Improvements in and relating to Steam Boiler Furnaces.
Year: 1899

page_text: Date of Application, 22nd Aug., 1899-Accepted, 21st Oct.,
1899
COMPLETE SPECIFICATION.
Improvements in and relating to Steam Boiler Furnaces.
I, JOHN MILTON, of Hotel Dunbarton, in the City of Washington, District of
Columbia, in the United States of America, 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: -
This invention relates to steam boiler furnaces and has for its object the pro-
duction of an improved exhaust regulating attachment which is adapted more
particularly for use in connection with locomotive engines. The invention con-
templates the provision of an air inlet adjacent to the stack through which air
in controllable quantity is admitted for the counteraction of the influence of the
air blast occasioned by opening the furnace door, and also for overcoming the
effects of excessive exhaust produced while the engine is being started, or is
moving slowly up a heavy grade, or when the driving wheels slip in relation:
in all of which cases the exhaust is from a wide open valve and with practically
full boiler pressure. The effects of the exhaust under the cited conditions are
to tear the fire and disintegrate the fuel to such an extent as to produce, by
the forcible, intermittent draft thus created, emissions of sparks and cinders
which, aside from the danger and discomfort attending their formation, accom-
plish by their exclusion from the furnace a very material loss of heat cand,
consequently, power.
The nature of my invention will be readily understood reference being had
to the following detailed description and to the accompanying drawing which
forms a part thereof and in which
Figure 1 is a side elevation, partly in section of a locomotive engine embodying
my invention. Figure 2 is a rear end elevation. Figure 3 is a fragmentary top
view. Figures 4 and 5 are respectively enlarged detail side and central sectional
views of the door of the smoke box showing the air inlet, valve and valve operating
means. Figure 6 is an enlarged view in elevation of the front of the smoke box
with the number plate removed.
Referring to the said drawings by letter, A denotes the fire box of a locomotive
engine, B is the boiler, and C, the smoke box or extension front, these parts being
of the usual construction and needing no description except that the fire box
has the usual door a, and that in the smoke box or front is the exhaust pipe c,
and the smoke stack c¹ into which the exhaust pipe discharges.
The door d of the smoke box or front is preferably of special construction,
being formed with an unusual camber or outward bend, and provided centrally
with an opening d' over which is the usual number plate e. This opening
constitutes the inlet for the air, and the plate e is located a sufficient distance
therefrom to allow of the admission of air in proper quantity. On the inner side
of the door around the opening d¹ is secured a ring the inner face of which
forms a seat for the valve F, said valve being pivoted at its lower side to open
inwardly. Any suitable pivotal connection for the valve may be provided, but
I prefer the construction shown, which consists of ears d³ and f formed respec-
tively on the ring and valve, and a pintle ¹ passed through said ears. The valve

page_text: is made to rest closely against its seat when in closed position to render the smoke
box at this point approximately air tight under normal conditions.
On the outer side of the door adjacent to the lower side of the opening is secured
a bracket having ears g¹ which support a rod h. Pivoted on this rod is a
lever the upper arm of which has link connection with the valve, while its
lower arm is connected by a rod with the upper arm j¹ of a second lever j
pivoted to a post 2 secured to and extending outwardly from the door d. The
lower end of the lever j is free and is provided with a lateral projection *.
Pivoted on the post immediately to one side of the lever j, is an arm k, which
in one direction abuts against the projection . The outer end of this arm k
is connected by a rod 7 with the stoking door a the movement of which controls
through the connections just described the movement of the valve F, as will
presently be more fully explained.
The normal closed position of the valve is effected by the action of right and
left coiled springs m m each of which is connected at one end to the lever i
and at the other end to an adjusting nut m by which the tension of the
springs may be varied. The valve is thus opened against the action of springs
the tension of which may be so delicately adjusted as to render the valve
exceedingly sensitive to the action of the exhaust which operates through the
external air pressure or impact to move the valve inwardly to uncover the opening
and admit the proper quantity of air to neutralize the tendencies of the exhaust
when, as before stated, the engine is being started, or is moving slowly up a
heavy grade, or when the driving wheels slip in rotation. The operation of the
valve under the action of the exhaust is thus entirely automatic, and the
quantity of air admitted past the valve is governed entirely by the force of the
exhaust under the extraordinary conditions stated. This excessive exhaust is
only temporarily occasioned and the automatic operation of the valve and
consequently the admission of the air to counteract the injurious effects, which
would otherwise be produced, depends entirely upon this increased strength or
power of the exhaust. It may be here stated that should there be an improper
adjustment of the engine valves and consequently a relative variation in the
successive exhausts from the cylinder, the air valve may be employed to indicate,
by its irregular movements, such fault in adjustment, and to aid in remedying
the defect.
The automatic operation of the valve under the action of the exhaust is entirely
distinct from the operation of controlling the inlet coincidently with the manipu-
lation of the stoking door. In the automatic movement of the valve to uncover
the opening or air inlet, the lever j is rocked, and its lower arm 3, which carries
the projection, is moved independently of the arm k. In operating the valve by
the movement of the stoking door, however, the lever j is, by the engagement of
the arm & with the projection j, rocked with said arm, and through the described
connection with the valve the latter is opened against the action of the springs m,
admitting air in proportion to the volume of air entering the stoking opening.
The pintle a of the door hinge carrying an
rod n¹ to one of the arms of a bell crank lever n³, the other arm having direct
arm n which is connected by a
connection with rod 1.
The door d of the smoke box carries a partition o extending from the base to
a point about centrally of the valve F. This partition is employed to keep the
valve free from cinders, and also to deflect the air entering the inlet towards the
stack and away from the accumulation of cinders in the smoke box. Above the
partition is a screen o¹ which serves with the partition to keep the interior of the
door free from cinders. Any fine cinder which finds its way into the door may
be removed through a hand hole shown as closed by a cover p.
My invention in its broadest sense consists in the provision of an air inlet
adjacent to the stack of a steam boiler furnace having an exhaust draft, an inlet
controlling device operating automatically under the action of excessive exhaust
to admit air for the counteraction of the tendencies of such excessive exhaust,

