CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATHEW
LEAHY, formerly of Great George Street, but now of Charing Cross, both in
the City of Westminster, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifth day of November, in the tenth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Mathew
Leahy, Her especial licence, full power, sole privilege and authority, that I,
the said Mathew Leahy, my executors, administrators, and assigns, and such
others as I, the said Mathew Leahy, my executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein mentioned, should and lawfully might
make, use, exercise, and vend, within England and Wales, and the Town
of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS IN STEAM
ENGINES;" in which said Letters Patent is contained a proviso, obliging me, the
said Mathew Leahy, by an instrument in writing under my hand and seal, par-
ticularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be inrolled
in Her Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
Mathew Leahy, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is particularly described and
ascertained in and by the following description thereof, reference being had to
the Drawings hereunto annexed, and to the letters and figures marked thereon
(that is to say):-
any
My Invention of improvements in steam engines relates to that description
of steam engines known as locomotive steam engines, and consists in a novel
or improved construction or arrangements of parts, whereby the fire box may
gauge in
be extended laterally beyond the width of the
advisable degree,
and consequently afford a larger amount of fire surface with a greater extent of
fuel in a state of ignition and acting upon the water surface of the boiler than
is at present generally used or employed, thereby increasing the evaporating
power of the engine or boiler, and consequently the power of the engine, the
other parts being made in proportion. I am enabled to effect the object I have
in view by so arranging the driving and running wheels which support the
hinder part of the engine as to allow the fire box to be extended laterally
between the driving and hinder running wheels and over the rails to any
extent that may be considered desirable.
And in order that my Invention may be clearly understood, I have shewn in
the accompanying Drawings different arrangements or modes of conveying
my improvements into effect; premising, however, that although the plans
or arrangements therein shewn and hereafter described will be found fully to
answer the proposed end, I do not by any means intend to confine myself
rigidly thereto, as various modifications in the several parts may doubtless
be made without departing from the nature and object of my Invention.
Figure 1 represents a diagram of a side elevation of a locomotive engine con-
structed according to my improvements; and Figure 2 is a diagram plan of the
same. A, A, is the fire box, which is situated between the driving wheels and
the hinder pair of running wheels. All the wheels are placed within the outside
framing, which is made to enclose the fire box and every part of the engine.
The width between the rails, as shewn in the plan view, is the narrow, or four
feet eight inches and a half gauge; and it will be seen that the fire box extends
over the rails, but the bearings of the running wheels being affixed to the out-
side framing, the over-hanging weight of the fire box will not be in any degree
detrimental to the safety of the engine even at the highest speed. Figure 3,
Sheet II., represents a side clevation of a modification of the plan just described,
the hinder running wheels consisting of two pairs, being mounted in bearings
attached to a "bogie," or pilot truck, or small additional carriage, connected by

page_text: a pivot to the main carriage, as usual; Figure 4 is a plan view of the same,
with the engine driver's platform removed to shew the parts beneath; Figure 5
is a general end view, and Figure 6 a partial sectional elevation, of the fire box
and of the engine, drawn upon an enlarged scale. In this case also the running
wheels are mounted in outside bearings. The manner in which the "bogie"
or pilot truck is attached to the after part of the engine carriage will be best
understood by reference to the plan view, Figure 4, and detached sectional
elevation, Figure 6. In order to facilitate the passage of the engine round
sharp curves, it is connected to the "bogie" or pilot truck by a strong centre pin
or pivot, round which it may turn. This pin or pivot forms the centre of the
"bogie" or pilot truck, which I construct in an improved manner, so that not
only a portion of the weight of the engine may be transferred to and carried by
the pilot truck, but the strain on the centre pin is much lessened. On the
under side of the engine driver's platform is a ring or circular plate t, with an
inclined surface, as seen in the enlarged view, Figure 6; and a corresponding
ring or plate u, also with an inclined surface, is affixed to the framing of the
bogie." A number of conical rollers v, v, which correspond to the inclination
of the rings t and u, are mounted in bearings made in the rings w, w. .In the
Figure these rings w are represented as being supported by radial arms, the
inner ends of which are attached to a collar x, that surrounds the centre pin ;
but, if thought desirable, the radial arms and collar round the centre pin may
be dispensed with. The conical rollers v, v, are placed between the rings
t and u, and the friction of the working parts is thereby much reduced, and by
the conical rollers v, v, drawing against the inclined surfaces of the traverse
rings t and u, the strain from the draught on the centre pin or pivot is much
lessened. Although in the Drawing the axes of the conical rollers t, v, are
represented as being horizontal, or nearly so, it will be evident that they may,
if required or thought desirable, be inclined in any suitable degree, when the
injurious strain on the centre pin will be still further reduced.
Figure 7, Sheet 1, represents another modification, in which the fire box is
still further increased in size, by being extended over the hinder running
wheels, a part of the fire box being arched out for that purpose; Figure 8 is
a plan view of the same. Partitions filled with water are introduced, as shewn
in the Drawing, for the purpose of increasing the evaporating surface exposed
to the direct action of the fire, as well as to strengthen the fire box, and
admit of a greater depth of fuel being used on the fire grate than is usual.
These partitions are made of such a form as to interfere as little as possible
with the draft of the fire. Additional side fire grates, as at F, F, are made to
heat those portions of the fire box and boiler which extend over the hinder

page_text: running wheels, as seen in the plan view, Figure 8, and the smoke and com-
bustible gases evolved from the fires on these side grates will be consumed as
they pass over the ignited fuel on the other grates to the flue. As it may
sometimes be necessary to reduce or increase the air space between the fire
bars, I make these latter adjustable, so that by moving them slightly on one
side the width of the air space may be altered. This is effected by means of
a rack bar, which, by being placed upon and made to hold the upper sides
of the ends of the fire bars, will, by being slightly moved or shogged laterally
either way, incline the bars on one side, and reduce or enlarge the air space
between them, as the case may require; or, if preferred, the rack bar for
adjusting the fire bars may be made to act against the under side of the fire
bars, and the same effect will be produced. As it is always advisable for the
engine driver to be able to ascertain if any of the bearings or working parts are
getting warm, I effect this object by constructing an instrument or apparatus
which will immediately indicate any considerable alteration in the temperature
of a bearing or other working part. A small chamber or reservoir is made in
or near the bearing or working part, and is furnished with ether, or some other
highly volatilo fluid, and a pipe is conducted therefrom to some convenient spot
near the driver, where it must terminate in a glass vessel or tube, and immedi-
ately that any increase in the temperature of the bearing takes place sufficient
to volatilize the ether or other liquid, this latter will come over and be condensed
in the glass tube or vessel near the engine driver, who will then be aware that
the bearings are becoming heated. It is evident that other materials besides
ether may be employed to indicate by their volatilization or expansion an
increase or rise in the temperature of the working parts, such, for instance, as
mercury, or any substance that will readily liquify at any temperature that
would be injurious to the bearings. In order to reduce the temperature of
the bearings when they become heated, or prevent them from becoming so,
I conduct a pipe from the water reservoir in the tender, and by means of a
small pump worked by the engine I force a small stream of water on to the
bearings or other working parts.
Having now described my Invention, and the manner in which the same is
to be performed, 1 would observe that I do not intend to confine myself to the
precise arrangement or construction of parts herein shewn, so long as the main
features or principle of my improvements are retained; but I claim as the
Invention secured to me by the herein-before in part recited Letters Patent,
First, extending the fire box laterally over the rails and between or over the
wheels, for the purpose of increasing its size and heating surface, as above set
forth, or any modification thereof.

page_text: Inrolled the same Fifth day of May, in the year above written.