IMPROVEMENTS IN STEAM ENGINES AND VALVES FOR THE SAME, APPLICABLE ALSO FOR OTHER PURPOSES
Year: 1877

page_text: LETTERS PATENT to Loftus Perkins, of Seaford Street, Gray's Inn Road, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN STEAM ENGINES
AND VALVES FOR THE SAME, APPLICABLE ALSO FOR OTHER PURPOSES"
PROVISIONAL SPECIFICATION left by the said Loftus Perkins at the Office
of the Commissioners of Patents on the 6th February 1877
LOFTUS PERKINS, of Seaford Street, Gray's Inn Road, in the County of Middlesex
"IMPROVEMENTS IN STEAM ENGINES AND VALVES FOR THE SAME, APPLICABLE ALSO
FOR OTHER PURPOSES"
Heretofore in steam engines when the valves used for controlling the passage of
steam to or from the steam cylinders have been lifting valves, such valves have
been attached to a rod passing downwards through a stuffing box from the chamber
containing the valve, and have been lifted at the times required by a cam acting
upon an aim fixed to the rod before mentioned This arrangement is however only
applicable to engines running at comparatively slow speeds, owing to the friction of
the stuffing box around the valve rod, as the closing of the valve is effected only
by the weight of the valve and rod and by the small amount of pressure on the top
of the valve in excess of that on the bottom
According to my Invention I mount the valve loosely upon the top of the valve
rod, the valve rod I carry down through a stuffing box as before and I give to it
a positive motion in both directions, that is, both when rising and falling, in such
manner that the first part of the upward movement of the valve rod shall take place
slowly until the valve rod has come against the valve and lifted it, and that the
remainder of the lift shall then be effected quickly, by this means all noise in the
lifting and closing of the valves is avoided and the valves can be used with quick
running engines equally as well as with slow running engines
The lifting and lowering of the valve rod may be effected by a rocking crank so
arranged that the crank arm is downwards when commencing to move the valve
rod upwards, and moves towards a horizontal position as it completes the lifting of
the valve When closing the valve the crank arm will move towards a vertical
position, and when it has moved through half its traverse it will leave the valve

page_text: resting on its seat
In the remaining half of its traverse it will move beyond the
vertical position but not to such an extent as to again lift the valve at the end of
the back stroke A rocking or revolving cam may also be used for giving a similar
movement to the valve rod
In order to facilitate the starting of compound engines such as are described in
the Specification of a former Patent granted to me on the 20th January 1875,
No 224, in which the high-pressure cylinder is single acting, it is now usual to
provide a valve by which steam may at the time of starting the engine be con-
tinuously admitted to the high-pressure cylinder so that it may pass from thence
to the second or expansion cylinder of the engine and act on the larger area of the
piston of this cylinder When I employ a lifting valve as above described for con-
trolling the admission of steam to the high-pressure cylinder I do away with the
necessity of thus providing an additional starting valve by placing a tubular sleeve
around the valve iod, and carrying this sleeve up through the stuffing box though
When
which the valve rod passes so that its end may come just below the valve
starting the engine the sleeve is by a screw and nut or otherwise shifted upwards
So soon as
along the valve 1od, and the valve is thereby continuously held open
the engine has been started the sleeve is again diawn down allowing the valve to
perform its regular duty of controlling the admission of steam to the high-pressure
cylinder
When a sliding D valve is used for controlling the admission of steam to the
cylinders of steam engines, and when it is desued that at starting, steam may bo
admitted at the back of the piston during the whole of each stroke whilst when
the engine is in iegular work, that steam may be admitted to the cylinder for a
portion only of each stroke, I form a small port at each extremity of the sliding
valve and connect these ports by a passage formed in the back of the valve behind
the central exhaust space
When the engine is to be started I admit steam from the valve chest continuously
to this passage by opening a small valve, by this means the lap of the shde valve
When
1s desta oyed and steam is admitted to the cylinder for the whole stroke
the engine has been started the small valve before mentioned is closed, the lap of
the valve will then come into play and only adınıt steam to the cylinder for a half
stroke or any other portion of the stroke, as desued
In order to be able to open or close the small valve before mentioned whenever
dosned, the valve is caned by a 1od which passes out from the valve chest through
a stuffing box, and moves to and fio with the valve, the valvo 10d may have a
hand wheel on its outer end, by turning which the valve may be moved on to and
off its seat, there being a sciew thread on the rod working into a corresponding
thread carried by the slide valve
When the slide valve has a cut off or expansion valve working upon it at the 4
back I connect the two steam ports which are formed though the main slido valve
by a passage, and at one end of the main slide valve I provide a valve by which
steam may be admitted continuously to the passage just mentioned, and I provide
means as before explained for opening this valve at the time of starting the engine
and closing it when the engine has been started The effect of this will be that 4
when the engine is started, steam will be admitted to the cylinder throughout the
stroke or nearly so and that afterwards the cut-off valve is brought into play
Thus the engine may be started without interfering in any way with the cut-off
valve or altering its adjustment.
