IMPROVEMENTS IN ACTUATING SLIDE VALVES
Year: 1873

page_text: *44
LETTERS PATENT to Joseph Rome, of Hornsey, in the County of
Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN
ACTUATING SLIDE VALVES."
•
Sealed the 7th November 1873, and dated the 28th June 1873.
PROVISIONAL SPECIFICATION left by the said Joseph Rome at the
Office of the Commissioners of Patents, with his Petition, on the
28th June 1873.
I, JOSEPH ROME, of Hornsey, in the County of Middlesex, Engineer,>
do hereby declare the nature of the said Invention for "IMPROVEMENTS:
IN ACTUATING SLIDE VALVES," to be as follows, that is to say :-
This Invention relates to improvements in the means of actuating
slide valves for that class of direct acting steam engines or steam
pumps in which the valve motion is effected by steam only, without
employing any mechanical gear connected with the piston of piston
rod; and these improvements consist chiefly in the employment of,

page_text: one, or in some cases, two small slide valves working transversely
across the casing or main slide valve; or the main slide valve and
casing may be arranged to act without an additional slide or slides.
When only one small slide is employed to shift the main slide I
prefer making it as an ordinary D slide, and placing it in a cylindrical
space in the casing across the main slide, and open to the live steam
from the inlet; from each side of the valve casing passes a port or
steam passage opening into the cylinder of the engine, but at some
distance from the ends thereof. These passages communicate with
opposite ends of the cylindrical space of the small slide valve. Ports
or steam passages also pass from the sides of the small slide valve
right through the valve casing. An exhaust passage is also provided
passing from one end of the bottom of the small slide to the main
exhaust. By this arrangement steam entering from the inlet pipe
will fill the interior of the small slide, and also the main slide casing,
and pass through the main port into the cylinder of the engine, and
move the piston towards the opposite end of the cylinder, thereby
uncovering one of the said ports or steam passages through which
live steam will then rush from the cylinder and move the small
slide so as to open one of the said ports passing right through the
casing; steam from the interior of the small slide will pass through
this port, the exhaust escaping by a similar port at the opposite end
of the casing, whereby the steam acting on the reverse end of the
slide casing will move it, and thereby the small and main slides
towards the other end of the valve box, and will reverse the motion
of the piston by admitting steam into the opposite end of the cylinder
to that first described.
When I employ two small slides they may be either of an ordinary
form, similar to that herein-before described, or they may be arranged
to act radially. In both cases the slides are placed at the ends of the
main slide valve or casing, and are connected together by a small rod
working in the casing of the main slide, the ports being arranged alike,
whether one or two small slides are used.
When the main slide and casing are employed alone steam ports
or passages are provided corresponding to the ports herein-before
described, and communicating with the ends of the main slide or
casing so that at each stroke of the piston steam from the cylinder

page_text: passes up through one of these ports and shifts the slide further over,
thereby admitting steam alternately to opposite ends of the casing, and
changing the direction of the steam to the cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Rome in the Great Seal Patent Office on
the 23rd December 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
ROME, of Hornsey, in the County of Middlesex, Engineer, send
greeting...
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of June, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joseph Rome, Her special
licence that I, the said Joseph Rome, my executors, administrators, and
assigns, or such others as I, the said Joseph Rome, my executors, admi-
nistrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN ACTUATING
SLIDE VALVES," upon the condition (amongst others) that I, the said
Joseph Rome, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that. I, the said Joseph Rome, 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, reference being had to the Drawings hereunto
annexed, will more fully and at large appear.

