An Improved Arrangement of Valves and Ports for Reversing and for Admitting Steam to and Exhausting it from the Cylinders of Steam and other Fluid Pressure Engines.
Year: 1888

page_text: Date of Application, 5th May, 1888
Complete Specification Left. 5th Feb., 1889
Complete Specification Accepted, 4th May, 1889
An Improved Arrangement of Valves and Ports for Reversing and
for Admitting Steam to and Exhausting it from the Cylinders of
Steam and other Fluid Pressure Engines.
JAMES WILLIAM DONOVAN 4 Elizabeth Street Newcastle Road Sunderland Engineer
do hereby declare the nature of this invention to be as follows:-
This improvement consists of an arrangement whereby the reversal is attained by
admitting steam to the inner or outer edge of the main valve and of means for
working same expansively. The cylinder has two faces and two sets of valves which
are contained in separate chambers, the cylinder faces have the usual three ports and
the ports in the two faces communicate with each other, one set of valves act as steam
Reversing and distributing valves and the other valves act as Exhaust Reversing &
distributing valves. The ports in faces and valves are alike in construction excepting
that the Exhausting valves have larger ports to facilitate the Exhaust.
.
The distributing valves both steam and Exhaust have corresponding ports to cylinder
faces which are carried through back of valves, on the back of this valve is a mid-plate
free enough to follow valve as it wears but prevented from moving in direction of
travil, this mid-plate has corresponding ports to distributing valves, and are carried
through plate, the ports in mid-plate on side next distributing valve being longer in
direction of travil so that the main valve is allways full open to ports in mid-plate,
On the back of the
when ports in main valve are full open to ports in cylinder face.
mid-plate is the Reversing valve which is simply a flat plate with one port through
centre, the distributing valves are worked by single excentric and rod and the steam
valve can be given sufficient lap to work expansively. The travil of Exhaust distri-
buting valve can be so arranged to facilitate the exit of the Exhaust steam. The
reversing valves (steam and exhaust) are worked by spindles through stuffing boxes,
and connected outside to a single lever so placed that the valves are moved in contrary
directions.
The action is as follows-When the Steam Reversing Valve is moved to right and
Exhaust Reversing Valve to left steam is then being admitted and distributed by
outside of main steam valve, and exhausting through centre of main exhaust valve and
nice neren

page_text: Where it is not required to work expansively one face and one set of valves only
are used, the Reversing valve has then two faces at right angles to each other with a
central port in each face communicating with each other, one face works over a port
in steam chest which port establishes a communication to atmosphere or condensor.
Dated this 4th day of May 1888.
COMPLETE SPECIFICATION.
An Improved Arrangement of Valves and Ports for Reversing and
for Admitting Steam to and Exhausting it from the Cylinders of
Steam and other Fluid Pressure Engines.
I JAMES WILLIAM DONOVAN Engineer, 4 Elizabeth Street, Newcastle Road,
Sunderland, do hereby declare the nature of my said invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
The invention relates First. To a cylinder or cylinders with two faces and two sets
of valves and worked by eccentrics without link motion. Second. To a cylinder or
cylinders with the face extended at right angles to direction of travel and an extra
port in such extended part of the face, with corresponding extra ports in the valves
and loose plate. Third. To a cylinder or cylinders with two faces and one set of valves,
the cylinder faces being at right angles to each other.
In the accompanying drawings the same letters of reference agree in all the
figures.
Figure 1 is a longitudinal elevation of a cylinder with two faces showing the valves
in position for running in one direction part of valve back P, P¹ being shown cut
away to show ports open.
Figure 2 is a partial longitudinal section through a, b, Figure 1, with the valves and
plate complete.
Figure 3 is a vertical section throug c, d, Figure 1.
Figure 4 is a longitudinal section through e, f, Figure 3.
In this arrangement the cylinder has two faces in separate chambers and two sets
of valves, one face and one set of valves having short ports are steam valves, and the
other with longer ports are exhaust, E and E being steam and exhaust distributing
valves respectively. F and F are loose plates with ports through them, the plates
being free enough to follow the distributing valve as it wears but prevented from
moving in the direction of travel.

