Improvements in and relating to Central Draft Lamps.
Year: 1893

page_text: Date of Application, 20th July, 1893-Accepted, 16th Sept., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by THE EDWARD MILLER AND COMPANY, a
company incorporated and located and doing business in Meriden, in the
County of New Haven, State of Connecticut, one of the United States of
America.]
Improvements in and relating to Central Draft Lamps.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 central draft lamps and is illustrated in the accom-
panying drawings in which
Figure 1 represents a view in side elevation of a draft-tube constructed in
accordance with the invention and located in an ordinary lamp-fount, the upper
section of the tube being shown as lifted above the lower section thereof.
Figure 2, a view of the tube in vertical section on the line a-b of Fig. 1.
Figure 3, a similar view on the line c-d of Fig. 2.
Figure 4, a plan view of the lower tube-section.
Figure 5, a broken view in vertical section of one of the modified forms which
the invention may assume.
Figure 6, a view in transverse section on the line e-f of the preceding figure.
This invention relates to an improvement in that class of central-draft lamps
which have their draft tubes constructed to intercept and dispose of any oil which
may find its way into their upper ends, whereby the lamps are prevented from
"weeping" as the saying is, and especially adapted for the use of air-distributers
constructed to be set within the upper ends of their draft-tubes instead of over the
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same.
Heretofore, the tubes of such lamps have been provided with inside annular
troughs, constructed to .intercept and retain the escaping oil until the same can be
disposed of through-lateral openings formed in the tubes, and leading horizontally
out of the troughs to the wick. Such old constructions have been found objection-
able, or account of the liability of the openings to clog up, causing the troughs to
overflow, and also on account of the difficulty and expense of securing the troughs
within the tubes, so that they will not leak.
The object of the present invention is to dispense with troughs such as have been
before used, and by a simple and inexpensive construction to make adequate
provision for the interception and disposition of any oil which may find its way
into the upper ends of the tubes of central-draft lamps.
With this end in view, the invention consists in a central-draft tube for a central-
draft lamp, having its outer surface forced inward to form an oil-pocket, opening.
at its upper end into the bottom of a catch-flange located within the tube.
The invention further consists in a draft-tube for a central-draft lamp, the said
tube being made in two parts or sections, of which the lower section is contracted
at its upper end to permit the upper section to fit over it, and has its upper edge
set inward to form a catch-flange, and is constructed with an oil-pocket produced in
its exterior surface by forcing the same inward, opening at its upper end into the
said flange and leading downward therefrom.
The invention further consists in certain details of construction and combinations
of parts as will be hereinafter described and pointed out in the claim.
As herein shown, the improved draft-tube is composed of a long lower section A,
and a short upper section B, both of the same external diameter. The upper end

page_text: of the lower section is contracted, as at A', to adapt the upper section to fit over it.
A shoulder a formed by contracting the upper end of the lower section, provides a
seat for the lower end of the upper section. The extreme upper edge C, of the
lower section is set inwardly at an angle to form an inside catch-flange D, for
the interception of any oil which may escape into the upper section, which forms the
upper portion of the tube. The said catch-flange is therefore formed integral with
the tube. The oil intercepted by the said flange is conveyed to the outer surface
of the tube and disposed of by means of depressed exterior oil-pockets, consisting
of two deep vertical grooves or depressions E E, produced in the exterior of the
tube by forcing portions of the surface of the lower section A, of the same inward,
beginning at its inwardly set contracted upper edge, and extending downward, the
lower ends of the said pockets tapering out and gradually merging into the full
exterior diameter of the said section of the tube, and their upper ends opening into
the bottom of the said flange. The operation of forming such a tube as described
above, is very simple, the upper end of its lower section being contracted and
grooved in a suitable die, after which the short upper section is applied, and it does
not matter if the joint between the two sections is not tight, for any oil that
escaped through the joint would be discharged into the fount of the lamp. By
constructing the tube in this manner, the expense of soldering an independently
made catch-flange into the tube which is a difficult operation, is not only avoided,
but also leakage from defective soldering is escaped.
Each of the pockets formed in accordance with this invention as above described,
is capable of containing a considerable amount of oil, so that the weight of the oil
aids in its absorption by the wick, a large area of which is exposed by each pocket.
Furthermore, the agitation of the oil confined in the pockets, and consequent upon
the movement of the wick up and down, assists the process of disposing of the oil.
It should be noted, also, that the oil instead of being discharged laterally from the
flange, flows directly downward from the bottom of the same, whereby the wash of
the oil has the effect of keeping the flange clear and free of accumulations of debris.
It will be readily seen that under this invention a larger area of the wick is enabled
to be exposed for the absorption of the oil of interception, than could be done in
any arrangement of transverse openings leading laterally out of a trough through
the tube to the wick, without weakening the tube and probably interfering with
the right action of the lamp.
In the operation of this improved draft-tube, the oil is simply caught by the
flange, which immediately deflects it into the pockets formed in the exterior surface
of the tube, where it is retained until it is disposed of by absorption by the wick, or
by its return to the body of oil in the fount, whereas, under prior constructions, the
oil was retained in the trough to which the flange corresponds, only so far as the
interception of the oil is concerned.
The air-distributer F, may be of any approved construction, so long as it is
adapted to be ect within the upper end of the sectional tube in which it may be
supported in any desired manner, as, for instance, by forming inwardly projecting
bumps c, within the upper section B. The lower end of the air-distributer should
be enough smaller in diameter than the internal diameter of the sectional tube, to
form a narrow annular space between the distributer and tube for the oil to flow
through on its way to the inside trough.
By means of this invention an inside air-distributer may be employed, and at the
same time any leakage or " weeping" of the oil through the inside of the draft-
tube, as often occurs when inside air-distributers are used with draft-tube of
ordinary construction, avoided. The interference with the wick which an air-
distributer adapted to fit over the outside of the tube entails, is also avoided.
This improved draft-tube may be used in combination with central-draft lamps
of any approved construction. Nothing is shown herein but a fount J, and a
burner-socket K.
This invention is not limited however to forming the catch-flange and establishing
communication between the same and the oil-pockets, in the manner described, the

page_text: invention contemplating, broadly, oil-pockets produced in the exterior surface of a
draft-tube, located below a catch-flange situated within the same, and communicating
at their upper ends with the said flange.
One of the modified forms which the invention may assume, is shown by
Figures 5 and 6 of the drawings, in which the draft-tube L is made in one piece,
and provided with a catch-flange m, which is made independent of it, and soldered
or otherwise secured in place. The tube is constructed with one or more oil
pockets N, formed in the manner described, and opening at their upper ends into
the said flange, the tube being transversely slit at the upper ends of the said
pockets, as at n, and the flange being constructed with openings m formed in its
lower portion and registering with the upper ends of the pockets.
It is understood that a two-part draft-tube is old, and that feature is therefore
not claimed broadly, nor is there broadly claimed herein an oil pocket formed
in the exterior surface of the tube for receiving and disposing of the oil of
interception.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondents I declare that what I claim is :-
First. A draft-tube for a central-draft lamp, having its outer surface forced
inward to form one or more oil-pockets, each opening at its upper end into the
bottom of an annular catch-flange located within the tube, substantially as
described.
Second. In a central-draft lamp, a sectional draft-tube made in two sections of
which the lower section is contracted at its upper end to permit the upper section
to fit over it, and has its upper edge set inwardly to form a catch-flange, and is
constructed with one or more pockets leading downward from the said catch-flange
into which the upper end of each pocket opens, the flange being formed integral
with the lower section of the tube and in such a manner that it will not leak into
the inside of the same, all substantially as described.
Dated this 20th day of July 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.