IMPROVEMENTS IN STEAM ENGINES
Year: 1855

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of Glasgow, North Britain, Gentleman,
for the Invention of "IMPROVEMENTS IN STEAM ENGINES."-A communi-
cation from Narcisse Duvoir, of Liancourt, in the Empire of France,
Mechanical Engineer.
Sealed the 7th August 1855, and dated the 17th March 1855.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
17th March 1855.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN STEAM ENGINES," a
communication from Narcisse Duvoir, of Liancourt, in the Empire of France,
Mechanical Engineer, to be as follows:-
This Invention relates to a peculiar construction and arrangement of the
cylinders and valves of steam engines, and the working parts connected, there-
with, whether high pressure or condensing, whereby the construction is greatly
simplified and rendered less expensive, inasmuch as stuffing boxes of all kinds.
are entirely abolished, while at the same time a greater effect is obtained from
the steam, and the waste thereof is obviated to a great extent.
.'1

page_text: According to one modification the cylinders are placed horizontally, though
they may also be placed in a vertical or oblique position. Each cylinder is
fitted with a separate and distinct piston and rod, and both are single acting,
inasmuch as the steam is merely admitted on one side of the pistons, the
opposite side being entirely open to the atmosphere, thereby dispensing with
stuffing boxes. The cross heads of each piston rod are united by side rods,
and to these side rods are attached two connecting rods, which are also
united by a cross, head, to which, is, secured, the crank rod. Steam passages,
or ports in the, sides of the cylinders are entirely dispensed with, the valve
chest being placed between the contiguous ends of the cylinders, and the
steam is admitted into the inner end of each cylinder alternately by a slide
valve worked by a rack and segment. The spindle carrying the segment is
not passed quite through the valve chest on one side, so that no stuffing will
be required there; and on the other side, where it enters the steam chest, it is
fitted with a conical collar or shoulder, which works in a conical aperture in
the steam chest, and may thus be tightened up to any required extent to pre-
vent escape of steam. A greater effective power is obtained by reason of the
absence of the piston rod in that part of the cylinder where the steam is
admitted, so that no reduction will be required for the area of the piston rod in
the down stroke, both strokes being equally effective. By avoiding steam
ports and long steam passages cast on the cylinders, they may be made much
cheaper than hitherto, and when in action the loss of steam by condensation in
the steam passages will be avoided.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said. John Henry Johnson in the Great Seal Patent Office on
the 17th September 1855.
TO ALL TO WHOM THESE. PRESENTS SHALL COME, I, JOHN
HENRY. JOHNSON,. of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of Glasgow, North Britain, Gentleman; send greeting..
.
..WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of March, in the year of our
Lord One thousand 'eight hundred and fifty-five, in the eighteenth year of
Her reign, did, for Herself; Her heirs and successors, give and grant unto
me, the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my exécutors,' administrators, and assigns, or such others

page_text: as I; the said John Henry Johnson, my executors, administrators; or 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 " IMPROVEMENTS
IN STEAM ENGINES,a communication from Narcisse Duvoir, of: Liancourt, in
the Empire of France, Mechanical Engineer, upon the condition (amongst
others) that I, the said John Henry Johnson, by an instrument in writing
under my hand and seal, 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 Letters
Patent.
::
NOW KNOW YE, that I; the said John Henry Johnson, 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 fol-
lowing statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:
The said Invention relates to a peculiar construction- and arrangement of
the cylinders and valves of steam engines, and the working parts connected
therewith, whether high pressure or condensing, whereby the construction is
greatly simplified and rendered less expensive, inasmuch as stuffing boxes of
all kinds are entirely abolished, whilst at the same time a greater effect is
obtained from the steam, as the waste thereof is obviated to a great extent.
According to one modification the cylinders are placed horizontally, though
they may also be placed in a vertical or oblique position. Each cylinder is
fitted with a separate and distinct piston and rod; and both are single acting,
inasmuch as the steam is merely admitted on one side of the pistons, the oppo-
site side being entirely open to the atmosphere, thereby dispensing with stuffing
boxes. The cross heads of each piston rod are united- by side rods, and to
these side rods are attached two-connecting rods, which are also united by a
cross head; to which is screwed the crank rod. The steam passages: or ports
in the sides of the cylinders are entirely dispensed with, the valve chest being
placed between the contiguous ends of the cylinders, and the steam admitted
5 into the inner end of each cylinder alternately by a slide valve worked.. by a
rack and segment or other suitable-arrangement.. The spindle. carrying the
segment 'is not passed quite through the valve chest on one side, so that no
stuffing will be required there; and on the other side, where it enters the steam
chest, it is fitted with a conical collar or shoulder, which works in a conical

