Improvements in or connected with Steam and other Motive Fluid Engines.
Year: 1893

page_text: Date of Application, 15th Feb., 1893
Complete Specification Left, 8th June, 1893-Accepted, 8th July, 1893
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam and other Motive
Fluid Engines.
IWALTER CHARLES CHURCH of No. 6 Trinity Square Brixton in the County
of Surrey Engineer do hereby declare the nature of this invention to be as follows:-
My invention relating to steam and other motive fluid engines has for its object
to provide means whereby steadiness in the movement of the working parts is
ensured, friction reduced, and economy of motive fluid and increased power
obtained.
According to my invention as applied to steam engines I construct the chests or
cases containing the valves in such a manner that ready egress of the water is
obtained so that comparatively dry valve chests or cases are maintained. For this
purpose I make the lower side or bottom of the valve chest inclined towards the
exhaust outlet for instance in the case of compound engines I make the lower side
or bottom of the valve chest of the high pressure cylinder to incline towards an
outlet or exhaust which communicates with a passage leading into the interior
cavity in the valve of the lower pressure cylinder through which passage the water
from the said valve chest or casing passes with the exhaust steam from the high
pressure cylinder into the cavity or cavities in the valve of the lower pressure
cylinder whence it passes into the lower pressure cylinder and out therefrom into
the valve chest or case of the said lower pressure cylinder. The lower side or
bottom of this valve chest or case is also inclined towards an outlet or exhaust
leading to the atmosphere or to a condenser according to whether the engine is
worked as a non-condensing or a condensing engine. I connect the valve rods of
multiple cylinder engines to a crosshead driven by a single eccentric or other
operating device the said crosshead having long bosses or arms fitted to slide in
guides suitably arranged to ensure the rods working truly. The piston rod of
the high pressure cylinder and the piston rod of the lower pressure cylinder are
connected to a crosshead in such a manner as to admit of more power being
exerted on the crosshead at one end than at the other end without straining or
laterally distorting the piston rods. With this object the high pressure piston rod
is connected to a gudgeon provided with trunnions free to turn in the crosshead or
the trunnions may be formed on the piston rod itself. The piston rod of the lower
pressure cylinder is also connected to a gudgeon with trunnions or has trunnions
formed thereon which fit so as to be free to turn when required in holes in the
crosshead. The connecting rod is attached to the crosshead at a point such that
when the crank is at right angles to the line of motion and consequently the rod
at its greatest angle the distance between the centres of connection of the piston
rod and the connecting rod will be such as to give the greatest power exerted by
the piston of the lower pressure cylinder over that of the piston of the high
pressure cylinder so as to relieve the friction between the slipper or slippers and
the guide when the piston is making its inward stroke the position of the connection
varying according to differences of pressures and diameters of the cylinders. By
this means a shorter connecting rod than hitherto may be used. This arrangement
may be applied not only to engines with two cylinders but also to single cylinder
engines or engines with a larger number of cylinders than two to relieve the
friction between the crosshead and its guides on the inward strokes of the piston.
The crosshead may if desired be made solid and the piston rod or rods be passed
therethrough and secured therein by means of a collar on one side and washer and
nut on the opposite side of the bearing surfaces of the collar and the washer being
concaved to correspond to convexed surfaces formed on the crosshead so as

page_text: to admit of the crosshead being pressed more at one end thereof than at the
other without causing any lateral strain on the piston rod or rods or the
convexed surfaces may be formed on a block or blocks fixed to or fitted to slide
on the crosshend.
The crosshead may be made of two slabs or cheeks connected together by bolts
or otherwise and with distance pieces between to maintain them at the required
distance apart. In either construction of cross head, bosses or journals may be
formed on the sides of the cross head for the attachment of the forked end of a
connecting rod or a single ended connecting rod may be connected to the crosshead
by a gudgeon pin on which the connecting rod works which rod in the last named
construction may be between the two cheeks or slabs.
In order to maintain the guides between which the crosshead works parallel to
each other I connect together by means of tie rods or equivalent means the said
guides or the frame or columns which carry them and to admit of the movement of
the cylinders due to expansion of the metal under heat without affecting the
position of the guides I form on one or more of the cylinders a lug or bracket or
lugs or brackets having a slot or slots therein through which passes a stud or bolt
or studs or bolts carried on the frame or column or columns to which the guide or
guides is or are attached. On this stud or bolt (or each of these studs or bolts) is
placed or formed a distance piece or collar onto which a plate or washer is forced
by a nut or nuts screwed on the end of the stud or by means of a cotter or other
suitable means so as to leave freedom for the movement of the lug or bracket to
slide between the plate or washer and a shoulder or flange on the column or framing
as the cylinders expand or contract.
To allow of this movement of the cylinders without straining the piston rods the
connection of the piston rods or one of them to the cross head may be effected so
that the connection can slide in or on the crosshead.
The attachment of the valve rods to their crosshead may be similarly effected to
accommodate the movement under expansion of the cylinders, or the crosshead
itself may be made so that it will slide telescopically to accommodate the
movement.
In rectangular slide valves of steam engines in which the live steam is admitted
to the interior thereof I provide a cap which fits over the back of the valve and
has a rectangular bearing surface which bears against the internal surface of the
valve chest or case.
The rectangular form of the face of this cap affords a greater bearing surface for
a given sized valve than would be the case if the surface be circular whilst the
friction of the rubbing surfaces is reduced owing to the increased area of the
rectangular form over that of the circular form and at the same time it admits of
the valve chest or casing being made narrower or reduced in size.
Dated this 15th day of February 1893
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London.
COMPLETE SPECIFICATION.
