AN IMPROVED STEAM ENGINE
Year: 1866

page_text: LETTERS PATENT to George White, of 68, Queen Street, Cheapside, in
the City of London, Patent Agent, for the Invention of "AN IMPROVED
STEAM ENGINE."-A communication from abroad by Mr. Ernesto Ansaldi,
Mechanical Engineer, Leghorn, Italy.
Sealed the 7th May 1867, and dated the 10th November 1866.
PROVISIONAL SPECIFICATION left by the said George White at the
Office of the Commissioners of Patents, with his Petition, on-the 10th
November 1866.
I, GEORGE WHITE, of 68, Queen Street, Cheapside, in the City of London,,
Patent Agent, do hereby declare the nature of the said Invention for "AN,
IMPROVED STEAM ENGINE," that it has been communicated to me from abroad
by Mr. Ernesto Ansaldi, Mechanical Engineer, Leghorn, Italy, to be as
follows:-
This improved steam engine is constructed in such manner, so as not to
require a flywheel for overcoming what in steam engines are called the dead.
points. For this purpose the engine has two cylinders, viz., a large or outer.
and a small or inner one; the latter situated in the inside and concentric with
the outer cylinder, the inner cylinder being provided with an ordinary piston,

page_text: and the outer one with an annular piston working air-tight round the outside
of the inner cylinder, both pistons being connected to the main arbor or
driving shaft by suitable connecting rods and cranks, the cranks for the piston
of the inner cylinder being set at right angles with those for the piston for the
outer cylinder for the purpose that when one of the pistons reaches one of its
dead points, the other having only completed part of its stroke, this latter
piston will cause the other one to overcome the said dead point. The steam
arriving from the boiler is allowed to work alternately on either side of the
pistons, for which purpose three slide valves are provided on the outer
cylinder, the rods of which valves are connected to the main arbor or driving
shaft by suitable eccentrics, suitable ways or steam passages allowing the
steam to act on the pistons at the required moments.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George White in the Great Seal Patent Office on the
10th May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WHITE, of 68, Queen Street, Cheapside, in the City of London, Patent Agent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George White, Her special license that I, the said George
White, my executors, administrators, and assigns, or such others as I, the said
George White, 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 "Ar
IMPROVED STEAM ENGINE," a communication. to. me from abroad by Mr.
Ernesto Ansaldi, Mechanical Engineer, Leghorn, Italy, upon the con-
dition (amongst others) that I, the said George White, my executors or
administrators, by an instrument in writing under my, or their hands
and seals, 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:

page_text: calendar months next and immediately after the date of the said Letters
Patent...
"
NOW KNOW YE, that I, the said George White, do hereby declare
the nature of the said. Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by; the
following statement
[:
This improved steam engine is constructed in such manner so as not to require
a fly wheel for overcoming what in steam engines are called the dead points.
For this purpose the engine is provided with two cylinders of different
diaineters which may be situated side by side, and be suitably connected
according to the principles. hereafter to be explained, or they may be set
concentrically to each other, viz., the: small cylinder be situated within the
larger one, the entire being arranged in such manner that the pistons of the
two cylinders mutually cause each other to overcome their dead points.
In order to make the-arrangement and the mode of working of this
improved. steam engine readily understood, I will in this description thereof
refer to the annexed Drawings, in which Fig. 1 represents a side elevation;
and Fig. 2 a plan view of an engine constructed according to this Invention,
the cylinders of: which are set concentrically to each other; Fig. 3 shows a
longitudinal vertical, and Fig. 4 a horizontal sectional view of the engine
taken over the axis of the cylinders; the Figs. 5, 6, & 7, show transverse
vertical sectional views respectively taken over the lines X, X, X, X', and
X3, X3; of the Figs. 2 & 1; Fig. 8 shows a transverse vertical sectional view
of a modification. in the situation of the steam valves, and Fig. 9.an outside-
view of this. modification with the valves and their boxes removed in order to
show the steam: ports.: The.Figs. 10, 11, 12, and 13. represent vertical
sectional views of, the cylinders, & valves (these latter in various positions):
of an engine, the two cylinders of which are set side by side. In the.
Figures 1, 2, 3, 4;.5, 6; 7; 8, & 9, the same letters of reference relate to
corresponding: parts..
.::
...The principle on which. my..improved steam engines is based is to cause
merely the large or outer cylinder consume steam whereas the small one.
principally serves for part of the steam to pass through; and by, reacting at:
the required moments on its piston cause the piston.of the large cylinder. to
overcome its dead points; the crank of. the piston of..the small cylinder being.
situated at right angles with those of the piston of the large cylinder in such
manner that whenever the crank or cranks of the large cylinder merely reach
their dead point the crank of the small cylinder is nearly exerting its maximum:
effect; so that the cranks of both cylinders mutually cause each other to over->

