Improvements in Steam Engines and Pumps.
Year: 1893

page_text: Date of Application, 25th Feb., 1893
Complete Specification Left, 9th Dec., 1893-Accepted, 3rd Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in Steam Engines and Pumps.
We,
WILLIAM FOX CRABTREE, of Southtown Iron Works, Great Yarmouth,
in the County of Suffolk, Engineer, and JONAS DALBY, of Colchester, in the
County of Essex, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention chiefly relates to steam engines of the kind in which the steam acts
upon one side of the pistons only and which are specially designed to run at a high
speed, but my improvements are also applicable to pumps and the object of my
invention is to provide an improved construction of valve mechanism whereby a
single valve serves for controlling the ports of two cylinders, the said valve in the
case of a steam engine being applicable for distributing high pressure steam to both
cylinders or high pressure steain to one cylinder and exhaust steam into the other.
In carrying out my invention I arrange the valve which is of cylindrical shape in
a chamber between the two cylinders, the single steam port of each of which
communicates with the said chamber through a bifurcated passage, that is to say, a
passage having two openings into the said chamber one of which serves for the inlet
of steam and the other for the exhaust. The valve itself is provided with two
circumferential passages into one of which the steam is admitted from the steam
supply pipe through suitable openings in the valve and the other of which com-
municates with the exhaust. The said circumferential grooves are so arranged
that when that through which the steam enters is opposite the inlet port for one
cylinder the other will be opposite the exhaust port of the other cylinder and
vice versa. The steam exhausts into a chamber adjacent to the valve with which
chamber the ends of the cylinder into which the steam does not enter communicate
so as to prevent the formation of a vacuum under the pistons.
•
In order to equilibrate the valve to prevent excessive wear and friction, the port
openings in the valve chamber communicate with circumferential recesses in the
walls of the chamber so that the steam can pass all round the valve.
When my valve is to be used for distributing high pressure steam to one cylinder
and exhaust steam to the other cylinder, the high pressure cylinder is provided with
a bifurcated passage in connection with its port one of which serves to admit steam
and the other to allow the escape of the exhaust whilst the low pressure cylinder
has only a single passage. Around the wall of the valve chamber is formed a recess
which communicates with the exhaust and in the valve is formed another circum-
ferential recess which serves to alternately place the exhaust passage of the high
pressure cylinder in communication with the steam passage of the low-pressure
cylinder and the said steam passage of the low pressure cylinder in communication
with the exhaust.
By the arrangement of the ports as hereinbefore described the steam passages
are very short whereby condensation is reduced, to a minimum.
Deted the 25th day of February 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.

page_text: We, WILLIAM FOX CRABTREE, of Southtown Iron Works, Great Yarmouth,
in the County of Suffolk, Engineer, and JONAS DALBY, of Colchester, in the
County of Essex, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention chiefly relates to steam engines of the kind in which the steam
acts upon one side of the pistons only and which are specially designed to run at a
high speed, and the object of the invention is to provide an improved construction
of valve mechanism whereby a single valve serves for controlling the ports of
two cylinders, the said valve in the case of a steam engine being applicable for
distributing high pressure steam to both cylinders or high pressure steam to one
cylinder and exhaust steam to the other.
In carrying out the invention we arrange the valve which is of cylindrical shape
in a chamber between the two cylinders, the single steam port of each of which
communicates with the said chamber through a bifurcated passage, that is to say, a
passage having two openings into the said chamber, one of which serves for the
inlet of steam and the other for the exhaust. The valve itself is provided with two
circumferential passages into one of which the steam is admitted from the steam
supply pipe through suitable openings in the valve and the other of which com-
municates with the exhaust. The steam exhausts into a chamber adjacent to the
valve with which chamber the ends of the cylinder into which the steam does not
enter communicate so as to prevent the formation of a vacuum under the pistons.
In order to prevent excessive wear and friction of the valve, the port openings in
the valve chamber communicate with circumferential recesses in the wall of the
chamber so that the steam can pass all round the valve.
When the valve is to be used for distributing high pressure steam to one cylinder
and exhaust steam to the other cylinder, the high pressure cylinder is provided
with a bifurcated passage in connection with its port, one of which serves to admit
steam and the other to allow the escape of the exhaust whilst the low pressure
cylinder has only a single passage. Around the wall of the valve chamber is
formed a recess which communicates with the exhaust and in the valve is formed
another circumferential recess which serves to alternately place the exhaust passage
of the high pressure cylinder in communication with the steam passage of the low
pressure cylinder and the said steam passage of the low pressure cylinder in
communication with the exhaust.
By the arrangement of the ports as hereinbefore described the steam passages are
very short whereby condensation is reduced to a minimum.
To enable our invention to be fully understood we will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a sectional elevation of two high pressure steam cylinders having
a single valve constructed and arranged according to my invention between them;
and,
Figures 2 and 3 are an elevation and end view respectively of the said valve
detached:
Figure 4 is a sectional elevation shewing a modification of the arrangement shewn
in Figure 1; and,
Figure 5 is an elevation of the valve detached:
Figure 6 is a view similar to Figure 1 but shewing the valve arranged for
working in conjunction with high and low pressure cylinders; and,
Figure 7 is an elevation of the valve detached:

