IMPROVEMENTS IN THE MODE OF SUPPLYING LAMPS OR LANTERNS WITH ATMOSPHERIC AIR FOR SUPPORTING THEIR ILLUMINATING FLAMES
Year: 1870

page_text: LETTERS PATENT to Martin Benson, of the "National Patent Office,"
Southampton Buildings, London, Consulting Engineer, for the In-
vention of "IMPROVEMENTS IN THE MODE OF SUPPLYING LAMPS OR LANTERNS
WITH ATMOSPHERIC AIR FOR SUPPORTING THEIR ILLUMINATING FLAMES."-A
communication from abroad by John Henry Irwin, of 4, College
Place, New York City, State of New York, United States of
North America.
COMPLETE SPECIFICATION filed by the said Martin Benson at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 23rd May 1870, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
BENSON, of the "National Patent Office," Southampton Buildings,
London, Consulting Engineer, send greeting.
IN
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
THE MODE OF SUPPLYING LAMPS OR LANTERNS WITH ATMOSPHERIC AIR FOR

page_text: SUPPORTING THEIR ILLUMINATING FLAMES," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her Royal
Letters Patent for the same, and have made solemn Declaration that
it has been communicated to me from abroad by John Henry Irwin,
of 4, College Place, New York City, State of New York, United States
of North America.
NOW KNOW YE, that I, the said Martin Benson, do hereby declare
that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and in
what manner the same is to be performed, in and by the following
statement:-
_
This Invention relates to improvements in the manner of introducing
atmospheric air to support the illuminating flame of a lamp or lantern.
That the Invention may be fully understood I think it necessary to
describe the natural principles or modes of operation.
Lamps or lanterns are commonly constructed with inlets for
fresh air below and very near to the burner, and an outlet for the
products of combustion at a greater or less distance above the flame
according as the character of the flame requires a greater or less elevation
of chimney to produce the necessary draught. A lamp or lantern so
constructed operates satisfactorily so long as the surrounding atmosphere
is relatively at rest, but when exposed to atmospheric disturbances then
its action becomes very vacillating and unsatisfactory, or it is obstructed
entirely. One reason for this is the well-known exhausting effect of a
current of air moving across the open mouth of the inlets and causing
a reversal of the feeding currents. The supply of oxygen is diminished
or entirely cut off. This effect is illustrated in Figure 5 of the Drawings.
Another cause is the swinging motion frequently imparted to a lantern
when being carried in the hand. This swinging or oscillating motion
acting through centrifugal forces upon the column of air within the
chimney causes it to be impeded in its upward flow or to be reversed in
its direction and returned upon the flame, combustion is thus obstructed
or destroyed. It will readily be perceived that both of these causes will
frequently be in operation at the same moment, as when the lantern is
being carried in the hand the oscillation generates centrifugal force and
causes an atmospheric disturbance in its immediate vicinity. The
remedy which I have devised for these difficulties consists in an

page_text: arrangement of feeding tubes through which all the atmospheric air
to support combustion is received at a distance above the flame and
arranged in such a way that the same outside current of air which
induces an accelerated outflow at the top of the chimney will cause an
equally accelerated inflow at the feeding tubes and burner. By means
of feeding tubes, such as described, it will be perceived when the lamp
is at rest there will be a current of fresh air descending through said
tubes to the burner, and an ascending current of hot products of com-
bustion within the chimney. When the lantern is agitated or swung back
and forth the ascending current will be retarded by the centrifugal force
while the downward current will be accelerated by the same force. The
acceleration in the feeding tubes will, however, balance the retardations
in the chimney and combustion will go on undisturbed. The peculiar
manner of arranging the deflecting plates at the air inlet and at the
top of the chimney or outlet secures a complete equilibrium of pressure
when the lantern is exposed to wind or vertical or lateral motion and
none but fresh atmospheric air will be admitted to the feeding tubes.
The object therefore of the first part of this Invention is to procure a
uniform supply of atmospheric air to the burner flame, whether the
lantern is at rest or exposed to currents of air produced either by wind
or motions imparted to the implement itself.
The second part of this Invention consists in the arrangement of an
annular chamber around the chimney and connecting with the feeding
tubes through which a flow of air is induced by heat.
The third part of this Invention consists in the manner of constructing
the burner and burner conc so as to secure accuracy of connection in
putting the parts together.
The fourth part of this Invention consists in an easy manner of
constructing the feeding tubes with the air chamber below the burner
cone so as to dispense with elbows at the lower ends of the feeding
tubes.
Having now set forth the nature and scope of this Invention, I will
describe its several parts in detail by referring to the accompanying
Drawings and to the figures and letters of reference marked thereon, and
made to form part of this Specification.
Figures 1, 2, and 3 are sectional elevations of a lantern with my
| improvements.

