IMPROVEMENTS IN STEAM ENGINES
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by the said James Gray Lawrie at
the Office of the Commissioners of Patents, with his Petition, on the
19th July 1855.
I, JAMES GRAY LAWRIE, of Glasgow, Engineer, do hereby declare the nature
of the Invention for "IMPROVEMENTS IN STEAM ENGINES" to be as follows:-
This Invention has for its object improvements in steam engines, for the
purpose of rendering them more effective, and at the same time more econo-
mical in the consumption of steam.
One part of my improvements has for its object a more convenient arrange-
ment or combination of the parts of steam engines used in giving motion to a
screw or such like propeller of a steam ship or vessel.
Another part of my improvements has for its object a method of regulating
the admission of steam to the steam cylinders when working steam expansively
where a valve is introduced, for the purpose of regulating the admission of
steam to the box or case containing the usual slide valves.
Another part of my improvements has for its object a construction of slide
valves and steam ports, used to regulate both the induction and eduction of
steam.

page_text: Another part of my Invention has for its object a peculiar arrangement or
combination of valve box and equilibrium slide valves, when working with two
steam cylinders. For these purposes, in constructing a steam engine one of the
steam cylinders is placed perpendicularly over the crank or propeller shaft;
the other steam cylinder is placed horizontally and at one side of the crank or
propeller shaft. The piston rods of both cylinders work through the covers
most distant from the crank or propeller shaft, and by cross heads and con-
necting rods give motion to the crank or propeller shaft. The condenser, or
the condenser and air pump or pumps, are placed on the other side of the crank
or propeller shaft to that on which the horizontal steam cylinder is placed.
This combination or arrangement admits of considerable compactness of con-
struction, and allows of the main parts of the engine, consisting of the two
steam cylinders, the air pump, and the condenser, being made in one casting.
In working steam expansively, when using an expansive valve or valves to
regulate the supply of steam to the valve box, a link or similar motion is
applied gradually to reverse the valve by the excentric motion of the engines,
dispensing with the use of cams, and thus obtaining the advantage of working
steam expansively in steam engines when working in both directions. The
extent of motion of the slido valves (when cach valve is arranged to regulate
both the induction and eduction of steam) is reduced by increasing the number
of the ports, and in using equilibrium slide valves between two steam cylinders,
giving motion to a propeller shaft. The valve box or casing is divided by a
partition. The valves have packings adjusted by a screw from above, which
prevent the steam pressing on the backs of the valves.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Gray Lawrie in the Great Seal Patent Office on the
17th January 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
GRAY LAWRIE, of Glasgow, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of July, in the year of our Lord
-One-thousand-eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Gray Lawrie, Her special licence that I, the said James Gray
Lawrie, my executors, administrators, and assigns, or such others as I, the said 3
James Gray Lawrie, my executors, administrators, and assigns, should at any

page_text: 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, exer-
cise, and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN STEAL
ENGINES," upon the condition (amongst others) that I, the said James Gray
Lawrie, my executors or administrators, by an instrument in writing under
my, or their, or one of 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 calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said James Gray Lawrie, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say):-
Part of my Invention consists of a peculiar combination of the parts of a
steam engine, consisting of two steam cylinders, air pump, and condenser.
DESCRIPTION OF THE DRAWING, SHEET 1.
Figures 1, 2, 3, 6, 7, 8, show different views of the arrangement of the parts
in the new combination. A are two steam cylinders; B, cylinder cross heads;
C, crank shaft; D, condenser; E, air pump; F, side or connecting rods, of
which there is one connected with each end of the piston cross heads and the
cranks on crank shaft; A', air pump levers; B', air pump cross head; F, air
pump side rods; D', feed and bilge pumps; E', guide bars for cylinder cross
heads; E, frames for holding upper ends of guide bars; G, primary valves with
rods, or the valves which regulate both the induction and eduction of the steam
to and from the steam cylinders; H, the valves with rods, which regulate the
admission of the steam to the valves G; I, I, two excentrics, with hoops and
excentric rods on the crank shaft, placed at right angles to each other; C¹, a
shaft, with a lever on each end equal in length to the eccentricity of the
excentrics I, 1'; I, two excentrics of link motions for valves; G, K, two
excentrics for link motions of valves; II, the excentrics; I and K are on the
shaft C; T, the links attached to the excentric rods which regulate the action
of the valves G; U, the corresponding links for the valves II; W, wyper shafts,
receiving motion from the links T, and imparting the effect to the valves G;
W¹, wyper shafts, receiving motion from the links U, and imparting the effect
to the valves H; C, a shaft carrying three levers, two of them Q, Q', con-
nected by links T, T', to the links T, the third Q being the lever, adjustable

