above that occupied by the steam-valve axis or
spindle, instead of in the same horizontal plane therewith. With the arrangement
illustrated in Figure 5, the parts would be in the same plane, or nearly so.
While I do not limit myself thereto, the inclination of the exhaust-valve-seat, as
shown in Figure 1, is very desirable, because the valve is thereby located as near
as possible to the interior of the cylinder.
I wish it distinctly understood that, although I prefer that the valves should be
constructed and operated as shown and as hereinbefore particularly described, I am
aware that fairly good results can be attained by the use, in combination with a
steam-cylinder, of a sliding exhaust-valve and a semi-rotating steam-valve irre-
spectively of the gridiron feature and also of the particular manner of gearing
them to the crank-shaft of an engine, or of enabling the steam-valves to be
controlled by the governor; and I am also aware that comparatively good results
can be attained if the gridiron feature be adopted with the exhaust-valve, whether
the latter be a sliding valve or a semi-rotating valve, provided it be so coupled to
the excentric rod that it can rest during a portion of the longitudinal movement of
the said rod as above described.
Moreover my invention has for one of its objects to simplify, and economize in,
the construction of such steam-engines as embody in their cylinder-castings valve-
seats integral with the said castings and have valves which are, or may be,
operated by rock-shafts. In accordance with one part of my invention, I provide
taper holes in the cylinder-casting but without any valve-seat therein. The valve
irrespectively of its character is op rated by a rock-shaft and is mounted in a
skeleton plug containing a valve-seat integral therewith, or attached thereto, and
having ends or heads which serve as bonnets to the valve-chamber and afford one
or two bearings for the rock-shaft by which the valve is operated. With this
construction, the plug can be first fitted to its bearing or seat in the taper bole and
then removed therefrom; the valve-seat can then be conveniently worked up or
prepared, the valve mounted theregn; thô rock-shaft placed in its bearings, coupled

page_text: for use.
to the valve, and put in perfect working order on a work bench, and then all these
parts as a whole can be easily inserted into the bearing or seat for the plug ready
In this manner I avoid the employment of valve-seats in the cylinder-
casting, the great trouble in forming and finishing them which is always incident
to working on a heavy mass of metal, and the difficulty of repairing them when
necessary. The internal steam pressure being equal against both ends or heads of
the plug, bolting at each end is not required as in the case of bonnets, it being
obvious that the slightest abutment of the outer surface of the plug at its large end
against a stop will prevent its working outwardly.
I have embodied this portion of my invention with semi-rotating valves and also
with slide-valves, and, although in the latter case, this part of my invention is of
the greatest value, I will illustrate and describe it in connection with both forms
of valve.
Another object of my invention is to provide, in the case of a sliding steam-
valve operated by a liberating cut-off valve-gear comprising a dash-pot and weight,
for a complete closure of the valve before the said weight reaches or enters its
checking space.
"
This combination of sliding steam-valve, rock-shaft, crank, link, dash-pot and
weight is believed to be new and of substantial value, even if the parts are not
arranged as herein described to afford the desired "lost notion" between the crank
and valve, or, in other words, with a crank which does not pass its "dead centre
and stand in line with the link. In the mechanism above described with reference
to Figures 1 to 5 of the drawings, there is a combination embracing a semi-rotating
steam-valve and a sliding exhaust-valve, and the latter is operated by a rock-shaft,
a crank-arm thereon, and one or more links, and, in this combination, there is a
similar "lost motion," between the rock-shaft and slide-valve, to that hereinafter
described but without the results sought and obtained by me in connection with a
steam or induction valve. With the above described arrangement, I obtain a
desirable clearance, but, with the arrangement hereinafter described, this feature
is considerably improved, as I am enabled to locate my exhaust and steam valves
in very close proximity to each other, and to have them co-operate with one
cylinder-port in closer proximity to the end of the cylinder than has heretofore
been practicable with any form of valve. Certain minor improvements will also be
hereinafter described.
Referring to the drawings,
Figure 6 illustrates, partly in section and partly in side elevation, a steam-
engine-cylinder with my improvements, in what I deem their most advantageous
form, applied thereto.
Figure 7 comprises several views illustrating a slide-valve its seat, rock-shaft
and skeleton-plug detached, but all set up and ready for insertion bodily into a
taper hole serving as the bearing or seat for the plug in a cylinder-casting, as
shewn, for example, in Figure 6.
