IMPROVEMENTS IN DISTRIBUTING AND REVERSING VALVES FOR STEAM ENGINES
Year: 1885

page_text: I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said invention for IMPROVEMENTS IN
DISTRIBUTING AND REVERSING VALVES FOR STEAM ENGINES, a communication to
me from abroad by Robert Hall Cowdrey of Chicago, United States, Manufacturer,
to be as follows:-
This invention embraces an improved construction in balanced slide valves for
controlling the cylinder parts of the steam engine, and also an improvement in
reversing valves adopted for use either with the balanced valve mentioned, or
other forms of steam valves.
In the accompanying drawings:
Figs 1 and 2 are central longitudinal sectional views of an engine cylinder
illustrating this invention.
Fig. 3 is a horizontal section taken upon line xx of Fig. 1.
Fig. 4 is a horizontal section taken upon line y y of Fig. 1.
Fig. 5 is a vertical section taken upon line of Fig. 2.
As shown in the accompanying drawings A, is an engine cylinder having a
piston B, and piston rod C, of ordinary construction. D is a steam chest which is
provided with opposite parallel plane surfaces forming valve seats D1 and D' the
valve sent D', as herein shown, being adjacent to the cylinder and provided with
ports ff, communicating with the ends of the cylinder by means of the passages
F, F, in the usual manner. Within the steam chest D, is a centrally open or
hollow slide valve E, which is operated by means of valve rod e, passing through
an ordinary stuffing box d in the wall of the steam chest D. The said valve is as
herein shown and preferably constructed rectangular in form and narrower than
the space between the side walls of the steam chest, so as to permit the passage of
steam around it from one end to the other of said steam chest and is constructed
to bear at its edges upon the opposite valve seat D¹, and D' of the steam chest-
G and H, are steam inlet and exhaust passages communicating with the steam
chest in its position inside of and exterior to the slide valve. The ports f, f, are

page_text: arranged at the same distance apart as the transverse end pieces E¹, of the
valve E, and the said valve operates in connection with said ports to admit steam
alternately to opposite ends of the cylinder in a well known manner. The bearing
surfaces upon the side of the valve E, are preferably made of the same width, so
that the area of such surface in contact with each of the valve seats D1 and D2 is
the same and the steam pressure upon the valve will thereby be perfectly balanced.
The valve E, is preferably provided at one of its edges with a separate part or
strip e, which is held outwardly in contact with the valve seat by means of metal
or other springs so as to form a packing in a well known manner. The same effect
will obviously be produced by permitting the entrance of steam between the porta
of the valve so as to press said ports against the opposite valve seats thus forming
what is known as a steam packing. The valve E, is as herein shown held between
guides d¹ d formed upon opposite surfaces of the steam chest adjacent to the valve
seats. The said valve may however, be otherwise held and guided, as may be
found convenient and practicable and the particular form of guides shown are not
essential to the operation of the valve. I, is a valve chamber with which the
passages G and H, leading from the steam chest communicate and which may be
located upon said steam chest as herein shown, or elsewhere or at a distance there-
from as found desirable. The said chamber I, is connected with suitable inlet
pipes L, leading from the steam generator, and is provided with an exhaust pipe M,
for the exit of the steam therefrom.. The passages G and H, which connect the
steam chest with the valve chamber I, terminate within the latter chamber in
ports g and h, and within said chamber I, is located a slide valve K, which is
generally similar in construction to the valve E, before described, and operates in
contact with opposite parallel valve seats I¹ I' in said chamber. The ports g and h
are as herein shown, formed in the valve seat l' and the valve K, operates in
connection with the said ports to bring either the inlet L, or exhaust passage M,
into communication with the passage G or H, as hereinafter more particularly
described.
The valve K, is as shown of rectangular form and provided with four walls fitted
at their edges to the opposite plane faces of the chamber, spaces being left between
the sides of the valve and the side walls of the chamber as clearly shown in Fig..5
to permit the passages of steam from one end of the chamber to the other around the
valve. The said valve is as herein shown operated by means of a valve stem or
rod k, passing through a suitable stuffing box i, in the wall of the chamber I, and
its transverse end portions K, are located at the same distance apart as the ports g
and h of the passages G and H, so that when the valve is moved a distance equal
to the width of one of the ports plus the thickness of one of the parts K¹ the ports
will be brought inside or outside of the valve in a well known manner. The
guides are as herein shown formed upon the opposite parallel faces of the valve
chamber I, between which guides the valve K., is arranged to slide; but any other
well known means of supporting the said valves may obviously be used in con-
nection with the form of valve illustrated. The valve K, is preferably provided
with a separate piece or packing strip e similar to that before described in
connection with the valve E, and the said valve having equal opposite bearing
surfaces as before set forth in connection with the said valve E, is also perfectly
balanced with reference to steam pressure tending to force the valve against its seat
in either direction.
The inlet pipe L, enters the valve chamber I, in its central portion, and com-
mmunicates with the space of the chamber within the hollow valve K, and exhaust
pipe M, communicates with the portion of chamber exterior to the valve; the said
inlet and exhaust pipes being so arranged that they are unaffected by the move-
ment of the valve; which operates upon the ports g and h, only the effect of
changing the position of the valve K, with reference to the ports is obviously to
reverse the course of the steam through the passages G and H, and thereby change
the direction of motion of the engine as will be rendered clear by an inspection of
Figs 1 and 2, of the accompanying drawings, in which the valve K, is shown in two

