IMPROVE- MENTS IN STEAM ENGINES
Year: 1856

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN STEAM ENGINES."-A communication from Narcisse Duvoir, of
Liancourt, in the Empire of France, Mechanician:
Sealed the 30th December 1856, and dated the 20th August 1856.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
20th August 1856.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan St, in the City of Glasgow, North
Britain, Gentlemen, 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, Mechanician, to be as follows:-
This Invention relates to certain peculiar constructions and arrangements of
steam engines applicable as stationary, marine, or locomotive engines, whereby
greater effect is obtained, combined with compactness and solidity. According
to one modification, two cylinders are employed, placed endwise in the same
axial line, either vertically, horizontally, or obliquely, fitted on to suitable fixed
supports, and divided from each other by one common division plate, serving as
the bottom to each cylinder. The two cylinders are both double-acting, and
are fitted each with a seperate piston and rod of their own, passing through

page_text: sutffing, boxes at the extreme ends of the combined cylinders. These rods are
connected to seperate cross heads, which are again united by side rods. To
these rods at or near their centres are jointed two connecting rods, which are
united at their opposite ends by a cross head connected by a short rod to the
crank. The valve for the inlet of the steam is seperate and distinct from the
escape valves, and both sets of valves are worked from seperate eccentrics of
their own.
The inlet valve consists meerly of a rectangular plate having a
rectangular opening in the middle of it, and this valve works in a steam chest
placed over the division plate of the two cylinders. It is actuated by two
arms fixed to a rocking valve spindle, which is passed through a stuffing box
in the side of the steam chest. On the outer end of this spindle is a toothed
segment, gearing into a corresponding segment which works on a stud centre.
A species of link is cast on the lower part of this last-mentioned segment, in
the curved slot of which is a sliding block or pin, which serves as an attach-
ment for the end of the connecting rod, and also for a rod connected with the
governor. The valve is thus enabled to work with a variable expansion through
the action of the governor. There are two ports for each cylinder in the steam
chest face, making four in all, namely, one for the top and one for the bottom
of each cylinder.
The slide is so constructed, that when its central aperture is over the port
leading to the bottom of one cylinder, the edge of the slide will be just past
the port leading to the top of the other cylinder, and vice versa.
own.
The exhaust or escape valves, of which there are four, are all connected to
one rod, which is worked by a segment actuated by an eccentric and rod of its
The steam on escaping may either enter a condenser or escape into
the atmosphere, according as the engine is used as a condensing or high-
pressure engine. The same eccentric which works the escape valves works
also a feed pump.
When applied to a single cylinder, the arrangements herein-before described
are necessarily slightly modified, since there is only one piston rod to be con-
nected to the crank. In this arrangement the crank works at the opposite end
of the cylinder to that at which the piston rod comes out at, and the piston rod
is made to work in two fixed guide brackets. A cross head is fixed on to the
piston rod, and to each side of this cross head is attached a connecting rod,
the two connecting rods being united behind the cylinder by another cross
head which is connected by a short rod to the crank. In this modification the
two side rods in the double cylinder arrangement are dispensed with. The
rest of the parts remain the same, or nearly so, as those referred to in the
first-described arrangement. The inlet slide valve, when one cylinder only is

page_text: used, may be slightly modified, and may consist of a long plate extending from
the top to the bottom port of the cylinder, such ports opening direct into
the steam chest, which is extended for that purpose, in place of having
long steam passages cast in the cylinder.
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 20th February 1857.
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 166, Buchanan Street, in the City of Glasgow, North Britain, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of August, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, tho said
John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others 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, Mechanician, 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 bo per-
formed, and cause the same to be filed in the Great Seal Patent Offico 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
déclare 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, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:—

