CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES
Year: 1827

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JACOBI
PERKINS, of Fleet Street, in the City of London, Engineer, send greeting..
WHEREAS His present most Excellent Majesty King George the Fourth,>
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-second day of March, in the eighth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said Jacob Persons, His especial licence, that I, the said Jacob Perkins, my
exors, admors, and assigns, or such others as I, the said Jacob Perkins, my
exors, admors; 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 expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, and also in His said Majesty's.
Colonies and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS
IN THE CONSTRUCTION OF STEAM ENGINES;" in which said Letters Patent is con-
tained a proviso obliging me, the said Jacob Perkins, by an instrument in
writing, under my hand and seal, particularly 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 His Majesty's High Court of Chancery within.
six calendar months next and immediately after the date of the said recited.
Letters Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said.
Jacob Perkins, do hereby declare the nature of my said Invention to consist in...

page_text: a steam engine, constructed in such manner, first, with respect to the boiler or
generator,_that_the_density-of-the-steam-may-be-regulated with respect to its
temperature, so as to be used in whatever state may be most approved by the
operator, and which I therefore denominate perfect steam; secondly, with
respect to the piston and cylinder, that a sufficient vacuum is made on the
eduction side of the piston without the use of the air pump or the usual
quantity of condensing water; and thirdly, with respect to the last-mentioned
improvement, that it may be applied to using high-pressure steam upon a
second piston in a second cylinder after it has acted upon a first piston without
creating any reaction on the said first piston. And whereas, in order more
particularly to explain the nature of my said first improvement, I will here
observe, that I have found by experience that to generate steam by heating
water in tubes, all the parts of which are exposed to the fire, steam will become
more or less surcharged with caloric, and will often shew a much higher tem-
perature for the power it is exerting than would be the case if it had had its
proper proportion of water, thereby wasting much of the caloric as it passes off
with the steam without a proportional power being derived, at the same time
injuring parts of the engine by overheating them; to effect this important
object, of insuring to the steam its due proportion of water, I have caused a
strong metallic cylindrical vessel, which I denominate a steam chamber, to be
fixed in some non-conducting material, having no part of it in contact with the fire.
In this vessel I keep constantly more or less water. I also insert in the bottom
of the steam chamber a steam tube, which is connected immediately with the
last generating tube; this steam tube enters through one side, and at the bottom
of the steam chamber it runs horizontally till it comes in contact, or nearly so,
with the other side; the under side of that part of the tube which is inside
the steam chamber is perforated with a sufficient number of holes to allow the
surcharged steam to rush downwards, and impinge on the bottom of the steam
chamber; after which it rises by its own levity through the water, taking in
its ascension its due proportion of water so necessary to form perfect steam, or
steam of its proper density, with respect to its temperature. To insure a
sufficient supply of water to the steam chamber a small tube is connected with
the pipe of the feed pump, which is attached to the bottom of the steam
chamber or the steam pipe leading to it. To prevent the supply being too great
a regulating stopcock is inserted in this tube; thus, by surcharging the steam
and afterwards allowing it to pass through the water which is forced into the
steam chamber for that purpose, great economy is effected. And whereas, in
further compliance with the said proviso, I, the said Jacob Perkins, do hereby
describe the manner in which my said. Invention is to be performed by the

page_text: The Drawing marked A, No. 1, consists of two Figures, and has reference
to my said first improvement only; the parts thereof I describe as follows, it
being observed that where the same letters are used in both Figures they denote
similar parts. A, Fig. 1, shews the section of a generating furnace. A, Fig. 2;
shows a side view of the generating furnace; B, B, B, B, &c., are the
generating tubes which contain the water that is kept from expanding into.
steam by means of the pressure valve being loaded with sufficient weight for
that purpose; C, the pressure valve; the parts marked D are similar tubes,
which I call the receiving tubes, into which the expanding water rushes,
which in its course takes up not only caloric enough to convert it into
steam, but to surcharge it; by which means the water which is forced
directly from the force pump into the bottom of the steam chamber is also
converted into steam, thereby rendering the steam what I call perfect; E,
the steam chamber; shows the height of the water in the chamber, which
may be varied at the pleasure of the operator; F, the passage from the
last receiving tube to the steam chamber; G, the steam pipe; H, the
escape valve; I, I, I, the descending flue; K, a valve for opening a more
direct communication with the chimney, by which means the fuel is more
readily ignited when. the furnace is cold; L, a valve for admitting air into the
chimney, by which means the quantity requisite for combustion is regulated;
M, the ash-pit; N, the injection pump; O, the injection pipe; P, the hot
water cistern; Q, the pipe leading from the hot water cistern to the injection
pump; R, the chimney; S, S, S, S, the caps and screws of the connecting'
tubes shown by dotted lines in Fig. 1; T, T, the injection tube, which leads
immediately from the injection pump into the steam chamber, (that is to say)
without having passed through the steam generator; V, the stopcock, for
regulating the quantity of water which is forced into the steam chamber for the
purpose of being expanded into steam by the steam surcharged with caloric;
W, regulating screw. which determines the length of the stroke of the pump,
and, of course, the quantity of water which is forced into the tubes or gene-
rators and steam chamber; X, X, the stopcocks, by which the quantity of
water in the steam chamber is ascertained by the operator. The tubes of the
generator may be square or round, it being immaterial which of the two..
3
The Drawing marked B, No. 2, consists of two Figures, and has reference to.