page_text: Figure 8 18 a sectional elevation illustrating a modification of the arrangement
shewn in Figure 6; and,
Figure 9 is an elevation of the valve detached.
Similar letters of reference indicate corresponding parts in the several figures.
a, a¹ are the cylinders, and b, b' are the pistons working therein respectively. c is
the valve chamber, and d is the cylindrical valve working therein. e is the steam
inlet, and f is the outlet for the exhaust steam. 9, 9 are the passages for allowing
air or steam to pass into and out of the cylinders a, a' behind the pistons to prevent
the formation of a vacuum.
The valve d shewn in Figure 1 is provided with two circumferential grooves h, i,
the former of which communicates with the steam inlet e through the holes or
passages h³, h¹ and the latter with the exhaust through the holes or passages i¹,
j, are the passages establishing communication between the cylinders a, al
respectively and the valve chamber, the former passage having a steam port k and
an exhaust port k' and the latter a steam port and an exhaust port
The operation of the apparatus shewn in Figure 1 is as follows:-The valve d
being in the position shewn in the said figure the steam enters over the upper
end of the valve d through the port and into the cylinder a and the steam from
the cylinder a exhausts through the port into the groove i and thence through
the passages to the exhaust f As the pistons b, b₁ move through their
cylinders the valve d moves to fully open the ports k, and to again close the
same. As the movement of the valve continues the groove h opens to the port l
and the groove i to the port k¹ so that the steam previously introduced into the
cylinder a passes to the exhaust and live steam enters the cylinder a'. It will
thus be understood that as the valve opens the steam port for one cylinder it
simultaneously opens the exhaust for the other cylinder.
In the arrangement of our invention shewn in Figure 1 the steam by entering at
one end of the valve chamber is continuously exerting pressure upou one end of
the valve. In order to overcome this objection we find it advantageous to
introduce the steam at the centre of the valve chamber, and for this purpose we
form in the walls of the same a groove m (as shewn in Figure 4) with which the
steam inlet e is in communication, the valve being also recessed at its central part,
as shewn clearly in Figure 5, to allow of the groove m being put in communication
with either of the steam ports of the cylinders, a single port only being used for
each cylinder in this arrangement for the admission and exhaust of steam.
valve which in this case is made hollow has around it at each end a groove n
which communicates through holes n', with the interior of the valve, the
interior being in communication at one end with the exhaust f
The
With this arrangement it will be understood that when the steam enters the
cylinder a in the direction of the arrow 1 the exhaust steam from the cylinder a¹
escapes in the direction of the arrow 2, the exhaust port of one cylinder being
closed when the steam port of the other cylinder is open.
The arrangement wherein our valve is adapted to distribute high pressure steam
to one cylinder and low pressure steam to the other cylinder is shewn in Figure 6.
The valve d in this case has only a single circumferential groove, as shewn most
clearly in Figure 7, and the high pressure cylinder has a bifurcated steam
passage, o, ol being the two branches of the same whilst the low pressure cylinder
has a single passage p. q is a passage formed around the valve chamber and
communicating with the exhaust f. It will be understood that in the operation of
this valve the steam first enters the high pressure cylinder through the passage o
as indicated by the arrow Figure 6 and at the same time the steam from the low
pressure cylinder escapes through the passage p, the groove in the valve and the
groove q in the valve chamber to the exhaust f. When the valve is moved to close
the steam port o of the high pressure cylinder the groove in the said valve
establishes communication between the port o' of the high pressure cylinder and
the passage p of the low pressure cylinder so that the steam which escapes from
the high pressure cylinder will enter the low pressure cylinder.

page_text: In the modification of this arrangement shewn in Figures 8 and 9, the valve is
made hollow and the steam is introduced into a groove m around the valve-
chamber and exhausts through a groove 9 also around the valve-chamber. In
the drawings, the valve is shewn in the position for admitting steam to the
high pressure cylinder and for allowing the escape of the steam from the low
pressure cylinder through the interior of the valve and the holes n', n' formed
therein to the exhaust. By the time that the high pressure piston has reached the
opposite end of the cylinder to that at which it is shewn the valve has returned in
the direction of the arrow 1, Figure 8, and moved so far as to allow the steam
from the high pressure cylinder to pass directly to the low pressure cylinder through
the valve chamber, the holes n', n' in the valve being cut off from the exhaust
passage q.
Although we have described our invention as applied to steam engines it is to be
understood that the arrangement of valve mechanism shewn in Figures 1 to 5 is
also applicable to pumps.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An engine or pump provided with a single valve adapted to control the
entrance and exit of fluid into and from two cylinders having single acting pistons,
substantially as described.
2. In an engine of the kind in which two cylinders having single acting pistons
are employed the use of a single valve for controlling the ports of the two
cylinders, the said valve being adapted for distributing high pressure steam to both
cylinders or high pressure steam to one cylinder and exhaust steam to the other,
substantially as described.
3. A steam engine having a single cylindrical valve constructed arranged and
operating substantially in the manner described by reference to Figures 1 to 3 of
the accompanying drawings.
4. The modification of the arrangement shewn in Figure 1 substantially as
described by reference to Figures 4 and 5 of the accompanying drawings.
5. A compound steam engine having a single cylindrical valve constructed,
arranged and operating substantially in the manner described by reference to
Figures 6 and 7 of the accompanying drawings.
6. The modified arrangement of valve for a compound steam engine substantially
as described and illustrated in Figures 8 and 9 of the accompanying drawings.
Dated the 9th day of December 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.