Improvements in or connected with Steam and other Motive
Fluid Engines.
1, WALTER CHARLES CHURCH, of No. 6, Trinity Square, Brixton, in the
County of Surrey, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relating to steam and other motive fluid engines has for its object
to provide means whereby steadiness in the movement of the working parts is
ensured, friction reduced, and economy of motive fluid and increased power
obtained. In compound steam-engines I arrange a high-pressure cylinder, or a

page_text: pair of high-pressure cylinders, by the side or sides of a low or lower-pressure
cylinder of considerably greater diameter than that of the high-pressure cylinder
or cylinders, and I provide each of the cylinders with a valve, arranged to have
steam admitted to its internal cavity or cavities, and exhaust into the valve chest
or case. The high-pressure valve chest or chests communicates or communicate
directly with a port or passage, or with ports or passages, leading into the cavity
or cavities of the low or lower-pressure slide valve. As applied to steam engines
generally, I construct the chests or cases containing the valves in such a manner
that ready egress of the water is obtained, so that comparatively dry valve chests
or cases are maintained. For this purpose I make the lower side or bottom of the
valve chest inclined towards the exhaust outlet; for instance, in the case of
compound engines, I make the lower side or bottom of the valve chest of the high-
pressure cylinder to incline towards an outlet or exhaust which communicates with
a passage leading into the interior cavity in the valve of the low or lower-
pressure cylinder, through which passage the water from the said valve chest
or casing passes with the exhaust steam from the high-pressure cylinder into the
cavity or cavities in the valve of the low or lower-pressure cylinder, whence it
passes into the low or lower-pressure cylinder, and out therefrom into the valve
chest or case of the said low or lower-pressure cylinder. The lower side or bottom
of this valve chest or case is also inclined towards an outlet or exhaust leading to
the atmosphere, or to a condenser, according to whether the engine is worked as a
non-condensing or a condensing engine. From this arrangement it follows that, as
the high-pressure piston makes its stroke (or the high-pressure pistons make their
strokes) subject to the high pressure on its or their one side or sides of steam from
the boiler, the exhaust steam from its or their other side or sides, acts on the low
or lower-pressure piston to move it in the same direction as that in which the high-
pressure piston or pistons is or are moving; and, as there is no compressing of the
steam into a reservoir or receiver, there is not that loss of power which occurs in
ordinary compound engines, due to the compressing of the steam into the receiver
during the portion of the stroke of the high-pressure piston before the exhaust is
closed and also to the increasing compression of steam as the piston completes its
stroke after the exhaust passage has been closed.
When the cylinders are above the crank, and the invention is applied to
condensing engines, I prefer to attach to the rod of the low-pressure slide valve
a piston working in a cylinder below the valve case, the outer end of this cylinder
being in communication with the atmosphere. As the pressure in the valve chest
is considerably below that of the atmosphere, the excess of outside pressure sustains
the weight of the slide valve or valves.
This, it is obvious, is also applicable when the cylinders are below the crank,
and to low-pressure slide valves or piston valves of condensing engines generally.
Either slide valves, piston valves, or other suitable valves may be employed for
one or the other or for all the cylinders.
The crosshead may be made of two slabs or cheeks connected together by bolts
or otherwise, and with distance pieces between to maintain them at the required
distance apart. Bosses or journals may be formed on the sides of the crosshead
for the attachment of the forked end of a connecting rod, or a single-ended
connecting rod may be connected to the crosshead by a gudgeon pin on which the
connecting rod works, which rod may be between the two cheeks or slabs.
Or the crosshead to which the piston rod or rods are attached may, if desired,
be made solid and the piston rod or rods be passed therethrough and secured
therein by means of a collar on one side and washer and nut on the opposite side,
the bearing surfaces of the collar and the washer being concaved to correspond to
convexed surfaces formed on the crosshead, so as to admit of the crosshead being
depressed more at one end thereof than at the other without causing any lateral
strain on the piston rod or rods, or the convexed surfaces may be formed on a
block or blocks fixed to or fitted to slide on the crosshead.
When three cylinders are arranged side by side, and the three piston rods are

page_text: connected to a crosshead arranged parallel to the crank shaft, the connecting rod
may be attached to the crosshead in line with the piston rod of the central
cylinder and with the centre of the crank shaft, but in this case the friction
between the slippers and their guides, due to the angle of the connecting rod, will
not be reduced. By attaching one or more of the piston rods to an arm or
projection, or arms or projections, on one side of the crosshead, the friction between
the slippers and their guides, due to the angle of the connecting rod, will be
reduced, and the power of the engine increased.
When the three cylinders are arranged in a line at right angles to the crank
shaft, the connecting rod may be attached to the crosshead in line with the piston
rod of the central cylinder, and with the centre of the crank shaft. By making the
two outer cylinders of different diameters, the friction due to the angle of the con-
necting rod, between the slipper and its guide at that end of the crosshead to which
the piston rod of the larger of the two outer cylinders is attached is reduced, and
consequently the power of the engine increased as before.
The piston rod of the low or lower pressure cylinder may be attached to the
crosshead at a point such that, when the crank is at right angles to the line of
motion of the pistons, and consequently the connecting rod is at its greatest angle,
the distance between the centres of connection of the piston rod and the connecting
rod with the crosshead will be such as to nearly equalize the power on both ends
of the crosshead, or so as to give the greater power exerted by the low or lower
pressure piston over that of the piston of the high pressure cylinder, as to relieve
the friction between the slipper or slippers and their guides, the position of the
connecting points being varied according to the differences of pressures and
diameters of the cylinders. By this means a shorter connecting rod than hitherto
may be used. This arrangement may be applied, not only to engines with two
cylinders, but also to single cylinder engines, or to engines with a larger number
of cylinders than two, to relieve or reduce the friction between the crosshead and
its guides.
