IMPROVEMENTS IN STEAM ENGINES
Year: 1855

page_text: LETTERS PATENT to William Rothwell Lomax, of Hammersmith, in the
County of Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS
IN STEAM ENGINES."
Sealed the 14th March 1856, and dated the 19th September 1855.
PROVISIONAL SPECIFICATION left by the said William Rothwell Lomax
at the Office of the Commissioners of Patents, with his Petition, on the
19th September 1855.
I, WILLIAM ROTHWELL LOMAX, of Hammersmith, in the County of Middle-
sex, Civil Engineer, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN STEAM ENGINES" to be as follows:-
This Invention has for its object several improvements in steam engines.
In order to use the steam advantageously, a peculiar form of expansion
valve is employed, which consists of a seat, which is formed in the following
manner-There are two openings with passages which conduct the steam to
the ordinary valve box; and in addition to these openings, on the face of the seat
of the valve there are two recesses, which extend to a greater radius than the
openings, and are so formed, that when the two hollow parts of the rotating
valve, which are of the form of the openings through the seat, partly cover the
recesses in the seat and also the openings (which lead to the ordinary valve
box), steam will pass from the expansion valve to the ordinary valve box; but
when the hollows or recesses in the rotating valve only cover the openings
through the seat, no steam will pass from the expansion valve to the engine,
and the working of the engine will be by the expansion of the steam previously

page_text: allowed to pass. The rotatory valve receives motion from the engine by a
strap or band. And I would state, that although I have mentioned the valve
as having two recesses, and the seat as having two openings through it, this
may be varied, so that in one revolution of the expansive valve the steam
might be admitted and cut off more than once.
In order to govern and regulate the admission of steam from the boiler to
the engine. I employ a crank or arm on the shaft which is fixed, and another
crank or arm which is moveable on the shaft, and I interpose a spring or
springs between the moveable and fixed arms or cranks, so that the driving
will be through the spring or springs. On the boss of the moveable arm are a
series of inclines, which correspond with a similar series of inclines on a sliding
collar on the shaft, which collar is constantly pressed towards the boss by a
spring or springs. The collar acts on the end of a lever which acts on the
throttle valve; hence, when an excess of steam passes to the engine, the lever is
acted on by the collar; or, in place thereof, the two sets of inclines may be on
an axis, and acted on by the vibration of a pendulum, or by an apparatus acting
in a similar manner to a pendulum. And when the driving is through a
secondary axis, then the first and second axes are geared together by two spur
or cog wheels, and the end of the second axis is carried by a lever, so that the
end of the second axis may rise and fall. One end of the lever is carried and
moves on the main shaft or axis of the engine; the other end of the lever gives
motion to the throttle valves, and is resisted by a spring or springs.
In order to cool the water used for injection, where water is scarce and it is
desirable to use the same water over and over again, I cause the water, after it
has been used and before it is again injected, to be minutely divided, and allow
it to descend in showers in a chamber, through which the cool air which is
passing to supply the ash-pit passes. By these means the water will be cooled
and the air raised in temperature.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Rothwell Lomax in the Great Seal Patent Office 30
on the 19th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROTHWELL LOMAX, of Hammersmith, in the County of Middlesex, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 35
Patent, bearing date the Nineteenth day of September, in the year of our

page_text: Lord One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Rothwell Lomax, Her special licence that I, the said William
Rothwell Lomax, my executors, administrators, and assigns, or such others
as I, the said William Rothwell Lomax, my executors, administrators, 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 STEAM ENGINES," upon the condition (amongst others) that
I, the said William Rothwell Lomax, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Rothwell Lomax, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
This Invention has for its object several improvements in steam engines.
In order to use the steam advantageously, a peculiar form of expansion
valve is employed, which consists of a seat, which is formed in the following
manner-There are two openings with passages, which conduct the steam to
the ordinary valve box; and in addition to these openings on the face of the seat
of the valve there are two recesses, which extend to a greater radius than the
openings, and are so formed, that when the two hollow parts of the rotating
valve, which are of the form of the openings through the seat, partly cover the
recesses in the seat, and also the openings (which lead to the ordinary valve
box), steam will pass from the expansion valve to the ordinary valve box; but
when the hollows or recesses in the rotating valve only cover the openings
through the seat, no steam will pass from the expansion valve to the engine,
and the working of the engine will be by the expansion of the steam previously
allowed to pass. The rotatory valve receives motion from the engine by a
strap or band. And I would state, that although I have mentioned the valve
as having two recesses, and the seat as having two openings through it, this
may be varied, so that in one revolution of the expansive valve the steam?
might be admitted and cut off more than once.
In order to govern and regulate the admission of steam from the boiler to