page_text: and means independent of the exhaust for controlling the inlet coincidently
with the manipulation of the stoking door to admit air for the counteraction of
the effect of the air blast in the opening of the door during stoking and manipu-
lation of the fire. This air inlet and the controlling device therefor may be located
at any desired point which is in sufficiently close proximity to the stack and
exhaust to secure the desired results; but for economy of construction and facility
of installation, I prefer that the opening, the opening controlling device and
operating means be applied to the door of the smoke box as shown, whereby not
only can the invention be readily attached to existing furnaces, but in the case of
locomotive engines where access to the smoke box must frequently be had, the
device being carried by the door affords no obstruction to such access when the
latter is opened.
My invention while applicable to steam boiler furnaces of the character above
named, is more especially designed for use in connection with locomotive boiler
furnaces, the same in addition to regulating the draft and relieving the exhaust
under the conditions stated, operating to prevent the formation of sparks and
cinders and thereby to avoid the danger of firing adjacent property, and ensure
comfort to the occupants of the train.
In addition, by the use of my improved appliance not only is there a great saving
of fuel but also in the time and labor incident to the manipulation of the fire,
as the bed of fuel is not subjected to the tearing and disintegrating action of
sudden strong drafts through the grate induced by the excessive exhausts.
The foregoing description read in connection with the accompanying drawing
will enable anyone skilled in the art to which my invention relates to understand
its nature and practice it in the form I prefer to employ it; but it will be under-
stood that my invention is not limited to the precise form and construction herein
illustrated and described, as various modifications and changes may be made
without exceeding the scope of the claims in which my invention is set out.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In a steam boiler furnace of the character described, an air inlet adjacent
to the furnace stack and exhaust outlet, a self-closing valve at said inlet open-
able under the action of excessive exhausts, and means independent of the action
of the exhaust for opening said valve coincidently with the manipulation of the
stoking door.
2. In a steam boiler furnace of the character described, an air inlet adjacent to
the furnace stack and exhaust outlet, a spring controlled valve at said inlet open-
able under the action of excessive exhaust, and means independent of the action
of the exhaust for opening said valve coincidently with the manipulation of the
stoking door.
3. In a steam boiler furnace of the character described, a chamber between
the boiler flues and stack, a door closing said chamber having an opening pro-
viding an air inlet, a spring controlled valve at said opening carried by the
door and openable under the action of excessive exhausts, and means independent
of the action of the exhaust for opening said valve coincidently with the manipu-
lation of the stoking door.
4. In a steam boiler furnace of the character described, a chamber between
the boiler flues and stack, a door closing said chamber having an opening providing
an air inlet, a spring controlled valve hinged to the door and controlling said inlet
and openable under the action of excessive exhausts, and means located without the
chamber operating independently of the action of the exhaust to open the valve
coincidently with the manipulation of the stoking door.
5. In a steam boiler furnace of the character described, a chamber between the
boiler flues and stack, a door closing said chamber having an opening providing
an air inlet a valve for said inlet hinged to the door and openable against the

page_text: action of a spring by excessive exhausts, a lever operatively connected with the
door and provided with a projection, and an arm operatively connected with the
stoking door and adapted when moved in one direction coincidently with the
movement of the latter to engage the projection on the lever and open the valve.
6. In a steam boiler furnace of the character described, a chamber between the
boiler flues and stack, a door closing said chamber having an outer wall provided
with an opening affording an inlet for air, and an inner wall perforated at its
upper portion, a spring controlled valve hinged to the front wall and normally
closing said opening, said valve being openable under the action of excessive
exhausts.
7. In a steam boiler furnace having a chamber between the flues and stack,
an inlet at said chamber, an inlet controlling device operated under the action of
excessive exhausts, and means for controlling the inlet coincidently with the
manipulation of the stoking door.
Doted this 92nd day of At 1800
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.