Improvements in Valves for Steam Engines and their Actuating Mechanism.
Year: 1889

page_text: Date of Application, 2nd Aug., 1889-Accepted. 14th Sept., 1889
COMPLETE SPECIFICATION.
Improvements in Valves for Steam Engines and their Actuating
Mechanism.
GEORGE RICHARDS of Altrincham in the County of Cheshire Engineer in com-
nunication from David Welles Payne of Elmira New York U.S.A. 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:-
The object of my invention is the combining of a shaft, or wheel governor with the
Corliss wrist-plate motion, and use in the combination seperate supply or cut off and
exhaust valves, actuated by seperate eccentrics on the main shaft (in which case the
supply valves or cut-offs would be connected to the shaft or wheel governor. In this
case the lead, release and compression would be fixed & only the cut-off variable and the
supply or cut-off valves would be controlled by the Corliss wrist-plate motion, which
would itself be controlled by the operation of the shaft or wheel governor.
Furthermore 1 may in furtherance of the object of this invention, for simplicity,
place the supply valves at the bottom of the cylinder, and the cut-off valves within
the main or supply valves; or I may place the cut-off valves at the top of the
cylinder, and the exhaust valves at the bottom thereof, or reverse the relative positions
of the valves from that just mentioned. In other there may be four valves, two
supply and two exhaust, or there may be only two valves performing the functions of
admission and cut-off, release and compression. In this instance I have shown
rotary or oscillatory valves, but it is evident that sliding, or reciprocating valves may
be substituted therefor. It is well known that the Corliss wrist-plate motion has a
rocker arm projecting from the cylinder or frame and actuated by eccentric or cam.
The rocker is connected by rods or cranks on the valve stems. The connections are
so placed that the motion communicated through them to the valves shall be the most
rapid at times of steam admission and cut-off, and slower when they are lapped, or
the exhaust open. By these notions quick and free admission, sharp cut-off and free
release are obtained. An arrangement for releasing the supply valves from con-
nection with the wrist plate when cut-off should take place is provided, and to ensure
a quick cut-off, dash pots, or their equivalents are connected to the valves or their
cranks. This construction limits the Engine to a comparatively low rate of speed.
Now by combining the wrist plate motion with the shaft or wheel governor, and
dispensing with the releasing gear or dash pots, the Engine is enabled to obtain
higher rotative speed, its construction is simplified, the cost thereof reduced, and
the developement of much greater power over cylinders of equal diameters 15
complished

