IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES
Year: 1883

page_text: LETTERS PATENT to John Henry Johnson, of 47 Lincolns Inn Fields, in the
County of Middlesex, Gentleman for an Invention of "IMPROVEMENTS IN
LOCOMOTIVE STEAM ENGINES" communicated to him from Theophile Ricour
a person resident at Paris in the Republic of France
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 7th March 1883.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES" a communication
to me from Theophile Ricour a person resident at Paris in the Republic of
France
'
The object of this Invention is to provide a free admission of external air to the
interior of the steam chest or slide valve casing and cylinders of locomotive engines
when running with the steam shut off and thereby to obtain among other
advantages a diminution of the friction and consequently of the wear of the slide
valves pistons and cylinders resulting from the contact with the heated gases
charged with ashes which have heretofore been drawn into the steam passages
when the engine is running with the steam shut off.
In carrying out this Invention an air valve of a section calculated in such a
manner as to prevent the pressure inside the steam chest from falling much below
atmospheric pressure when the steam is shut off whilst the engine is running at
full speed is arranged upon the steam pipe or upon the side of the steam chest and
in order to prevent this air valve from knocking or rattling continually upon its
seat when the steam is shut off the said valve provided with a spring which lifts
the valve off its seat directly the pressure of the steam is removed
In order to obviate the friction and consequent wear of the slide valve when
the engine is running without steam certain special arrangements are employed as
hereinafter described according as the Invention is applied to a flat or to a
cylindrical valve
'
When flat valves are employed they are held in equilibrium at the smallest
possible distance from the seat by means of blade springs attached at the centre to

page_text: the back of the valve and bearing at their extremities alone upon the edges of the
guiding frame in such a manner that when the steam is shut off there is no friction
between the valve and its seat. Filling pieces placed under the spring enable the
position of the valve to be adjusted and compensate for wear. The low temperature
which is maintained in the valve casings and in the cylinders, affords great
facilities for lubrication and admits of the employment of mineral or hydro
carbon oils.
The corrosion of the boilers caused by the acids resulting from the decomposition
of fatty matter or vegetable or animal oils is thus obviated and the pistons cylinder
ends, ports and other parts are kept free from deposits of oleates. These surfaces
may be enamelled and a considerable saving of steam thus effected by reducing the
loss by condensation during the period of admission
The air from the exterior drawn in through the valves is expelled through the
exhaust pipe and produces a strong draught in the chimney which enables the
boiler to be supplied with water when the steam is shut off without lowering
the pressure
The slide valves are rendered susceptible of a high polish so that the waste of
steam power in overcoming friction is considerably diminished and the valve gear
or reversing levers are enabled to be worked with less exertion on the part of the
Engine driver. The air valve is contained in a valve box provided at its upper
part with a screwed plug which serves to limit the rise of the valve and enables
access to be readily obtained to the interior of the apparatus.
In order that the air valve may remain slightly lifted from its seat when the
steam is shut off the lower part of this valve is placed upon a spring retained in
position by a cross piece fixed under the orifice for the admission of air to the valve
this cross piece is provided with a central stud or boss which acts as a guide to the
spring. In order to lift the slide valve slightly from its seat when the steam is
shut off, flat springs are attached to the back of the valve and rest at their
extremities upon the edges of a frame or guide at the side of the valve. A pin
having a square shauk is screwed into a boss cast on the valve and a small
rectangular locking plate let into a recess in the back of the slide valve locks this
pin and prevents it from becoming unscrewed. The two locking plates of a slide
valve may be made in one piece engaging simultaneously with the pins of both
the springs and in this case there is no necessity for a recess in the back of the
vulve.
In the case of locomotives with cylindrical slide valves the air valve is preferably
fitted to the side of the steam pipe and in order to reduce the friction of the piston
valves the packing rings of these pistons are made of a diameter slightly less than
the diameter of the cylindrical steam chest This slight difference of diaineter
enables the piston valve to work under the same conditions as the flat valve herein-
before described that is to say to work without touching the sides of the cylinder
when the steam is shut off
According to this invention the piston or the cylindrical slide valve is composed
of three principal parts consisting of a male portion or block a female portion or
block and a packing ring
The two blocks fit one into the other so as to form the body of the piston and
the packing ring consists of a split cylinder provided on its external surface with
four grooves for the purpose of preventing leakage
On the interior of the packing ring is provided a web or thin internal flange
with sides made perfectly true and flat and which enters freely between the two
portions of the body of the piston
The ends of the ring forin an angular or step joint with an intervening space
which enables the ring to contract when the pressure of the steam is removed
The female portion is composed of a hollow cylinder which fits over a boss or
projection on the male portion
When the two portions are fitted together and are rigidly connected to the valve
rod they present between them an annular space exactly sufficient to contain the