page_text: by hand, to place the valves G, by means of the links T, where necessary in
working the engines. Upon the shaft C2 is a short hollow shaft or socket
carrying three levers R, R1, R2, answering for the valves H the same purpose
as the levers Q, Q, Q, for the valves G; S, the steam pipe; V, the eduction
pipes leading from the exhaust passages to the condenser. In consequence of
the steam cylinders being placed at right angles to each other, the side or con-
necting rods F, which connect the cranks with the cylinder cross heads, give a
continuous rotary motion to the crank shaft, which may either be connected
with the propeller shaft directly, or by the intervention of gearing; the air pump
receives by means of its levers A¹ and side rods Fits motion or action from
the cross head of the upright cylinder; the shaft C¹ receives a rotary motion
from the shaft C by means of the excentrics I¹. The wyper shafts W, W¹,
receiving their motion, and in turn act upon the valves by the operation of the
link motions, of which the excentrics I, K, on the shaft C₁, are a part. This
arrangement of engines, or disposition of cylinders, condenser, and air pump,
can be used with a variety of valves and motions, which would receive their
action from excentrics placed on the shaft C', in the same way as valve motions
commonly receive their action from excentrics on crank shafts; but the mode
of constructing the particular valve arrangements shown on the Drawing will
be pointed out in the explanation of Sheet 2, and on reference to that expla-
nation it will be seen that by the construction shown in Figure 7, Sheet 2, the
steam is excluded from the steam cylinder, when the edges H', H2, cover
respectively the sides G, G³, of the ports for the admission of the steam. The
construction of expansion valve, shown in Figure 7, Sheet 2, I prefer to that
shown in Figure 8 of the same Sheet.
By the above arrangement or combination it will be seen, that when the
engines are not very large, the two steam cylinders, the air pump, and the con-
denser may be with advantage made in one casting, though the parts may, if
preferred, be made separate. By the peculiar combination constituting this
part of my Invention framing is dispensed with, and the combined engine
rendered very compact, and so as to occupy comparatively small space for the
power.
I would state that I make no claim to any of the parts separately, nor do I
confine myself to the details shown and explained; but I claim, in respect to
this part of my Invention, the combination herein described.
I will now describe another part of my Invention, which relates to working
steam expansively, and consists of applying link motions to or combining link
motions with expansion valves employed to regulate the supply of steam to the
valves or valve boxes, by which steam is admitted to the steam cylinders.

page_text: cause the link T to traverse or move up and down (in this case), and so regulate
the action of the valve G; C, a shaft for the valve H, which, in a similar way
to C for the valves G, affords means by which the hand wheel R², operating
upon the levers R, R', can traverse or move up and down the links U, and so
regulate the action of the valves H. The valve II working upon the valve G,
excludes the steam from the cylinder when (constructed as shown in Figure 7).
The edges H, H, cover respectively the sides G', G, of the ports for the
admission of the steam. The operation of these valves and motions when
properly adjusted affords the means of excluding the steam from the cylinders
during certain portions of the stroke of the piston, and also of varying the
portions of the stroke during which steam is excluded.
Figures 5, 6, and 7 are explanatory of the manner of making the necessary
adjustments to obtain the effect of excluding the steam during certain portions
of the stroke. Lis the position of the crank at the commencement of a stroke,
and is supposed to be going in the direction of the arrows; M, the position of
the centre of the excentric which is called the heading excentric, for working
the primary valve G; M², the position of the centre of the backing excen-
tric for the same valve; and N, N¹, respectively, the position of the centres
of the heading and backing excentrics for the valves H. The lines M, M',
N, N', should be parallel, or nearly so, to the diameter O, R", drawn at right
angles to the crank at the commencement of the stroke, and at a distance
from that diameter varying according to circumstances, and to some extent
according to the taste of the constructor of the machinery. The perpendicular
distances from the points M, M', to the diameter O, R, and which are fre-
quently called the "advance" of the valve or excentrics, are usually equal
to the steam cover of the valve, added to the amount of lead required for the
admission of the steam at the commencement of the stroke. The position
of the line N, N¹, must be varied according to the portions of the stroke from
which it is desired to exclude the steam, and also according to the length of
stroke of the valves G and H.
In my own practice, in making designs for both marine and locomotive
engines, I usually adopt the following proportions:-
Length of extreme stroke of valve G = 1
Cover on steam side of
-do.
Lead at commencement of stroke
Length of extreme stroke of valve H
Length of valve H from H' to H
from G' to G multiplied by about.
==
==
a'v
=
length of valve G
= 1