page_text: the engine, I employ a crank or arm on the shaft which is fixed, and another
crank or arm which is moveable on the shaft, and 1 interpose a spring or
springs between the moveable and fixed arms or cranks, so that the driving
will be through the spring or springs. On the boss of the moveable arm are a
series of inclines, which correspond with a series of inclines on a sliding collar
on the shaft, which collar is constantly pressed towards the boss by a spring or
springs. The collar acts on the end of a lever which acts on the throttle
valve; hence, when an excess of steam passes to the engine, the lever is acted
on by the collar; or, in place thereof, the two sets of inclines may be on an
axis, and acted on by the vibration of a pendulum or by an apparatus acting
in a similar manner to a pendulum. And when the driving is through a
secondary axis, then the first and second axes are geared together by two
spur or cog wheels, and the end of the second axis is carried by a lever, so that
the end of the second axis may rise and fall. One end of the lever is carried
and moves on the main shaft or axis of the engine; the other end of the lever
gives motion to the throttle valve, and is resisted by a spring or springs.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows the face plate of an expansion valve according to my
Invention Figure 2 is a section thereof; Figure 3 shows the rotating valve.
separately; Figure 4 shews a plan of the valve and the valve seat together;
and Figure 5 shows a section, the valve seat, the rotating valve, and the steam
case or cover combined as when in use. The valve is caused to rotate in the
direction indicated by the arrows in Figures 3 and 4. In cach of these
Figures the same letters are used to indicate the same parts. a is the seat of
the expansion valve, which when in use is connected with the ordinary valve or
slide box of a steam engine. a', a', are the two steam passages which conduct
the steam (allowed to pass by the rotating valve) to the ordinary valve box; b, b,
are two recesses in the face of the valve seat; c, c, is the rotating valve, which
is formed with two passages c', c', through it, by which when the passages c¹, c¹,
are over and correspond with the passages a, a, in the seat a of the valve,
steam will flow freely through the openings c', c', in the valve, and also through
the openings a', a', in the valve seat; and when the valve partly covers such
openings a', a', the steam will flow into the hollows b, b, in the seat under the
hollow portions d, d, of the valve, and thence into the openings a', a', at the
same time as steam flows through so much of the openings c', c¹, as are open
to the openings a', a', as will be understood by reference to Figure 4; but when

page_text: the parts d, d, have passed the hollows b, b, and the passages a', a', are covered,
no further steam will pass till by the rotation of the valve the openings a¹, a',
are progressively uncovered. I would remark, that although only two openings
a', a', in the seat and two openings c¹, c', in the valve are shewn, this may be
varied, and more such openings used; and I shall in reference to other Figures
of the Drawings describe another arrangement where eight of each of such
openings are used. The valve c receives motion from the steam engine to
which it is applied in any suitable manner, the motion being communicated to
the axis or spindle e, which fits loosely into the recess at the back of the valve,
and motion is communicated to the valve c by a projection or clog f, fixed on
the axis or spindle e, which comes between the projections c², c², formed on the
back of the valve. g is the steam case or box of the valve, which is fixed steam-
tight to the valve seat. The valve is pressed to its seat by springs h, h, acting
on the bar i, as shown. Figure 6 shows the seat of another expansion valve
with eight openings a¹, according to my Invention, and in like manner other
valves and seats may be made with other numbers of openings. Figure 7 shows
a plan of the rotating valve separately; Figure 8 shows an intermediate plate
with passages through it. This plate is made so as to be set or fixed in
different positions, so that the steam may be cut off earlier or later in the
rotation of the valve. Or this plate may be acted on by the pressure of the
steam in such manner, that when the steam gets too high in pressure, it may
move the plate and cause the steam to be cut off at an earlier period of the
stroke. By the use of this plate, a like effect is produced as resulting from
the recesses before described, but with this difference, that the positions of the
recesses in respect to the steam passage through the valve and its seat are
capable of being varied. Figure 9 shows the seat, the plate and the rotating
valve combined correctly together; Figure 10 shows so much of a side
elevation of a steam engine with the expansive valve applied thereto as will
enable a workman more readily to understand the application of such descrip-
tions of valves. a, a, are the steam passages in the valve seat a; b, b. is the
intermediate plate, having as many holes through it as there are steam passages
in the valve and seat; but the holes in the plate are larger than those in the
valve, in order that the plate may act, in substitution of the recesses b, in
the valve seat, before described. c is the rotatory valve, having stean passages
c, c, therein. The plate 6 is moveable, and has on it teeth a, a, as shewn, into
which the teeth a³ of a lever a takes and such lever is actuated from a piston a³
in a cylinder, into which the steam is allowed to pass constantly; so that when
the steam increases in pressure, it presses up the piston and acts on the disc
or plate b, so as to vary the passages, and thus cause the steam to be cut off at