I also construct steam engines with a high-pressure cylinder at one end of a 5
medium pressure cylinder, and with the pistons of the two cylinders carried by one
piston rod as described in the Specification of the Patent before mentioned, in
page 3 hereof, but in place of using two such single acting high and medium pres-
sure cylinders together with one double acting low-pressure cylinder as described
in that Specification, I now use with the one double acting low-pressure cylinder 5
one single acting high-pressure cylinder only, and one single acting inedium-pressure
cylinder, the high-pressure steam being caused to act first in the outer end of the

page_text: high-pressure cylinder, then to exhaust into the opposite end of the medium-pressure
cylinder, and from there into the space between the two pistons and to the low-
piessure cylinder
I also enclose all the cylinders of a steam engine in a chamber, the sides of which
are made double and filled in with non-conducting material The chamber thus
forms as it were a hot an bath enclosing the cylinders, valve chambers, and
passages.
In place of forming the feed pump valves cach with a stem composed of radial
wings as heretofore to act as guides to the valve as it lifts, I form the valves with
a hollow cylindrical stem fitting the cylindrical passage which the valve closes, and
I form around the cylindrical stem just below the valve a groove or hollow from
When the valve lifts,
which holes or channels pass to the interior of the stem
water passes through these holes or channels and past the valve, and at the same
time a slight rotation is given to the valve by cason of the holes or channels being
made somewhat tangentially to the stem By this means the valve is perfectly
guided as it opens and closes and is also kept turning upon its seat, and is therefore
not liable to be bruised at any one point by repeatedly striking at the same spot
against any obstruction which may happen to lodge between the valve and its soat.
Valves thus constructed are also applicable for other purposes
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Loftus Perkins in the Great Seal Patent Office on the 4th August
1877
LOFTUS PERKINS, of Seaford Street, Gray's Inn Road, in the County of Middlesex.
IMPROVEMENTS IN STEAM ENGINES AND VALVES FOR THE SAME, APPLICABLE ALSO
FOR OTHER PURPOSES
"
Heietofore in steam engines when the valves used for controlling the passage of
steam to or from the steam cylinders have been lifting valves such valves have been
attached to a 1od passing downwards through stufhing box from the chamber con-
taining the valvo, and have been lifted at the times required by a cam acting upon
an aim fixed to the 1od before mentioned This aangement is however only
applicable to engines running at comparatively slow speeds, owing to the friction
of the stuffing box around the valve rod, as the closing of the valve is effected only
by the weight of the valve and 1od and by the small amount of pressure on the top .