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1
This. Invention relates to certain improvements in the means of
actuating slide valves for direct acting steam engines, steam pumps, &c.
>
The said improvements consist, amongst other things, in the arrange-
ment of a main slide valve, with piston heads attached, working in a
cylindrical casing, having one, or in some cases two, small plugs or slide
valves working transversely across the casing or main slide valve, or the
main slide valve and casing may be arranged to act without an additional
slide or slides.
Such being the nature of this Invention, I will now describe more in
detail the manner of performing the same, and in order that the same
may be more readily understood I have annexed hereunto one Sheet of
Drawings marked with letters of reference corresponding with those in
the following explanation thereof, that is to say:-
On the accompanying Drawings one modification is illustrated in
Figs. 1, 2, and 3. Figure 1 is a longitudinal section of this Invention;
Fig. 2 is a transverse section of the same; Fig. 3 is a sectional plan
through the main slide valve casing and the casing of the small plug or
slide. The letter A is the main steam cylinder of the engine; B is the
piston. The steam in the cylinder A is changed by the action of the
slide valve E, which is of ordinary construction, and is enclosed in a
casing F. The slide valve E is provided with a small plug or slide G,
which acts as a slide valve to the main slide valve E, and works trans-
verscly in a cylindrical casing a. Steam enters at H, and has constant
access into the valve casing F between the two piston heads I, I. The
main steam passages 6 and 6¹ run as usual from the interior of the valve
casing F from between the two heads I, I', of the valve E, to the ends
of the cylinder A. The steam, being directed into alternate ends of the
cylinder A, to give the desired reciprocating motion to the piston B as
usual by the reciprocation of the valve E, which is caused as and by the
means, that is, the arrangement of ports in the cylinder A, valve E, and
casing F, herein-after immediately described.
b
In addition to the main steam passages 6, 6', above mentioned, I
provide two steam ports c, c', which communicate one from the interior
and near each end of the cylinder A with the same end of the valve
casing F, also two exhaust ports d, d', which communicate one from the
interior and near the end of the casing F to the same and at the extreme
end of the cylinder A. Four other ports e, e¹, and f, f¹, communicatė

page_text: from the interior of the small casing a of the plug G with the ends of
the casing F. An exhaust port 9 communicates between the interior of
the small casing a of the plug or slide G with the common exhaust j of
the engine.
Supposing steam to be entering at the inlet H of the casing F it fills
the interior of the casing between the heads I and I', and passing by the
port 6 into the cylinder A. moves the piston from right to left; on or
near the termination of its stroke it uncovers the port c in the cylinder
A. Steam therefrom rushes up the said port, and passing through the
end of the casing a containing the small plug G, moves the small plug
or slide G over the exhaust, escaping to the cylinder A by the port d³,
which allows steam (entering the small casing by the port h) to pass by
the port c¹ to this end of the casing F, and acting between the casing F
and the head I of the valve E shifts the valve E to the right, the exhaust
steam escaping from the end F¹ of the casing by the port f¹ in the slide
valve head I³, which now communicates with the main exhaust J through
the small port g, which communication has been made by the D shaped
recess in the small plug or slide G. This movement of the slide valve
E shuts the communication between the small slide casing and this end
of the cylinder A, and opens the communication between the reverse end
of the small slide casing and the right end of the cylinder A. The
movement of the slide valve has also changed the motion of the piston
B, as the piston B returns as soon as it uncovers a similar port c¹ at this
end of the cylinder, which is now in communication with the opposite
end of the small plug casing a. Steam from the cylinder rushes up and
again shifts the plug G in the reverse direction to that before described,
the exhaust from the small casing escaping by the port d, which is now
in communication with the exhaust end of the cylinder A. Steam from
the interior of the small casing a now passes by the port e to this end F¹
of the casing, shifts the heads I and I¹ and the valve E back again.
The piston B is thus reversed in its motion and the action is repeated.
'
I prefer taking the exhaust ports d and d¹ from the small casing
to the ends of the cylinder A, but the communication may be made direct
to the exhaust J by simply having a channel across the main slide casing
F at each end.
In a second modification, represented by Figs. 4, 5, and 6, I employ
two small slides or plugs G and G³, otherwise the relative positions of
the steam cylinder A, valve E; casing F, and small ports e, e', f, f¹, and

page_text: t
g may be as above described. The two plugs or slides G, G³, are con-
nected by a small rod which works in the interior of the casting con-
taining the main slide valve E, so that the two plugs G and G¹ move in
the same direction. Supposing the piston B to be moving in the direction
of the arrow; Fig. 4, near the termination of its stroke it uncovers the
port c leading from the cylinder to this end of the valve casing and com-
municating with the interior of the small casing of the plug G. Steam
from the cylinder then shifts this plug or slide G (which by the rod
moves the other plug G¹ at the opposite end of the slide valve E) over,
thereby changing the direction of the steam to this end of the casing F,
and by the slide or plug G¹ exhausting from the end F¹ of the casing
the slide therefore moves over to the right, and the motion of the piston
B is changed; as soon as the piston in its return motion uncovers the
corresponding port c¹ at this end of the cylinder A the steam passes up
and acting on the plug G₁ reverses it, and also the plug G at the other
end the slide valve E returns and the operation is thus continued.
The rod may be dispensed with and the two small slide valves G, G³,
worked independently by steam.
In a third modification, Figs. 7 and 8, the small plugs or slides G, G¹,
instead of being of the ordinary form, similar to that herein-before
described, are arranged to act radially and are connected by a rod 1, and
therefore move together. Supposing as in Fig. 4, the piston B to be
moving from right to left, as soon as the port c is uncovered, steam
passing by this port and through the casing F and acting on one side
of this radial slide valve G, Fig. 8, moves it (and by means of the rod
the slide Gat the other end of the main slide valve E) sufficient to
change the direction of steam by the port e¹, and the exhaust by the
portf¹, and the steam acting on the end F of the casing reverses the
slide E. The piston B then makes its return movement and uncovers a
similar port at the other end of the cylinder, steam passing up this port
and through the casing containing the radial slide valve G₁ (which is
now open by reason of the valve E being at this end. F¹ of the slide
valve casing) moves the valve G¹ in the reverse direction to that
before described, and the flow of steam to the ends of the main valve
casing, the slide E is therefore reversed and also the piston's motion, the
action is thus continued.
When two small plugs or slides are employed instead of working