page_text: my, said second improvement only, showing how the vacuum is produced on the
eduction side of the piston. Fig. 1 represents-a-section-of-the-cylinder, piston,
and condenser; and Fig. 2 represents an elevation of the engine. Where
similar parts occur in each Figure they are denoted by similar letters. This
engine is what I call a single stroke high-pressure safety engine. A, the
cylinder; B, the flexible metallic piston; C, the condenser; D, the receptacle
for the uncondensed steam; E, E, the valve, for shutting off the uncondensed
steam from that which is to be condensed; F, the induction valve; G, the
throttle valve; H, H, the steam pipe; I, I, the frame for supporting the
cylinder, &c.; K, the piston rod; L, L, the parallel guides; M, M, the in-
jection pipe; N, the lever, for' opening and shutting the injection pipe by the
means of a stopcock; O, the lever, for opening the induction valve; P, the
pump rod; Q, the fly wheel; R, the aperture for letting off the uncondensed
steam; S, the tube for leading the condensed steam and heated water into the
pump cistern; T, T, T, T, perforations around one end of the cylinder, where
the piston arrives at the end of the stroke, giving sufficient time while at the
dead point for the principal part of the steam to flash out into the condenser C
and the receptacle D, from thence into the aperture R, leading to the chimney,
when it becomes steam at atmospheric pressure, which allows the vacuum
valves E, E, to close, at this moment the injection pipe delivers its jet of water
into the condenser C, which contains about one sixth or one eighth of the
steam used in the cylinder, and falls on the valves E, E, together with the
injection water, when, at the next flash, the water, as well as the air, is thrown
into the receptacle D, and passes down the tube S, into the feed pump cistern,
from whence the heated water is forced into the generator; should any steam
remain uncondensed in the cylinder after the piston passes the perforations, in
its ascent it will pass through the valve V, which is opened by the spindle
coming in contact with the cap of the cylinder in which the perforations are
made, and be perfectly condensed before the steam is again admitted to the
cylinder, thereby taking away all resistance from the eduction side of the piston;
W, lever, by which the throttle valve is regulated.
The Drawing marked C, No. 8, consists of two Figures, and has reference
to my said third improvement, only showing the application of my said second
improvement to, using high-pressure steam upon a second piston, in manner
aforesaid. This engine is what I call a double single-stroke safety engine, from
its being composed of two single-stroke cylinders, of different sizes, the object of
which is to take the utmost advantage possible of the expansive property of
steam, thereby producing much greater economy in the fuel, particularly when
worked with very high steam.
pillars forming part of the frame.