of the valve in excess of that on the bottom
According to my Invention I mount the valve loosely upon the top of the valve
rod, the valve rod I carry down through a stuffing box as before, and I give to it a
positive motion in both directions, that is, both when rising and falling, in such manner
that the first part of the upward movement of the valve rod shall take place slowly
until the valve 1od has come against the valve and lifted it, and that the remainder
of the lift shall then be effected quickly By this means all noise in the lifting and
closing of the valves is avoided, and the valves can be used with quick running
engines equally as well as with slow running engines
The lifting and lowering of the valve iod may be effected by a rocking crank, so
aanged that the crank aim is downwards when commencing to move the valve
rod upwards, and moves towards a horizontal position as it completes the lifting of
the valve When closing the valve the crank arm will move towards a vertical
position, and when it has moved through half its traverse it will leave the valve
esting on its seat
In the remaining half of its traverse it will move beyond the
vertical position, but not to such an extent as to again lift the valve at the end of
the back stroke A locking 01 revolving cam may also be used for giving a similar
movement to the valve rod
In order to facilitate the starting of compound engines, such as are described in
the Specification of a former Patent, granted to me on the 20th day of January

page_text: 1875, No 234, in which the high-pressure cylinder is single acting, it is now usual to
provide a valve by which steam may at the time of starting the engine be continuously
admitted to the high-pressure cylinder, so that it may pass from thence to the
second or expansion cylinder of the engine and act on the larger area of the piston
of this cylinder When I employ a lifting valve, as above described, for controlling
the admission of steam to the high-pressure cylinder I do away with the necessity
of thus providing an additional staiting valve by placing a tubular sleeve around
the valve rod and carrying this sleeve up though the stuffing box, through which
the valve rod passes, so that its end may come just below the valve When starting
the engine the sleeve is by a screw and nut, or otherwise, shifted upwards along the
valve iod, and the valve is thereby continuously held open So soon as the engine
has been started the sleeve is again drawn down, allowing the valve to perform its
regular duty of controlling the admission of steam to the high-pressure cylinder
When a sliding D valve is used for controlling the admission of steam to the
cylinders of steam engines, and when it is desned that at starting steam may be
admitted at the back of the piston during the whole of each stroke, whilst when
the engine is in regular work that steam may be admitted to the cylinder for a
portion only of each stroke, I form a small port at each extremity of the sliding
valve, and connect these poits by a passage formed in the back of the valve behind
the cential exhaust space
When the engine is to he started I admit steam from the valve chest continuously
to this passage by opening a small valve By this means the lap of the slide valve
18 destroyed, and steam is admitted to the cylinder for the whole stroke When
the engine has been started the small valve before mentioned is closed, the lap of
the valve will then come into play and only admit steam to the cylinder for a half
stroke, or any other portion of the stroke as desired
In order to be able to open or close the small valve before mentioned whenever
desued the valve is carried by a rod which passes out from the valve chest through
a stuffing box, and moves to and fro with the valve The valve 10d may have a
hand wheel on its outer end, by tuining which the valve may be moved into and
off its seat, there being a sciew thread on the rod, working into a corresponding
thread carried by the slide valve
When the slide valve has a cut-off or expansion valve working upon it at the
back I connect the two steam ports which are formed though the main slide valve
by a passage, and at one end of the main slide valve I provide a valve by which
steam may be admitted continuously to the passage just inentioned, and I provide
means, as before explained, for opening this valve at the time of starting the engine,
and closing it when the engine has been started The effect of this will be that
when the engine is started steam will be admitted to the cylinder throughout the
stroke, or nearly so, and that afterwards the cut-off valve is brought into play
Thus the engine may be started without interfering in any way with the cut-off
valve or altering its adjustment
I also constinct steam engines with a high-pressure cylinder at one end of a
medium-pressure cylinder, and with the pistons of the two cylinders canned by
one piston rod, as described in the Specification of the Patent before mentioned, but
in place of using two such single-acting high and medium vies,ure cylinders
together with one double-acting low-pressure cylinder, as described in that Specifica-
tion, I now use with the one double-action low-pressure cylinder one single-acting
high-pressure cylinder only and one single-acting medium-pressure cylinder, the
high-pressure steam being caused to act first in the outer end of the high-pressure
cylinder, then to exhaust into the opposite end of the medium-pressure cylinder,
and fiom there into the space between the two pistons, and to the low-pressure
cylinder
I also enclose all the cylinders of a steam engine in a chamber, the sides of which
are made double and filled in with non-conducting material The chamber thus
forms as it were a hot an bath enclosing the cylinders, valve chambers, and
passages.

