IMPROVEMENTS IN LOCOMOTIVE AND OTHER STEAM ENGINES
Year: 1857

page_text: LETTERS PATENT to Thomas Forsyth, of the City of Manchester, Engineer,
for the Invention of "IMPROVEMENTS IN LOCOMOTIVE AND OTHER STEAM
ENGINES"
Sealed the 12th June 1857, and dated the 5th January 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Forsyth at the
Office of the Commissioners of Patents, with his Petition, on the 5th
January 1857.
I, THOMAS FORSYTH, of the City of Manchester, Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN LOCOMOTIVE AND OTHER
STEAM ENGINES," to be as follows:-
The nature of my Invention consists in making the steam ports of the
cylinder with corrugated or angular edges, and the valve with corresponding
edges, for the purpose of enlarging the area of the inlet and outlet of steam
at early portions of each reciprocation of the valve. The valve and the ports,
instead of being placed at right angles to the direction of the traverse of the
valve, are placed diagonally, whereby the area of the outlets for the exhausted
steam is conveniently enlarged, and the exhausted steam is allowed to escape
at both ends of the exhaust port into the same exhaust pipe. One of the
outlets is in direct communication with the exhaust pipe, and the other by
means of a passage or pipe passing round the cylinder.
My improvements in pistons consist in making the body piece either solid

page_text: on the piston rod or otherwise fastened to it. Segmental bearing pieces or
packing rings furnished with a retaining groove fitting on the body piece, and
having overlap joinings, are pressed against the inside of the cylinder by one
or more angular springs fitting in dovetailed recesses in the packing rings.
Another part of my Invention consists in an improved feed-water heating
apparatus for locomotive steam engines. A box containing divisions to cause
the water to pass through it by a defined tortuous route, and furnished with
tubes, is placed in the smoke box; the products of combustion after passing
through the tubes of the boiler in the ordinary manner, are conveyed through
the tubes of the water-heating apparatus before they enter the chimney,
thereby imparting their heat to the water in the heating box in its passage
from the tender to the boiler. I prefer to place this water-heating apparatus
above the tubes of the boiler, so that it may not interfere with the cleaning
out of the said tubes, but it may be placed in such wise that the tubes of
the water-heating chamber coincide with those of the boiler.
My Invention further consists of an improved blast regulator; which may
be placed on the ordinary blast pipe or between the feed-water heating
apparatus, above referred to, and the bottom of the chimney. A conical shell,
having numerous perforations or slots in it, is placed on the blast pipe; these
perforations or slots are opened or closed at pleasure by means of a conical
cover having corresponding perforations or slots through it; this cover is
furnished with suitable gearing, by means of which the engine driver can
regulate the position of the cover.
The last part of my Invention consists in enclosing the cylinders of "out-
side cylinder" locomotive steam engines by so arranging the form of the
smoke box or chinney end as to enclose the cylinders therein, thereby pro-
tecting them from the cooling influence of the external atmosphere.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Forsyth in the Great Seal Patent Office on
the 3rd July 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME. I, THOMAS
FORSYTH, of the City of Manchester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of January, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the saiḍ

page_text: Thomas Forsyth, Her special licence that I, the said Thomas Forsyth, my
executors, administrators, and assigns, or such others as I, the said Thomas
Forsyth, 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 LOCOMOTIVE
AND OTHER STEAM ENGINES," upon the condition (amongst others) that I, the
said Thomas Forsyth, 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 Thomas Forsyth, 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 fol-
lowing, statement (that is to say):-
The nature of my said Invention consists:-
First, in placing the valve and the ports of steam engines in a diagonal
position instead of at right angles to the direction of the. traverse of the
valve, as heretofore.
Secondly, in making the exhaust steam escape from both ends of the
exhaust port into the exhaust or blast pipe, instead of from one end only,
as heretofore.
Thirdly, in an improved metallic piston.
Fourthly, in an improved mode of constructing the packings or wearing
rings or segments of metallic pistons.
Fifthly, in an improved stop piece for pistons.
Sixthly, in an improved feed-water. heating, apparatus.
Seventhly, in an improved blast regulator.
And, lastly, in enclosing the cylinders of outside cylinder locomotive engines
within the smoke box, and causing the hot products of combustion to circulate
around the cylinders of locomotive engines in passing to the chimney.
And in order that my Invention may be fully understood and readily
carried into effect, I will proceed to. describe the accompanying Sheet of
Drawings, reference being had to the figures and letters marked thereon.
Figure 1 is a side elevation of a locomotive. steam. cylinder constructed
according to my improvements; and Figure 2, a.section. of the same.. a-is