page_text: positions taken by it at the opposite limits of its throw. In Fig. 2, the reversing
valve K, above referred to is shown in position with the passage G, in communi-
cation with the space within the interior of the valve K, and the passage H, in
communication with the space of the valve chest exterior to the said valve, so that
the passage is afforded for steam from the inlet pipe L, which opens into the
interior space of the valve, through the said passage G, to the steam chest, and also
from the passage H, to the exhaust passage M. In this case the passage G,
obviously forms the steam inlet to, and the passage H, the exhaust passage from
the steam chest. In Fig. 1, the valve K, is shown at the opposite end of its throw
from that shown in Fig. 2, the inlet passage L, being in this case in communication
with the passage H, and the exhaust pipe M, in communication with the passage G,
so that the passage G, has become the exhaust passage of the steam chest and the
passage H, the inlet passage thereto. The slide valve E, is shown in the same
position in both figures mentioned and the course of the steam by arrows. It is
obviously immaterial to the operation of the valve E, and K, as to the points at
which the inlet and exhaust passages enter the steam chest and valve chamber. It
only being necessary in either case that one of the passages communicate with the
interior space of the valve and the other with the space of the valve chest or
chamber exterior thereto. That said passages may for instance enter the valve
chest or chamber at the side thereof opposite to that which they are shown as.
entering it in the same manner that the steam inlet and exhaust passages used in
connection with an ordinary "D" valve usually enter the valve chamber.
•
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
1. The combination with a steam chest and valve of an engine of an auxiliary
valve chamber having opposite parallel valve seats, and ports communicating with
the steam chest a centrally open slide valve in said chamber constructed to operate
in connection with the opposite valve seats and steam inlet and exhaust pipes
communicating with the portion of the valve chamber within this slide valve and
with the space of the valve chamber exterior to said valve substantially as and for
the purpose set forth.
2. The combination with the cylinder of a steam engine of a steam chest having
opposite parallel valve seats a centrally open slide valve operating in contact with
the opposite valve seats of said steam chest suitable steam passages connecting the
steam chest with the cylinders an auxiliary valve chamber having opposite
parallel valve seats and ports communicating with the portion of the steam chest
with the slide valve and with the space of the steam chest exterior to the valve, a
centrally open slide valve within said valve chamber constructed to operate in
contact with the opposite valve seats of said valve chamber and the steam inlet
and exhaust pipes communicating with the space of the valve chamber enclosed by
the slide valve and with the space of the chamber exterior to said slide valve
substantially as and for the purpose set forth.
3. The combination with the cylinder of a steam engine of a steam chest having
opposite parallel valve seats, a centrally open slide valve of less width than the
space between the walls of the steam chest constructed to work in contact with
the opposite valve seats and guides d' within the steam chest for retaining the said
valve in position substantially as described.