page_text: Figures 4 and 5 are diagrams mustrating the elects of currents of
air moving across the orifices of tubes.
Figure 6 is a vertical section of my burner.
A is the oil pot, and B is the burner seated in the top of the same,
the cone or jacket C of the burner may be closed or perforated according
to the manner adopted for mounting the chimney or globe D. The
method which I prefer is shown in the Drawings, and consists of a
perforated platform E. which is supported upon the burner cone or
jacket C and receives inside a suitable guard or collar; at the lower
edge of said chimney, between the upper surface of the oil pot and the
burner, is an air chamber F into which air from the feeding tube flows
on its way to the burner. These parts are common to all my lanterns
and will require no further description. The feeding tubes G, G, open
at their lower ends into the air chamber F at their upper ends, said
tubes open into the chamber H which surrounds the upper end of the
chimney I. The air chamber H is open at the bottom and closed at
the top. The chimney I is surmounted by an annular deflecting plate J
and surrounded by another annular deflecting plate K, separated from the
chimney by an annular space. The purpose of the plate K is to impart
a slightly upward deflection to a current of air moving against the
chimney so that it may exert to the largest extent the above-mentioned
effect upon the ascending current within the chimney. At the bottom
of air chamber H are two annular deflecting rings L, M, corresponding
in diameter and relative disposition with the plates J, K. The line X, X,
cutting through the centres of the upper orifices of the tubes G, G, is
equidistant from the plates J, K, and rings L, M, respectively, so that
the practical effective lengths of the chimney and feeding tubes will be
equal and any effect of a current of air moving across the top of the
chimney to accelerate the upward motion of rarified air within the
chimney will be balanced by an equal effect to accelerate an inflow of
air at the upper ends of the feeding tubes, and thus the supply of fresh
air to support the burner flame is under all circumstances equal to the
outflow of rarified air at the top of the chimney. In the case of vertical
or oscillatory motion of the lantern the centrifugal tendency imparted to
the currents of cool air moving through the feeders in the direction of
said centrifugal force will more than equal the effect of said force upon
the warn air in the chimney moving in opposition to said force becauso

page_text: of the difference in specific gravity of cold and warm air, and also
because of the momentum of the moving currents.
In another part of my Invention the feeding tubes G, G, connect at
their upper ends with an annular air chamber N, through which a current
of air is induced by means of heat imparted by the hot current of the
product of combustion within the chimney, and it is more particularly
designed for use in a comparitively calm atmosphere, as for illumination
indoors. In this case the globe D, Figure 2, is made shorter than that
shown in Figure 1, and the upper continuation may be a metallic flue I
which is surmounted by a cap plate J, and its orifice surrounded by a
deflecting plate or flange K, the purpose of which has been above stated.
The annular chamber N in form and length corresponding to the
chimney I is formed by the jacket O. The chamber N is opened but
closed at the top. The bottom portion is made flanging outward, not
only to conform to the shape of the chimney, but also to present a more
extended opening to admit an inflowing current of air. All the air
which passes through the flame opening in the cone enters through the
chamber N and tubes G. The chimney I is heated by the products
of combustion ascending from the burner flame and a large portion of
said heat is imparted to the air within the chamber N. The air within
said chamber becoming thereby rarified ascends and flows off laterally
through the tubes G where it looses a portion of its heat and is con-
ducted to the air chamber beneath the cone O. It will readily be
perceived that the current of air moving through the tubes or feeders G,
when the lamp is at rest, are impelled by two independent forces;
firstly, by the ascending current of hot products of combustion within
the chimney I; and, secondly, by the ascensive force of a column of air
rarified within the chamber N. Thus while the ascending hot air within
the chimney I would "draw" a current of cold air through the tubes G,
the rarified air within the chamber N would also force a similar current
through the tubes G and the supply of air to the flame is much more
abundant than would be effected by either of these forces alone. The
current of air as it enters below the burner cone C is deflected away
from the base of the flame by the plate or flange U, which is placed at
the top of the wick tube S for that purpose. From the plate U the
current moves to the inner surface of the cone and returns to the flame
in the slit V. This deflection of the feeding current away from the
base of the flame secures the flame against the lifting effect of an

