IMPROVEMENTS IN STEAM ENGINES
Year: 1864

page_text: LETTERS PATENT to John France, of No. 1, Gloucester Terrace, Clarendon
Road, Notting Hill, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN STEAM ENGINES."
Sealed the 30th May 1865, and dated the 3rd December 1864.
PROVISIONAL SPECIFICATION left by the said John France at the
Office of the Commissioners of Patents, with his Petition, on the
3rd December 1864.
I, JOHN FRANCE, of No. 1, Gloucester Terrace, Clarendon Road, Notting
Hill, in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
This Invention applies firstly to the cylinders, pistons, and valves of steam
engines; and, secondly, to a certain novel construction and arrangement of the
various parts of a steam engine whereby space, labor, and material are greatly
economized, and whereby a very compact and powerful engine is produced at
a greatly reduced cost.
In carrying out my Invention I propose firstly to make the cylinders and
pistons of steam engines of a rectangular form in section, instead of their being
circular as hitherto, by which means I obtain a much greater area of piston in
a given diameter, and consequently an increased power in a given space, or
the same power in a much smaller space. My improved valve is of the form
of a flat circular box, having radial inlet openings passing directly through and

page_text: corresponding with the cylinder ports, against the face of which the circular
box valve revolves. On the inner face of the said valve are other openings
not passing through the valve, but communicating with a central space in con-
nection with the exhaust passage. These openings are separated from the
inlet openings above mentioned by means of radial divisions or partitions.
The inlet and exhaust openings in the revolving valve are arranged alternately,
and so placed with regard to the cylinder ports that when one is admitting
steam the other is open to the exhaust and vice versa. By having a sufficient
number of openings in the valve the latter will only require to make one
revolution for every two, four, six, or other number of strokes of the piston,
and in working a pair of cylinders side by side the same valve will answer for
both cylinders, the ports of one cylinder being on one side and those of the
other cylinder on the opposite side of the centre on which the valve revolves,
care being taken so to arrange the ports that one piston may be half-stroke in
advance of the other. When it is desired to work the steam expansively, I
place on the back of the revolving valve a circular plate or disc having open-
ings corresponding exactly with the cylinder ports. When the plate is in the
position with its openings immediately over the steam ports the engine works
with full steam, but upon turning this plate so as to give these openings a
slight "lead" of the cylinder ports the steam will be cut off sooner, and thus
the steam will work expansively, d this will not in any way interfere with
the exhaust, which will work precisely as before.
In constructing a pair of engines according to this Invention I propose to
place the two rectangular cylinders side by side in a horizontal position, the
cylinders being a sufficient distance apart to allow the exhaust steam to escape
by a passage between them. Each cylinder has two rectangular pistons fitted
in it, and through the centre of the two cylinders (between the two pistons)
the driving shaft passes transversely, being provided with steam-tight conical
bearings at each side. The driving shaft is furnished inside each cylinder
with an arm having a pin projecting therefrom working in a slide which
moves in a vertical slot between the two pistons, by which means the recipro-
cating motion of the latter imparts a rotary motion to the main shaft. The
steam chest is placed over the centre of the two cylinders, and in it is a
revolving valve of the construction previously described, the valve being pro-
vided with a rim of bevil teeth on its circumference driven by a bevil pinion
keyed on a spindle which passes out of the steam chest through a stuffing
box, and is driven by a pair of spur wheels from the main shaft. The valve
spindle is also capable of being moved independently of the main shaft by
means of a hand wheel when it is required to reverse the engine. If it is

page_text: desired to work the steam expansively a "cut off" plate similar to that above
described is placed on the back of the valve, and is set to the required "lead"
by means of a lever keyed upon a spindle passing vertically through a stuffing
box in the top of the steam chest.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John France in the Great Seal Patent Office on the
. 3rd June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN FRANCE,
of No. 1, Gloucester Terrace, Clarendon Road, Notting Hill, in the County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John France, Her special licence that I, the said John
France, my executors, administrators, and assigns, or such others as I,
the said John France, 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 John France, my executors or administrators, by an instru-
ment 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 inime-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John France, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, and on reference to the accompanying Drawings, that is
to say:
This Invention applies firstly to the cylinders, pistons, and valves of steam
engines; and, secondly, to a certain novel construction and arrangement of the