Figure 8 comprises several views illustrating one of the valve-plugs stripped of
all the parts mounted thereon.
Figure 9 is a side elevation, partly in section, drawn to an enlarged scale,
illustrating a slide-valve with its seat, rock-shaft, crank, link, dash-pot, weight,
and outside arm or lever.
Figure 10 comprises several views illustrating a skeleton valve-plug with a
concave valve-seat and semi-rotating valve, and a rock-shaft mounted therein.
Figure 11 is a view of the large ends of the valve-plugs and a strip or plate by
which they are secured in position for use.
The construction of the cylinder A may be varied without affecting my present
invention, it being immaterial what form the steam-chests or exhaust-passages
may have, provided they are susceptible of affording bearings or seats for the
reception of the valve-plugs. A desirable arrangement of steam and exhaust
passages a and a below the cylinder is shewn in Figure:6, both of which passages
are in communication with the interior of the cylinder at each end thereof through

page_text: a port b. Closely adjacent to each of the said ports, the steam-valve B and
exhaust-valve C are located.
The cylinder-casting is transversely bored through the side walls of the steam
and exhaust passages adjacent to their junction with either port, the holes being.
tapered for the reception of the skeleton valve-plugs D and D¹.
,
The steam-valve B and its plug D differ from the exhaust-valve C and its.
plug D¹ only in being smaller and in having a light spring for supporting the
valve B when not held against its seat by the steam pressure, as the said valve is,
in this instance, below its seat d, this unusual position being incidental to this
particular arrangement devised with especial reference to desirable clearance. The
combination of the plug, its seat, and a slide-valve held in place by a spring is of
special importance, because the valve is thus held to its seat irrespectively of the
adjustment of the plug. Both plugs D and D¹ are taper, and each has a valve-
sent d or d and ends or heads e and e¹ with which their respective valve-seats are
either rigidly connected or (preferably) integral; the heads e are as much larger in
diameter than the. heads el as would be due to the tapered configuration requisite
to secure a firm or tight fit of the plugs in their bearings or seats. To afford a seat
for the spring f at the back of the steam valve B, which spring is either bent, as
shewn, or spiral, or of other suitable shape, the plug D has a longitudinal bar f¹
opposite the valve-seat d and parallel therewith. Whether this bar be used or not,
the plugs are of skeleton form, that is to say, each end or head is a perfect plug
and the said ends or heads are rigidly connected by a valve-seat.
The two heads e, e¹ of each plug D, D¹ may be centrally or otherwise bored for
the reception of the two ends of a shaft. When arranged to operate a slide-valve,
only the smaller head e¹ need be bored, as illustrated in Figures 7 and 8, but, in
this case, the said head is provided with a long sleeve-bearing so as to properly
support the said shaft, which need only extend inwardly to a point approximating
more or less to the longitudinal centre of the valve.
As shewn in Figures 7, 9 and 10, each valve has a rock-shaft g or g¹ having at
its inner end a crank h or h¹ and this is coupled by a link i or i¹ to its respective
slide-valve. In order to obtain the best results, the said valves should be gridiron-
valves, so that they will afford ample opening with a short range of movement.
By having the rock-shaft-bearings excentrically located in the heads e, any desired
space can be afforded between the rock-shaft and the back of the valve, and any
desired length of crank and link thus provided for. The exhaust-valve C, its
link, rock-shaft g¹ and crank h¹ are all substantially similar to those above
described, but they are mounted on a skeleton plug so that the valve and rock-shaft
may be properly connected there with and the whole inserted simultaneously into
operative position. One head of the plug being a little larger than the other, will
be proportionately exposed to an excess of internal pressure, but a single metal
strip or plate k secured by suitable. bolts or screws, or otherwise, will be sufficient
to retain each pair of plugs in place, if arranged between the plugs and overlapping
a portion of each of the larger ends e thereof, as clearly indicated in Figure 11.