In order to maintain the guides between which the crosshead works parallel to
each other, connect together, by means of tie rods or equivalent means, the
columns or frames which carry them, or the said guides may be directly connected
together to admit of the movement of the cylinders, due to expansion of the metal
under heat, without affecting the position of the guides. I form on one or more
of the cylinders a lug or bracket, or lugs or brackets, having a slot or slots therein,
through which passes a stud or bolt, or studs or bolts, carried on the frame or
column, or columns, to which the guide or guides is or are attached. On this stud
or bolt (or each of these studs or bolts) is placed or formed a distance piece or
collar, on to which a plate or washer is forced by a nut or nuts screwed on the end
of the stud, or by means of a cotter or other suitable means, so as to leave freedom
for the lug or bracket to slide between the plate or washer, and a shoulder or
flange on the column or framing as the cylinders expand or contract, or I provide
one of the guides with studs, on which the frame or column in connection with the
cylinders can slide.
To allow of this movement of the cylinders without straining the piston rods, the
connection of the piston rods, or of one of them, to the crosshead may be effected,
so that the connection can slide in or on the crosshead.
The attachment of the valve rods to their crosshead may be similarly effected to
accommodate the movement under expansion of the cylinders, or the said crosshead
itself may be made so that it will slide telescopically to accommodate this move-
ment, and may be provided with long bosses or arms fitted to slide in guides
suitably arranged to ensure the rods working truly.
I may operate the valves of compound engines separately, or I may connect the
valve rods to their crosshead driven by an eccentric or eccentrics or other operating
device.
The piston rod of the high pressure cylinder, and the piston rod of the low or
lower pressure cylinder are connected to a crosshead in such a manner as to admit

page_text: of more power being exerted on the crosshead at one end than at the other end,
without straining or laterally distorting the piston rods.
.
With this object the high pressure piston rod may be connected to a gudgeon
provided with trunnions free to turn in blocks fitted to slide in slots in the cross-
head, or the trunnions may be formed on the piston rod itself. The piston rod of
the low or lower pressure cylinder may also be connected to a gudgeon with
trunnions, or have trunnions formed thereon which Et so as to be free to turn,
when required, in holes in the crosshead.
Two or more sets of cylinders such as herein described may be arranged to work
several cranks on one shaft.
In rectangular slide valves of steam engines, in which the live steam is admitted
to the interior thereof, I provide a cap which fits over the back of the valve and
has a rectangular bearing surface which bears against the internal surface of the
valve chest or case.
The rectangular form of the face of this cap affords a greater bearing surface for
a given sized valve than would be the case if the surface be circular, whilst the
friction of the rubbing surfaces is reduced, owing to the increased area of the
rectangular form over that of the circular form, and at the same time it admits of
the width of the valve chest or casing being made narrower or reduced in size.
And, in order that my invention may be well understood, I will further describe
the same, with reference to the accompanying drawings, as applied to a compound
steam engine containing one high pressure cylinder and one low pressure cylinder,
it being understood, however, that the invention is also applicable to engines
containing more than two cylinders and partly to single-cylinder engines.
Fig. 1 of the drawings represents in elevation partly in section a compound high
and low pressure engine, constructed according to my invention, the covers of the
valve chests being removed.
Fig. 2 is a part plan, and part horizontal section taken along the line a b,
Figs. 1 and 4.
Fig. 3 is a vertical section of the high pressure cylinder and its valve chest, the
section being taken along the line ed in Fig. 2.
Fig. 4 is a vertical section of the low pressure cylinder and its valve chest, the
section being taken along the line e, Fig. 2.
Fig. 5 is a horizontal section of the crosshead shown in Figs. 1, 3 and 4, to which
the high and low pressure piston rods are connected.
Fig. 6 is a vertical section, and Fig. 7 a plan of a modified construction of the
crosshead, showing my improved method of connecting the piston rods thereto, for
preventing undue lateral strain on the piston rods by the expansion and contraction
of the cylinders.
Fig. 8 is a top view of a convex piece fitted to slide on the top of the crosshead
and through which the rod of the low pressure piston passes. Fig. 9 is a similar
view of a corresponding convex piece fitted to slide on the under surface of the
crosshead.
Fig. 10 is the concave piece or collar carried on the piston rod, and which
fits the convex piece Fig. 8, and Fig. 11 is a concave piece or washer fitting the
convex piece Fig. 9. The low pressure piston rod passes through these pieces and
through an elongated hole in the crosshead, and is secured thereto by a nut
or nuts.
Figs. 12, 13, 14 and 15 are pieces (similar to the pieces 8, 9, 10 and 11) through
which the high pressure piston rod passes, and to which it is secured by a nut
or nuts.
Figs. 16 and 17 show in section and plan respectively a portion of a crosshead,
having convex projections formed thereon instead of being free to slide thereon, as
in the arrangements illustrated by Figs. 6 to 15, and Figs. 18 and 19 are exterior
views of the concave pieces which fit the top and bottom convex surfaces respectively
on the crosshead.
Figs. 20 and 21 represent respectively in sectional elevation and plan a crosshead

page_text: for a single-cylinder engine, showing my improved mode of connecting the piston
rod and crank connecting rod thereto.
Figs. 22 and 23 are views of the inner sides of the top and bottom convex pieces
respectively, fitted to slide on the crosshead, and
Figs. 24 and 25 are views of the inner sides of the top and bottom concave pieces
which fit on the convex pieces, Figs. 22 and 23.