page_text: web herein-before referred to on the packing ring. In order to prevent the ring
from revolving upon its axis it is provided with a stop screwed into the side of.
the ring
In order to prevent the steam from escaping through the opening in the ring a
joint cover is provided in a recess hollowed out in the female portion of the piston
valve. The joint cover slides freely in this recess and is pressed by a spring against
the opening which it is employed to close
In order to facilitate the operation of placing the springs in position in the valve
an annular space is provided between the cylindrical surfaces of the male and
female portions for the reception of a cylindrical ring which may be placed inside
the female block so as to cover the base of the recesses provided for the reception
of the spring. The joint cover and the caps with their respective springs are then
inserted into these recesses from without and the divided packing ring is placed
over the female portion of the piston in such a manner that the opening in the
ring coincides with the centre of the joint cover. This being done the male
block is placed in position and the two portions of the piston secured upon the
valve rod
When steam is admitted to the slide valve casing and enters between the two
piston valves it passes into a space provided between the ring and the body of
each piston and presses the cylindrical surface of the ring against the side of the
cylinder at the same time pressing the web forcibly against the flat flange on the
male blocks so as to prevent leakage

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John' Henry Johnson in the Great Seal Patent Office on the
7th September 1883.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES" a communication
to me from Theophile Ricour a person resident at Paris in the Republic of
France
The object of this invention is to provide a free admission of external air to the
interior of the steam chest or slide valve casing and cylinders of locomotive
engines when running with the steam shut off and thereby to obtain among other
advantages a diminution of the friction and consequently of the wear of the slide
valves, pistons and cylinders resulting from the contact with the heated gases
charged with ashes which have heretofore been drawn into the steam passages when
the engine is running with the steam shut off.
The means employed for carrying out this Invention in practice are hereinafter
described in detail and consist of the following arrangements. namely.
1. In order to ensure a free admission of air to the valve case and cylinder an
air valve is employed of a section calculated in such a manner as to prevent the
pressure inside the steam chest from falling much below atmospheric pressure when
the steam is shut off whilst the engine is running at full speed. This valve is
arranged on each side of the engine upon the steam pipe or upon the side of the
steam chest. In general it will suffice to make the disc or clack of each air valve
of about three and a quarter inches diameter In the case of engines constructed
with one steam chest common to both cylinders a single air valve may be attached
to this chest but the size of the valve must be increased.
2. In order to prevent the air valve from knocking or rattling continually upon
its seat when the engine is running with the steam shut off the said valve is
provided with a coiled. or other spring which when the pressure of the steam is
removed holds the valve open to the extent of about one or two sixteenths of an
inch. Consequently the valve only bears on its seat when steam is admitted to the
steam chest and is lifted off its seat directly the steam is shut off.
3. In order to obviate the friction and consequent wear of the slide valve when
the engine is running without steam certain special arrangements are employed as
hereinafter described. according as the Invention is applied to a flat or to a
cylindrical distribution valve. When flat valves are employed they are held in
equilibrium at a small distance from the seat by means of a couple of parallel blade
springs attached at the centre to the back of the valve and bearing at their
extremities alone upon the edges of the guiding frame in such a manner that when
the steam is shut off there is no friction between the valve and its seat. Filling
pieces placed under the spring enable the position of the valve to be adjusted and
compensate for wear.
In the case of cylindrical or piston valves that is to say when the valve consists
of two pistons upon one rod and working over parts formed in a cylindrical steam
chest the same effect is produced as in the case of the flat valve by making the
packing rings of the piston valves of a diameter slightly less than that of the
cylinder in which they work and adjusting the centre of each ring so as to coincide
truly with the axis of the valve case or cylinder by means of internal springs
taking their bearing on the central part of the valve. The pressure of these springs
is such as to balance the weight of the ring without pressing it against the sides
of the casing. The rings expand under the pressure of the steam admitted to the