page_text: various parts of a steam engine, whereby space, labor, and material are greatly
economized, and whereby a very compact and powerful engine is produced at
a greatly reduced cost.
In carrying out my Invention I propose, firstly, to make the steam chambers
enclosing the pistons (which are usually cylindrical and called the cylinders)
as well as the pistons of steam engines of a rectangular form in section, instead
of their being circular as hitherto, by which means I obtain a much greater
area of piston in a given diameter, and consequently an increased power
in a given space, or the same power in a much smaller space; and I may
here remark that wherever in this Specification I have used the word
"cylinder" I intend to signify thereby a rectangular steam chamber enclosing a
rectangular piston, and answering the same purpose as the cylinder of an
ordinary steam engine. My improved valve is of the form of a flat circular
box having radial inlet openings passing directly through and corresponding
with the cylinder ports, against the face of which the circular box valve
revolves. On the inner face of the said valve are other openings not passing
through the valve, but communicating with a central space in connection with
the exhaust passage. These openings are separated from the inlet openings
above mentioned by means of radial divisions or partitions. The inlet and
exhaust openings in the revolving valve are arranged alternately, and so
placed with regard to the cylinder ports that when one is admitting steam the
other is open to the exhaust and vice versa. By having a sufficient number of
openings in the valve the latter will only require to make one revolution for
every two, four, six, or other number of strokes of the piston, and in working
a pair of cylinders side by side the same valve will answer for both cylinders,
the ports of one cylinder being on one side and those of the other cylinder
on the opposite side of the centre on which the valve revolves, care being
taken so to arrange the ports that one piston may be half-stroke in advance
of the other. When it is desired to work the steam expansively I place on
the back of the revolving valve a circular plate or disc having openings cor-
responding exactly with the cylinder ports. When the plate is in the position
with its openings immediately over the steam ports the engine works with
full steam, but upon turning the plate so as to give these openings a slight
"lead" of the oylinder ports the steam will be cut off sooner, and thus the
steam will work expansively, and this will not in any way interfere with the
exhaust which will work precisely as before.
In constructing a pair of engines according to this Invention I propose to
place the two rectangular steam chambers or "cylinders" side by side in a
horizontal position, the cylinders being a sufficient distance apart to allow the

page_text: exhaust steam to escape by a passage between them. Each cylinder has two
rectangular pistons fitted in it, and through the centre of the two cylinders
(between the two pistons) the driving shaft passes transversely, being pro-
vided with steam-tight conical bearings at each side. The driving shaft is
furnished inside each cylinder with an arm having a pin projecting therefrom
working in a slide which moves in a vertical slot between the two pistons, by
which means the reciprocating motion of the latter imparts a rotary motion to
the main shaft. The steam chest is placed over the centre of the two
cylinders, and in it is a revolving valve of the construction previously described,
the valve being provided with a rim of bevil teeth on its circumference, driven
by a bevil pinion keyed on a spindle which passes out of the steam chest
through a stuffing box, and is driven by a pair of spur wheels from the main
shaft, or it may be otherwise driven. The valve spindle is also capable of
being moved independently of the main shaft by means of a hand wheel when
it is required to reverse the engine. If it is desired to work the steam expan-
sively a "cut off" plate similar to that above described is placed on the back
of the valve, and is set to the required "lead" by means of a lever keyed
upon a spindle passing vertically through a stuffing box in the top of the
steam chest.
Such being the nature and object of my said Invention for " Improvements
in Steam Engines," I will now proceed to describe more in detail the manner
in which the same is to be or may be performed or carried into practical
effect; and in order that the same may be distinctly understood I have annexed
hereunto two Sheets of Drawings illustrative thereof, and have marked the
same with figures and letters of reference corresponding with those in the fol-
lowing explanation thereof, that is to say :-.
In Sheet 1 of the annexed Drawings, Figure 1 is an end elevation, Figure 2
a front view, Figure 3 a vertical transverse section, and Figure 4 a vertical
longitudinal section of a pair of engines constructed according to my Inven-
tion. In Sheet 2 of the Drawings, Figure 5 is a plan view of the same,
Figure 6 is a plan view (shown partly in section) of my improved valve, and
Figure 7 is a view of the facing or cylinder ports over or on which it works.
a, a, are the rectangular steam chambers (which although a confessed mis-
nomer I shall for convenience of description cail the "cylinders") placed
horizontally side by side, and made by preference in one casting. b, b, is a
passage between the two cylinders by means of which the exhaust steam
escapes. Each cylinder has two rectangular pistons c, c, (see Figure 4) fitted
in it, and through the centre of the two cylinders (between the two pistons)

