Improvements relating to Distributing Valves, Chiefly Designed for Use in Steam Engines.
Year: 1889

page_text: Date of Application, 26th Mar., 1889
Specification Accepted, 11th May, 1889
COMPLETE SPECIFICATION.
0
[Communicated from abroad by THOMAS TRIPP, of Avon, Massachusetts, United States
of America, Mechanical Engineer.]
Improvements relating to Distributing Valves, Chiefly Designed for
Use in Steam Engines.
HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex 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 relates to steam engines, especially of the locomotive class, and of the
reversing type; one object of which is to relieve the steam cylinders of such engines
of excessive pressures, when piston valves are used, in a manner.equally as efficient, as
when the ordinary D slide valve is used.
Another object of the said invention is the use of mechanical devices designed to be
theoretically and mechanically correct. That is to say-Devices that are of simple,
durable, and mechanical construction, which in use are efficient and economical, readily
and cheaply manufactured and easily applied.
In the accompanying drawings
Figure represents the said devices in central vertical section as applied to
locomotive cylinder provided with a piston valve. The steam chest, valve cylinder, and
cylinder being represented in central vertical section, and the piston valve and rod
and piston and rod being represented in side elevation.
Figure 2 is a full sectional view of Figure 1 on line 20-20, except that the piston
valve and rod are represented in plan.
Figure 3 is an end view of piston valve cylinder.
Figure 4 is an end view of piston valve cylinder, with poppet plate removed.
Figure 5 is a plan of piston valve cylinder.
Figure 6 is a rear elevation of poppet plate 58.
Figure 7 is a vertical sectional view of Figure 5 on line 21-21.
Figure 8 is a vertical sectional view of Figure 5 on line 22—22.

page_text: The following are parts of an ordinary locomotive-cylinder, designed to be provided,
with the usual D slide valve Steam cylinder 23 provided with heads -24 and 25
head 2 being provided with the stuffing box 26; inlet ports 27, 27 supply ports 28
and 29 exhaust port 30; piston 31; piston rod 32; steam chest 33, provided with
stuffing box 34 and cover 35; and valve seat 36. These parts are made of the usual
material and are bolted or otherwise secured together in the usual manner.
Instead of using an ordinary D slide valve upon the valve seat 36, the valve
cylinder 37 and piston valve 38 are used.
The valve cylinder 37, the bottom area of which is equal to and is the same form of
the valve seat 36, to which it is bolted by means of bolts 39.
The valve cylinder is constructed as follows:-It is provided with the supply ports 40
and 41; exhaust port 42 and cylindrical bore 43 to which is fitted the piston valve 38,
which is provided with the heads 44 and 45 and which has fitted to it the valve rod 46.
This construction and arrangement of valve cylinder, and piston valve is of the common
form and arrangement and are designed to operate in the usual well known manner.
The valve cylinder is provided with the following additional ports which are constructed
within the valve cylinder, as follows:-The port 47 extends from the exhaust port 42
through partition 48, supply port 41 and partition 49, to the end portion 50 of the valve
cylinder and the port 51 extends from supply port 41, through partition 49 to the
end portion 50 of the valve cylinder. In a like manner, the port 52 extends from the
exhaust port 42; through partition 48, supply port 41 and partition 49, to the end
portion 50 of the valve cylinder, and the port 53, extends from supply port 41 through
partition 49 to the end portion 0 of the valve cylinder. The end portion 50 of the
valve cylinder where the ports 47 and 51 and ports 52 and 53 end are provided with
the seats 54 and 55, respectively. These seats are covered in a manner similar to valves
and their seats, by the poppet plate seats 56 and 57 respectively. The poppet plate 58,
provided with the seats 56 and 57 is held in its position of oppositeness to the seats 54
and 5 by means of bolts 59 and 60 which pass respectively through the enlarged
holes 61 and 62 of the toppet plate ears 63 and 64 and are securely screwed into the
cars 65 and 66 of the valve cylinder. The plate is guided in its lift or travel by means
of the bolts 59 and 60 which serve as guides, and the plate is held in its position of
contact by means of pressure exerted by means of the spiral springs 67 and 68 which
are placed between the bolt heads and ears of the plate. The seat portions of the
plate 58 are annularly united by means of the portions 69 and 70.
The construction of the valve cylinder and the arrangements of its ports is the same
for both ends. Therefore the end portion 50' of the valve cylinder is provided with
the following ports and parts in duplicate, as follows:-Port 47'; partitions 48'.
and 49 ports 511 52 and 53'; seats 54 and 55'; plate seats 56' and 571; poppet
plate 581 bolts 59 and 60'; enlarged holes 61' and 62¹ plate ears 631 and 64';
valve cylinder ears 65 and 66¹; spiral springs 671; and 68¹ and portions 691
and 70¹.
Excessive pressures are produced in cylinders by many well known and understood
causes; and, for the purpose of illustrating the operation of my invention I have
assumed to exist, in Figures 1 and 2, excessive pressure producing conditions, due
to causes to be hereinafter set forth. It is assumed that a locomotive running
ahead under a full head of steam is provided with the cylinder 23, and that, at
about the time the piston 31-commences its stroke ahead, the piston valve is reversed:
Then the piston; when it reaches a position in the cylinder - as shown moving:
towards the front head, in the direction as indicated by an arrow, may have produced
an excessive pressure within the cylinder; between the front head and the piston,
when the piston has reached a position of its stroke, as shown in drawings or
during the completion of its stroke towards the front head. This excessive pressure,
which should be relieved, and which could not be relieved by the piston valve, for
the reason, that the piston valve head 45, covers the supply port 41; and as the
piston valve is moving in the direction as indicated by an arrow. Figure 1, the supply
port 41 might not be uncovered by the piston valve head 45 until the excessive
pressure produced, tinless-relieved, may have caused disastrous effects, such as the