I
The sliding exhaust-valve thus coupled by a link, crank, and rock-shaft to an
excentric rod, has special advantages by reason of the dwell afforded while the
crank of the rock-shaft is passing its "dead centre," irrespectively of the character
of the steam-valve with which it co-operates. The novel combination of the
rock-shaft, its crank and link with the sliding steam-valve as hereinafter described,
enables me to obtain results which cannot be obtained in similar combinations
which include the exhaust-valve, because the steam-valve is closed by a weight
which is checked or cushioned in its fall by a dash-pot or its equivalent. With
the slide-valve, link, and rock-shaft-crank, the induction or steam valve may be
completely and quickly closed by the weight just before the rock-shaft-crank
reaches its "dead centre" and then, as the weight enters its checking space, the
crank can freely pass its "dead centre" without moving the valve. This I deem
an important feature in view of the well known fact that cut-off valves generally
are not properly closed by their weights when the said valves have been only

page_text: slightly opened, because the weights on entering their checking space have not yet
completed their duty in closing the said valves, and, as the weights have been only
slightly lifted, they cannot have sufficient momentum to enable them to properly
control their valves. As sbewn in Figure 6, each rock-shaft g or gl has, at its
outer end, the bell-crank-lever 1, to one arm of which the dash-pot-weight m is
attached, but it will be seen that the character and construction of the dash-pot
and weight and of the governing and liberating or tripping mechanism which may
be employed therewith, will not vary this capacity of the weight to fully close the
valve before it fairly reaches its checking space, so that it may then continue its
movement throughout its cushioned fall to a complete rest without causing further
movement of the valve.
It will, moreover, be obvious that this portion of my invention is in no manner
dependent upon the mounting of the said valve and its rock-shaft in a skeleton
plug, as above described, nor upon any special location of the said valve either
with reference to the cylinder or to the exhaust-valve co-operating therewith.
The two exhaust-valves are coupled by arms n to the excentric rod o and each of
the said arms is coupled to the lever of the adjacent steam-valve by a latch-link p,
which is arranged to be tripped, in a variable manner, by the cam-lever q connected
with the governor rod r.
In order to further illustrate the economic advantages of my novel valve-plug
containing a valve-seat and valve and having heads which afford bearings for a
rock-shaft by which the valve is operated, I will refer to Figure 10, wherein,
instead of a slide-valve, a semi-rotating valve E is shown with a concave valve-
seat. In this case, the valve is keyed to the rock-shaft g, which has bearings in
both of the heads of the plug. The ease and economy with which any valve
capable of being operated by a rock-shaft can be mounted in a plug of this kind
and applied to, or removed from, the hole formed for its reception in an engine-
cylinder will be apparent. It will also be obvious that this construction affords
the widest possible range of convenient adjustment. The plug can be rotatively
adjusted to any desired position with relation to the steam and exhaust passages,
and the rock-shaft can also be rotatively adjusted in its bearings and with
relation to its external connections for obtaining any desired movement of the
valve.
The small cost of a pair of extra valve-plugs, with or without the valve and
rock-shaft, will always warrant keeping a spare set at hand to enable a change to
be promptly made in case of need. The necessity for stopping the machinery
driven by an engine (to permit of repairs to the valve) can thus be obviated.
I desire to specify that the principal feature of my invention being the combina-
tion and construction of the distributing valves and mechanism, these may be
combined with any known types of steam-cylinder or steam engine, without
departing from the nature of my said invention.
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
In a steam-engine:
First. The employment, at each end of the cylinder, of a sliding exhaust-valve
of the gridiron or other type, arranged in combination with a semi-rotating or
oscillating steam-valve, for the purpose specified.
Second. The means for operating the semi-rotating. or oscillating steam-valve
and the sliding exhaust-valve, comprising a rock-shaft coupled to the said exhaust-
valve by disc-cranks or arms and so connected with the steam-valve and its
excentric rod that both valves will be actuated by the said excentric rod, and the
exhaust-valve will remain in its closed position during a portion of the longitudinal
movement of the said rod, substantially as; and for the purpose, set forth.
Third. The employment of a taper skeleton plug containing a valve-seat and a
gliding valve (with or without a spring) and having heads which afford bearings

page_text: for a rock-shaft whereby the said valve is operated, all substantially as above
described, and for the purposes specified.
Fourth. The combination, of a sliding steam-valve, a rock-shaft provided with a
crank, a link coupling the said crank to the valve, an arm on the said rock-shaft,
and a dash-pot connected with a weight coupled to the said arm, substantially as,
and for the purpose, set forth.
Fifth. The combination, substantially as herein before described, of a sliding
exhaust-valve and a sliding steam-valve co-operating with one cylinder-port, a
rock-shaft for each valve coupled thereto by a crank and link, an excentric rod
and connections whereby both valves are actuated by the said excentric rod, as,
and for the purposes, specified.
HASELTINE LAKE & Co.,
For the Applicant.