page_text: come their dead points, thus allowing of doing. away with the use of a fly
wheel, and rendering my improved engines particulary usefull for marine steam
engines. The general arrangement of the engine does not differ materially
from that of ordinary steam engines; the same is provided with two:eccentrics
and with the well-known arrangements for imparting the forward or backward
motion, whilst my improved system is applicable to engines of any size and
shape, whether-fixed or moveable. In case the cylinders are set concentrically
to each other the piston of the large or outer cylinder is to be of the annular
shape.
:
I will now describe, first, the arrangement and. mode of working of an engine
with 'concentric cylinders, and thereby refer to the Figs. 1 to 7; in which a
horizontal engine of that class is shown; B is the large or outer cylinder; the
annular piston Z of which works on the outside of the inner.or small.cylinder
G; the engine is fixed on a platform or base plate A¹. C, D, & D show three
steam boxes covering their respective steam valves y³, y³, & y¹.; E & Fare
the lids of the large and G that of the small cylinder; J is an arm fixed to:
the part K, the latter gliding in-guides L, L, and moving.the.shafts. 1 & 2 of:
the slide valves C & D ; M is a rod connected to the part K, and sliding.in-
the top of the standard O,- which rod catches the shaft or arbor As and carries
two friction rollers rollers P, P, receiving a to-and-fro motion by means of the
elliptic eccentric N. fixed on the arbor A³, which eccentric.consequently moves
the parts M, P, P, K, and J, and thereby imparts the required forward and
backward motion to the two slide valves C & D, causing them to stop for a while
towards the middle of their stroke; Q, Q, are two standards, to the top of
which are fixed the guides R, R, between which works the curved cross head
S, to which latter are fixed the. shafts V, V, of the annular piston Z of the.
large or outer cylinder B and the rods V, V, working the cranks V, V, fixed
on the arbor A³; T is a forked rod connecting the shaft T of the piston G³. of
the small or inner cylinder G¹ with a crank U also fixed on the main
arbor A; the shaft T glides in a guide or bracket T. The crank U of the
small cylinder is situated at right angles with those V, V, of the large one.
A', A¹, are two plummer. blocks for the main arbor A³. The slide valve D
constructed on the ordinary principle receives motion by means of its shaft D³
connected by the rod D³ to a circular eccentric D* fixed on the main arbor A³,
the shaft D glides in a guide rest D; H & H are tubes respectively
connecting the valve D with those C & D¹.
..
I now will describe the mode of working of the engine. By means of the
tube x the steam is admitted from the boiler into the steam box or chest D¹..
and the same enters at the same time freely, into the box D by means of the

page_text: connecting tube H¹; the.slide valve y³ of the box D distributes the steam into
the inner cylinder G¹ by means of the steam channels or passages 3 & 4; the
third steam box C receives the steam by means of the tube H, which steam does
not come directly from the boiler, but is the surplus steam of the inner cylinder,
and passes through the hollow part of the valve y³, which, as shown in Fig. 5,
takes place according to whether this valve puts the tube H in communication with
one or the other of the channels 3 & 4; this steam consequently passes from
the box C into the outer cylinder B, either through the channel 7 or through the
one 8, according to which of these channels is opened. Supposing now the engine
to be with the cranks V, V, at their dead point, viz., as shown in the Figs.,1,
2, 3, & 4, the steam enters by the tube and fills both steam boxes D¹ & D.;
in this moment the ports leading into the outer cylinder are kept shut by the
valve y', which latter is ready for opening the channel 6 whilst in the box D.
The valve has already opened the channel 4, and thus allows the steam
entering thereby, and carry back the piston G of the inner cylinder, the
crank U of which being situated in the position for exerting its maximum
effect will carry the cranks V, V, of the large cylinder beyond their dead:
point, and accompany them through an are of about 45°, whilst arrived at!
about 30° the valve-y opens the channel.6, and thereby allows the steam of
passing into the large cylinder, the piston Z of which has already commenced
its return stroke, which it will thus be compelled to complete. I must now.
call attention to the mode of working of the steam in consequence of the
arrangement of the slide valves 'y' & 'y. Immediately after the crank has
reacted at 45° beyond the vertical position the elliptic eccentric N drives the
said valves y & y³ forward to one-half of their full stroke, when the valve y*.
allows the steam of passing through the two channels 3 & 4, and thereby
enter in the small cylinder on both sides of the piston G³, and entirely fill the
said.cylinder. The valve y³ (which is by preference made in two separate
parts, viz., in the manner.as shown in Fig. 4) also taking the middle position
shuts both channels 7 & 8; this valve is kept pressed firmly against these
latter by the effect of a spring.y and partly by the steam acting against the
back of this valve. The shutting of the channels 7 & 8 is to take place in
due time in order that. the steam admitted by the valve y' and acting on the
piston Z'be prevented from passing into the boxes C.& D. It is to be.
observed that contrarily to the mode of acting in ordinary steam engines the
steam is in this arrangement admitted simultaneously on both sides of the
piston G³, so as to keep this latter in full equipoise at the required moments,
and not impede its progress, it being required that this piston should recede
freely by the effect of the large piston Z when this latter is completing its:

