Improvements in and connected with Valve Gear for Steam Engines.
Year: 1894

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Valve Gear for Steam Engines.
I, CHARLES EDWIN PRICE, Mechanical Engineer, of the "Firm of Taylor,
Struvé, Eaton, and Price, of Vale of Neath Engineering Works, Neath, and
Briton Ferry Foundry, Briton Ferry, both in the County of Glamorgan South
Wales, General Engineers, and Iron and Brass Founders, do hereby declare the
nature of this invention to be as follows :—
This invention for improvements in, and connected with valve gear for steam
engines, refers to that class of valve gear, wherein the steam inlet valves are
generally arranged on the upper part or parts of the cylinders, while the exhaust
valves are arranged upon the lower parts thereof, although the invention is equally
applicable to valves. however or where located. In such valve gear it has
been
proposed heretofore to operate the inlet valves from a rotary shaft, by means of
the
an eccentric with link or bar connections and contact táppets or trip ratches,
effective action of the latter being controlled and regulated by connections from
the governor.
In some cases the controlling influence of the governor has acted to
remove one of the tappets beyond the reach of the other, or to displace the tappets
before the finish of their co-action; in other cases the arm of a lever in connection
with the valve spindle has been acted on by a tappet piecé, operated by links and
levers, from the eccentric, and regulation of the valve motion has been effected by
the action of the governor sliding the fulcrum of the valve lover. Levers have
been pivotted upon the eccentric rods to engage with valve levers, and the said
levers upon the eccentric rods, bave been thrown out of action by one of their arms
being brought into contact with a governor-controlled tappet árin.
-
Now the principal object of my invention is to simplify the construction of valve
gear of this class, and at.. the same time to retain the advantages and efficient
automatic action, which some few of the more complex mechanisms hereinbefore
referred to, possess. With this object in view I provide the end of the eccentric
rod with a trip piece to act on the tail of a valve controlling lever, or valve rod,
and to cause the trip action (when automatically operative) I connect the connecting
rod itself with the governor, by means of a rock shaft, links, levers, or the like,
whereby the action of the said governor, will rock the connecting rod, and bring
the trip catch into or out of operation, and control its time of action as required,
and according to circumstances.
;
By way of an example of construction, the revolving cam shaft. is, located
parallel with the cylinder, and carries the eccentrics, (one for each inlet valve).
The valve gear being symmetrical for each valve, I will describe one such. Upon
the end of the eccentric rod, which may conveniently be turned down or reduced,
I place a catch-block of larger diameter than the rod, of polygonal shape, having
plain upper and lower surfaces and drilled centrally, or formed with a suitable
aperture to fit the eccentric rod; this catch-block may be held in place by an
ornamental or other nut. The face of this catch-block is adapted to engage with
a catch plate, on the lever for lifting the inlet valve, and the construction of the
catch-block presents advantages, in that it can be turned round and reversed, áš.its
striking parts become worn. To the eccentric rod at a point in its length between
the eccentric shaft and the catch-block, there is pivotted a link made adjustable or
not, the link being itself pivotted to an arm of a rock shaft, to which motion is

page_text: communicated from the governor, or the link may be adjusted by hand or set to
fixed length. Generally the valve is carried down upon its seating by a spring.
By this mechanism the valve is lifted or opened by the contact of the catch block
with the valve lever, and inay be retained open during any required portion of the
stroke, unless the action of the governor or the setting of the link, rocks the
eccentric rod and removes the catch-block out of the sphere of its action.
In valve gear of this class it is common to employ a dash-pot, consisting of a
piston upon the valve stem working in a cylinder provided with an adjustable air
escape passage, generally controlled by a tap, whereby the return of the valve is
cushioned in the required degree. This construction presents disadvantages, in
that great accuracy of fitting is required in the guides and glands, to ensure a true
seating for the valves. Now according to my invention I overcome this difficulty
and moreover improve the efficiency of this part of the mechanism in the following
manner. Upon the valve rod I provide a loose collar, having an upper projecting
flange, the latter being located within the air space of the dash-pot cylinder, the
smaller part of the collar projecting through an aperture. somewhat larger than the
collar in the base of the cylinder. The lower end of the collar is interiorly drilled
out and provided with a gland, whereby the collar is retained to its rod with a
certain amount of friction; the under side of the upper flange of the collar is faced
or lined with leather, rubber, or the like, and has a seating upon the inner side of
the cylinder, acting to close or open the aperture existing between the exterior of
the collar and the said aperture through which it passes. An air escape cock or
regulator, of the usual description, is also provided. By this construction, the rise
of the valve spindle lifts the collar until the flange of the gland comes in contact
with the base of the cylinder, in which grooves are formed for the passage of the
air; the valve spindle then slides in the collar, and upon the descent of the valve
spindle, the projecting upper flange of the collar descends therewith, and closes the
aperture, preventing escape of air, excepting by way of the escape cock. By this
construction I am enabled to dispense with the necessity of accurate alignment of
the aperture in the base of the "dash-pot" cylinder with respect to the valve
Beating, and at the same time retain and improve the efficiency of the action and
cushioning.
Dated this och 1001
COMPLETE SPECIFICATION.
Improvements in and connected with Valve Gear for Steam Engines.
I, CHARLES EDWIN PRICE, Mechanical Engineer, of the Firm of Taylor,
Struvé, Eaton and Price, of Vale of Neath Engineering Works, Neath, and
Briton Ferry Foundry, Briton Ferry, both in the County of Glamorgan, South
Wales, General Engineers and Iron and Brass Founders, 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 for improvements in and connected with valve gear for steam
engines, refers to that class of valve gear wherein the steam inlet valves are
generally arranged on the upper part or parts of the cylinders, while the exhaust
valves are arranged upon the lower parts thereof, although the invention is equally
applicable to valves however or wherever located.
In such valve gear it has been proposed heretofore to operate the inlet valves
from a rotary shaft, by means of an eccentric with link or bar connections and
contact tappets or trip catches, the effective action of the latter being controlled
and regulated by connections from the governor. In some cases the controlling-