Figs. 26 and 27 represent in sectional elevation and plan respectively a crosshead
for compound engines, having spherical convex surfaces, and corresponding cup-
shaped concave pieces fitted thereon, so as to form universal joints between the
piston rods and the crosshead.
Figs. 28 and 29 are exterior views of the top and bottom spherical pieces, through
which the low-pressure piston rod passes, and Figs. 30 and 31 are interior views of
the corresponding cup-shaped concave pieces which fit thereon.
Figs. 32 and 33 are the spherical convex pieces through which the high-pressure
piston rod passes, and Figs. 34 and 35 are the corresponding cup-shaped concave
pieces which fit thereon.
Figs. 36, 37 and 38 are respectively a longitudinal sectional elevation, a sectional
plan, and an end elevation of a crosshead constructed according to my invention, to
which the valve rods of a compound engine are connected, the said crosshead
admitting of the movement of the cylinders by expansion and contraction of the
metal thereof without bending or distorting the said valve rods.
Figs. 39 and 40 are views of the interiors of the covers of the high and low-pressure
valve boxes or cases respectively.
Fig. 41 is a view of the back of the high-pressure valve with the cap removed.
Fig. 42 is a view of the face of the high-pressure valve.
Fig. 43 is a section of the high-pressure valve taken along the lines gh, Fig. 41,
and Fig. 44 is a compound section taken along the lines i k l m in Fig. 41.
Figs. 45 and 46 are respectively views of the face and back of the cap of the
high pressure slide valve.
Fig. 47 is an elevation and Fig. 48 a transverse section of the spring packing
ring interposed between the cap and back of the high pressure valve.
Fig. 49 is a view of the back of the low pressure slide valve with its cap removed,
and Fig. 50 is a section of the same taken along the line no, Fig. 49.
Fig. 51 is a compound section taken along the lines P andrs, Fig. 49.
Fig. 52 is a view of the face of the low pressure valve, and
Figs. 53 and 54 are respectively a face view and a back view of the cap of the
low pressure slide valve.
Fig. 55 is an elevation and Fig. 56 section of the spring packing ring
interposed between the back of the low pressure valve and its cap.
Referring to Figs. 1, 2, 3 and 4, 1 is the high pressure cylinder, and 2 is
the lower pressure cylinder. These cylinders are arranged side by side or
parallel to each other, and may be cast together as shown, or they may be each
cast separately, and be connected together by any suitable means.
The lower pressure cylinder is of such considerably greater diameter than the
high pressure cylinder as to utilize, as far as practicable, the pressure of the steam
which passes directly into it from the high pressure cylinder. For example, in the
engine illustrated the diameter of the low pressure cylinder is four times that of the
diameter of the high pressure cylinder, and consequently about sixteen times
the area, the boiler pressure being presumed to be 215 pounds per square inch, but
the proportions will, of course, vary according to the boiler pressure for which the
engine is designed, and according to the class of engine and the purpose for which it
is to be used. When the engine is making 60 revolutions per minute, the steam
occupies only about one second in passing through both cylinders to the atmosphere
or condenser, as the case may be, and therefore loss by condensation is greatly
reduced. 3 is the chest or casing containing the high pressure slide valve 4,
and 5 is the chest or casing containing the valve 6 of the lower pressure cylinder.
These valve chests or casings may be cast in one with the cylinders, and be

page_text: provided with covers 7 and 8 shown detached in Figs. 39 and 40, or they may be
cast separately and connected to the cylinders, in which case the loose covers 7
and 8 may be dispensed with. The pistons 9 and 10 of the high and the lower
pressure cylinder are connected by their rods 11 and 12 to gudgeons 13 and 14
mounted in a crosshead 15, or the said gudgeons or trunnions may be formed on the
piston rods themselves if desired. The trunnions of the high pressure piston rod is
fitted into blocks 16 which can slide in slots 17 in the crosshead to prevent any
undne lateral strain on the piston rod or rods by the expansion and contraction of
the cylinders. This crosshead may consist of a solid bar, having the piston rods and
also the connecting rod connected thereto, as shown in Figs. 6, 7, 16, 17, 20, 21, 26
and 27, and hereinafter described, or the said crosshead may be constructed as
shown in Figs. 1 and 5 of two sides or cheeks 18 connected together between their
opposite ends by bolts 19 and 20 and also at their ends by slippers 21, 22 which
constitute the guiding surfaces to slide in the guides 23, 23 distance pieces 24
being interposed between the sides or cheeks 18 to maintain them at the required
distance apart.
The bolt 20 passes through bosses 25, formed on the sides or cheeks 18 of the
crosshead, which bosses constitute the journals to which the forked end of the
connecting rod 26 is connected. This bolt 20 may be prolonged in either or both
directions, and be utilized for driving pumps or the like. The positions of the
journals, with reference to the points of connections of the piston rods to the cross-
head, are arranged according to the difference in the comparative diameters of the
cylinders and also to the differences of pressures exerted on the pistons, so that
when the crank is at a quarter stroke, that is, at right angles to the line of motion of
the pistons, and the connecting rod is at its greatest angle, as shown in Figs. 1
and 6 (partly broken away in Fig. 1), the leverage between the journals or
trunnions 25 and the centre of the low or lower pressure piston rod 12 is such as to
give greater power on that end of the crosshead, and thereby counteract the strain
thrown by the angle of the connecting rod on the slipper 21 against the guide 23 at
that end of the crosshead when the pistons are making their inward strokes and the
crank is rotating in the direction indicated by the arrow on the crank pin in Fig. 6.