page_text: stroke; this arrangement consequently prevents these pistons acting in
opposition to each other. The large piston Z having now nearly completed
its stroke, and the cranks V, V, being consequently situated at about an
angle of 30° with their dead points the piston Gs will have reached nearly the
middle of its stroke, and its crank will also be nearly at an angle of 30° with
its dead point. The elliptic eccentric now carries the valves y & y³ from
the middle to. the end of their stroke, and thereby open the channels 3 & 7,
the latter communicating with the outer cylinder. The steam admitted from
the boiler by the pipes & H will now press on one side of the piston G³,
whilst the steam existing on the opposite side, and which, as above mentioned,
had filled-the cylinder G passes into the box C through the hollow part of
the valve y', which latter puts in communication the channel 4 and tube H
(middle channel). The valve y³ of the box C allows the steam from passing
by the channel 7 into the outer cylinder B, the piston Z of which is about
completing its stroke, and will then begin its return stroke, in which moment
this steam finds itself a little compressed, viz., in the same manner as occurs
in ordinary steam engines when the valve admits the steam a few moments
before the piston begins its return stroke. It ought to be observed here that
in my improved arrangement this advance or lap in the engine does not take
place by the effect of the valve itself, but from the opposite side; this steam
exerts its pressure on Z, and by its own elasticity and by being driven by the
piston G³, which latter is pressed on the opposite side by the steam admitted
immediately from the boiler; this piston G³ drives the other Z till the steam
is allowed to enter by the valve y¹ of the box D, which steam compels the
piston Z of completing its stroke in the same manner as in ordinary steam
engines. In the meanwhile the valve y³ shuts the channels 7 & 8, whilst
the valve y admits the steam on both sides of the piston G³, both slides taking
the middle position by the effect of the elliptic eccentric N, the curve of
which latter is duly constructed for this purpose, and in such manner that a
full revolution of this eccentric N causes the valves y & y³ of taking
successively the three required positions. The above-described motions"
taking place in regular succession the engine will consequently work with
the utmost regularity, and not the slightest variation in speed will be
perceptible at the various positions of the cranks, because in the same
measure those V, V, advance towards their dead points the crank U
advances towards its maximum effect. is the escape or exit opening for
the waste steam.
⚫ The position of the slide valves might be modified in the manner as shown
in the Figs. 8 & 9,-viz., the one y¹ be situated on one side, and those y³ & y³.

page_text: close: to each other on the opposite side of the cylinder B. In this arrange-
ment the steam is admitted from the boiler into the steam box D', and by
the: channel H passes into the box D, and by the channel H into the box C;
thence the same is admitted by the channel 3 into the inner and by the
channel 7 into the outer cylinder, viz., in the manner as 'has been described
above. :
It will be understood that many variations in the position of the steam;
boxes and valves.may take place without interfering with the mode of
working above described. The same is to be said about the cylinders, which
may be set side by side and connected together in the manner as shown by
the vertical-sectional views Figs. 10, 11, 12, & 18, in which Figures the same
letters refer to corresponding parts. In this latter arrangement the steam is
admitted from the boiler by the tube a into the steam boxes C & C³, and
enters either into the small or into the large cylinder, according to which of
the steam ports is open at the time. In the Drawings the channel 4 of the
small cylinder B being open the steam acts on the piston G¹ in order to
cause the crank of the other piston Z of passing beyond its dead point, whilst
the steam on the opposite side of the piston G¹ enters into the channel 3,
passes through the hollow part of the valve D, and is admitted by the
channel 5 into the box C¹, in which latter the valves E are in the position for
keeping shut the channel 7, whilst the other 6 is open and admits the steam
into the large cylinder A; in this moment the piston G¹ causes the other Z
to pass beyond its dead point, and by the compression of the steam against
the piston Z gives sufficient power to the crank, thus acting for a moment in
a manner similar to that of an ordinary Woolf's engine. The piston G'
having now driven the one Z to about 45° beyond its dead point the valves E
shut the channels 6 & 7, and the valve D reaching at the same time the
middle of its stroke keeps open part of the channels 3 & 4, viz., sufficiently
for establishing the equipoise on the piston G' in the manner as shown in the
Figs. 12 & 13, and preventing any communication to take place between the
two cylinders, whilst at the same time the valve F opens the channel 2,
thereby admitting the remainder of the steam required for causing the
piston Z of completing its stroke. The cylinder A consequently has received at
first a portion of the steam from the other B, and afterwards receives directly
from the boiler and by the valve F the remainder of the steam required for
causing this piston to complete its stroke.
.
Having now described and particularly ascertained the nature of the
Invention, and the manner in which the same is or may be put into
operation, I wish it to be understood that I do not intend to restrict or limit

page_text: myself to the precise details of the arrangements above described, as many
variations may be made therefrom without departing from the main features
or principles of the Invention; but what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters. Patent is,. the general arrangement and
principles of working of the above-described improved steam engine,
substantially as described and illustrated in the annexed Drawings.
In witness whereof, I, the said George White, have hereunto set my
hand and seal, this Ninth day of May, in the year of our Lord One
thousand eight hundred and sixty-seven.