page_text: equal to the steam cover of the valve G, added to the lead at the commence-
ment of the stroke. The portions of the stroke of the piston from which steam
is excluded can be varied within limits by traversing either one or both of the
links T, U, so as to shorten the stroke of either or both of the valves G
and H; and the hand wheels Q³, R2, with the other connections, supply the
means of doing so.
DESCRIPTION OF THE DRAWING, SHEET 3.
This Drawing shows various views of means, according to this part of my
Invention, of using steam expansively applied to a pair of trunk engines, in
which the diameter of each steam cylinder is sixty inches, and length of stroke
three feet. In this adaptation the valves of the cylinders for regulating the
passage of the steam are placed on the top of the cylinders, and receive their
motion from wyper or weigh shafts, upon which the link motions operate.
The primary valves are of a form similar to that known as the D valve, and
the expansion valves which regulate the admission of the steam to these
primary valves work upon a plate interposed betwixt them and the primary
valves.
The letters upon this and Sheet 2 represent the same or corresponding
parts, and therefore the description of Sheet 2, with the exception of that part
referring to the valve arrangements, is equally explanatory of Sheet 3, if to
that description be added the following observations:-
From the construction of the wyper shafts W, W', which give motion
respectively to the valves G and H, the levers upon those wyper shafts which
receive the action of the link motions are in each case shorter than the levers.
which give motion to the valves, and therefore the extreme stroke of the
valves is greater than the extreme stroke imparted to the pins of the levers
with which the link motions are connected. The shafts C, C, are in this
case so constructed as that C¹ passes through C³, instead of, as in Sheet 2,
being outside of it. In making designs with the valves G and H arranged
as in this adaptation, the following are proportions I usually adopt :-
Length of extreme stroke of valve G = 1
Cover on steam side of
do.
Lead at commencement of stroke
Length of extreme stroke of valve H
Breadth of each port through valve H
Do. of each port through stationary}
plate on which valve H works
=
-
-
=
=
nearly.