page_text: influence of the governor has acted to remove one of the tappets beyond the reach
of the other, or to displace the tappets before the finish of their co-action; in
other cases the arm of a lever in connection with the valve spindle. has been acted
on by a tappet piece, operated by links and levers,, from the eccentric, aud
regulation of the valve motion has been effected by the action of the governor
sliding the fulcrum of the valve lever. Levers have been pivotted upon the
eccentric rods to engage with valve levers, and the said levers upon the eccentric
rods have been thrown out of action by one of their arms. being brought into
contact with a governor-controlled tappet arm.
Now the principal object of my invention is to simplify the construction of valve
gear of this class and at the same time to retain the advantages and efficient
automatic action which some few of the more complex mechanisms hereinbefore
referred to, possess.
With this object in view I provide the end of the eccentric
rod with a trip piece to act on the tail of a valve controlling lever, or valve rod,
and to cause the trip. action (when automatically operative) I connect the
connecting rod itself with the governor by means of a rock shaft, links, levers,
or. the like, whereby the action of the said governor will rock the connecting bar
or link and bring the trip catch into or out of operation, and control its time of
action as required and according to circumstances.
In valve gear of this class it is common to employ a dash pot, consisting of n
piston upon the valve stem working in a cylinder provided with an adjustable air
escape passage, generally controlled by a tap, whereby the, return of the valve' is
cushioned in the required degree. This construction presents disadvantages in
that great accuracy of fitting is required in the guides and glands to ensure a: true
seating for the valves. Now.according to my invention I overcome this difficulty
and moreover improve the efficiency of this part of the mechanism as hereafter
described whereby I am enabled to simplify the manufacture, improve, the action,
and increase the efficiency.
'
:
In order that my invention may be readily understood. I will describe same by
reference to the accompanying drawings.
.
Figure 1 is an end elevation showing by way of example so much of a steam
engine with my improvements applied, as will be necessary to describe same.
Figure 2 as a view in plan of the trip-piece drawn to a somewhat larger scale
than the previous figures.
וי
Figure 3 shows in plan the valve controlling lever..
Figure 4 is a plan view of an adjustable link hereafter mentioned, and Fig. 5 is
a similar view of a modified construction of the said link.
i
Figure 6 is an elevation of so much of a steam engine and governor as will be
necessary to describe my..valve gear in connection therewith. and
Figure 7 is a vertical-section showing my improved construction of.." dash-pot"
drawn to a somewhat larger scale than the previous figures.
Referring more particularly to Figure 1, A is the revolving_cam_or eccentric
shaft which may be located as shown parallel with the cylinder B, and carries the
eccentrics C (one for each inlet valve). The valve gear being symmetrical for
each valve, I will describe one such. Upon the end of the eccentric rod C¹, which
may conveniently be turned down or reduced, I place a catch block D of larger
diameter than the rod, which may conveniently be turned down or reduced, I
place a catch block D of larger diameter than the rod C, such catch-block may
be of square or polygonal shape, having plain upper and lower surfaces and drilled
centrally, or formed with a suitable aperture to fit the eccentric rod C. At
Figure 2 the catch block D.is shown detached in plan, the aperture being slotted.
and the part of the rod C, upon which it has a seating, being similarly. formed
the block may be accurately placed. This catch-block D may be held in place by
an ornamental or other out. The face of this catch-block D, is adapted to engage
with a catch plate E on the valve controlling lever F (shown detached in plan
at Figure 3) for lifting the inlet valve by its valve rod G, and the construction of
the catch block D presents advantages, in that it can be turned round and