page_text: aperture in the steam chest, and may thus be tightened up to any required
extent to prevent escape of steam. A greater effective power is obtained by
reason of the absence of the piston rod in that part of the cylinder where the
steam is admitted, so that no reduction will be required for the area of the
piston rod in the down stroke, both strokes being equally effective. By
avoiding steam ports and long steam passages cast on the cylinders, they may
be made much cheaper than hitherto, and when in action the loss of steam by
condensation in the steam passages will be obviated.
And in order that the said Inventiou may be fully understood, I shall now
proceed particularly to describe the same, and for that purpose I shall refer
to the several Figures on the Sheets of Drawings hereunto annexed; the same
letters of reference indicating corresponding parts throughout all the Figures.
Fig. 1 on Sheet 1 of the Drawings represents a side elevation of the engine
in working order; Fig. 2 is a plan of the same; and Figs. 3 and 4 are sec-
tional details of the slide valve and steam chest.
It will be seen, on reference to the Drawings, that one modification of the
improvements is applied to a horizontal engine, and the cylinders are both
situated in the same axial line. This arrangement may, however, be varied
according to circumstances, without interfering with the principle of the said
Invention.
The two cylinders A, A', of the same length and diameter, are placed in
the same axial line, and are bored internally to receive the pistons which are
fitted to the separate horizontal piston rods B, B'. These two cylinders have
no lateral openings or passages, but each opens as its lower or inner end into
the steam chest C, as shewn in detail at Figures 3 and 4, where it will be seen
that the bottom of the cylinders is formed by opposite sides of the steam chest.
By means of a slide valve shewn at P, the steam is, according to one modifi-
cation of my Invention, introduced & allowed to escape from the cylinders
alternately without producing any great loss by condensation, by reason of the
shortness of the steam passages.
The piston rods B, B', are fixed at their extremities to the cross heads
D, D', which in their turn are connected with each other by means of the
side rods E, E, thus forming a rectangular frame, the motion of which is
precisely similar to that of the pistons. This frame moves always in a hori-
zontal plane, the two side connecting rods being kept in that position by means
of the guides F, F, placed on each side of the cylinders, and bolted to the
main framing G, which I propose to cast in one piece in order to give greater
solidity to the machine.
To the centre of the side rods E, E¹, is jointed the forked connecting rod

page_text: H, H', which is connected at its other end with the crank J. This crank is
fixed as in the ordinary engines on the main shaft K, carrying the fly wheel L,
and the pulleys or gearing by which the power of the engine may be turned to
account in driving machinery.
The upper or outer end of each cylinder is not provided with either a
covering or stuffing box of any kind. The two pistons as I have herein-before
stated work independantly of each other; but through the intervention of
the rectangular frame formed by the side rods E, E', and cross heads D, D',
the motion produced is precisely similar to that of an ordinary double-action
engine. This arrangement possesses also the advantage of giving out the same
power at each stroke, no space being taken up by the piston rod, as is the
case in the down stroke of an ordinary engine. The steam chest C has cast on
its upper side the branch M, to which is bolted the steam pipe for supplying
the steam from the boiler to the engine. A branch N it also cast on the
under side, to which branch is connected the exhaust pipe. 0, 0¹, are
the two passages or steam ports leading, one into the cylinder A, and the
other into the cylinder A². The valve P, when properly adjusted, allows
the steam to enter first into one cylinder and then into the other, thus forcing
one piston from the right to the left, and the other from the left to the right.
The valve P is fitted with a rack a, which is in gear with the toothed
segment fixed to the wrought-iron horizontal spindle c. This spindle is
only passed through the body of the steam chest on one side, whilst the
other end of the spindle works in a recess in the side of the steam chest,
and therefore does not require a stuffing box at that part. That part of the
spindle which passes through the steam chest is enlarged slightly, and is formed
into a conical shoulder or collar, and this collar is kept pressed into the conical
recess made to receive it by the flange e, which is tightened up by bolts in the
same manner as the gland of an ordinary stuffing box. It will thus be obvious
that notwithstanding the motion imparted to the spindle when the engine is in
action, no steam can escape from this joint, although no stuffing boxes are used.
On the end of the valve spindle c is keyed a forked lever f, to which the
required, movement is imparted by means of the eccentric rod g and eccentric h
on the shaft K. This engine may obviously be worked either as a high
pressure, or as a condensing engine. The steam on leaving the cylinder N
would in the latter case be conveyed to the condensers which would be of any
of the well-known existing arrangements.
Having now shewn one modification of the construction of the steam chest,
and valve or valves regulating the entrance and exit of the steam into and
from the cylinders, I proceed to shew other modifications thereof, which,