page_text: I place the line N, N¹, parallel to O, R³, and at a distance from it equal to
the breadth of each port through the valve H. The portion of the stroke
of the piston from which steam is excluded can be varied within limits by
traversing the link U, so as to shorten the stroke of the valve H, and the hand
wheel R2, with the other connections, supply the means of doing so.
DESCRIPTION OF THE DRAWING, SHEET 4.
This Drawing by several views shows an adaptation of using steam expan-
sively applied to a pair of upright direct acting engines, in which the piston
rods pass through the bottom of the cylinders. In this adaptation the valves
of the cylinders for regulating the passage of the steam are placed betwixt
the cylinders, and are connected directly with the link motions, without the
intervention of wyper or weigh shafts. The primary valves are of the same
form as described in Sheet 2, and the expansion valves which regulate the
admission of the steam to these primary valves work at their back. In the
Drawing, A are steam cylinders; C, crank shaft; D, condenser; E, air pumps;
F, connecting rods; and so on with all the other parts usual or necessary in
engines of this description, and which are drawn more or less completely. G,
the primary valves with rods, or the valves which regulate both the induction
and the eduction of the steam to and from the cylinders; H, the valves with
rods which regulate the admission of the steam to the valves G; I, the excen-
trics and hoops of the link motions for the valves G; K, the excentrics and
hoops of the link motions for the valves H; T, the links attached to the excen-
tric rods which regulate the action of the valves G; U, the corresponding
links for the valves H; C, a shaft carrying three levers, two of which Q, Q',
are connected by links T, T', to the links T, and the third Q, not shown on
Drawing, is placed conveniently on the shaft, being the lever to be worked by
hand in placing the link motions of the valves where desired. C, a short
hollow shaft or socket, working loosely on C¹, and which in like manner carries
three levers, of which the two R, R¹, being connected to the links U, supply
the means by the hand lever R³, not shown on Drawing, whereby the links U
can be placed where desired for the regulation of the valves H. The manner
of adjusting valves such as those used in this adaptation has already been
pointed out in the explanation of Sheet 2.
Figures 5 and 10 explain more fully the construction of the link motions used
in this adaptation, and also that employed on Sheet 2. C is the crank shaft,
on which is placed the excentrics; G, the spindle or rod of valve G; T, the
links of the link motions regulated by the excentrics I; T, T, the links which
connect the link T to the levers Q on the shaft C, which shaft carries also the

page_text: hand lever Q, by means of which the link T can be made to traverse, and so
regulate the valves G in like manner. The links U of the link motions for
the valves H can be made to traverse and to regulate those valves; X, an
arm attached to some stationary part, to form a guide for steadying the valve
spindles, which are carried or extended under the links T, (in Sheet 2 this
guide is marked S), for the purpose of being guided.
Figures 6, 7 and 8 explain a modification of the link motions applied to the
valve H, which in certain cases may be used and preferred. The link motions,
hitherto explained as applied to the valves H, afford the means of using the
steam expansively when the engines are working backwards as well as when
they are worked in the forward direction; but in any case in which it is not
desired to have the means of using the steam expansively when the engines
are working backwards, although it be desired to have the means of using the
steam expansively when the engines are working in the forward direction,
one of the excentrics K of each link motion for the valve H should be
made with the excentricity reduced to nothing; and with such a construction,
instead of having a separate excentric and rod for the back end of each
link U, one rod K¹ is sufficient for the back ends of both links U, and
that eccentric rod may at the crank shaft end grasp either an excentric
wheel, in which there is no eccentricity, or the shaft itself without the inter-
vention of a wheel, or may be suspended from any point K with a link or
rod in such a way as will permit the traverse of the links U similarly as in the
construction shown in Figures 5, 10, 6, and 8.
DESCRIPTION OF THE DRAWING, SHEET 5.
This Drawing shows an adaptation of means of using steam expansively
applied to a locomotive steam engine. This adaptation is perhaps more pecu-
liarly suitable for locomotives, but is applicable to many other variations of steam
engines besides. The link motion is connected directly to the valves gearing
without the intervention of wyper or weigh shafts; the primary valves are of a
similar form to those described on Sheet 2; and the expansion valves, which
regulate the admission of the steam to those primary valves, work upon
their back.
In the Drawing, A is the steam cylinder; C, the crank shaft or driving wheel
shaft; G, the primary valve with its rod, or the valve which regulates both
the induction and the eduction of the steam; H, the valves with its rod, which
regulates the admission of the steam to the valves G; G', H', are respec-
tively links extending from the rods of the valves G and H to the link T of
the one link motion, which in this adaptation serves for both valves G and H.

