VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES
Year: 1821

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
BRODERIP, of London, Esquire, now residing in Glasgow, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by
His Letters Patent under the Great Seal of that part of the United Kingdom
of Great Britain and Ireland called England, bearing date at Westminster,
the Fifth day of December, One thousand eight hundred and twenty-one,
give and grant unto me, the said Charles Broderip, my exors, adiñors, and
assigns, His Majesty's special licence; full power, sole privilege and authority,
that I, the said Charles Broderip, my exors, adñiors, and assigns, during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend my "VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES,"
within England, Wales, and the Town of Berwick-upon-Tweed, and also
in all His Majesty's Colonies and Plantations abroad; in which said Letters
Patent there is contained a proviso that if I, the said Charles Broderip, should
not particularly describe and ascertain the nature of my said Invention, and
in what manner the same is to be performed, by an instrument in writing under
my hand and seal, and cause the same to be enrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after
the date of the said Letters Patent, that then the said Letters Patent should
cease, determine, and become void, as in and by the said Letters Patent,
referrence being thereunto-had, will more fully and at-large appear..

page_text: NOW, in compliance with the said Letters Patent, 1, the sand Caries
Broderip, do particularly describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, in and by this instrument
in writing under my hand and seal, as follows, that is to say:-
First, in steam engines, more especially where the cylinder is placed hori-
zontally and the lower part thereof does not communicate with the condenser,
I place at such lower part and at such end of the cylinder a pipe or pipes,
the outer end or ends, extremity or extremities, of which has a valve or
valves loaded with a weight or weights somewhat exceeding the extreme
pressure of the steam upon the inner surface of the said valve or valves
in such a manner that the said valve or valves will remain closed, except
when an accumulation of water shall take place in the cylinder, so as to
exert, together with the pressure of the steam, a power greater than the
said weight or weights, and thereby opening the said valve or valves and
allowing the said water to discharge itself from within the cylinder, or other-
wise the said valves or valves might be loaded with a heavier weight, in which
case the said valve or valves must be opened by hand or otherwise previous to
starting the engine, in order to let the inclosed water escape, if any such
should have accumulated in the cylinder. In cylinders with two pistons
I place an additional pipe and valve similarly loaded, and communicating
with that portion of, the lowest part of the cylinder which is between the two
pistons when at their nearest approach to each other.
Secondly, I place and firmly fix to the bottom of the engine cylinder in
vertical engines, and to the end opposite to the cover in horizontal engines, a
rod or cylinder of brass or other suitable metal, which said rod or cylinder is
placed truly in the axis of the engine cylinder, and. extends the whole length
thercof, or nearly so, and I make the piston rod hollow for somewhat a greater
length than the before-mentioned rod or cylinder, and the hollow thereof may
be made to fit and slide truly upon the before-mentioned rod or cylinder for its
whole length, or it may be formed of a greater diameter than the said rod or
cylinder, and the portion thereof which is fixed to the piston may have a ring
or bush of steel or other suitable metal truly fitted to the said rod or cylinder
upon which it is to slide, and also firmly fitted to the said piston rod. In
cylinders with two pistons, and more especially in such engine cylinders when
placed in a horizontal position, I fix this rod or cylinder by its middle part in
the centre of a plate or diaphragm placed in that portion of the engine cylinder
which is between the two pistons when at their nearest approach to each
other, in such a manner that the said rod or cylinder extends in opposite direc-
tions to the two ends, or thereabouts, of the engine cylinder, being in the axis

page_text: thereof, and allowing the two piston rods and pistons to slide truly thereon,
and to counterpoise each other, as they alternately recede from and approach
each other.
Thirdly, when the engine cylinder is placed in a horizontal position, and
especially when it has two pistons, I place an additional cylinder and piston,
but in a vertical position; this additional cylinder being only one half of the
diameter and length of the large cylinder or thereabouts, and communicating
with the steam pipe and condenser of the large cylinder. The piston rod of
this vertical cylinder is connected with the crank of the large cylinder by levers
or other usual means, in such a manner that when the piston or pistons of the
large cylinder is or are at the end of the stroke, the piston of this small
cylinder is at or about the middle of its stroke, and, on the contrary, when this
last piston is at the end of its stroke, the piston or pistons of the large cylinder
is or are at or about the middle of its or their stroke. The steam valve or
valves of this small cylinder is or are also connected with the working gear of
the valve or valves of the large cylinder in such a manner that the whole may
be thrown in and out of gear at one and the same time, and the engine started
either for the forward or back stroke by one and the same operation.
In witness whereof I the said Charles Broderin have hereunto set my
the year of our Lord 1822, the aforesaid Charles Broderip came before our said
Lord the King in His Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of the
Inrolled the Fifth day of June, in the year of our Lord One thousand
eight hundred and twenty-two.