IMPROVEMENTS IN TUBULAR LAMPS.
Year: 1872

page_text: LETTERS PATENT to Martin Benson, of No. 9, Southampton Buildings,
London, for the Invention of "IMPROVEMENTS IN TUBULAR LAMPS.".
A communication from abroad by John Henry Irwin, in the City
and County of Philadelphia, and State of Pennsylvania, United
States of North America.
Sealed the 13th May 1873, and dated the 6th December 1872.
COMPLETE SPECIFICATION filed by the said Martin Benson at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 6th December 1872, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
BENSON, of No. 9, Southampton Buildings, London, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN TUBULAR LAMPS," 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 the same is a
communication from abroad by John Henry Irwin, in the City and

page_text: 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 :-
The following is a description of my improvements, reference being
made to the accompanying Drawings by the letters of reference marked
thereon and made to form part of this Specification. Similar letters
refer to corresponding parts.
Fig. 1 is a side elevation of the lamp; Fig. 2 is a transverse' section
of the air tube of the same on line x, x, of Fig. 1; Fig. 3 is a sectional
elevation of the air tube and inlets.
Fig. 4 represents a modification of the same, as a table lamp.
Fig. 5 represents a modified construction of the air inlet end of the
air tube.
This Invention relates to that class of lamps and lanterns known as
tubular lamps, in which a tube or tubes are used to convey fresh air
from a point. above the level of the flame down to the burner to
support combustion, whereby the ordinary draft chimney is dispensed
with and the effect of lateral currents of air is neutralized. Hereto-
fore lamps of this class have been constructed either so as to admit
a portion of the products of combustion with the fresh air into the
air tubes or so as to utilize only so much of the heat from the flame
as will radiate naturally through the wall of the escape tube or flue.
The object of the present Invention is to utilize to the greatest degree
the heat from the flame of the lamp to heat the feed air, and to
produce a current through the air tube without permitting the entrance
of any of the products of combustion into said tube, and it therefore
consists of a novel construction of the receiving end of the air tube,
whereby the heat from the flame acts directly upon the tube, and
the inlets for fresh air are placed out of the ascending current of
products of combustion, and said products are thereby prevented from
entering said tube.
•
I shall only describe a side or wall lamp provided with one air

page_text: that to duplicate the air tubes so as to make the lamp more ornamental
or symmetrical, to adapt it to the purposes of a hand lamp, hanging
lamp, or chandelier, would not involve any further Invention, unless
as to details of form or method of constructing the parts.
A is the oil pot and B is the burner surmounted by a slotted cone C
and surrounded by a jacket C³, forming an air chamber, from whence
there is no egress except through the slot in the cone. D is a
descending tube entering the air chamber below the cone and com-
municating at top with the ascending tube E placed over the flame
of the lamp in a vertical line above the slot in the cone and extending
down near enough to the flame to be well affected by the heat thereof,
but not near enough to break or elongate the flame by attraction
or to obscure the light. The bottom of tube E is closed by the
plate e, which receives directly the greater portion of heat from the
flame. From the sides of the tube E, at or near the bottom, proceed
the smaller horizontal radial tubes F, open at or near their outer
ends for the admission of fresh air to the tube E.
With a burner having a slotted cone the flame ascends in a flat
sheet widening from the conc upward, and the products of combustion
continue to flow upward in a similar form until dissipated in the
surrounding atmosphere. The radial tubes F carry the openings for
the admission of fresh air out of this ascending current of the products
of combustion, and none but fresh air gains admittance to the tube
E. Therefore the radial tubes should be placed diagonally to the
slot, or in such a manner that the broad line of the flame will stand
away from the inlet apertures, as shewn in Fig. 2.
It is preferred to use a protector G, of glass or other suitable
material, not only on account of its ornamental appearance, but for the
purpose of preventing the flaring of the flame in lateral currents of air;
it has no other value in connection with this lamp.
For the sake of convenience in removing the protector G, which
is represented as resting upon the open gallery g supported from
the cone, the ascending tube E may be made in two parts to telescope
or slide one upon the other, and the lower portion of said tube may
then be raised to render the removal of the protector G unobstructed;
shewn at Fig. 2, fitting a
a bead or rib is worked upon one part, as
groove in the other to prevent rotation. From the outer. extremity

page_text: of the radial tubes tips f are prolonged to rest upon and retain
the protector G in position.
To protect the tube E from the cooling effects of the outside air
currents I sometimes place an annular jacket H around the ascending
tube E, closed at the top and open at the bottom, to receive a portion
of the hot products of combustion rising from the burner.
The operation of the Invention is as follows:- The heat of the
flame upon the lower end of the tube E rarifies and lightens the
column of air in said tube, so that a current or flow of air is established
upward through the tube E, into and downward through the tube D
to the burner, and thus a continuous uniform current of fresh hot air
is supplied to the flame, while the burned air and products of
combustion pass up and are diffused in the surrounding atmosphere,
a portion of the heat thereof however being utilized in heating the
sides of the tube E if the jacket H is employed.
Arrows are employed in the Drawings to shew the direction of
the various currents, the pure air being indicated by arrows supplied
with an open circle midway of the shaft, and the burnt air and
products of combustion being indicated by arrows supplied with a
filled or blackened circle.
Instead of employing radial tubes F, the tube E may be constructed
in a variety of ways, so as to place the air inlets out of the current
of burnt air rising from the flame, without removing said tube E
from the direct action of the flame, as for instance, as shewn in
Fig. 5. These are but modifications of the same device and do not
introduce any new result.
The principal advantages of my present Invention are :—
1. The burner has a larger supply of pure air than heretofore.
2. The air is raised to a high temperature before entering the burner,
and the flame is thereby intensified.
Having described my Invention, what I claim as new is:—
1. The combination in a tubular lamp of the tube E, provided
with the radial inlet tubes F, substantially as set forth.
2. The combination in a tubular lamp of the air tube E. with
closed bottom, placed vertically over the flame and provided with

page_text: laterally extended air inlets, so as to receive none but fresh air and
heat the same before it enters the burner, substantially as and for the
purpose set forth.
3. The combination in a tubular lamp of the tube E, radial tubes F,
and heating jacket H, substantially as specified and shewn.
4. The combination in a tubular lamp of the radial tube or tubes F,
tube E, and protector G, substantially as shewn and described.
In witness whereof, I, the said Martin Benson, have hereunto
set my hand and seal, this Sixth day of December in the year
of our Lord One thousand eight hundred and seventy-two.