page_text: In place of forming the feed pump valves each with a stem composed of radial
wings, as heretofore, to act as guides to the valve as it lifts, I form the valves with
a hollow cylindrical stem fitting the cylindrical passage which the valve closes, and I
form around the cylindrical stem just below the valve a groove or hollow, fiom
When the valve lifts
which holes or channels pass into the interior of the stom
water passes through these holes or channels and past the valve, and at the same
time a slight rotation is given to the valve by reason of the holes or channels being
made somewhat tangentially to the stem By this means the valvo is perfectly
guided as it opens and closes, and is also kept turning upon its seat, and is there-
fore not liable to be bruised at any one point by repeatedly striking at the same
spot against any obstruction which may happen to lodge between the valve and its
seat Valves thus constructed are also applicable for other purposes
Having thus descubed the nature of my Invention I will proceed to describe
more fully the manner of performing the same
At Figures 1, 2, 3, and 4, of the Diawings hereunto annexed I have shewn
valious views of an engine constructed as above described Figures 1 and 2 are
vertical sections taken at 11ght angles to one another of the engine, Figure 3 is a
plan view with the top of the cover which encloses the cylinders and valve chambers
removed, Figure 4 is a horizontal section of the engine taken below the cylinders
A, Figure 1, is the valve for admitting steam to the top of the high-pressure
cylinder, it is shown in dotted lines as it is situated in front of the line in which
the section is taken A is the rod by which the valve is lifted, around this rod
18 a tube A² foi lifting the valvo A at the time of starting the engine
The 10d
and tube pass down through a tubular casing to below the bed Z, upon which the
cylinders are called and pass out from the bottom of the tubular casing through
a stuffing box A³.
At the lower end of the tube A² is also a stuffing box A',
through which the rod A¹ passes, and the lower end of the 1od is coupled by a link
A³ to an eccentric Aº (see Figure 4) on the crank shaft Y of the engine, and the 1od
is by it lifted and lowered to open and close the valve at the times required On
the lower end of the tube A² is a screw thread A7 screwing through a fixed bracket
A When it is desired to keep the valve A lifted, a partial tuin is given to the
tube A² by a lever arm A° (see Figure 3) at its lower end, the tube is thereby
caused to rise, and its upper end lifts the valve
B is the valve for exhausting steam from the high-pressure cylinder, and allowing
it to pass to the under side of the piston in the medium-pressure cylinder B¹ 15
the rod for lifting this valve, it passes out through a stuffing box B³, and carries at
its lower end a fork B³, canying a sliding block which embraces a crank pin B',
carried by an aim on the rocking shaft X, this shaft receives a rocking motion by
an ordinary link motion, as shewn, a crank pin X² on another arm on the shaft
entering a sliding block carried by the slide X2, which is coupled at its end by links
to eccentrics Xs on the main crank shaft Y, X' is a link coupling the slide X2 to
the starting and reversing lever X³, which can be locked in any position to a rod
X by a clamp X', the crank pin B' is oscillated through an arc of about 90°, as
shewn by the lines 1, 3, whilst it is moving in the upper half of this arc, that 15,
between the lines 1 and 2, it is lifting or lowering the valve, but as it descends
below the line 2 the valve is left on its seat, and the rod B¹ moves down away
from it, whilst the crank pin B' is moving through half the distance between the
lines 2 and 3, afterwards the crank pin as it comes up to the line 3 again lifts the
rod but not sufficiently to lift the valve, the crank pin then moves back in the
opposite direction, and as it passes beyond the line 2 it again lifts the valve
C is the exhaust valve from the medium pressure cylinder, and C¹ the rod by
which it is worked, the 1od passes down through a stuffing box C2, and at its lower
end has a rising and falling motion given to it in the same way as above described
by another crank pin C, carried by the rocking shaft X, this crank pin oscillates
through an arc between the Ines 2 and 4, as shewn, and it will act to open and
close the valve Cin the same way as described with reference to the valve B, and

page_text: consequently both of these exhaust valves will be opened and closed quietly as
herein-before explained
D, Figures 2 and 3, is the valve for admitting steam which has passed from the
medium-pressure cylinder to pass to the top of the low-pressure cylinder. There is
a similar valve at Dx, see Figure 3, for adinitting steam to the bottom of the low-
pressure cylinder The rods D', which lift these valves, are each surrounded by a
tube D, by which either of the valves can be lifted, so as to be able to admit steam
in any position of the engine, either to the top or bottom of the low-pressure
cylinder at the time of starting The tube D surrounding one iod has a right-
hand screw thread upon it, and the other a left-hand thread, these screw through
corresponding fixed nuts D³ On the lower end of each tube is an arın D' (see
Figures 2 and 3), these are coupled together by a rod D³, and by moving thus rod
in one or other duection either the valve D or the valve D* can be lifted The
rods by which the valves D, D*, are opened and closed after the engine has
been started have a 18ing and falling motion given to them at then lowo ends
in the same way as just described with icference to the valves B and C by ciank
pins carried by a rocking shaft W, which is 1ocked, as shewn, through a link
motion by eccentrics on the main crank shaft Y The slide of the link motion 18
connected by a connecting rod to an arm on the axis X³ of the stopping and reversing
lever X5
E is the exhaust valve for allowing steam to pass from the top of the low-pressure
cylinder to the condenser, and E the exhaust valve for the bottom of this cylinder.