page_text: T', links supporting the link T from the stationary shaft or stud B, and
in such a way that the link T is itself free to oscillate by the action of
the eccentric rods I round the point or stud D, while the stud D, from
the same action of the same excentric rods, is free to oscillate round or
upon the shaft B. C¹, a shaft carrying two levers, of which one of them
Qis connected by the link T to the link G¹, and the other, which is not
shown on the Drawing, is so placed and arranged as that by hand the
link G¹ can be made to traverse the link T, and so regulate the valves G.
C³, a tube or hollow shaft placed and working on C¹, which also carries two
levers, of which one of them R is connected by the link U¹ to the link H¹,
and the other R' is placed and arranged so as that by band the link H' can
be made to traverse the link T, and so regulate the valve II. Figure 4 is
a cross section of the link T to a larger scale, showing more plainly how
it is constructed, so that the links G, H, may traverse the link T clear of
each other, and showing also recessed provision, as at T3, for slide blocks
attached to the links G', H', in the way that is usual in link motions of this
description.
Figure 5 is explanatory of the manner of making the necessary adjustments
to obtain the effect of excluding the steam during certain portions of the
stroke. In this adaptation, L is the position of the crank at the com-
mencement of a stroke, and is supposed to be going in the direction of the
arrow; M, the position of the centre of the excentric which is called the
heading excentric, for working the primary valves G; M', the position of
the centre of the backing excentric for the same valve. The line M, M',
should be parallel or nearly so to the diameter O, R³, drawn at right angles
to the valve spindle; and the perpendicular distances from the points M, M
to this diameter, as already explained for Sheet 2, are usually equal to the
steam cover added to the amount of lead. It has already been pointed out
that in this adaptation there is only one link motion, though of what may
be called a double construction, for the regulation of both valves G and H,
because the link T, which regulates the valve G by the link G¹, also regulates
the valve H by the link H'.
Having thus shown and described the manner in which I perform this part
of my Invention, I would state that I make no claim to the several parts of
the steam engines shown and described, neither do I confine myself to the
application of my improvements to the arrangements of steam engines shown ;
but what I claim is, the combining "link motions" with expansion valves used
to regulate the supply of steam to the valves or valve boxes, by which the steam
is admitted to the steam cylinders.

page_text: equilibrium slide valves between two cylinders arranged to give motion to a
propeller shaft.
DESCRIPTION OF THE DRAWING, SHEET 1.
Figures 4 and 5 of Sheet 1 show the construction of slide valves whereby
the stroke of the valves, with a given amount of opening in the ports of the
steam cylinders admitting the steam, may be reduced to less than is possible
with the ordinary construction of valves, and the same Figures explain also
the construction of equilibrium slide valves.
A are steam cylinders; A' are steam passages; A2, A3, A', ports or openings
into the passages A¹ for the purpose of admitting the steam into the cylinders,
or its egress from them. The faces of the valves are constructed that the valve
in its motion only admits steam by the ports A, only gives egress through the
ports A², and gives both ingress and egress by the openings A³. There are
thus, as shown on the Drawing, the two ports A³, A, which both admit steam
to the cylinders at each stroke of the piston, and there are the two ports A², A³,
which both in like manner afford egress. In the construction of steam engines
it is usually considered desirable to have larger provision for the egress of the
steam than for the ingress, and a modification of this construction accomplishes
that arrangement very completely by shutting up the ports A, and retaining
the others. With this modification there are two ports, which for each stroke
give egress to the steam, and one port to admit the steam.
In the con-
struction of valve casing shown on the Drawing, there are two divisions or
plates or diaphragms marked B, which are formed, dividing the casing in this
instance into three compartments S, S', S²; in S the valve G works; in S² the
valve G¹ works; and in S', to which alone steam direct from the steam pipe is
admitted, the expansive valves I work, and which valves, as explained in
Sheet 3, regulate the admission of the steam to the valves G and G'. G' is
the construction of valve in which the pressure of the steam is in part removed
from the back, and forms more or less completely an equilibrium slide valve.
E are brass plates shaped to fit the back of the valve. D, spaces filled with
hemp or other suitable packing; C, metallic blocks, formed suitably to press
or compress, by the action of the screws T, the packing in the spaces D, and to
prevent the steam passing at the outer circumference of the valve directly to
the condenser without having acted in the cylinder.
I would remark in respect to this part of my Invention, that I do not claim

page_text: extra ports to steam cylinders, but the mode of combining extra ports with
valves, as herein described.
And I also claim the mode of applying equilibrium valves herein described.
In witness whereof, I, the said James Gray Lawrie, have hereunto set my
hand and seal, this First day of January, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
FRED HARRIS.
J. G. LAWRIE. (L.S.)