If the crank is arranged to turn in the opposite direction to that indicated by the
arrow, it is obvious that the positions of the piston rods with reference to the
journals or trunnions 25 will be reversed. The length of the slippers 21, 22 will be
governed by the difference of power exerted on the crosshead on opposite sides of
the journals or trunnions 25, the length of the slippers being increased according to
the excess of power exerted on one end of the cross head over that exerted on the
opposite end thereof, to act as leverage to maintain the crosshead in position at
about right angles to the piston rod, and thereby reduce the friction between the
slippers and their guides and give increased power to the engine.
The arrangement illustrated by Figures 20 and 21 shows this part of my
invention as applied to a crosshead having a single piston rod connected thereto,
from which it will be readily understood that similar actions will take place with
crossheads having two or more piston rods connected thereto. The piston rod 11 is
shown in this example as being connected to the crosshead at a point midway
between the centre of the shaft and the centre of the crank pin, when the crank is
at right angles to the line of motion of the piston, and the connecting rod is at its
greatest angle. The leverage provided between the centre of the journals or
trunnions 25 and the centre of the piston rod will reduce the friction between the
slipper 21 and its guide about 50 per cent. from what it would be if the piston rod
be connected in the usual manner in line with the centre of the journals or
trunnions 25. It is, therefore, obvious that a shorter connecting rod can be used
than heretofore, without loss of power by increased friction on the slippers and
their guides.
When the centre of the crank pin arrives at the point 3*, in the
circle representing the traverse of the centre of the crank pin, it is then in line with
the centre of the piston rod 11; the angle of the connecting rod has no tendency to
force the slipper 21 against its guide, and, consequently, the friction is reduced to a

page_text: minimum. While the crank pin is moving from the point 3* to the point 4* the
exhaust port will be opened, and consequently there is very little or no power
exerted on the crosshead, while the piston is completing its inward stroke. When
the piston commences its inward stroke, that end of the slipper 21 which is nearest
to the crank, and that end of the slipper 22 which is furthest from the crank, are
caused to bear against their guides with greater pressure than at their opposite
ends, which opposite ends are slightly removed from their guides, and will allow
lubricant to pass between the slipper 21 and its guide. When the piston commences
its outward stroke this is reversed, that end of the slipper 21 which is furthest from
the crank, and that end of the slipper 22 which is nearest the crank, being caused
to bear against their guides with greater pressure than at their opposite ends, which
opposite ends are slightly removed from their guides, and will admit of lubricant
passing between the slipper 22 and its guide. The slippers and their guides are
thus maintained thoroughly lubricated. The distance of the centre of the piston
rod from the journals or trunnions 25 may be varied, but should be connected to the
crosshead at a point between the centre of the crank pin and the centre of the shaft
when the crank is at right angles to the direction of motion of the piston, and the
piston is moving inwards.
To prevent the distance between the working faces of the guides 23, 23* from
being affected by the expansion and contraction of the cylinders, I connect by the
bolts or rods 34 (see Figs. 1 and 2) the column or frame 35 to which the guide 23*
is attached to a foot 36 to which the framing or column 37 carrying the other
guide 23 is attached. The column, 35 is provided with a stud 38, which passes
through a block 39 fitted in a slot 40 formed in a lug or bracket 41 on the high-
pressure cylinder, which block 39 forms a distance piece, on which a plate or
washer 42 is forced by a nut 43 or otherwise (by a collar, for example), so as to
allow freedom for the movement of the lug 41 between the plate or washer 42 and
a flange or cottar 44 on the column or frame 35 to allow the cylinders to expand
and contract under changes of temperature without affecting the position of the
guides 23, 23*.
The crosshead illustrated in Figs. 6 and 7 consists of a solid bar 18, having
bosses or trunnions 25 formed thereon, to which the upper forked end of the
connecting rod 26 is secured. To the ends of the bar 18 are fixed the slippers 21, 22
which slide in guides 23, 23*. These guides, as shown in this arrangement, are
connected together, and to one of the frames or columns 37 which support the
cylinders, by the rods 34 so as to maintain the said guides rigid and parallel, or at
a uniform distance apart, and maintain a working fit between the slippers and the
guides. The guide 23* is connected to the column 35 by studs 39 attached to the
guide by bolts 39*, these studs being fitted to slide in holes 40 in the column, go
as to admit of the cylinders (to which the column 35 is attached), expanding and
contracting without distorting the guides.
To permit of the expansion and contraction of the cylinders without laterally
distorting the piston rods 12 and 11, there are provided near the opposite ends of
the crosshead 18 elongated vertical holes 11*, 12*, through which the lower ends
of the piston rods pass. On the piston rods 11 and 12 respectively are fitted, as
shown in Fig. 6, concave collars 15*, 16*, which fit and are free to rock on corre-
spondingly convexed pieces 13*, 14*, fitted to slide on the top of the crosshead,
these convexed pieces being provided with elongated holes corresponding to
the holes 18*, 12* in the crosshead through which the high and low piston rods
respectively pass. On the underside of the crosshead are convexed pieces 17*, 18*,
with which engage concaved washers 19*, 20*, secured by nuts 21*, 22* to the
lower projecting ends of the piston rods. The ends of the piston rods on which the
nuts 21, 22 screw are reduced in diameter so as to form shoulders, between which
shoulders and the nuts may be interposed, as shown in Fig. 6, collars 24* to prevent
the concaved washers and collars from being jammed too tightly against the
convexed pieces, thereby leaving the said convexed pieces free to slide automatically
on the crosshead to accommodate any movement of the piston rods owing to

page_text: expansion of the cylinders, and also to prevent lateral strain on the piston rods
should the crosshead be depressed more at one end than at the other end. The
collars and washers being free to rock on the convexed pieces 13*, 14*, 17, 18*
prevent the cylinders from being worn oval on the sides at right angles or transverse
to the shaft by the pistons being pressed more on one side than on the other during
their strokes. Or the nuts may be recessed on their faces adjacent to the washers
to receive packing rings or distance pieces for this purpose. When any expansion
or contraction of the metal of the cylinders takes place, one or other or both of the
piston rods will be caused to slide in the elongated hole or holes in the crosshead,
the convexed piece at the same time moving on the crosshead by the engagement
therewith of the concaved collars and washers on the piston rods, and thereby
prevent any distortion of the piston rods or the glands in which they work. Instead
of the convexed pieces 13, 14, 17, 18* being free to slide on the crosshead as
herein before described, those in connection with the piston rod nearest the fixed
column or frame 37 may be formed on the crosshead, as shown in Figs. 16 and 17.