The rods which open and close these valves are in the same way as the other valves
raised and lowered by crank pins on a rocking shaft V
The high-pressure cylinder is marked F, the lower part of the medium-pressure
cylinder is marked G, and the steam space above the piston of this cylinder G³, I
is the low-pressure cylinder It will be seen that the cylinders are all carried by a
bed plato Z, and that this plato also carries the valve chambers and steam passages,
and the plate is formed all around its edge to receive a cover I, by which the whole
of these parts of the engine may be covered in By preference I form this cover
with double sides, and fill in the sides with non-conducting material The bed
plate Z is, as shewn, carried by uprights J from the lower bed plate K of the
engine
I will now proceed to described more fully the manner in which I form the sliding
D valves of steam engines to admit steam to the cylinder throughout the entue
stroke at starting, and afterwards when the engine has been started to admit steam
for one-half or any other portion of the stroke, as desued, without interfering with
the movement of the valve Figure 5, shews a D slide valve with my improve-
ments applied to it In this Figure A is the fixed valve face, B the sliding D
valve, C, the small ports formed in the two ends of this valve, D, the passage
connecting these ports, E, the valve for controlling the admission of steain to this
passage On the stem of the valve is a screw thread screwing into a nut carried by
the sliding valve B The end of the stem of the valve E passes out from the valve
chest through a stuffing box, and as the stem of the valve E is parallel with the
1od by which the slide valve is moved to and fro it in no way interferes with the
movement of the slide valve The outer end of the stem of the valve E passes
though a wheel or lever handle, by which it can be turned, and the valve E so
opened or closed When the valve F' is opened steam passes to the small port in
the ends of the D valve, and the lap of the valve is destroyed When the valve E
15 closed steam is cut off from these ports, and the slide valve works as an ordinary
slide valve.
Figure 6 shews a back view of a slide valve adapted to have cut off or expansion
plates working on it at the back, these plates A, shown by dotted lines, are moved
to and fio in the ordinary manner by a rod, not shown in the Drawing, B, B, are
the two steam ports of the main slido valve, these are connected by a passage C, 5
which passes through the central exhaust hollow of the valve, D is the small valve,
by which steam can be admitted to the steam ports at the time of starting the

page_text: engine This valve can be opened in a similar way to that above described with
reference to the small valve in Figure 5 without in any way interfering with the
movement of the main slide valve or of the cut-off plates which work above it
When the valve is opened steam is admitted to the cylinder throughout the stroke,
and when the valve is closed the slide valve and expansion plates will control the
working of the engine in the ordinary manner
Figure 7 shows a section of a feed pump valve constructed according to my
Invention, valves formed in a similar manner may be used for other purposes. A
is the hollow cylindrical valve stem fitting the passage which the valve closes ; B,
the inclined passages passing from the interior of the sten to its exterior just below
the valve
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,-
First The combined arrangement of apparatus, substantially as herein described,
for opening and closing lifting valves of steam engines.
Second The arrangement, substantially as described, for holding open the valvos
without interfering with the mechanisin by which the valves are at other times
opened and closed
Thud The combined arrangement of steam engine, substantially as herem
described, with one single-acting high-pressure cylinder, one single-acting medium-
pressure cylinder, and one double-acting low-pressure cylinder
Fourth Enclosing the cylinders, valves, chambers, and steam passages of steam
engines within a chamber or casing of non-conducting material, substantially as
herein described
Fifth The construction of the slide valves of steam engines, substantially as
herein described, to be able to admit steam to the cylinders at starting throughout
the stroko, and after starting to cut off tho admission of stoam at one-half or other
portion of the stroke without interfering with the movement of the valve itself
Sixth The construction of pump valves and other valves substantially as herein
described
In witness whereof, I, the said Loftus Perkins, have hereunto set my hand
and seal, this Third day of August, in the year of our Lord One thousand
eight hundred and seventy-seven.