page_text: The said Invention relates to certain peculiar constructions and arrange-
ments of steam engines applicable as stationary, marine, and locomotive
engines, whereby greater effect is obtained, whilst compactness and solidity are
combined in the construction of the engine. According to one 'modification,
two cylinders are employed, placed endwise in the same axial line, either
vertically, horizontally, or obliquely, fitted on to suitable fixed supports, and
divided from each other by one common division plate, serving as the bottom
for each cylinder. The two cylinders are both double-acting, and are each
fitted with a separate piston and rod of their own, passing through stuffing boxes
in the cylinder covers. These rods are connected to separate cross heads
which are again united by side rods. To these rods, at or near their centres,
are jointed two connecting rods, which are united at their opposite ends by a
cross head connected by a short rod to the crank. The valve for the inlet of
the steam is separate and distinct from the escape valves, and both sets of
valves are worked from separate eccentrics of their own. The inlet valve
consists merely of a rectangular plate having a rectangular opening in the
middle of it, and this valve works in a steam chest placed over the division
plate of the two cylinders. It is actuated by two arms fixed to a rocking
valve spindle, which is passed through a stuffing box in the side of the steam
chest. On the outer end of this spindle is a toothed segment, gearing into a
corresponding segment which works on a stud centre fixed to the framing. A
species of link is cast on the lower part of this last-mentioned segment, in the
curved slot of which is a sliding block or pin, which serves as an attachment
for the end of the eccentric rod, and also for a rod connected with the governor.
The valve is thus enabled to work with a variable expansion through the 'action
of the governor. There are two ports for each cylinder in the steam chest
face, making four in all, namely, one for the top and one for the bottom of each
cylinder.
The slide is so constructed, that when its central aperture is over the port
leading to the bottom of one cylinder, the edge of the slide will be just past
the port leading to the top of the other cylinder, and vice versa.
own.
The exhaust or escape valves, of which there are four, are all connected to
one rod, which is worked by a segment actuated by an eccentric and rod of its
The steam on escaping. may either enter a condensor or escape into
the atmosphere, according as the engine is used as a condensing or high-
pressure engine. The same eccentric which works the escape valves works
also a feed pump.
When applied to a single cylinder, the arrangements herein-before de
scribed are necessarily slightly modified, since there is only one piston rod

page_text: A
to be connected to the crank. In this arrangement the crank works at
the opposite end of the cylinder to that at which the piston rod comes out
at, and the piston rod is made to work in two fixed guide brackets.
cross head is fixed on to the piston rod, and to each side of this cross head is
attached a connecting rod, the two connecting rods being united behind the
cylinder by another cross head which is connected by a short rod to the crank:
In this modification the two side rods in the double cylinder arrangement are
dispensed with; the rest of the parts remain the same, or nearly so, as those
referred to in the first described arrangement. The inlet slide valve, when one
cylinder only is used, may be slightly modified, and may consist of a long plate
extending from the top to the bottom port of the cylinder, such ports opening
direct into the steam chest, which is extended for that purpose, in place of
having long steam passages cast in the cylinder.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 of the Drawings represents a longitudinal section, taken through
the axis of the double cylinder engine; Figure 2 is a corresponding sectional
plan of the same, taken along the line 1, 2, which passes through the valve
chest; Figure 3 is a transverse section, taken along the line 3, 4; and Figure 4
is a partial side elevation, shewing a portion of the valve gear..
The two cylinders A and A' are similar, being of the same length and
diameter, and are placed in the same axial line, one division piece AⓇ serving at
the same time to limit the course of both pistons P and P¹. These pistons are
fixed to the rods B and B', united to the cross heads C and C, which are in
their turn connected together by the side. rods D, in such a manner as to form a
rectangular frame, which is moved by the reciprocatory motion of the pistons.
To the middle of the side rods D is jointed one extremity of each of the two
connecting rods E by the bolts d, whilst their opposite extremities are united
to a cross head E' in one piece with the short rod E². This is itself connected to
the pin of the crank M on the driving shaft O, so that the short connecting
rod E and the longer ones E form in reality a double rod of a considerable
5 length, by which the reciprocating motion of the pistons is transformed into
the required rotatory one of the crank shaft.
The induction of the steam to both cylinders is regulated by the single
valve F, enclosed in the chest F. This valve is simply a flat rectangular plate
of cast iron, in the middle of which is formed a rectangular port f. This