A concave collar 15* is fixed on the piston rod 11 to bear on the upper convex
piece 13", and a concave washer 19* caused to bear against the convex piece 17*
on the underside of the crosshead by a nut 21* as before described. When the
convex pieces are fitted to slide on the crosshead as hereinbefore described, they
may be provided on their under sides with lugs or projections 1* which enter slots
or recesses 2 in the crosshead, as shown in Figs. 20 and 21 as applied to a single-
cylinder engine, which lugs or projections admit of the convex pieces moving in a
longitudinal direction on the crosshead, but prevent them from turning. By con-
necting the piston rod of a single-cylinder engine to the crosshead in the manner
described, should the crosshead be depressed more on one end than on the opposite
end, the piston rod and its gland in which it works will not be distorted, and the
friction between the slipper 21 and its guide, due to the angle of the connecting rod
when the piston is making its inward stroke, will be reduced; it also prevents the
cylinder from being worn oval, as hereinbefore described with reference to Figs. 6
and 7. The convexed pieces 13*, 14*, 17", 18", Figs. 6, 7, 16, 17, 20 and 21, may
be of spherical form, and the concaved collars 15*, 16* and washers 19*, 20*
engaging therewith cup-shaped, as shown in Figs. 26 to 35 of the drawings, so
that the connections of the piston rods to the crosshead are similar to ball and
socket joints, and permit of the expansion and contraction of the metal of the
cylinders in any direction without distorting the piston rods, and also admits of the
piston or pistons turning in its or their cylinder or cylinders during its or their
strokes, and thus prevent the internal diameters of the cylinders and the glands in
which the piston rods work and also the piston rod from being worn oval or from
being worn into grooves. In this arrangement the holes in the crosshead 18 and
also in the spherical pieces 13, 14, 17, 18* through which the piston rods pass
are circular instead of being elongated as herein before described, so as to admit of
the said rods moving in any direction. Should the crosshead be depressed more at
one end than at the opposite end, or should the cylinder or cylinders be slightly out
of line, the universal connection thus provided prevent any lateral strain on the
piston rod or rods or on or in the glands in which they work."
The spindles 28 and 29 of the valves 4 and 6 are connected to sleeves or arms 30
formed on the opposite ends of a crosshead 31, shown detached in Fig. 2ª, which
sleeves or arms are fitted to slide in guides 32, shown in Figs. 1, 3, and 4, as being
cast on the valve boxes 3 and 5, but which may be attached thereto or to any
other suitable part of the engine. This crosshead is connected at 33 to the
mechanism by which the valves are worked, and may be made in one piece, as
shown in Fig. 24; but in order to accommodate the movement of the cylinders
under expansion and contraction, I construct this crosshead in parts, as shown in
Figs. 36, 37, and 38, the part 31 being fitted to slide in the part 31*, a cottar or
key 30 being passed through the part 31* and through a slot or elongated hole in
the part 31 to allow of the elongation of the crosshead by the expansion of the
B

page_text: cylinders, and at the same time maintain the arms 30 parallel one to the other
when the engine is at work.
When the cylinders 1 and 2 of a condensing engine are arranged above or below
the crank (in Figs. 1 to 4 of the drawings I have shown them arranged above the
crank) I balance the weight of the slide valve 6 of the low pressure cylinder by
means of a piston 45 fixed on the spindle 29 of the said valve 6, and working in a
cylinder 46 which may be cast in one with the valve chest or case 5, as shown in
Fig. 4, or which may be made separate therefrom, and be connected thereto in any
suitable manner. One end of this cylinder is open to the interior of the valve chest
whilst the opposite end is open to the atmosphere, so that as the pressure in the
valve chest 5, and consequently on the inner face of the piston 45, is below the
atmospheric pressure acting on the outer face of the piston, the excess of
the atmospheric pressure serves to sustain the weight of the slide valve. Steam
from the boilers is admitted by the passage 47, Figs. 1, 2 and 3, and enters the
cavity 47 in the high pressure valve 4, whilst the exhaust steam from the valve
chest 3 passes by a passage 48 (shown clearly in Fig. 2) into the cavity or
cavities 49 in the valve 6 of the lower pressure cylinder 2 (see Figs. 4 and also
Figs. 50, 51 and 52 hereinafter referred to).
сар.
The internal capacity of the high pressure valve and forms the high pressure
steam chest, and the internal area of the cap is greater than the area of the valve
face in contact with the port face of the cylinder, so that the pressure tending to
keep the valve to the port face of the cylinder is greater than the pressure tending
to force it from the said port face, and thereby its tightness is ensured.
