IMPROVEMENTS IN LAMPS
Year: 1871

page_text: LETTERS PATENT to George Henry Bachhoffner, of Marylebone Road,
in the County of Middlesex, Doctor of Philosophy, for the In-
vention of "IMPROVEMENTS IN LAMPS."
PROVISIONAL SPECIFICATION left by the said George Henry Bach-
hoffner at the Office of the Commissioners of Patents, with his
Petition, on the 11th July 1871.
I, GEORGE HENRY BACHHOFFNER, of Marylebone Road, in the
County of Middlesex, Doctor of Philosophy, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN LAMPS," to be as
follows:-
My Invention relates to improvements in lamps (such as those used
for burning paraffin and other light hydrocarbon oils), which improve-
ments have for their object the removal of danger from the upsetting
of such lamps by preventing the escape of the fluid contained and
extinguishing the light.

page_text: According to one arrangement the lamp may be constructed with an
inner or wick chamber to contain only a small quantity of fluid and an
outer chamber serving as the reservoir, which is supplied with oil
through a hole closed by a tightly fitting screw stopper. This reservoir
communicates with the wick chamber by means of a coiled or circular
tube or enclosed channel running round on or formed in the upper or
under surface of the bottom of the reservoir, and one end of which tube
or channel opens to the reservoir, and the other to the wick chamber
to which the fluid is conveyed from the reservoir through the said tube
or channel. On the plate forming the top of the reservoir is a similar
tube or channel to admit. air to the reservoir to supply the place of the
fluid as the latter is consumed. A valve is fitted within the reservoir
by which this pipe or channel is closed when the lamp is inverted. The
wick chamber rises through or above the top of the reservoir and has
a fixed or moveable wick tube inserted through the top of the said wick
chamber and descending therein to a sufficient depth to prevent the
escape of the fluid contained in the said chamber should the lamp be
inverted or laid on its side. The wick tube may be attached to the top
of the wick chamber by a screw and washer or by other means, or it
may be permanently fixed thereto. Any of the burners now in use for
the combustion of liquid hydrocarbons may be employed with the lamp,
such burners, being connected with the wick tube or attached to the lamp
itself by means of screws or otherwise. The above arrangements are
suitable for lamps which by their external form are prevented from
rolling if overturned.
In bracket or reading lamps the chamber for the immediate supply
of the wick would be placed exterior to the reservoir but connected
therewith by means of the before-mentioned pipe or covered channel
leading from the bottom of the reservoir.
In order to more effectually prevent the escape of liquid from lamps
which from their external shape are likely to roll if overturned, the
top and bottom of the reservoir may each be made double or of two
plates separated by a small space, and each provided with a tube or
channel, as before described, leading through it in a circular (but
reverse) direction. A valve is placed in the reservoir to close the end
of the pipe or covered channel of the lower of the two top plates should
the lamp be inverted.

page_text: My improvements may be applied to "Sinumbra " lamps by leaving
an annular space between the reservoir and the chamber holding the
small quantity of fluid in immediate contact with the wick and making
the fluid connection by means of the coiled tube before described.
To extinguish the light should the lamp be overturned I apply a
sliding tube or casing to the wick tube of the burner, on which it fits
loosely; this outer tube or casing may be rounded or otherwise shaped
at the top, so that when raised above the wick tube of the burner it
may serve as a guide to the scissors in trimming the wick to a proper
shape, and for this purpose it may have hinged sides to clip the wick.
The said tube or casing is made of sufficient weight or otherwise
so loaded as to fall by its own gravity and enclose the burning portion
of the wick and thus extinguish the light when the lamp. is overturned.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Henry Bachhoffuer in the Great Seal
Patent Office on the 11th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
Henry BachhOFFNER, of Marylebone Road, in the County of Middlesex,
Doctor of Philosophy, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of July, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Henry Bachhoffner, Her special
licence that I, the said George Henry Bachhoffner, my executors,
administrators, and assigns, or such others as I, the said George
Henry Bachhoffner, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make,, use, exercise, and vend, within the United Kingdom of
Great Britain and Ircland, the Channel Islands, and Isle of Man, an
LAMPS," upon the condition (amongst
others) that I, the said George Henry Bachhoffner, my executors or
Invention for "IMPROVEMENTS IN