page_text: A, the large cylinder;. a, the small cylinder; B, the large piston; b, the small
piston; X, X, valves in the pistons; C, c, the piston rods; D, d, the connecting
joints shewn in section at d; E, e, the connecting rods; F, the relief valve
to large cylinder; G, the fly-wheel; H, the relief valve to small cylinder;
I, I, i, i, guide wheels; K, K, k, k, guides which produce the parallel. vertical
motion; L, throttle valve; M, the induction valve; m, communication lead-
ing from small, to large cylinder; N, N, N, the steam pipe; O, the lever for
opening induction valve; P, the injection pump rod; Q, Q, the crank brasses;
R, the vacuum valve; S, the adjusting. rod, which is depressed by the tappet
T, and at the same time forces down the arm of the lever O, by which means
the induction valve will open more or less as the adjusting rod is lengthened
or shortened by the adjusting screw X; T, the tappet for opening the induction
valve; S, S, shows, by the dotted lines, the passage of the steam into the con-
denser; U, the condenser; V, v, the metallic stuffing-boxes for keeping the
steam from escaping by the piston rod; W, w, shows a series of apertures
through which the steam passes, first from the small cylinder into the large
one, and from thence into the. condenser, after it has performed its proper
degrees of expansion, and is condensed in the same manner as has been de-
scribed in the single stroke engine, C, No. 3, Fig. 1; X, the adjusting screw,
used to lengthen or shorten the adjusting rod, by which means the induction
valve is opened more or less, as circumstances may require; Y, Y, double
crank; A, spring for shutting the induction valve; B, that part of the frame
which makes firm the plummer box; C', C', the base on which the engine is
fixed; D', D', screws, which pass through the pillars and base, for the
purpose
of holding all firm together. It will be seen that the large cylinder in this
Drawing is eight times the content of the small one, and that both the pistons
are worked with the same crank. The steam is first, admitted through
a very small induction valve at the lower end of the small cylinder, at a
pressure, say, for example, of one hundred or more atmospheres, and when
the small piston has ascended, say one eighth of the stroke, the induction
valve is closed and all further communication is cut off until the downward
stroke of the large piston is completed; when the small piston has finished its
stroke and has entered the enlarged space of the top of the cylinder, the steam
which has expanded to ten or more atmospheres rushes through the communi-
cation pipe (which is never, closed) from the small to the large cylinder, and
at the beginning, of the downward stroke of the piston in the large cylinder
the steam acts with a force equal to about one eighth of the power it had on
each square inch with, which it acted on the small piston at the beginning of
the stroke; but as it acts on a piston whose area is eight times that of the

page_text: small one, the power will be the same. It will be seen by this modification
that there can be no reaction on either piston; when the small piston is moving
upwards and doing the work of the engine the large one is also moving in the
same direction, but as the pistons valve X is open by the spindle G coming in
contact with the bottom of the cylinder, if any steam should remain uncon-
densed, the pressure will be equal on both sides of the piston, and when
the large piston is descending and doing its work the small one is also
descending, but as its valve X is then open by a spindle coming in contact
with the top of its cylinder, the pressure of the steam is equal on both sides of
this piston also, and the reaction is on the bottom of the small cylinder; that
the steam should not begin to act on the large piston before it has reached the
dead point it is made to have finished its stroke when the small one has made
nineteen twentieths of its stroke, at which time the communication between
the two cylinders is opened by the small piston having entered the enlarged
space where the perforations before alluded to are made; the large piston in its
turn having finished its stroke sooner than the small one, the condensation
will begin to take place before the small piston has reached its dead point, and
of course before the induction valve is opened. The vacuum is effected at the
bottom of the large cylinder in the same manner as has been described in the
single stroke engine; it will be seen that this double stroke engine requires no
eduction valve to either cylinder, and but one small induction valve to the
small cylinder. Fig. 2 is a sectional plan of the lower part of the large
cylinder, where the perforations are made for the escape of the steam into the
condenser as before described, and is supposed to be taken from a to e.
Now, whereas I claim as my Invention the three several improvements
herein-before named (that is to say):-
First, the improvements in the construction of the boiler by the addition of
the steam chamber E, for the purposes aforesaid, and the arrangement of the
tubes D, D, D, D, D, with reference thereto, as shewn in Drawing
marked A, No. 1:
Secondly, the improvement in the construction of the cylinder, with an
enlarged space and perforatiors as before described for the purposes aforesaid,
as also the arrangement of the condensing apparatus C, D, E, with reference
thereto, as shewn in the Dwawing marked B, No. 2:
And thirdly, the improved construction and relative arrangement of the two
pistons and cylinders shewn in the Drawing marked C, No. 3, whereby the
bigh-pressure steam which has acted upon. one piston is conveyed to and acts
upon a second piston without causing any reaction on the first, as before stated:
-And whereas such said three several improvements being, to the best of my

page_text: knowledge and belief, entirely new, and never before used within that part of
His said Majesty's United Kingdom of Great Britain and Ireland called
England, His said Dominion of Wales, or Town of Berwick-upon-Tweed, I do
bereby declare this to be my Specification of the same, and that I do verily
believe this my said Specification doth comply in all respects, fully and without
reserve or disguise, with the proviso in the said herein-before in part recited
Letters Patent contained; wherefore I hereby claim to maintain exclusive
right and privilege to my said improvements.
In witness whereof, I, the said Jacob Perkins, have hereunto set my
hand and seal, this Twenty-first day of September, in the year of our
Lord One thousand eight hundred and twenty-seven.
JACOB (L.S.) PERKINS.
AND BE IT REMEMBERED, that on the Twenty-first day of Septem-
ber, in the year of our Lord 1827, the aforesaid Jacob Perkins 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 Statute made for that purpose.
Inrolled the Twenty-second day of September, in the year of our Lord
One thousand eight hundred and twenty-seven.