page_text: COMPLETE SPECIFICATION.
Improvements in Distributing and Reversing Valves for Steam
Engines.
J, HERBERT JOHN HADDAN, of 67, Strand,. in the City of Westminster, Civil
Engineer, do hereby declare the nature of this invention, a communication to me
from abroad by Robert Hall Cowdrey, of Chicago, United States, Manufacturer,
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 an improved construction in steam valves for engines.
It embraces an improved construction in balanced slide valves for controlling the
cylinder parts of the steam engine, and also an improvement in reversing valves
adapted for use either with the balanced valve mentioned, or other forms of steam
valves, and it consists in the matters hereinafter described and pointed out in the
claims.
In the drawings filed with the Provisional Specification Figures 1 and 2
are central longitudinal sectional views of an engine cylinder illustrating the
invention.
Figure 3 is a horizontal section taken upon line x x of Figure 1.
Figure 4 is a horizontal section taken upon line y y of Figure 1.
Figure 5 is a vertical section taken upon line z z of Figure 2.
As shown in the drawings A, is an engine cylinder having a piston B, and piston
rod C, of ordinary construction D, is a steam chest which is provided with opposite
parallel plane surfaces forming valve seats D¹, and D* the valve seat D', as herein
shown, being adjacent to the cylinder and provided with ports ff communicating
with the ends of the cylinder by means of the passages F F in the usual manner.
Within the steam chest D, is a centrally open or hollow slide valve E, which is
operated by means of valve rod e, passing through an ordinary stuffing box d in
the wall of the steam chest D. The said valve is as herein shown and preferably
constructed rectangular in form and narrower than the space between the side
walls of the steam chest, so as to permit the passage of steam around it from
one end to the other of said steam chest and is constructed to bear at its edges
upon the opposite valve seat D1 and D2 of the steam chest-G and H. are steam
inlet and exhaust passages communicating with the steam chest in its position
inside of and exterior to the slide valve. The ports ff are arranged at the same
distance apart as the transverse end pieces E', of the valve E, and the said valve
operates in connection with said ports to admit steam alternately to opposite ends
of the cylinder in a well known manner. The bearing surfaces upon the side of
the valve E, are preferably made of the same width, so that the area of such surface
in contact with each of the valve seats D1 and D2 is the same and the steam
pressure upon the valve will thereby be perfectly balanced. The valve E is

page_text: preferably provided at one of its edges with a separate part or strip e¹, which is held
outwardly in contact with the valve seat by means of metal or other springs so as
to form a packing in a well known manner. The same effect will obviously bo
produced by permitting the entrance of steam between the ports of the valve so as
to press said ports against the opposite valve seats thus forming what is known as a
steam packing. The valve E, is as herein shown held between guides ď ď formed
upon opposite surfaces of the steam chest adjacent to the valve seats. The said
valve may however, be otherwise held and guided, as may be found convenient and
practicable and the particular form of guides shown are not essential to the
operation of the valve-I is a valve chamber with which the passages G, and H,
leading from the steam chest communicate and which may be located upon said
steam chest as herein shown, or elsewhere or at a distance therefrom as found
desirable. The said chamber I, is connected with suitable inlet pipes L, leading
from the steam generator, and is provided with an exhaust pipe M, for the exit of
the steam therefrom. The passages G and H, which connect the steam chest with
the valve chamber I, terminate within the latter chamber in ports g, and h, and
within said chamber I, is located a slide valve K, which is generally similar in
construction to the valve E, before described, and operates in contact with opposite
parallel valve seats I' I' in said chamber. The ports g and h are as herein shown,
formed in the valve seat I' and the valve K, operates in connection with the said
ports to bring either the inlet L, or exhaust passage M into communication with
the passage G or H, as hereinafter more particularly described.
The valve K, is as shown of rectangular form and provided with four walls fitted
at their edges to the opposite plane faces of the chamber, spaces being left between
the sides of the valve and the side walls of the chamber as clearly shown in
Figure 5 to permit the passage of steam from one end of the chamber to the other
around the valve. The said valve is as herein shown operated by means of a valve
stem or rod k, passing through a suitable stuffing box i, in the wall of the
chamber I, and its transverse end portions K, are located at the same distance
apart as the ports g and h of the passages G and H, so that when the valve is
moved a distance equal to the width of one of the ports plus the thickness of one of
the parts K¹ the ports will be brought inside or outside of the valve in a well
known manner. The guides are as herein shown formed upon the opposite
parallel faces of the valve chamber I, between which guides, the valve K, is
arranged to slide; but any other well known means of supporting the said valves
may obviously be used in connection with the form of valve illustrated. The
valve K, is preferably provided with a separate piece or packing strip similar to
that before described in connection with the valve E and the said valve having
equal opposite bearing surfaces as before set forth in connection with the said
valve E, is also perfectly balanced with reference to steam pressure tending to force
the valve against its seat in either direction.
The inlet pipe L, enters the valve chamber I, in its central portion, and
communicates with the space of the chamber within the hollow valve K, and
exhaust pipe M, communicates with the portion of chamber exterior to the valve;
the said inlet and exhaust pipes being so arranged that they are unaffected by the
movement of the valve; which operates upon the ports g, and h, only the effect of
changing the position of the valve K, with reference to the ports is obviously to
reverse the course of the steam through the passages G and H, and thereby change
the direction of motion of the engine as will be rendered clear by an inspection of
Figures 1, and 2 of the drawings in which the valve K, is shown in two positions
taken by it at the opposite limits of its throw. In Figure 2 the reversing valve K,
above referred to is shown in position with the passage G in communication with
the space within the interior of the valve K, and the passage H, in communication
with the space of the valve chest exterior to the said valve, so that the passage is
afforded for steam from the inlet pipe L, which opens into the interior space of
the valve, through the said passage G, to the steam chest, and also from the