page_text: administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Henry Bachhoffner, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the two
Sheets of Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say) :-
My Invention relates to improvements in lamps (such as those used
for burning paraffin and other light hydrocarbon oils), which improve-
ments have for their object the removal of danger from the upsetting
of such lamps by preventing the escape of the fluid contained and
extinguishing the light.
According to ono arrangement the lamp may be constructed with an
inner or wick chamber to contain only a small quantity of fluid, and
an outer chamber serving as the reservoir, which is supplied with oil
through a hole closed by a tightly fitting screw stopper. This reservoir
communicates with the wick chamber by means of a coiled or circular
tube or enclosed channel running round and formed in the upper or
under surface of the bottom of the reservoir, and one end of which tube
or channel opens to the reservoir and the other to the wick chamber, to
which the fluid is conveyed from the reservoir through the said tube or
channel. On the plate forming the top of the reservoir is a similar tube
or channel to admit air to the reservoir to supply the place of the fluid
as the latter is consumed. A valve is fitted within the reservoir, by
which this pipe or channel is closed when the lamp is inverted. The
wick chamber rises through or above the top of the reservoir, and has a
fixed or movable wick tube inserted through the top of the said wick
chamber, and descending therein to a sufficient depth to prevent the
escape of the fluid contained in the said chamber should the lamp be
inverted or laid on its side. The wick tube may be attached to the top
of the wick chamber by a screw and washer or by other means, or it
may be permanently fixed thereto. Any of the burners now in use for

page_text: the combustion of liquid hydrocarbons may be employed with the lamp
(provided the wick tube will carry the extinguisher hereafter described),
such burners being connected with the wick tube or attached to the
lamp itself by screwing or otherwise. The above arrangements are
suitable for lamps which by their external form are prevented from
rolling if overturned.
In bracket or reading lamps the chamber for the immediate supply of
the wick would be placed exterior to the reservoir but connected there-
with by means of the before-mentioned pipe or covered channel leading
from the bottom of the reservoir. In order to more effectually prevent
the escape of liquid from lamps which from their external shape are
likely to roll if overturned the top and bottom of the reservoir may each
be made double, or of two plates separated by a small space, and each
provided with a tube or channel, as before described, leading through it
in a circular (but reverse) direction. A valve is placed in the reservoir
to close the end of the pipe or covered channel of the lower of the two
top plates should the lamp be inverted.
To extinguish the light should the lamp be overturned I apply a
sliding tube or casing to the wick tube of the burner, on which it fits
loosely. This outer tube or casing may be rounded or otherwise shaped
at the top, and provided with hinged sides, so that when raised above
the wick tube of the burner it may serve as a guide in trimming the
wick to a proper shape, which is best effected by pinching off the
carbonized portion with a rag or cloth whilst the wick is held by the
hinged sides of the extinguisher. The said tube or casing is made of
sufficient weight or otherwise so loaded as to fall by its own gravity and
enclose the burning portion of the wick, and thus extinguish the light
when the lamp is overturned.
Figure 1 shows in elevation a central section of a table lamp with my
improvements applied; Figure 2 is a top plan of the same with the
burner and top of the wick chamber removed; Figure 3 is an under
side plan of the oil reservoir and wick chamber with the bottom plate
removed; Figures 4 and 5 are detached views of the extinguisher.
A is the reservoir surrounding the wick chamber B, and communi-
cating therewith only by a tube a bent into a circular direction around