page_text: however, are only illustrations of the same principles having the same objects
in view.
"
It is necessary, especially in engines calculated to work at great speed, 'that
the steam should be allowed to escape as rapidly as possible, and to effect this
there should be plenty of lead given to the valve. In cases, however, where
the same valve which: admits the steam. permits also of its exit, a difficulty
arises in bringing both the steam and exhaust ports into due. relation
with each other, especially when working expansively with the same valve.
If this: relationship is not preserved, 'the, result will be a counterpressure
on the piston, which prevents the effective working of the engine. ..Where
two valves, are used independently. of each other, the proper relationship
of the steam and exhaust ports is easily maintained: In that case a lead
may be given to the valve for the. exit of the steam, and a sufficient lap. given
to the one for the introduction of the steam. These objects are realized in a
simple and effective manner by the various arrangements illustrated on: Sheet 2
of the Drawings, which arrangements are shewn, as applied to my double
cylinder engine.,
87
.
...
Fig. 1, on Sheet 2: of the Drawings, represents a longitudinal: vertical
section of the two steam cylinders with the steam chest placed between
them; Fig. 2 is a transverse section of the same taken along the line 1, 2
and Fig. 3 is a horizontal section taken along the line 3; 4, in Fig. 1....
It will be seen, on:referring to these Figs., that the steam valve-T is simply
a flat plate formed with rack teeth.on its upper surface, by which,, through the
agency of the:seginent S, it is put in, motion, admitting the steam, first to. one
cylinder and then.to the other, through the steam ports a and a.. This valve
need not be hollow, as it does not serve for the escape of the steam.
The valve face. upon which it slides is not. furnished as usual with three
ports, but only with two ports communicating with the two. opposite. cylinders
C, C¹ the steam passages or 'ports a, a,are, as in the arrangement
. illustrated by Figs. 3 and 4, on Sheet1, extremely short, thus preventing any
loss of steam from condensation.
.
I
..
The spindle b which carries the segment Ș, and which. is prolonged, outside
the steam chest .B,. carries the slotted lever arm L (Figs. 2 and 4), which,
besides receiving a vibrating motion from the eccentric fixed on the fly-wheel
shaft, is jointed by the-same pin that connects it to the eccentric rod, to the
extremity of the rod d, which is connected at its upper end with the lever D,
the other extremity of which.. lever is forked and embraces the moveable
collar E, which slides along the governor spindle F. By this arrangement the
length of stroke given to the slide valve can be varied.