page_text: passage H, to the exhaust passage M. In this case the passage G obviously forms
the steam inlet to, and the passage H, the exhaust passage from the steam chest.
In Figure 1, the valve K is shown at the opposite end of its throw from that
shown in Figure 2, the inlet passage L, being in this case in communication with
the passage H, and the exhaust pipe M in communication with the passage G, so
that the passage G, has become the exhaust passage of the steam chest and the
passage H, the inlet passage thereto. The slide valve E, is shown in the same
position in both figures mentioned and the course of the steam by arrows.
It is
obviously immaterial to the operation of the valve E, and K, as to the points at
which the inlet and exhaust passages enter the steam chest and valve chamber.
It only being necessary in either case that one of the passages communicate with
the interior space of the valve and the other with the space of the valve chest or
chamber exterior thereto. That said passages may for instance enter the valve
chest or chamber at the side thereof opposite to that which they are shown as
entering it in the same manner that the steam inlet and exhaust passages used in
connection with an ordinary "D" valve usually enter the valve chamber.
By the construction above described in the reversing valve K, it is obvious that
means is provided for reversing the direction of motion of the engine without the
use of the link mechanism or other reversing gear heretofore used and that said
valve is perfectly balanced and may therefore be operated by the exertion of very
little force upon the valve rod. The reversing valve described is especially
valuable as applied to locomotive engines, for the reason that by its use the link
reversing gear heretofore used in such engines, which is objectionable on account
of its weight and cost, and the force required to operate it may be dispensed with.
It is obviously possible to use any kind of steam valve for controlling the cylinder
ports in connection with the reversing valve described instead of the balanced
slide valve herein shown; and it is also obvious that any suitable form of slide
valve may be used as a reversing valve in place of the balanced valve shown as
for instance an ordinary "D" valve I do not therefore limit myself to a con-
struction in which the reversing valve is used in combination with the balanced
slide valve shown except in the claims in which such is expressed nor do I limit
myself to the exact features of construction in the reversing valve or the steam
valve herein illustrated except in the claims in which each feature of construction
is set forth.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
I claim is
First. The combination with a steam chest and valve of an engine of an
auxiliary valve chamber having opposite parallel valve seats, and ports com-
municating with the steam chest a centrally open slide valve in said chamber
constructed to operate in connection with the opposite valve seats and steam inlet
and exhaust pipes communicating with the portion of the valve chamber, within
this slide valve and with the space of the valve chamber exterior to said valve
substantially as and for the purpose set forth.
Second. The combination with the cylinder of a steam engine of a steam chest
having opposite parallel valve seats a centrally open slide valve operating in
contact with the opposite valve seats of said steam chest suitable steam passages
connecting the steam chest with the cylinders an auxiliary valve chamber having
opposite parallel valve seats and ports communicating with the portion of the
steam chest with the slide valve and with the space of the steam chest exterior to
the valve, a centrally open slide valve within said valve chamber constructed to
operate in contact with the opposite valve seats of said valve chamber and the
steam inlet and exhaust pipes communicating with the space of the valve chamber
enclosed by the slide valve and with the space of the chamber exterior to said
slide valve substantially as and for the purpose set forth.

page_text: Third. The combination with the cylinder of a steam engine of a steam chest
having opposite parallel valve seats, a centrally open slide valve of less width
than the space between the walls of the steam chest constructed to work in
contact with the opposite valve seats and guides d' within the steam chest for
5 retaining the said valve in position substantially as described.