page_text: interior of the valve casing and prevent leakage but do not rub against the sides
of the said casing except when the steam valve is open. When the steam valve is
shut the rings resume their original diameter and cease to touch the sides of the
valve cylinder or casing.
The principal advantages resulting from the use of this invention are the following
videlicet.
1. Less wear of the slide valves and cylinders because the slide valves and
motive pistons are enabled to move in an atmosphere of pure fresh air instead of
moving in an atmosphere composed of the hot gases laden with ashes which are
alternately drawn in and expelled through the exhaust passages in engines of
ordinary construction. Owing to the air valves employed according to this
invention the slide valve seats are preserved from becoming encrusted with
deposits of ashes so that the slide valves may be readily separated therefrom and
wear is thus prevented.
2. Facility and economy of lubrication arising from the low temperature which
is maintained in the valve casings and in the cylinders which admits of the
employment of mineral or hydro carbon oils whereby valuable results are obtained
as hereinafter set forth.
J
A
3. Preservation of the boilers from corrosion-The corrosion of the boilers caused
by the acids resulting from the decomposition of fatty matter or vegetable or
animal oils is obviated by the facility afforded as hereinbefore described for the
employment of mineral or hydro carbon oils.
3. Prevention of deposits of oleates upon the pistons cylinder ends, ports and
other parts These deposits result in great measure from the decomposition of
vegetable oils and the combination of oleic acid with oxides of iron.. No deposit is
formed when hydrocarbons are employed for lubricating. The flat sides of the
pistons and the cylinder ends being thus kept clean free from deposits of oleates
their surfaces may be effectually enamelled and a considerable saving of steam is
thus effected by, reducing the loss by condensation during the period of admissiou.
4. Improved action of the furnace when the engine is running without steam.
The air from the exterior drawn in through the valves is pumped out through
the exhaust pipe as from a blowing engine and produces a strong draught in the
chimney which enables the boiler to be supplied with water when the steam is shut
off without lowering the pressure.
5. Reduction of the waste of power in overcoming frictional resistance
The slide valves are rendered susceptible of a high polish so that the amount
of steam power wastefully expended in overcoming friction is considerably
diminished.
6: Less fatigue for the Engine driver. This advantage results from the facility
with which the valve gear or reversing levers are worked owing to the easy notion
of the slide valves. The working of these levers on lines where stoppages are
frequent forms a considerable part of the manual labour of the engine driver.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and, for that purpose shall refer to
the several figures on the annexed sheets of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 sheet 1 of the accompanying drawings is a vertical section of a balanced
air valve constructed according to this invention.
Figure 2 is an elevation plan and side view of a bridge piece C employed to form
the bearing of a counterspring that balances the valve as hereinafter explained.
Figure 3 is a transverse section of a tube D leading from the slide valve casing
to the air valve and fitted to the cover of the said casing by means of a flange as
shown.
Figure 4 is an elevation of the cylinder and steam chest of a locomotive engine
fitted with an air valve arranged according to this Invention and having a flat slide
valve.
Figure 5 is a transverse section of the same showing the internal arrangement.

page_text: of the air valve and the application of springs to the back of the slide valve for
the purpose of holding the latter out of contact with its seat whenever the steam is
shut off.
Figure 6 is a transverse section of the slide valve which is represented as being
lifted out of contact with its seat.
Figure 7 is a plan of the said slide valve
Figure 7 is a transverse section of a valve spring drawn to a larger scale showing
the mode of attaching the latter to the back of the slide valve.
Figure 8 sheet 2 is a longitudinal section taken along the line 1. 2. 3 4 figure 9
and representing a cylindrical or piston slide valve having balanced packing rings
and provided with an air valve as hereinafter described.
Figure 9 is a transverse section of the said valves shewing the internal con-
struction of the pistons of the cylindrical slide or piston valve and the air valve
fitted to the steam pipe.
Figure 10 is a detail in section elevation and plan of a joint cover hereinafter
described and placed under the ends of the junk or packing ring of. the cylindrical
slide valve.
Figure 11 is a detail in elevation and plan of a cap used for covering the springs
employed to maintain the packing rings of the piston valve truly central in relation
to the axis of the cylindrical valve casing.
Figure 12 is a plan of a portion of the junk or packing ring of a piston slide
valve constructed according to this Invention.
Figure 13 is an elevation partly in section of the said ring and the two portions of
the piston valve to which the ring is connected by means of a projecting web as
hereinafter explained.
C
Figure 14 is a plan and elevation of the male portion of the piston valve.
Figure 15 is a plan and elevation of the female portion.
According to the arrangement illustrated in sheet 1 a valve box A containing a
yalve B is connected by means of a flanged tube D to a plate D¹ forming the cover
of the slide valve case of an ordinary locomotive engine cylinder X.
The valve box A is provided with a screwed plug z which by means of a
projection z limits the motion of the valve B and also enables access to be readily
obtained to the interior of the valve box A. The latter is fixed to the cover of the
slide valve casing by a flange formed upon the tube D as shewn in the drawing
The valve B controls an orifice B₁ communicating with the atmosphere and in
order that this valve may remain slightly lifted from its seat when the steam is
shut off it is provided with a spring E retained in position by a stud or boss F on
the bridge piece C (figures and 2) which is fixed underneath the air inlet
orifice B¹,
When the valve B is relieved from the pressure of the steam the spring E
immediately lifts the said valve and maintains it steadily at a distance of about
one eighth of an inch from its seat.
It is evident that other forms of air valves may be employed without affecting
the principle of the invention, that illustrated in the drawing being simply given
as an example and may be modified as found convenient in practice.
As shewn the figures 4. 5. 6. 7 and 7 the air inlet valve is employed in
combination with a flat slide valve G which is lifted slightly from its seat when
the steam is shut off by means of a couple of flat. springs a. b. c. d.(figure 7)
attached to the back of the valve G by bolts and nuts k. The extremities of
these springs press upon the edges of a frame H surrounding the valve (Figure 6
and 7) The arrangement for attaching the springs to the valve G is shown more
clearly in Figure 7 and consists of a pin Q having a square shank screwed into a
boss Q cast on the valve; a small rectangular locking plate p p let into a recess in
the back of the slide valve locks this pin and prevents it from becoming unscrewed.
The two locking plates of a slide valve may be made in one piece engaging
simultaneously with the pins Q of both the springs and in this case there is no
necessity for a recess in the back of the valve. The flat spring a is shown in