page_text: the body of the cylinder; b, b, the steam ports; and c, the exhaust port; dis
the outlet at one end of the exhaust port, which is in direct communication
with the exhaust pipe; and e is the outlet at the other end of the exhaust
port; this outlet is in communication with the same exhaust pipe by means
of the passage for a pipe passing round the cylinder a.
By placing the ports in a diagonal position, as shewn, the area of the
outlets for the exhausted steam is conveniently enlarged, and by making
an outlet at each end of the exhaust port great facility is afforded for the
escape of the exhaust steam.
Figure 3 is a transverse section of my improved metallic piston; Figure 4
is a front view; and Figure 5, a side view of the same. g is the body of the
piston, represented in this instance as being keyed to the piston rod, but it
may be made of the same piece of metal if preferred. is the packing or
wearing ring, furnished with a retaining groove fitting on the body piece g.
The inuer circumference of each packing ring is dovetailed, and the angular
springs i, i, fitting in these dovetailed recesses press the packing ring against
the inside of the cylinder within which the piston works. These springs have
snugs projecting from them, as seen in Figure 4, to facilitate the putting
together of the parts. The packing ring is shewn as being cut across in one
place, but it may be cut across in two or more parts if preferred. The stop piece
inarked is formed like the letter H, as shewn best in Figure 5, and has
overlap joinings fitting on the packing ring. The various pieces composing
my improved metallic pistons may be made of any suitable metal and in any
convenient manner, but I prefer the following mode of construction:-I make
the wearing rings or segments h by casting a cylinder of metal endwise (up-
and-down), and long enough to allow of several rings or sets of segments
being turned off it where the quality is well suited for the required purpose.
I either cast such cylinders with a slot or slots from end to end, or partially
from end to end; or I cut by hand, or machinery, or in any suitable mauner,
the requisite slots in the said cylinders before turning. I also, before turning,
cramp, contract, or close the said cylinders to diameters less than they have
before being cramped, and while so cramped or clipped into reduced diameters,
I turn them to the proper dimensions for use, that is, to fit their cylinders,
while having within themselves considerable elasticity to follow up the wear
of the periphery. The stop, herein-before described, is put into its place
before the piston is put into the cylinder, it having a portion of its inner
surface in contact with the spring i or other elastic media, which keep its
outer surface in contact with the cylinder, it being otherwise kept in its place
by the wearing parts of the piston only, and not by the body or block piece,

page_text: as shewn.
The stop piece is thus prevented from having any influence in
expanding the packing ring.
Figure 6 represents a sectional elevation of the smoke box end of an out-
side cylinder locomotive steam engine to which my improvements are applied;
Figure 7 is a sectional side view of the same. a, a, are the cylinders; k, the
smoke box; and, the boiler; is the steam pipe within the boiler; and l²,
the supply pipes conveying the steam to the cylinders a; m is the box or
casing of my improved feed-water heating apparatus, which I prefer to place
above the level of the tubes in the boiler, so that it may not interfere with the
cleaning out of the said tubes. The box m, seen best in the detached view,
Figure 8, is cast or otherwise made with divisions n, n, and it is furnished
with tubes o, o, through which the products of combustion, after passing
through the tubes of the boiler, pass before they escape through the chimney p.
The feed water enters the box m through the pipe q, and after passing along
the tortuous route formed between the divisions n, the objects of which are to
cause the feed water to come in contact with the surface of all the tubes o,
and to prevent or diminish the accumulation of sediment from the water, it is
taken away through the pipe », and pumped into the boiler, teuder, or any
intermediate receptacle; the temperature of the feed water is thus consider-
ably raised by the products of combustion in their passage to the chimney.
The ribs n, n, may be dispensed with, although I prefer to employ them or
other equivalent agent. This feed-water heating apparatus may be placed
in such a position that the tubes o coincide with the tubes in the boiler. I
prefer using a donkey pump in connection with this apparatus, so that the
feed water can be heated when the locomotive is at rest, as soon as there
is sufficient steam to work the donkey pump.
On referring to Figure 8 it will be seen that there is an opening through
the box m for the blast pipe s, which conveys the exhaust steam to the
chimney as usual, or through my improved blast regulator, shewn in Figures 6
and 7. This improved blast regulator consists of the conical shell t fixed to
the top of the blast pipe s; this conical shell has numerous perforations or
slots through it, which are opened or closed at pleasure by the conical cover u,
furnished with corresponding perforations or slots, the cover u is moved partly
round on the shell t by the lever fixed on the shaft w; the lever v takes on
a stud projecting from the cover u. To the shaft w another lever x is fixed,
which is acted upon by a rod and handle brought within convenient reach
of the engine driver. When the blast or draft on the fire caused by the
escaping steam is required to be increased, the openings in the shell t are
closed by the cover u, and the exhaust steam is forced to make its escape

