IMPROVEMENTS IN PORTABLE AND OTHER STEAM ENGINES
Year: 1871

page_text: LETTERS PATENT to James Marshall and William Bishop Harding,
of Gainsborough, in the County of Lincoln, Engineers, for
the Invention of "IMPROVEMENTS IN PORTABLE AND OTHER STEAM
ENGINES."
Sealed the 31st May. 1872, and dated the 9th December 1871.
PROVISIONAL SPECIFICATION left by the said James Marshall and
William Bishop Harding at the Office of the Commissioners of
Patents, with their Petition, on the 9th December 1871.
We, JAMES MARSHALL and WILLIAM BISHOP HARDING, both of
Gainsborough, in the County of Lincoln, Engineers, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN PORTABLE AND OTHER
STEAM ENGINES," to be as follows)
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page_text: The usual method of mounting the various parts of portable engines, such
as the crank shaft, slide bar, governor, and reversing gear brackets, is by
bolting them direct to the boiler, necessitating the cutting of a number
of bolt holes therein; and as the boiler is subject to expansion and con-
traction by considerable variations in temperature it has the effect of
disturbing the relative position of the various parts of the engine.
In order to avoid these objections according to our improvements we
attach the governor and reversing gear brackets to what we shall term a
bridge plate, which is so arranged as to be entirely independant of the
boiler, and is not affected by its expansion and contraction. The brackets
which it is customary to use for supporting the ends of the slide bars we
dispense with entirely and attach them to the bridge plate.
Another part of our improvements consists in the method of mounting
the supports for the crank axle upon wrought-iron plates, which are
rivitted to the boiler. To these plates we attach guides to receive the
carriages (into which are fitted the journals of the crank axle) so
arranged that the boiler is free to expand and contract, without affecting
the position of the journals in relation to the other parts of the engine.
1017
In order to combine strength with lightness we make the connection
between the cylinder at one end and the carriages of the crank shaft
journals at the other by means of tubular stays. These stays according to
our improvements are made to serve as the support for the bridge plate,
and the boiler is freed from all strain caused by the working of the
engine.

page_text: t
WHEREAS Her most Excellent Majesty. Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of December,' in the
year of our Lord One thousand eight hundred and seventy-one, vin
the thirty-fifth year of Her reign, did; for Herself, Her! heirswandy
successors, give and grant unto us; the said James Marshall and William,
Bishop Harding, Her special licence that we, the said James Marshall;and)
William Bishop Harding, our executors, dministrators, and assigns;ior.
such others as we, the said James Marshall and William Bishop Harding,
our 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, exer-
cise, and vend, within the United Kingdom of Great Britain..and
Ireland, the Channel Islands, and Isle of Man, an Invention, for "
PROVEMENTS IN PORTABLE AND OTHER STEAM ENGINES," upon the condition"
(amongst others) that we, the said James Marshall and William. Bishop.
Harding, "our executors or administrators, by an instrument, in writing
under our or their hands and seals, or under the hand and seal of one of
us or them, 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 immediately after the date of the said
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This Invention relates to the arrangement and construction of portable:
and other steam-engines where the working parts of the engines are
attached to the boilers, and in order that our improvements may be
clearly understood and readily carried into practice we will proceed to
describe the same, reference being made to the Drawings hereunto
annexed, which show a side and end elevation of a portable steam engine
arranged and constructed in accordance with our Invention.
.

page_text: The usual method of mounting the various parts. of portable engines,
such as the crank shaft, slide bar, governor, and reversing, gear brackets,
is by bolting them direct to the boiler, necessitating the cutting of. a
number of bölt-holes therein, and, as the boiler is subject to expansion.
and contraction by considerable variations in temperature it has the
effect of disturbing the relative position of the various parts. of the

page_text: to stationaery or other forms of steam engines where the working parts
are mounted upon or arranged in combination with the boiler.
In witness whereof, we, the said James Marshall and William
Bishop Harding, have hereunto set our hand and seal, this Sixth
day of June, in the year of our Lord One thousand eight
hundred and seventy-two.
JAMES MAROHALL.
(L.S.)
WILLIAM BISHOP HARDING. (L.S.)
Witness to the signatures of James
Marshall and William Bishop
Harding,
GEORGE KEIGHTLEY,
Gainsborough.