page_text: G¹ and G are steam and exhaust reversing valves, the valves E¹ and E are moved
with eccentric rods or other suitable means by the engine but without link motion, the
reversing valves G₁ and G are moved by suitable spindles H and H through stuffing
boxes and handle I.
The action is as follows, when the port J in reversing valve G is put in communication
with port R" in loose plate F the exhaust steam will then pass through ports Q and Q¹¹
in the distributing valve and ports R and R¹ in the loose plate into exhaust chamber T,
thence through exhaust pipe L to condenser, or atmosphere.
The valves in steam chamber S will be in a reverse position and live steam will flow
from steam pipe O through port J¹ in reversing valve G₁ through loose plate F¹ into
distributing valve E¹ and ports C and (3³ into cylinder, A and the engine will run in
one direction. If the position of valves G¹ and G be reversed so as to bring the port J
(in exhaust chamber T) in communication with R' in plate F, and the steam valves,
vice versa the direction of motion will be reversed.
Figure is a longitudinal section through e, f, and shows the connection of steam
ports in cylinder, C and C with C and C. The advantages of this arrangement are
the steam valves can have considerable lap and yet a free exhaust.
Where little or no lap is required on steam valve I may use a modification of the
combined distributing valve E, loose plate F and reversing valve G as shown in
Figures 5. 6. 7 and 8. This arrangement has one face and one set of valves, Figure 5
being longitudinal elevation of cylinder face which shows the usual three ports, but
the face is extended at right angles to direction of travel, and there is an extra port L
which is the main exhaust port.
Figure 6 is a partial longitudinal section of steam cylinder with valves complete.
Figure 7 is a cross section through g, h, Figure 6 and Figure 8 is elevation plan of
face of reversing valve G.
The distributing valve E has ports through the valve so arranged that they are
always full open to the ports in plate F, and the exhaust port Lopen to port L in
the face of cylinder.
The reversing valve G has one steam port M through valve, and N. N¹ are exhaust
ports communicating with port L' and L" in loose plate F and L in distributing
valve and main exhaust L.
?
The action is as follows when port M in reversing valve G is placed in communica-
tion with port K' in plate F steam will flow from the steam chest through centre
port R, and ports C and C¹ in cylinder; the exhaust flowing through ports R and R¹¹,
N, N', in reversing valve through L, L, L, aud L to atmosphere or condensor; the
engine will run in one direction. If the reversing valve be placed so as port M
communicates with R the engine will run in an opposite direction; if the roversing
valve is placed in mid position as shown at Figure 6 the engine will stop and remain
stationary.
Instead of forming an extra port L in cylinder face I may use a face with the
usual three ports but with another face at right angles as shown in Figures 9
and 10.
Figure 9 is a cross section through cylinder and valves, showing open to exhaust.
Figure 10 is longitudinal section through line i, j Figure 9 and shows reversing
valve in central position.
The reversing valve has then two faces at right angles to each other with a central
exhaust port V working over the main exhaust L in the steam chest the distribution of
steam and reversal being obtained in a similar manner as before described.
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 means herein described and shown in Figures 1. 2. 3. and 4 of the annexed
drawings for controlling the admission and exit of actuating fluid from steam and
other fluid pressure engines, such means consisting of a cylinder or cylinders, and
the valve E and E³, the loose plates F and F¹ and reversing valves G and G'.

page_text: 2. In means for controlling the admission and exit of steam from steam or other
fluid pressure engines as shown in Figures 5. 6. 7 and 8 of the annexed drawings the
combination of an extra port L for exhaust, the distributing valve. E, loose plate F
and reversing valve G with extra port M through same, operating substantially as
herein described.
3. The means for controlling the admission and exit of steam from steam and other
fluid pressure engines as shown in Figure 9 of the annexed drawings where the cylinder
has two faces at right angles to each other with reversing valve working over second
face and port in steam chest, as described.
4. The arrangement and proportioning of the ports through the reversing valve G,
loose plate F and distributing valve E in such a manner that the valve G being moved
as before described will have opposite effects on the piston of the working cylinder.
71 1
T1
1000
H. GARDNER,
166, Fleet Street, London,
Agent for the said J. W. Donovan.
H. GARDNER,
166, Fleet Street, London,
Agent for the said J. W. Donovan.