page_text: the driving shaft d, d, passes transversely, being provided with conical bearings
e, e, at each side. The shaft d, d, is provided inside each cylinder with an arm
or crank f,f, having a pin 9, 9, working in a slide h, h, which moves in a vertical
slot i, i, between the two pistons c, c, by which means the alternate recipro-
cating motion of the latter imparts a rotary motion to the shaft d, d, the two
arms or cranks being placed at right angles to each other so that one piston
is always half-stroke in advance of the other. The steam chest or valve box
k, k, is placed over the centre of the two cylinders, and is provided with a re-
volving valve seen in Figure 3 (Sheet 1) and in Figure 6 (Sheet 2). This
valve is made in the form of a flat circular box 1, 1, having radial inlet or
steam openings m, m, passing directly through it, and corresponding with the
cylinder ports n, n, in contact with the face of which the valve revolves. On
the inner face of the said valve are other or exhaust openings o, o, not passing
through the valve but communicating with a central space p, p, in connection
with the exhaust passage b, b. These openings are separated from the inlet
openings m, m, by means of the radial divisions or partitions which form the
sides of the latter as seen at Figure 6 (Sheet 2). The inlet and exhaust
openings being so arranged in regard to each other and to the cylinder ports
that one valve will answer for both cylinders, and the former will only be
required to make one revolution to four of the shaft. The valve is furnished
with a rim of bevil teeth q, q, and is caused to revolve by means of a bevil
pinion r, r, actuated by the spur wheels s, s, one of which is keyed on the driving
shaft d, d. When it is desired to work the steam expansively I place on the
back (or top) of the revolving valve à circular plate or disc t, t, (see Figure 3,
Sheet 1) having therein four openings corresponding exactly with the cylinder
ports n, n, (Figure 7, Sbeet 2). It will be evident that when this plate is in
such a position that its openings are precisely over the cylinder ports it will
have no effect upon the admission of the steam, but upon turning the plate
t, t, by means of the lever u, u, on the top of the steam chest, so as to give these
openings a slight "lead" of the cylinder ports, the steam will be cut off sooner
and will consequently work expansively without in any way interfering with
the exhaust which will work precisely as before.
Having now described the nature and object of my said Invention for "Im-
provements in Steam Engines," together with the manner in which the same
is to be or may be performed or carried into practical effect, I would remark in
conclusion that I claim as my Invention the improvements in steam engines
above described and set forth and exhibited in the Drawings annexed, or
any mere modification thereof constructed and operating in substantially

page_text: the same or a similar manner, and more especially I claim the rectangular
steam chambers or "cylinders" and pistons, and the revolving circular
box valve.
In witness whereof, I, the said John France, have hereunto set my
hand and seal, this First day of June, in the year of our Lord One
thousand eight hundred and sixty-five.
JOHN FRANCE. (L.S.)