page_text: reversed as its striking parts become worn. To the eccentric rod C¹, at a point in
its length between the eccentric shaft A and the catch-block D, there is pivotted.
a link H, the said link H being itself pivotted to an arm of a rock shaft, to
which notion is communicated from the governor as hereafter described; or, as
shown at Figure 1, the link H may be pivotted to a fixed lug or bracket H¹
and is adjustable by screw and nut H' by hand as desired or set to a fixed
Jength. If preferred the adjustable link H may be fitted with right and left hand
threads and milled nuts for adjustment, when for example the engine is running,
say as shown in detached plan at Fig. 5. Generally the valve is carried down
upon its scating by a spring. By this mechanism the valve is lifted or opened by
the contact of the catch block D with the valve lever F, and may be retained open
during any required portion of the stroke unless the setting of the link H rocks
the eccentric rod C' and removes the catch-block D out of the sphere of its action.
Jis a spring to prevent the valve lever F falling.
At Fig. 6 the valve gear is shown in connection with a governor K. Similar
letters of reference indicate like parts to those described and shown with reference
to the previous figures, the construction differing in that the adjustable link H,
instead of being pivotted to a fixed bracket or lug as at Figure 1, is pivotted to a
lever L fixed to a rock shaft L operated from the governor K by arm .L³,
connecting rod M, and two armed lever N.
I construct the dash pot, or valve retarding device P, as I will now describe
with reference to Fig. 7. Upon the valve rod & I provide a loose collar G¹ having
an upper projecting flange G, the latter being located within the air space of the
dash pot cylinder, the smaller part of the collar G' projecting. through an aperturo
somewhat larger than the said collar G', in the base of the cylinder P; the lower
end of the collar G is internally drilled out and provided with a gland R and
packing whereby the collar G¹ is retained to its rod G with a certain amount of
friction; the under side of the upper flange G' of the collar G₁ is faced or lined
with leather, rubber, or the like, and has a seating upon the inner side of the
cylinder acting to close or open the aperture existing between the exterior of the
collar G, and the said aperture through which it passes. An air escape cock or
regulator of the usual description is fitted in the aperture Px. By this construction
the rise of the valve spindle G, lifts the collar G until the flauge of the gland R
comes in contact with the base of the cylinder in which grooves S, Figs. 1, 6 and 7,
are formed for the passage of the air; the valve spindle G then slides in the
collar G and upon the descent of the valve spindle G, the projecting. upper
flange G of the collar G' descends therewith and closes the aperture, preventing
escape of air excepting by way of the escape cock. By this construction I am
enabled to dispense with the necessity of accurate alignment of the aperture in
the base of the dash-pot cylinder with respect to the valve seating, and at the same
time retain and improve the efficiency of the action and cushioning.
"
The invention is particularly applicable to valves of the equilibrium or double
beat type and which may be placed in a box on top, on the side, or underneath.
the cylinder; I find this class of valve best suited for high pressure steam in heavy
rolling mill engines as they do not require such careful attention and cleanliness as
so-called "Corliss" valves and also work very lightly. This trip gear may be applied
to equilibrium valves, "Corliss" valves (or block slides if not too large and heavy),
in fact any description of valve that can be worked with a trip gear, and in any
position, and it has this advantage over most other trip gears, it is very simple and
easy to make, there are very few wearing parts and those easily maintained in
order, and it can give steam the whole stroke or any part of the stroke; most
cut offs in other gears having to take place before half stroke.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
-1. In-valve gear for steam engines, the combination with a valve controlling

page_text: lever F, and an eccentric C, and rod C¹ for operating the lever, of the catch
block D (on the eccentric rod) adapted to be turned round as its striking faces
become worn, and a movable catch plate E on the lever F to receive the stroke
of the block D, substantially as hereinbefore described and illustrated in the
accompanying drawings.
2. In valve gear for steam engines an eccentric C, a rod C, and catch block D
on the rod C', to operate a valve controlling lever F, in combination with a
lengthwise adjustable link H, pivotted at one end to the eccentric rod C', between the
catch block and the eccentric shaft, and pivotted at the other end to a fixed axis,
whereby the catch block is brought into or out of operation and its time of action
controlled substantially as and for the purposes hereinbefore described and
illustrated in the accompanying drawings.
3. In valve gear for steam engines, an eccentric C, a rod C, and a catch block D
on the rod C¹ to operate a valve controlling lever F, in combination with a link H
(lengthwise adjustable or not) pivotted at one end to the eccentric rod C¹ between
the catch block and the eccentric shaft, an arm or arms L on the rock shaft L'and
to which the other end of link H is pivotted, and lever and rod connections from
rock shaft L to the governor whereby the latter will rock or control the
eccentric rod C¹ and bring the catch block into or out of engagement with the
valve lever as required, all substantially as hereinbefore described and illustrated
with reference to the accompanying drawings.
4. In valve gear for steam engines, the air inlet valve arrangements for the
dash pot cylinder, composed of a friction or gland collar on the valve rod passing
loosely through a larger aperture in the cylinder, an upper flange on the sliding
friction collar, within the cylinder, to close the aperture on the descent of the
dash pot piston, and a lower flange to make contact with a grooved part on the
cylinder to admit air and control the upward motion of the collar upon the rise of
the piston, substantially as herein before described and illustrated with reference to
the accompanying drawings.
5. The improvements in and connected with valve gear for steam engines.
constructed, arranged, and acting substantially as hereinbefore described and
illustrated with reference to the accompanying drawings.
Dated this 20th day of September 1895
BREWER & SON,
London and Leeds, Agents for Applicant.