page_text: section over the locking plate by cross batchings and a set of washers or filling
pieces of different thicknesses is placed over the spring and over these is screwed
the nut and a locknut. k¹.
In order to prevent the space between the valve G and its seat I from exceeding
the proper limits owing to the valve wearing away after a certain amount of work
a filling piece of suitable thickness may be placed under the spring so as to compensate
for the wear.
In the case of locomotives with cylindrical slide valves constructed according to
the arrangement illustrated in figures 8. 9. 10. 11. 12 and 13 sheet 2 the air valve A
is preferably fitted to the side of the steam pipe (figs 8 & 9) and in order to reduce
the friction of the piston valves the packing or junk rings of these pistons are made
of a diameter slightly less than the diameter of the cylindrical steam chest. This
slight difference of diameter enables the piston valve to work under the same
conditions as the flat valve herein before described that is to say to work without
touching the sides of the valve chamber or cylinder when the steam is shut off. This
result may be obtained by means of the arrangement illustrated in the accompanying
drawing by way of example.
According to this part of the Invention the cylinder X figures 8 and 9 is
provided with a steam distribution piston or cylindrical slide valve W W composed
of three principal parts consisting of a male portion or block t Figures 8, 13 and 14
a female portion or block x figures 8, 13 and 15 and a packing ring m.
The block t fits into the block x so as to form a piston round which is placed the
packing ring m consisting of a split cylinder provided on its external surface with
four grooves n figures 8 and 13 for the purpose of preventing leakage.
On the interior of this packing ring is provided a web or thin internal flange n
figures 12 and 13 with sides made perfectly true and flat and which enters freely
between the two portions t and x of the piston as shown in figure 13. The ends
of the ring form an angular or step joint as shown at a b c d figure 12; the spaces
left at a b, c d enable the ring m to contract and shorten its diameter when the
pressure of the steam is removed. The drawings construction and arrangement of
the two blocks forming the body of the piston will be readily understood by an
inspection of the drawing
The male block t is shown in section on the left hand side of figure 8 and figure 9
shows another section of the same taken at right angles to the section in figure 8
and also shows the mode of connecting this part of the piston valve to a valve rod W'
by means of a key u.
When the female portion x is fitted over the boss ť¹ (figure 14) on, the male
portion and both portions are fixed upon the valve rod W₁ as shown in the
drawing they present between them an annular space o figure 13 exactly sufficient
to contain the web n on the ring m the said web bearing on one side against the
male portion or block t and on the other side against the female portion so that
the ring is compelled to move with the valve The internal outline of the two
portions is indicated by dotted lines in Figure 13.
In order to prevent the ring m from revolving upon its axis it is provided with
a stop E figures 8 and 9 screwed into the side of the ring and which engages with
a cavity formed in the female portion of the piston valve. In order to prevent the
steam from escaping through the opening at ab in the ring m a joint cover s
(shown detached in Figure 10). is provided in a recess hollowed out in the female
portion of the piston valve. The joint cover & slides freely in this recess and is
pressed by a small coiled spring r against the opening at a b. Figures 8 and 9 show
the cylindrical surface of the joint covers in contact with the internal surface of
the ring m. In addition to the recess containing the joint cover 8 the female
portion of the piston is provided with other cavities in which slide caps c (figure 11)
acting as guides to two springs These two cylindrical cavities with the caps c
and springs placed in position are shown in section in figure 9 and in dotted
lines in figure 15.
In the example illustrated the joint cover 8 is diametrically opposed to the stop E

