Improved Exhaust Arrangements for Locomotive and other Engines.
Year: 1887

page_text: Date of Application, 23rd Aug., 1887
Complete Specification Left, 23rd May, 1888
Complete Specification Accepted, 17th Aug., 1888
Improved Exhaust Arrangements for Locomotive and other Engines.
I, JAMES ATKINSON, of No. 3 Nassington Road, Hampstead, London, N.W.
Engineer, do hereby declare the nature of this invention to be as follows:-
The nozzle of the blast pipe of a Locomotive or other engine is made larger in the
opening than usual, and is provided with a valve, which in the normal condition when
the engine is not at work closes this opening. This valve is provided with suitable
means of putting a variable resistanco on it, to prevent or check its opening, in such
a manner that when the engine is at work the exhaust steam in escaping lifts the
nozzle valve against the resistance, which defines the strength of the blast; the
greater the resistance to be overcome in lifting the valve the stronger the blast will
be. The variable resistance may be obtained by means of springs or weights, either
by themselves, or in combination with a dash-pot arrangement, which will steady the
motion of the valve, the resistance may also be caused by means of steam pressure
in a small cylinder, and may be made variable by means of varying the steam
pressure. A suitable valve for varying the steam pressure would be by means of a
small valve under control of the attendant, who can regulate the amount of steam
which passes this valve, a small leakage valve may be adjusted to allow of a small
constant leakage, and the pressure thus regulated. If desired to make the regulating
valve depend wholly or partially on the pressure in the boiler, the regulating valve
may be lifted by an adjustable spring against the steam pressure, which tries to close
it and is assisted in doing so by means of a piston or diaphragin larger in diameter
than the valve, and exposed to the pressure which passes the valve and which is
admitted to the small cylinder, operating in such a manner that as steam rises in the
boiler a less blast is obtained until at a certain adjustable pressure in the boiler no
steam is admitted to the small cylinder at all, and the blast is practically unrestrained;
if the boiler pressure falls steam is again admitted to the small cylinder, increasing
in pressure as the boiler pressure falls, and thus increasing the force of the blast.
I prefer in a Locomotive to admit the live steam blast into the exhaust pipe as it
will save complication and as it can only escape by lifting the nozzle valve it would
give a greater efficiency

page_text: As the nozzle valve will always close when steam is not passing through the engine,
no hot gases, cinders, or dust can be drawn into the engine; this will be of special
service to Locomotives when running down an incline, under such circumstances
with the valve gear in, forward position the engine will cause less resistance, but if
it should be desired to cause resistance the valve gear may be put more or less into
backward position, until almost all the available power of the engine may be utilized
as a brake, without running any risk of damaging the cylinders or valve faces, in
such conditions the live steam blast valve may be opened so as to ensure only steam
passing into the cylinders.
To equalize the draught through the tubes a baffle plate may be attached to the
forward tube plate above the tubes, and sloping a little downwards and forwards in
such a manner that the draught through the upper tubes must pass under this plate
which however does not drop sufficiently to cause any difficulty in cleaning out the
tubes, or if it does, it may be hinged so as to lift up when it is desired to clean
the tubes.
The regulating gear may be placed in any convenient position. If a small steam
cylinder is used it may be placed in the exhaust pipe under the nozzle valve; the
pressure regulating valve may be placed on the side of the smoke box, and may also
be made in combination with the live steam blast valve; suitable gear may be
arranged so as to regulate the pressure from the foot plate.
It will be seen that with those arrangements the attendant will have immediate
and perfect control over the strength of the blast; also if desired he can use the
engine as a brake without fear of damaging it, and thus save wear and tear of brake
blocks, tires, rails, &c.
It will be readily understood that the arrangements may be arranged in different
ways to suit varied conditions.
D
11°
1
1032

page_text: COMPLETE SPECIFICATION.
Improved Exhaust Arrangements for Locomotive and other Engines.
I, JAMES ATKINSON, of 3 Nassington Road, Hampstead, London, N.W. 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
The conditions under which Locomotives work are continually varying; the speed,
the ratio of expansion of the steam in the cylinders, the amount of steam required, the
condition of the fire, and other circumstances are constantly changing, and it is well
known that a convenient method of altering the strength of the blast to suit the
varying conditions would be of great utility. This invention is for the purpose of
enabling the driver to control the strength of the blast, to make it powerful or light
at will, and to vary it so as best to suit his requirements, the changes being made
instantly, with certainty, and to any desired extent; the invention also enables the
mouth of the exhaust pipe to be entirely closed when steam is not passing through the
exhaust pipe, thus preventing ashes, dust, or hot gases passing to the cylinders or
valve faces, and allowing the engine to be reversed whilst running, so that it may be
used as an efficient brake without the cylinders or valves being damaged.
In the accompanying drawing is shown the upper end of the blast pipe of a
Locomotive as constructed in accordance with this invention. The mouth of the
blast pipe is made much larger in area than is usual, (say twice the area), so that
when the valve A. is allowed to rise freely there is very little resistance put on the
exhaust steam, which can thus get easily away, the strength of the blast being
reduced to the minimum. In the normal condition when no steam is passing through
the exhaust pipe, the valve A. is in the position shown in the drawing, entirely
closing the exhaust pipe. The valve A. is constructed with a short, small cylinder D.
inside it; fitted to this cylinder D. is a stationary piston B, which by means of the
piston rod C. is fixed in any convenient manner; the valve A. can be lifted by the
exhaust steam being guided by the piston B. and piston rod C. until the bottom of
the cylinder D. comes into contact with the piston B, provided that there is no
pressure inside the cylinder D. The cylinder D. is provided with a passage E. by
means of which steam is admitted, the pressure of this steam being regulated by
means which will be hereinafter explained; it will be seen that the higher this
pressure is, the greater the resistance there will be to the exhaust steam, and the
stronger the blast; if the full boiler pressure is admitted to the cylinder D. the
strength of the blast will be at its maximum, and this maximum will be limited by