page_text: the interior and close against the sides of reservoir A at the lower part.
One end of this tube is open to the reservoir, the other being led
towards the centre of the lamp, and enters the wick chamber B at
bottom, as shewn, through which tube the whole supply of oil passes
from the reservoir into the wick' chamber. The reservoir is supplied
with oil through an opening at C closed by a tightly fitting screw cap.
In order to prevent the reservoir being completely filled a downwardly
projecting flange or tube c (Figures 1 and 3) is provided round the
filling hole at the under side of the top plate d of the reservoir, so as to
confine a portion of the air contained in the reservoir, which having
no escape except through an air tube e of small diameter, hereafter
described, causes the oil in excess to rise in the filling hole and indicate
when sufficient has been supplied. In the Drawing a blue line indicates
the maximum height of the oil in the reservoir after the fluid has
equalized itself in both chambers. e is a tube bent around the edge of
the top plate d, as shown in Figure 2, so as to form nearly an entire
circle (as in the case of tube a). One end f of the tube is open to the
external atmosphere, whilst the other end g opens through the top
plate d of the reservoir A, to which the tube e is soldered. This tube e
serves to admit air to the reservoir to supply the place of the oil as it
flows into the wick chamber. In lieu of tubes a and e channels may be
stamped in the top and bottom plates respectively of the reservoir A,
the said channels being covered and made fluid-tight by a corresponding
strip of metal soldered on to the top and bottom plates of the reservoir,
whereby passages in all respects equivalent to the tubes are formed,
openings being also made through the plates at the ends of the said
channels so as to give passage to the air and oil precisely in the same
manner as when tubes are used, but I prefer to employ tubes.
tubes (or channels) a and e lead in opposite directions, as shown by the
arrows. They should be of sufficient internal diameter to allow the air
or fluid, as the case may be, to pass through at a sufficient rate to supply
the wick freely. For a lamp burning an inch wick tubes or channels
about 1 inch in diameter will answer. E is a weighted valve placed
immediately opposite the end g of tube c, which opens into the reservoir,
It is fitted loosely in a socket carried by an arm E' fixed to the wick
chamber. The top of this weight is covered with some soft material,
such as wash leather, which will prevent the escape of oil through
tube e when the lamp is inverted by the weight E falling by its own
10
th
The

page_text: gravity against the under side of plate d, and so closing the orifice to
tube c, as shown in dotted lines.
I make the wick chamber somewhat contracted towards the lower
part, so as to hold but a comparatively small quantity of oil, but the
fluid will of course always be of the same height as in the reservoir.
The wick chamber is considerably enlarged in diameter at the upper
part at and above the highest level of the oil in reservoir A, and the
top g¹ of the wick chamber is provided with a tube / surrounding the
wick chamber at a little distance therefrom, and which dips down into
the wick chamber far enough to prevent the escape through the wick
tube of any of the oil contained therein when the lamp is inverted, the
oil being received in the enlarged part g2 of the chamber B around
tube h, which enlarged part must be of sufficient capacity to hold all
the fluid in whatever position the lamp may be placed. The wick tube i
is also carried down into the wick chamber as far as tube h. As the air
admitted to the oil reservoir through tube e does not come into contact
with the oil in the wick chamber no opening in the burner or top of the
wick chamber except for the passage of the wick is required. j is an
extinguisher (seen also detached in two shapes in Figures 4 and 5),
consisting of a weighted tube surrounding the upper part of the wick
tube, on which it is fitted to slide freely. When the lamp falls or is
inverted the extinguisher has a tendency to slide partially off the wick
tube and suddenly enclose the top of the wick, thereby extinguishing
the flame. The extinguisher is prevented from falling quite off by the
top of the burner, or a suitable stop. When a flat wick is employed
I prefer to make the extinguisher with loose sides j¹ pivoted at to the
ends, so that they may be closed together, as shown by the dotted lines,
Figure 4, and serve as a guage in trimming the wick, which is clipped
between them by the pressure of the fingers, the cxtinguisher being at
same time raised slightly above the top of the wick tube. The sides j¹
are made with projecting flanges j³ at bottom to limit their motion
outwards, or stops may be provided for the purpose.
Figure 5 shows the extinguisher in the form of a flattened tube,
simply weighted at its base as before. Should a lamp constructed as
herein-before described be thrown down on its side the oil cannot escape
from the reservoir through tube e, by reason of its coiled form and the
fact that the reservoir A is never completely full. If, however, the