page_text: an earlier period of the stroke. The valve receives its rotation by means of
the lever d, acted on by the rising and falling of the cross head c. On the
axis of the valve there is a ratchet or toothed disc f. which is actuated by the
claw g and driver h, as the lever d, to which they are attached, is moved up
and down by the working of the engine. The lever a (in the arrangement
Fig. 10) is shown with a connecting roda, which may be connected to a
piston acted on by the pressure of the steam, as above described; or it may be
connected with a governor, which may be used to vary the position of the
plate b, in place of the piston and apparatus, above described.
Another part of my Invention consists of an improved combination for
governing, the action of the throttle or other valve which regulates the passage
of steam to an engine. Figure 12 shows a transverse section, and Figure 13
part of the plan, of the driving shaft or axis of a steam engine with apparatus
according to this part of my Invention applied thereto. is the main or driving
shaft of an engine, on which there is a fixed arm or crank j and a moveable
arm, the two arms having between them a spring 1, in such manner that the
shaft by the fixed arms drives the moveable arm by the spring.
On the face of the nave or boss of the moveable arm are a series of inclines
n, which correspond with inclined notches o on a disc or plate, which is capable
of sliding on the shaft or axis, and this plate is constantly pressed up to the
surfaces n by a spring p, as shown. q is a lever, in connection with a valve
by a connecting rod, as shown; or other arrangement of valve and apparatus
may be used. The power of the engine is communicated to the moveable arm
or crank, and the power is transmitted through the spring to the fixed arm or
crank to the shaft or axis; hence, should the power increase, the interposed
spring between the arms will be compressed, and the inclines 7 will come into
action on the inclines o, and thus will the lever and valve connected thereto
be acted on; and such will be the case should the power decrease, as the spring
between the two arnis will expand, and the steam valve will be more opened.
Another arrangement or combination for this purpose is shewn in plan at
Figure 14, and side view at Figure 15, wherein a pendulum is used. s is a
short axis, which receives motion from the shaft of a steam engine by a strap t
on a pulley or drum v, which moves freely on the axis s. Against one face of
the boss of the drum there is a boss w, pressed so as to be driven round
by friction of the face of the drum v, and on the other face of the boss w are
inclines, which correspond with the inclines on the tube a, which is capable of
sliding on the axis s, but turns with it. y is a pendulum, arranged suitable in
length to swing a determined number of times per minute, according to the
number of strokes per minute. it is desired the engine should make; this

page_text: pendulum is connected by a rod to a crank on the axis. Under these
circumstances, if the engine by the pressure of steam moves too fast, it will
tend to move the pendulum at a greater speed than that due to it; and, on the
other hand, if the piston of the engine moves too slow, the pendulum will keep
up its true speed, and the inclines will, by the lever and connecting rod, as in
the previous case, act on the throttle or other valve used. Where driving
through a second shaft, I cause the bearings of the second shaft to be carried
by levers, as shewn in Figure 16, where a is the shaft, which receives motion
direct from the engine in the ordinary manner; b is the second shaft, for
transmitting the power; this second shaft moves in bearings carried by levers
c, c, one on either side of the cog wheels d and e. One end of each of such
levers moves freely on the shaft a, and at the other end they are connected
together, and are pressed on by a spring f on the stem g, which is fixed, as is
shewn. At the end of levers there is a connecting rod h, which gives motion
to the throttle or other valve. In this combination, motion is most conveniently
transmitted from the shaft or axis b, by having a pulley or drum thereon, in
order to give motion therefrom by a driving strap or band. By this arrange-
ment, in the event of the shaft a moving too fast or too slow, the levers c would
be acted on accordingly, and the spring f, by being compressed or by its
expanding, admit of the connecting rod and valve being varied as required for
allowing more or less steam to fall.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I make no claim to any
of the mechanical parts separately, nor do I confine myself to the precise
details; but what I claim is,
First, the combining mechanical parts into expansion valves, as herein
described.
And, secondly, I claim the combining mechanism as herein described for
regulating the supply of steam.
In witness whereof, I, the said William Rothwell Lomax, have hereunto
set my hand and seal, this Nineteenth day of March, in the year of
our Lord One thousand eight hundred and fifty-six.
Witness,
JNO. ALCOCK.
W. R. LOMAX. (L.S.)