page_text: accelerated current and prevents smoking or extinguishment of the
flame.
The object of the last part of my Invention is to improve upon any
tubular lantern as regards simplicity and cheapness, and I have also
attached a thumb piece to the movable top of the lantern to facilitate
raising it to remove the globe or glass.
The nature of this part of my Invention consists in inserting the
tube G into the top of the air space F, thereby effecting a great
reduction in cost of manufacture by avoiding the use of elbows at
the lower ends of said tubes.
It further consists in the thumbpiece for moving the top glass or
globe holder hereafter fully described.
The base of the lantern adapted to this part of my Invention is oval
or oblong, the longest axis in the direction of the feeding tubes G so as
to present a portion of the cover of the air chamber to the descending
feeders, as shown in Figure 4. This mode of construction dispenses
with the elbows otherwise required at the lower portion of the feeding
tubes, as shown in Figures 1 and 2. The glass or globe D is held at
the top by the open adjustable globe holder W which is held pressed
down upon
the top of the globe by the spring A¹. A wire loop
B¹ attached to the adjustable globe holder W at its two ends at opposite
sides of said holder, the chimney I is therefore located between the parts
of said loop; guides C₁ (one of which only is shown) retains said loop
in a position convenient to the finger of the operator when the hand is
resting upon the handle D¹. By these means the globe holder may be
raised so as to release the globe and allow its removal for cleaning or
repairs.
I do not desire to limit myself to the precise construction and arrange-
ment of the wire loop B' as it will be readily seen that any light wire
or strip of metal extending up from the globe holder to a position where
it would be sufficiently removed from the heat of the lamp to be always
cool, and where it could be conveniently reached would serve every
purpose.
Having now fully described the structure and mode- of using the
Invention as communicated to me by my foreign correspondent, what I

page_text: Firstly. The annular chamber or fresh air inlet H arranged with a
deflecting plate or plates (or their equivalents) in the manner sub-
stantially as shown and described.
Secondly. The top of the chimney or outlet for the products of
combustion arranged with a deflecting plate or plates (or their equi-
valents) in combination with a lamp or lantern, substantially as shown
and described.
Thirdly. The deflecting plates J, K, L, M, arranged relatively to
cach other in the manner and to secure the effects set forth.
Fourthly. The annular chamber H combined with the feeding tubes
G, G, substantially as specified.
Fifthly. A heating chamber N formed between the chimney I and
the jacket O or its equivalent, in combination with the feeding tube or
tubes G to conduct fresh air to the burner B, substantially as and for
the purpose set forth.
Sixthly. The air chamber or space F in combination with the air
tubes G, when said tubes are inserted in the top of said chamber as and
for the purpose specified.
Seventhly. The thumbpiece or loop B¹ in combination with the globe
holder W, when constructed and arranged substantially as and for the
purpose specified.
In witness whereof, I, the said Martin Benson, have hereunto set my
hand and seal, this Twenty-third day of May, in the year of our
Lord One thousand eight hundred and seventy.
MADIN DENSON