page_text: F represents an eccentric rod removably connected with the wrist-plate by being
recessed in the usual manner to receive and retain the rod block or pin F' which is
mounted on the wrist-plate.
G represents the main or crank shaft of the Engine to which the connecting
rod G₁, and piston rod G³, are connected in the usual manner. Upon the shaft is
loosely mounted the eccentric with arms H, H' constituting a part of the shaft or
wheel governor the outer ends of these arms being connected by a rod H³, with
arms H³, pivoted as at H, to the wheel I, mounted on the shaft G.
Weights J are mounted for movement along the rods H³, and springs J₁ are
connected to the rod J, and to the spokes J¹ or other suitable portion of the wheel i.
The arm H is provided with a pin H, which may be provided with an anti-friction
roller, which is projected into the curved slot L' of the eccentric carrying plate L.
The eccentric M is formed or attached to a face of the plate L, and is slotted for
movement across the shaft.
In Fig. 1 is shown a particular form of shaft governor, which may be used with a
single eccentric or two eccentrics. Where two eccentrics are used and the main
valve performs the function of admission and the other valve that of cutting off, the
governor mechanism may be attached to an eccentric on the shaft. I do not confine
myself to any particular form of shaft governor, but contemplate the use of any of
the various forms desired.
Instead of the particular form of governor described, the eccentric operating the
admission valves may rotate on the shaft, thus changing the angular advance as in the
Thompson gear.
In Fig. 1, I have illustrated a pin N to which the eccentric rod is connected,
although it is apparent that said rod may extend directly from the wrist-plate to.the
eccentric, as shown in other figures of the drawing.
In Figs. 2 & 3 I have illustrated upon a larger scale, the provision of doubles
valves and the connection of each seperate valve with a seperate eccentric.
In this instance there are extended from the side of the cylinder (and it may be
either the top or the bottom thereof in accordance with the desired_occupation of the
valves) brackets O, which serve as the bearing for the valve stems D, D₁ respectively.
The cranks C of the valve D are connected to the wrist-plate B by means of rods E,
and said wrist-plate is connected by means of the rod block F with the eccentric
rod F, in such a manner that by raising or lowering the handle 1x thereof it may be
connected or disconnected at will with the wrist-plate. This particular construction
is simply a matter of convenience to permit of disconnecting the eccentric rod with
the wrist-plate. The connection may be made permanent, or so as to disconnect at
will as desired. These exhaust valves are actuated by a fixed eccentric M¹. This
eccentric is of the ordinary type and is connected to the exhaust valves by a rod F³ as
shown in Fig. 2. The end of F2 fits over the piu F1, of the oscillatory plate B, and
thence the motion is carried to the exhaust valves by the arms E (Figs. 2 & 3).
In this instance the cut-off valves are arranged within the exhaust valves and the
stems D', of the former extend through the stems and cranks D of the later, and are
each provided with a crank C¹, and connected by means of rods E¹ to the second
wrist-plate B, which is connected and operated by an eccentric rod F, and shifting
eccentric M: This shifting eccentric actuates the inner cut-off to be varied inde-
pendently of the exhaust and compression.
In an arrangement of the valves at the bottom of the cylinder, I employ the
construction more particularly illustrated by Figs. 3, 4, & 5, but it will be apparent
that a mere reversal of these constructions will adapt the parts for a use of the valves
at the top of the cylinder. At each end of the cylinder there is a port A',
communicating directly with a cylindrical valve seat A', in the walls of which there is
formed a port A³, communicating with the exhaust passage A³. Another larger
port A, affords communication between the valve seat, and the supply chamber A*,
with which at any suitable point, the live steain or supply pipe may be connected as
shown by dotted lines in Fig. 4.
The double valve consists of a hollow cylinder P, having a spindle D, and within

page_text: the cylinder is arranged the inner or cut-off valve Q, having the spindle or stem D³,
passing through the spindle D, and projecting beyond the same. The valve P has an
opening P, adapted to be brought into communication with the port A', and an
opening P, adapted to be brought into communication with the port A¹. It also has a
peripheral recess P' adapted to be brought into communication with both the ports A¹
& A. The valve Q is recessed to stride the spindle D, so as to partake of its
motion and is adapted to close the port P². These constructions may be varied as
desired.
As shown in Fig. 4 the supply is cut-off at one side of the piston head, while the
exhaust is taking place from in front of the piston. Now it will be seen that the
variations in the load put upon the Engine will affect the shaft or wheel governor, in
such a manner as to vary its operation, upon the eccentric M and its rod F, and as
the variations will be directly communicated to the wrist-plate, and from thence
through the connecting rod to the valve stems, so that having been once properly
adjusted in their relative movement as to time and distance, the valves have the most
direct and accurate control of the governor, and readily partake of the slightest
effects in the variations of the governor.
R represents strips of packing of any suitable kind or nature seated in the
periphery of the valve Q and around the opening T¹, thereof, the object of which is
to take the larger part of the wear or friction of the valve from its seat and to
compensate for such wear and to maintain a steam tight connection between the valve
and its seat.
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. The combination with a fixed eccentric, a wrist plate and admission and exhaust
valves connected with the said wrist plate with a cut off, a wrist plate and shitting
eccentric connected directly with each other, substantially as specified.
2. The combination of the cylinder A having the ports A', A³, communicating with
the valve seats A, of the valves P, Q, the latter arranged within the former, valve
stems D, D', connecting rods E, E', wrist plates B, B¹, eccentric rods F, F³, shifting
eccentric M, and fixed eccentric M¹, substantially as specified.
Dated the First day of August 1889.