page_text: breakage of the front cylinder head. In such an event, whenever the pressure is
slightly greater, within the space between the piston and the front head and the
ports 29 and 41, than the pressure in the steam chest, the poppet plate 58 would be
force from the end portion 50 of the valve cylinder, thereby uncovering and con-
necting the ports 47 and 51, and the ports 52 and 53, and thereby permitting the
full escape of the compressed gases through the supply ports 29 and 41 to the
exhaust port 42 by means of the ports 51 and 47 on one side of the valve cylinder,
and on the other side by means of ports 53 and 52, all as indicated by arrows in
Figures 1 and 2.
It is obvious that whenever and for whatever cause, the pressure within the supply
port, 41 is slightly greater than the pressure within the steam chest, such pressure
would be permitted to freely escape through the ports 47, 51, 52, and 53 to the
exhaust port 42, which port is always in open connection with the atmosphere.
In a modification of the ports, which however is objectionable on account of the
necessary length of the same, causing increased cylinder clearance, which objection-
able feature may be offset by advantages, such as accessibility of parts and the use of
but one poppet plate, the ports 47' and 521, leading from the exhaust port 42 to the
end portion 50¹ of the valve cylinder may be omitted and the ports 51 and 531
instead of extending from the port 40 to the end portion 50' may extend from the
port 4 to the end portion 50, and be so arranged as to be covered by the poppet
plate 58, in which case the poppet plate would perform the duty that would be
performed by both poppet plates if the ports were constructed and arranged as
illustrated in the drawings.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is :-
First. A valve cylinder provided with the interiorly constructed ports extending
from its supply port or ports to its exhaust port the connection between said supply
ports and exhaust port being controlled by the poppet plate devices, substantially as
described.
Second. The valve cylinder 37, provided with ports 40, 41 and 42, 47, 51, 52, 53,
47, 1, 52, and 53' in combination with the poppet plates 58 and 581, operatively
constructed and arranged substantially as and for the purposes set forth.
Dated this 26th day of March 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.