page_text: the relative area of the valve A. and the area of the annular space between the piston
rod C. and the cylinder D. The regulation of the steam pressure in this cylinder D.
may be variously provided for, a suitable means being to make the piston B. and
piston rod C. easy fits, so that there is always a slight amount of leakage past them,
or to provide a small regulated leakage valve in connection with the passage E; this
passage E. is connected to a small valve which may be more or less opened by the
driver to admit more or less steam from the boiler, who can thus control the pressure
in the cylinder D. and by means of this, the strength of the blast; the sound of the
blast enabling him to judge of its intensity.
The small hole F. by which the steam passage E. is connected to the cylinder D. is
made small so that this cylinder D. acts partially as a dash pot, and prevents violent
movements of the valve A.
I prefer in a Locomotive to admit the live steam blast into the exhaust pipe as it
will save complication, and as the steam can only escape by lifting the valve A. it
would give a greater efficiency.
When the engine is running with steam shut off for any length of time, I would
prefer to open the live steam valve which would thus admit steam to the exhaust
pipe; the valves, and cylinders; this would be of special value if the engine was
running reversed so as to utilize the power of the engine as a brake. It is well
known that Locomotives cannot be so used without serious damage, the hot gases,
ashes, cinders, &c. being drawn in cause the valve faces, & cylinders to cut; with
this apparatus however the engine could be habitually used in this manner without
injury.
"In connection with a Locomotive the small pressure regulating valve might be
conveniently placed on the side of the smoke box, and may also be constructed in
combination with the live steam blast valve; suitable gear being arranged to enable
it to be worked from the foot-plate.
In running down hill, or at a high speed the back pressure in the cylinder of a
Locomotive is often very excessive owing to the small fixed area of the blast nozzle,
but by this arrangement the outlet is very much increased so as to materially reduce
the back pressure, and allow the engine to run much more freely and economically,
the blast being still sufficient to keep steam under such circumstances, the larger
circumference of the blast outlet giving more effect to the blast.
The pressure regulating valve may be so constructed as to be more or less
automatic, according to the steam pressure in the boiler; it would then consist of a
small valve G lifted by an adjustable spring against the boiler steam pressure,
which tends to close it, and is assisted in doing so by means of a piston or diaphragm I
larger in diamr. than the valve, and exposed to the pressure which passes the valve G,
and which is admitted to the cylinder D. by the passage E, the adjustment of the
spring pressure being under the immediate control of the driver, operating in such a
manner that as steam rises in the boiler a less blast is obtained until at a certain
adjustable pressure no steam at all is admitted to the cylinder D, and the blast is
practically unrestrained; if the boiler pressure falls steam is again admitted to
the cylinder D, increasing in pressure as the boiler pressure falls and thus increasing
the force of the blast.
This invention is also suitable for portable or other engines. The arrangement I
have more fully described however appears to me to be the most simple and
durable.
The arrangement shown in the drawing sheet 1 may be modified so as to give an
annular opening for the exhaust, having an internal passage for a portion of the hot
gases to pass through.
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. The construction and employment of a blast nozzle in a Locomotive or other
engine, having a variable opening so as to give a variable blast, the strength of this

page_text: blast being under the immediate control of the driver by means of the small steam
cylinder D. and the small steam regulating valve, as described and illustrated.
2. The construction and employment of a blast nozzle in a Locomotive or other
engine, having a variable opening so as to give a variable blast, in combination with
the valve A. which automatically closes the mouth of the exhaust pipe as soon as
steam ceases to pass through it, as described and illustrated.
3. The construction and employment of a blast nozzle in a Locomotive or other
engine, generally as described and illustrated.
Dated this 23rd day of May 1888.
Witness,
G. E. PRIDDLE,
60, Mansfield Road, London, N.W.
JAMES ATKINSON.