page_text: It will be seen by the Drawing, Fig. 2, Sheet 2, that when the collar E is
elevated, the rod d will lower the pin e, which connects the lever L with the
eccentric rod, and consequently will shorten the stroke of the valve. The
contrary. effect, of course, takes place when the collar. E descends.. This,
differential movement of the slide valve has no influence upon the exhaust
valves shown at T, T. These two, exhaust valves are, connected with.
each other by the rod f, and are actuated by the. pistons themselves in the
following manner: Just as the piston in cylinder C.completes its stroke, it.
strikes the valve T, and thereby drives, both that valve and the valve T into
the position, shewn in Fig. 1, Sheet, 2, thus closing the escape port,l, and
opening the escape. port ... In the same way the piston in cylinder C, at the
completion, of its stroke; strikes the valve T, and thereby drives that valve.
and the valve Tso as to open, the, escape port and close the escape port A.
It will thus be seen that, the opening, and closing of the escape ports are..
produced only when each piston has completed its stroke, whereby the steam
is allowed to escape freely out of one, cylinder, during the entire stroke of the
piston in the other cylinder, thereby preventing the occurrence of any counter-
pressure upon the under side of the piston in the cylinder from, which the.
steam is escaping..
Fig. 5 represents another and more simple arrangement for producing the
same result, with the exception that the differential movement of the steam.
valve is dispensed with, the valve always having the same amount of traverse
imparted to it. In this case the slide valve T is fitted with two; bent rods i.
andi', which pass through the steam; passages or ports; and.. project into the,
interior of the cylinders .C, C,.and are worked like the exhaust valves >>in.
Figs. 1, 2, and 3, by the, pistons themselves.The passages. or ports in this:
arrangement being, however, of smaller diameter than the exhaust ports or
passages, it is not necessary for the slide walve to have so great an amount.
of traverse as the exhaust, valves; and consequently the rods, and 2¹ of
the valve T do not project so far into the cylinders as the exhaust valves
Tand T. This, arrangement might be advantageously applied to engines
requiring no variation in the slides, and as no external mechanism.is.required.
to work the valves, the construction of the engine, will be greatly simplified...
An arrangement for producing a similar result, but of a different con:
struction of valves, is represented in longitudinal and transverse vertical section.
at Figures 6 and 7 respectively. »
According to this modification, the induction valve Tof: Fig. 5, is replaced.
by the two parallel S, S, which alternately: open and close the ports a, a¹;
on being alternately, pushed from, and upon themi by the action of the pistons.

page_text: These valves are united by the rod h, and are furnished with spiral springs
to lessen the shock of the blow of the pistons. As the rod h is guided by the
bearing J, the valves always accurately cover the ports alternately. The
eduction valves S¹, S¹, are connected by the rod k, and have a précisely similar
action communicated to them by the pistons. When the piston in cylinder C
opens the induction valve S to admit the steam, it simultaneously closes the
eduction valve S¹ of the same cylinder, and opens the induction valve S' of the
opposite cylinder C₁, whereby the steam is allowed to escape therefrom.
Since in some cases where it is necessary to drive the engines at a great
speed, the shock of the pistons striking the valves or the rods connected there-
with is likely to injure them, I propose to apply an external arrangement of
simple construction for working the valves, which I have represented in
longitudinal and transverse section at Figs 8 and 9 respectively. The steam
valve T is in this arrangement worked by means of the lever arm m adjusted
on the tubular spindle n, which is actuated by an eccentric placed upon the
driving shaft, and which transmits a reciprocating movement thereto.
The two exhaust valves T', T', are worked by the double lever M, which, like
the lever m, is inclosed in the steam chest, and is fitted on to the wrought-
iron spindle o, on which the tubular spindle n turns freely. This spindle o
is also actuated by an eccentric entirely distinct from the first one, so that it
receives its reciprocating motion entirely distinct from the tubular spindle.
An india-rubber washer is placed at the bottom of the cavity which
receives the end of the spindle o, in order by its elasticity to give the requisite
lateral pressure against the side of the steam chests, to keep the same steam-
tight at the parts where the spindles enter it. In this arrangement, as in all
the others, the steam passages are very short, by which the loss of stean is
reduced to minimum; and the action of the steam throughout all the arrange-
ments herein-before described, is direct upon the whole arca of the pistons,
which cannot be accomplished in the ordinary existing arrangements by reason
of the presence of the piston rods.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of the said 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,-
First, the general construction and arrangement of steam engines with two

page_text: or more cylinders, whereby stuffing boxes are entirely dispensed with, and
the steam passages considerably reduced in length, as herein-before described.
Second, the application and use of steam engines having two open cylinders
placed in the same axial line, and having the steam chest and its valve or
valves situated between the two inner ends of the cylinders, so as to dispense
with stuffing boxes, as herein-before described.
Third, the peculiar constructions and arrangements of valves for steam
engines, and the mode or modes of working the same, as herein-before
described, and illustrated on the two Sheets of Drawings hereunto annexed.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Seventeenth day of September, in the year of
our Lord One thousand eight hundred and fifty-five.
J. HENRY JOHNSON. (L.S.)