page_text: nally and independently, not being connected by a rod. This method is
illustrated in Fig. 9. Steam fills the interior of the casing F, between
the heads I and I¹ of the main slide valve E, and passing by the steam
space C into the cylinder by the main steam port 6¹ moves the piston in
the direction of the arrow, near the end of its stroke it uncovers the steam
port c at this end, and steam rushing up this port and acting against the
end of the small plug G moves it to the left. The other end of the small
plug G being now open to the exhaust end of the cylinder A by the
small port f, the small plug or slide having been shifted, a communi-
cation is made between the end F of the main casing and the exhaust
port g by the D shaped recess in the plug G (which recess is shewn on
the top of the plug, but may be placed on the bottom) live steam has
constant access to both ends of the valve casing F and F¹ through the
small dotted ports m, m¹. Steam being exhausted from this end F of the
casing the slide valve E and heads I and I' move over in the direction of
the piston's motion, and the flow of steam to the cylinder is changed;
as soon as the slide E reaches the end of the casing F a communication
is made from the steam by the recess n to the end of the plug, and the
plug is moved to its original position in the head I. As the piston B
returns and uncovers the corresponding port c¹ at the other end the
steam shifts in a precisely similar manner, the plug G¹ and the steam is
exhausted from the end F of the casing, the slide valve E reverses, and
the reciprocating motion of the piston B and the slide E continues.
The plugs instead of being shifted by steam from the cylinder may
have a small pin projecting into the cylinder, and being struck by the
piston thereby cause communication to be made with the exhaust, as
illustrated in Fig. 10.
To ensure the more perfect working of the slide E and piston B I have
provided a displacement steam lubricator, illustrated in Fig. 9, which is
applied to all the previous modifications. This lubricator may also be
used for steam engines and other purposes.
In the two previous modifications the slide valves may be shifted
by steam on one end, and exhausting from the other alternately, not
allowing steam constant access to both ends of the slide casing by
providing two extra steam ports.
According to a sixth modification, illustrated in Fig. 11, I dispense
entirely with the small plug or slide, and make the main slide with

page_text: projecting ends G, G¹, which are provided with steam and exhaust
ports e, e¹, and ff. The two heads I, I', are connected by the bar k.
Supposing the slide valve E and the heads I, I', to be in the position
shewn, steam is passing by the port 6' into the cylinder A, and is moving
the piston in the direction of the arrow. When the port c is opened
steam passes up, and acting between the end of the plug G¹ and the head I'
moves the main slide E still further over, and brings the port e opposite
to the port g, steam thereby acts on the end F of the casing, and the head
I of the valve, the exhaust escaping from the end F¹³, of the casing by
the ports g and f to the air. The motion of the main slide is thereby
reversed, and also the direction of the steam to the cylinder A. As the
piston returns it uncovers the port c¹ at the right end of the cylinder A,
and steam passing through this port acting between the head I and the
end of the plug G the steam is directed to the end of the casing F, and
the slide is moved back to its original position, the piston returns, and
the motion is repeated.
In the first, second, third, and fourth modifications the motion of the
slide may be caused by allowing steam constant access to both ends of
the casing F, and simply exhausting it therefrom, each end alternately.
I prefer working it by the four ports, two steam and two exhaust, as
shewn and described.
Having now described this Invention, and shown how the same may
be conveniently and advantageously performed, I declare that what I
claim is, the arrangement and combination of a slide valve and heads,
with one or in some cases two or more small slide valves, having ports and
passages, &c. in such relative positions as to cause the reciprocation of
the piston and rod in the cylinder, substantially as shewn and described,
or any mere modification thereof.
In witness whereof, I, the said Joseph Rome, have hereunto set
my hand and seal, this Twenty-third day of December, in the
year of our Lord One thousand eight hundred and seventy-three.