page_text: through the hole in the top of the shell at the highest velocity, but when
less blast is required the position of the cover u is gradually changed, so as
to open the perforations or slots in the cover; the exhaust steam can then
escape partly through the said perforations or slots, and partly through the
hole in the top of the shell at a reduced velocity. By this means the
amount of draught or blast can be regulated with facility.
Figures 6 and 7 represent a mode of constructing the last part of my
Invention, which consists in enclosing the cylinders of outside cylinder loco-
motive engines to protect them from the cooling influence of the external
atmosphere, and to superheat the steam in them by the hot products of com-
bustion. The casing of the smoke box is taken round the cylinders a, a,
and the products of combustion after passing through the tubes of the boiler
are or may be guided by the partition y, so as to pass around the cylinders
a, a, before they proceed through the tubes of the feed-water heating appa-
ratus or to the chimney; such a partition y is equally applicable to inside
cylinder engines to guide the products of combustion round the cylinders.
Figure 9 represents a section of my improved feed-water heating apparatus
as applied for heating the feed water of a stationary steam engine boiler;
m, m, are two heating boxes furnished with tubes o, o, and with partitions if
required, as in Figure 8. These boxes are placed in an enlarged part of the
flue z, and the sectional area of all the tubes o should not be less than that of
the flue z. I prefer to place a door between the two boxes m to enable the
attendant to clean out the tubes o when requisite; but the application of my
feed-water heating apparatus to the boilers of stationary steam engines admits
of numerous other adaptations to suit the different arrangements of boilers.
Having now described the nature of my Invention, and the best means
with which I am acquainted for performing the same, I wish it to be under-
stood that I do not limit myself to the details herein set forth, as the same
may be considerably modified without departing from the peculiar character
of my luvention; and I declare that I claim,-
First, placing the valves and the ports of steam engines in a diagonal
position in the manner and for the purpose described.
Secondly, making the exbaust steam escape at both ends of the exhaust
port in the manner and for the purpose described.
Thirdly, the combination of the parts marked g, h, i, and j, in Figures 3,
4, and 5, forming an improved metallic piston, or any modification of the
same or similar parts.
Fourthly, the improved mode of constructing the wearing rings or
packings of metallic pistons, as described.

page_text: Fifthly, the improved stop piece, marked in Figures 4 and 5, when
used in combination with my other improvements in pistons or when
applied to other pistons.
Sixthly, the improved feed-water heating apparatus described, and parti-
cularly the ribs or other agents forming the tortuous route for the feed water.
Seventhly, the improved blast regulator described, consisting of the
stationary shell and moveable cover u, or any equivalent parts.
And, lastly, enclosing the cylinders of outside cylinder locomotive steam
engines, and the application of the partition plate y or other equivalent, in
the manner and for the purposes described.
In witness whereof, I, the said Thomas Forsyth, have hereunto set my
hand and seal, this Second day of July, in the year of our Lord One
thousand eight hundred and fifty-seven.
5 Witness,
H. B. BARLOW,
Manchester.
THOMAS FORSYTH. (L.S.)