The valve 4 of the high pressure cylinder is preferably of rectangular form on its
working face 50, as shown in Figs. 41, 42, 43 and 44, and has on its back an
annular projection or rim 51, over which fits a rim 52 of annular form (as shown in
Fig. 46) on the cap or back plate. The face of this cap or back plate, which
works against the interior of the cover of the valve chest, is of rectangular form on
the exterior, but has a recess 53 therein, communicating by openings or passages 54,
with the cavity or cavities 55 in the valve. In this face of the cap or back plate
is an annular groove 56, with which are connected other grooves 57 in the face
arranged at right angles to the direction of motion of the valve, and extending
from the annular groove 56 to the edges of the cap, so that as the surface of the
cap rubs against the raised bearing surface 58 on the interior of the valve chest or
its cover (Fig. 39), should any fluid leak past the edge 59 of the bearing
surface 59 of the cap, it will enter the annular groove 56 and pass to outside the
valve by the grooves 57 without affecting the balance of pressure. The grooves 56
and 57 also serve to assist the lubrication of the rubbing surfaces. The surfaces
between the grooves serve to increase the bearing surface of the cap against the
surface 58 in the valve chest or its cover, whereby should any of the motive fluid
enter between the surface 59* and the surface 58, the pressure of the fluid in the
interior of the valve and cap, acting on the larger diameter or internal annular
surface area 52* of the cap, will prevent the cap from being forced from the
surface 58. The middle part of the projecting bearing surface 58 is recessed as
shown at 60, Fig. 39, the edges of this recess being so shaped that the inner edge 59
of the bearing surface of the cap will, at each stroke of the valve, overpass the
edge of the recess 60, as will also the outer edge of the face of the cap overpass the
outer edges of the projecting surface 58, and thus the formation of ribs or shoulders
by wear on the rubbing surfaces prevented.
The contiguous surfaces of the cap and the valve chest or cover are maintained
in contact (when no pressure is admitted to the cavity in the valve) by a spring 61
enclosed in the hollow boss 66 on the underside of the cap, which boss enters a
similar hollow boss 65 formed on the back of the valve. Between the top surface
or edge of the annular projection or rim 51 on the back of the valve and the inner
surface of the cap inside the rim 52 is interposed a spring packing ring 62 (shown
detached in Figs. 47 and 48) held in position by brackets 63, shown in section in Fig. 44

page_text: and in plan in Fig. 47. The outer circumference or periphery of this packing ring is
bevelled, as shown in Figs. 43, 44 and 45, for the purpose of reducing the area of
the outer diameter of the packing ring to less area than the inner diameter of the
said ring, so that the pressure on the interior of the ring presses the outer circum-
ference into tight contact with the interior surface of the rim 52, and also so that
the pressure on the face of the ring contiguous to the cap (which face is of greater
area than the face next the annular rim 51 on the valve) will force the ring into
tight contact with the top edge of the said rim 51, and prevent leakage of the pressure
thereat. The spring packing ring is divided at one part in its circumference to
admit of its expansion, the division being covered by a piece 64 fixed by one end to
the ring on one side of the division but free at the other end.
The external surface of the hollow boss 66 containing the spring 61, or the
internal surface of the boss 65, is slightly convex, or both the exterior of the boss 66
and the interior of the boss 65 may be convex, so as to admit of the valve and its
cap moving to accommodate themselves to unparallelism between the port face of
the cylinder and the surface against which the cap works, and also to allow either
end of the valve to be raised from the port face to relieve undue compression which
may take place in the cylinder by the completion of the stroke of the piston
compressing water contained in the cylinder after the exhausting port or ports is or
are closed by the valve.
This undue compression may arise from priming of the boiler or boilers, or by
starting the engine with excess of water in the cylinder, which would be compressed
by the piston when completing its stroke. The fracturing of the cylinder, or the
blowing off of the cylinder cover or covers, and damage to the piston or its rod, is
thus prevented, whilst the ordinary snifting valves employed for this purpose may
be dispensed with.
The cap and balancing mechanism of the low pressure valve are the same in
construction as those of the high pressure valve hereinbefore described, as will be
seen on referring to Figs. 49 to 56, the difference being in the dimensions. The
valve is double-ported to suit the ports in the port face of the low pressure cylinder,
as shown in Figs. 1 and 4. I have marked the corresponding parts in both valves
and their caps with the same numerals.
The internal area of the cap of this low pressure valve, with reference to the area
of working surface or surfaces of the valve face, should be such that the pressure
acting on the back of the valve, tending to keep the valve on the port face or faces
of the cylinder, is greater than the pressure tending to force the valve from the said
port face.
69 are the exhaust ports or passages in the valve. Either end of this
valve may be raised from the port face to relieve undue compression which may
take place in the cylinder in the same manner as described with reference to the
high-pressure valve.
The engine works as follows:-
The pistons 9 and 10 being at the end of their inward or top stroke, and the
valves 4 and 6 just opening to admit steam to the back or top sides of the pistons,
as shown in Figs. 3 and 4, and moving in the reverse direction to that of the pistons
at this period of the stroke, live steam admitted at 47 enters the cavity 47* of the
valve 4, and passes by the port or passage 70 to the top or inner end of the cylinder 1,
and acting on the piston 9 drives it towards the opposite or back end of the cylinder,
the exhaust steam from the opposite side of the piston passing out of the cylinder
by the port or passage 71 into the valve chest or casing 3, and out therefrom by
the passage 48 into the cavity or cavities 49 of the valve 6 of the lower pressure
cylinder 2. The valve 6 is a double-ported valve (as hereinbefore described), and
the ports 72, 72*, as shown are just opening to admit the exhaust steam passing
from the valve chest or casing 3 to the top or back of the piston 10 to drive the
piston towards the outer or downward end of the cylinder 2. As the area of the
piston 10 is considerably greater than the area of the high pressure piston 9,
the whole or nearly the whole of the pressure is taken by the outward or downward
movement of the piston 10 from the valve chest or casing 3 passage 48 and the

page_text: interior cavity of the valve 6, and at the same time the pressure is removed from
the back of the high pressure piston 9 and also from the high pressure valve rod or
spindle 28.