page_text: lamp be of such external form that it is liable to roll when overturned,
I provide it with a double arrangement of tubes, as shown in Figure 6,
which is a central vertical section of a lamp so constructed. In this
lamp the top and bottom plates with their respective tubes (or channels)
are duplicated, the passages in each pair leading, however, in opposite
directions. A is the oil reservoir, and B the wick chamber, as before;
d is the top plate, and e the air tube leading around and through the
same, also as before. In this case, however, the air tube docs not lead
directly into the oil reservoir, but into the space between plate d and a
second plate d similarly provided with a tube or channel e', which is led
around in an opposite direction to that of tube e (as indicated by the
'arrows), and communicates with the oil reservoir A. The bottom plates
are similarly arranged and provided. a is a tube led around and con-
veying oil in the direction of the arrows through plate m to the space
between it and bottom plate m³, whence it is conveyed by tube a¹ to the
wick chamber B, tubes a and a¹ being led in opposite directions, as
shown. The four tubes are so arranged moreover that the air entering
tube e follows the same direction as the oil flowing through tube a, and
similarly in the opposite direction with tubes e¹ and a', and the respective
ends of the four tubes are as nearly as possible in the same vertical line.
The filling hole C leads by a short tube c through the two top plates
directly into the body of the reservoir A, in which it descends slightly,
as before. E is the valve to close the orifice of the tube e¹ leading to
the reservoir to prevent the oil escaping when the lamp is inverted, as
before described.
Figure 7 shows a part sectional elevation of a "reading" lamp provided
with my improvements; Figure 8 is a horizontal section of same on
line 1-1, Figure 7, and Figure 9 is a similar section on line 2-2, in
same Figure. In this description of lamp the wick chamber is not
enclosed within the oil reservoir, as in that first above described, but is
connected thereto by an arm Z fixed to a standard Z. As the reference
letters indicate the same parts as those above described wherever they
recur, it is unnecessary to repeat the description of all the parts.
oil reservoir A is provided with a double bottom and double oil tubes or
passages a, a¹, as before described in reference to Figure 6, except that
the upper oil tube a is carried down nearly to the bottom plate, as
shown, and the tube a¹ which starts from the centre of the lamp is first
carried around in a circular direction, and then along the arm Z to the
The

page_text: wick chamber B. The entrance to the air tube e should be situate at
that side of the lamp which is nearest to the wick chamber, and the
entrance to the oil tube a should be in a diametrically opposite position.
Having described the nature of my Invention, and the manner of per-
forming the same, I declare that what I claim as my Invention to be
protected by the herein-before in part recited Letters Patent is,―
1st. The application to the oil reservoir of lamps for burning hydro-
carbon oils of a bent or coiled air tube (or covered channel) e, arranged
substantially as described and shown for the purpose specified.
2ndly. Connecting the oil reservoir and wick chamber by a coiled
tube (or covered channel) a, substantially as herein-before described and
shown in the Drawings, to convey oil to the wick chamber, but which
will prevent the flow of oil into the wick chamber when the lamp falls.
3rdly. The combination in a lamp provided with the wick chamber B,
constructed as herein-before described, of the air tube or channel e and
oil tube or channel a, as shown in Figures 1, 2, and 3 of the Drawings.
4thly. The combination with the air tube or channel e of the valve E,
to prevent the escape of oil when the lamp is inverted, substantially as
shown and described.
I also claim the combination of the said valve with the double air
tubes or channels.
5thly. The application of the double air tubes (or channels) and
double top to the oil reservoir to prevent the escape of oil when the
lamp rolls, arranged substantially as described and shown in Figure 6
of the Drawings.
Gthly. The double bottom m, m³, and double oil tubes (or channels)
a, a, arranged substantially as described and shown in Figures 6, 7,
and 8, to prevent an undue quantity of oil flowing into the wick
chamber when the lamp rolls.
7thly. The extinguisher j fitted on the wick tube, substantially as
and for the purpose shown and described.
Sthly. Providing the extinguisher with hinged sides, to aid in ex-
tinguishing the flame, and to serve as a guage to nip the wick when

page_text: in the Drawings.
In witness whereof, I, the said George Henry Bachhoffner, have
hereunto set my hand and seal, this Ninth day of January, in the
year of our Lord One thousand eight hundred and seventy-two.
GEO. HY. BACHHOFFNER. (L.S.)