page_text: on a line 1-2 passing through the centre of the valve in such a manner that wben
prolonged this same line 1-2 also passes through the axis of- the main or driving
cylinder of the engine as shown in Figure 9. The axis of the spring r¹ under the
cap c is placed at the saine angle with a vertical line drawn through the axis of
the piston valve as the axis of the spring of the joint cover and the axis of the
spring coincides with the said vertical line. The tension of the springs lis
equal the third spring (1) is capable of being adjusted so as to maintain the ring
truly central relatively to the valve case.
In order to facilitate the operation of placing these springs in position an annular
space is provided between the cylindrical surfaces of the male block tt and the
female block xx for the reception of a thin cylindrical ring c¹ say about one
twenty fourth of an inch in thickness as shewn in Figure 9 To put the parts
together this thin ring is placed inside the female block so as to cover the base of
the recesses or cavities provided for the reception of the springs 11 The joint
cover 8 and the caps c with their respective springs are then inserted into these
recesses from without and the divided ring m is placed over the female portion of
the piston in such a manner that the opening a, b (figure 13) coincides with the
centre of the joint cover 8 and the stop E engages with its recess. This being done
the male block is placed in position and the two portions of the piston secured
upon the rod W¹
The divided ring m balanced upon the three springs r, . . is thus maintained
truly concentric with the cylinder in which it works and being of a normal diameter
somewhat less than the diameter of this cylinder does not come in contact with
the sides of the latter at any point when the pressure of the steam is removed but
nevertheless expands and prevents leakage when the steam valve is open. As soon
as the Steam is admitted to the slide valve casing between the two pistons of the
valve it enters a space m¹ figure 13, between the ring m and the sides of the
piston valve and presses the cylindrical surface of the ring of both pistons against
the sides of the cylinder or valve casing, at the same time pressing the web_n,
forcibly against the flat flange on the male block t, so as to prevent leakage. The
joint is thus rendered self closing.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that I do not limit myself to the precise
arrangement and construction illustrated in the drawing as these may be modified
without departing from the principle of the Invention but what I consider to be
novel and original and therefore claim as the Invention to be secured to me by the
herein before in part recited Letters Patent is:
First, Admitting air to the Steam chests and cylinders of locomotive Engines
during the time that the engine is running with the Steam shut off substantially
as herein before described.
Second, Providing the slide valve casing or steam pipe of locomotive steam
engines with valves adjusted and balanced for the admission of air during the
time when the engine is running with the Steam shut off substantially as herein-
before described with reference to the accompanying Drawings.
Third, Providing the Steam distribution valves of Locomotive Steam Engines
with springs for the purpose of maintaining the said valves out of contact with
their seats or casing during the time that the engine is running with the steam
shut off substantially as hereinbefore described and illustrated in the accompanying
drawings.
Fourth. In locomotive steam engines the employment of an air valve constructed
and operating as hereinbefore set forth in which the valve disc is balanced on a
spring of such strength as to be capable of holding the said valve open when the
engine is running with the steam shut off substantially as herein before described
and illustrated in fig 1 of the accompanying drawings.
Fifth. In locomotive Steam engines the employment of a flat slide valve provided
with springs which hold the said valve out of contact with its seat when the

page_text: pressure of the steam is removed substantially as herein before described and
illustrated in figures 6. 7 and 7. of the accompanying drawings.
Sixth, The employment in locomotive steam engines of a piston valve having a
packing ring with an internal flange and joint cover the said ring being so
arranged as to contract when the pressure of the Steam is removed and remain
out of contact with the sides of the Cylinder in which it works and to expand
and prevent leakage when exposed to the pressure of the Steam all substantially
as hereinbefore described and illustrated in the accompanying drawings.
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this first day of September One thousand
eight hundred and eighty three.
T
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