page_text: opening or port having a reciprocating movement imparted to it, communicates
alternately with the two induction orifices a and a' (Figures 1 and 3) at the
bottom of the cylinders, whilst the edges of the slide at the same time open or
close the apertures of the passages 6 and 6, by which the steam is conducted
to the other induction orifices. Thus, when the steam from the boiler is
allowed to enter the chest F, it passes through the port ', for example, into
the cylinder A, as represented in Figure 1, and also into the cylinder A¹
through the orifice a¹ at the bottom; and when the valve is in the other posi-
tion, entirely to the left, the effect is reversed, it being the passage band
the orifice a through which the steam enters the cylinders; the two pistons
thus always acting in concert, the one receding from while the other approaches
towards the bottom A. By this combination the moveable frame of side rods
is actuated with great regularity, the two forces of the cylinders being by it
united and imparted in one force to the crank shaft.
To the moveable slide F, by which the steam is distributed, are united-the-
two arms g of the fork G, mounted upon the horizontal valve spindle g¹. This
spindle passes through a socket cast in one piece with the steam chest F', and
is furnished at its outer extremity with a toothed segment G¹ (Figure 4), which
gears with a similar segment H, turning on a small stud in the framing.
This second segment is forged in one piece with a slotted arm or link H,
in the slot of which is arranged a bolt i, which connects the eccentric rod I for
working the induction valve, so that at each revolution of the crank shaft, the
segment II moves in a reciprocating and circular direction around the stud h,
which movement is communicated by the first segment G³ to the spindle g
and the distributing valve F. This valve is constructed to work expansively, so
that by varying its stroke its dimensions will allow of the steam being cut off
at two-thirds, one-half, or one-third of the stroke of the pistons, or any other
proportion that may be found desirable. This variable expansion arrangement
is obtained by means of the governor, as shown at Figure 3. For this purpose,
on the prolongation of the stud or bolt i, by which the eccentric rod is con-
nected to the link II', is fixed a vertical link j, which is jointed to a connecting
rod J. This latter rod is attached to the lever K, the forked extremity of
which embraces the collark of the governor mounted on the vertical spindle L.
This spindle is rotated by means of the mitre wheels and the pulley R,
which is driven by a larger pulley on the crank shaft, so that as the velocity of
these pullies increases or diminishes, a corresponding variation takes place in
the motion of the spindle L, and the collar k is raised or lowered as the
governor balls approach to or recede from each other.
I thus obtain a variable expansion action, which is regulated by the engino

page_text: itself, the steam being always cut off at the most advantageous portion of the
stroke. The steam escapes through the four orifices a³ and 6 into the pas
sage N, which communicates by the pipe N¹ with the condenser, or, if the
engine be on the high pressure principle, with the atmosphere.
Four valves, o¹ and o³, all moved by one common horizontal rod s, open and
close tho escape orifices at the required times. A reciprocating motion is
imparted to the rod s by the eccentric and rod I' (Figures 2 and 4), the rod
of which is united to the extremity of the lever S¹, mounted on one end of the
spindle s, the opposite end being furnished with a small arm s¹, jointed to the
rod S, on which are fixed the studs o which actuate the escape valves.
A continuation of the lever S¹ is connected to a short rod q, by which it is
attached to the plunger of the feed pump Q, so that the eccentric I' actuates
by means of the lever S' both the eduction valves and the feed
pump.
A similar arrangement, by which the induction valve and the expansion gear
are actuated by one eccentric, and the eduction valve and feed pump by
another eccentric, is applied to a single cylinder double-acting engine, is shewn
at Figure 5, which represents a vertical section taken through the axial line of
the cylinder.
Figure 6 represents in detail a modification of the induction valve. The
same general arrangement is adopted here as in the engine I have just
described, the only differences being those which are necessitated by the
employment of one cylinder instead of two; and in order therefore to avoid a
repetition of the preceeding description, I have indicated those parts which are
similar in both Figures by the samo letters of referenco.
The main difference consists in the arrangement of the side rods, by which
the motion of the piston is transmitted to the crank; in fact, as there is only
one piston rod, the side rods D, which united the two rods in the former case,
are altogether dispensed with, the two connecting rods E attached to the cross
head C alone remaining. This cross head is fixed upon the piston rod B, which
is prolonged and made to pass through the supports U and U³, which serve as
guides.
The arrangement of valve shewn at Figure 6 possesses the advantage of
allowing the steam to pass directly from the chest F¹ into the cylinder by
means of the ports a and a¹, whereby the long passages 6 and 6' are avoided.
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

page_text: 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 constructions and arrangements of steam engines, as
herein-before described, and illustrated by the Drawings.
Second, the pecular constructions and arrangements of induction and educ-
tion valves, and the modes of working or actuating the same, as herein-before
described, and illustrated by the Drawings.
Third, the peculiar arrangement of variable expansion gear, as herein-before
described, and illustrated by the Drawings.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my band and seal, the Twentieth day of February, One thousand
eight hundred and fifty-seven.
J. HENRY JOHNSON. (L.S.)