The exhaust steam from the opposite side of the piston 10 passes by the
ports 73, 73* into the valve chest or casing 5, and out therefrom to the atmosphere,
or to a condenser by the pipe or passage 74. If the exhaust steam from the
casing 5 passes to the atmosphere, the pressure on the valve spindle will only be
momentary, but if it passes to a condenser, the valve spindle will be in a vacuum.
The same operations as those described will take place when the valves are reversed
to admit steam to the opposite sides of the pistons, the steam from the high
pressure valve chest 3 passing then through the passage 48 as before into the cavity
cf the valve 6, and therefrom through the ports 73, 73* into the cylinder 2, the
exhaust steam from this cylinder passing through the ports 72, 72* into the valve
chest 5, and thence through the pipe or passage 74 into the atmosphere or into a
condenser as before.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In steam engines in which the steam exhausts into the valve chest or casing,
or valve chests or casings, providing the valve chest or casing, or valve chests or
casings, with a bottom inner surface so shaped or inclined towards an outlet or
exhaust passage that water will readily pass out from the valve chest or casing,
or chests or casings, and thereby maintain it or them comparatively dry,
substantially as hereinbefore described and illustrated by the accompanying
drawings.
2. In steam or other fluid pressure engines wherein the piston rod or rods is or
.are secured to a crosshead, the attachment of the said rod or rods to the crosshead
by means which will allow of movement between the rod connection and the
crosshead, substantially as and for the purpose herein before described and illustrated
by the accompanying drawings.
3. A crosshead for steam or other motive fluid engines, consisting of slabs or
cheeks connected together so as to provide a space or spaces between the slabs or
cheeks, gudgeons or trunnions formed on or attached to the piston rod or piston rods,
slots in the slabs or checks, in which slots blocks are fitted to slide, the said blocks
receiving the trunnions on the piston rod or rods, or on one of the piston rods, so
that the said trunnions can turn in the blocks, substantially as and for the purpose
herein before described and illustrated in Figs. 1 and 5 of the accompanying
drawings.
4. In steam or other motive fluid engines, securing the piston rod or rods to the
crosshead by means of a collar on one side and a washer and nut or the like on the
opposite side, the bearing surfaces of the collar and the washer being concaved or
rounded to correspond to convexed or reversely rounded surfaces formed on or
fitted to slide along the crosshead, so as to prevent lateral strain on the piston rod
or rods, substantially as hereinbefore described and illustrated by Figs. 6 to 25 of
the accompanying drawings.
5. In steam or other motive fluid engines, securing the piston rod or rods to the
crosshead by means of a collar on one side and a washer and nut or the like on the
opposite side, the bearing surfaces of the collar and the washer being cup-shaped to
correspond to spherical convexed surfaces formed on the crosshead, or on pieces
fitted to slide thereon, so as to form a universal connection, and to admit of the
turning of the piston in the cylinder, and also so as to prevent the piston or
the cylinder, and the gland in which the piston rod works, from wearing unequally,
and the piston rod from being distorted laterally, substantially as herein before
described and illustrated by Figs. 26 to 35 of the accompanying drawings.
6. In steam or other fluid motor engines, wherein the cylinder or cylinders is or
are subject to movement under changes of temperature, and the supports carry

page_text: guides for a crosshead, the connection of the cylinder or one of the cylinders to the
supports by a sliding connection, substantially as and for the purpose hereinbefore
described and illustrated in Figs. 1 and 2 of the accompanying drawings.
7. In steam or other motive fluid engines wherein the cylinder or cylinders is or
are subject to movement under changes of temperature, the combination with
guides in which the crosshead works of means for connecting them together, and
for admitting of the movement of the cylinder or cylinders, due to the expansion
and contraction of the metal thereof, without affecting the parallelism of the
guides, substantially as hereinbefore described and illustrated in Figs. 6 and 7 of
the accompanying drawings.
8. Connecting the piston rod or piston rods of steam or other motive fluid engines to
a crosshead, at a point or at points between the ends or one end of the crosshead and
the point where the connecting rod is connected to the crosshead, so as to reduce
the friction between the slippers on the crosshead and the guides in which they
work, substantially as hereinbefore described and illustrated more especially in
Figs. 1, 6, 20 and 26 of the accompanying drawings.
9. Connecting the slide valve rods of a compound steam or other multiple
cylinder motive fluid engine to one and the same crosshead, the said crosshead
being made in parts connected together so as to be capable of moving telescopically,
or to vary its length to accommodate movements of the cylinders owing to the
expansion and contraction of the metal thereof, and thereby prevent the valve rods
from being distorted, substantially as hereinbefore described and illustrated by
Figs. 37, 38, and 39 of the accompanying drawings.
10. In compound or multiple cylinder steam or other fluid pressure engines with
slide valve rods connected to and operated from one crosshead, long bosses on the
crosshead sliding in guides, substantially as hereinbefore described and shown in
Figs. 1, 3, 36, 37, and 38 of the accompanying drawings.
11. Providing the slide valve of steam engines in which live steam is admitted to
the interior of the valve, and having a cap or cover which fits over the back of the
valve, with a rectangular bearing surface which bears against the internal surface
of the valve chest or case, substantially as and for the purpose hereinbefore
described and illustrated more especially in Figs. 43 to 46 and 50, 51, 53, and 54 of
the accompanying drawings.
Dated this 8th day of June 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.