IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR LIGHTING, EXTINGUISHING, AND REGULATING GAS FLAMES
Year: 1874

page_text: TTERS PATENT to Joseph Theodore Dann, of 43, Cowley Road,
North Brixton, in the County of Surrey, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR
LIGHTING, EXTINGUISHING, AND REGULATING GAS FLAMES."-A communi-
cation from abroad by Michael Flürscheim, of Gaggenau, in the
Empire of Germany, Manufacturer, and Leopold Baumeister, of
Gaggenau, in the Empire of Germany, Engineer.
:
caled the 7th August 1874, and dated the 8th June 1874...
PROVISIONAL SPECIFICATION left by the said Joseph Theodore
Dann at the Office of the Commissioners of Patents, with his
Petition, on the 8th June 1874.
I, JOSEPH THEODORE DANN, of 43, Cowley Road, North Brixton, in
the County of Surrey, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS
IOR LIGHTING, EXTINGUISHING, AND REGULATING GAS FLAMES," a communi-
cation to me from abroad by Michael Flurscheim, of Gaggenau, in the

page_text: Empire of Germany, Manufacturer, and Leopold Baumeister, of
Gaggenau, in the Empire of Germany, Engineer, to be as follows:-
This Invention has. for its object to substitute for the method of
lighting and extinguishing gas flames by hand, as practised at present, a
new system of lighting and extinguishing these flames by self-action,
and simultaneously regulating the consumption of gas by each burner.
To this effect I provide in close proximity to each burner of the usual
kind, herein-after called the main burner, an additional burner, by
preference of smaller proportions, herein-after called the auxiliary
burner, which I enclose in a double casing fitted around the main
burner, and having its sides perforated alternately in such a manner as
to admit sufficient air while shutting out the draught.
Upon the auxiliary burner I maintain a flame varying in proportion
according to the successive stages of ignition. It is of diminutive size
while the main burner is extinguished; it assumes a larger proportion
as soon as a certain pressure is put on the gas; it is reduced to nil or
extinguished when the main flame is fully lighted; as the gas pressure
decreases it is relighted by the main flame; and, lastly, at the
extinction of the main flame it is brought down to its original minuto
size.
In order to cause the two flames to pass through these various stages
I provide a tube communicating constantly with the gas pipe and
sliding within a guide piece connected with both burners. Within the
side of the tube I make three sets of apertures corresponding to three
canals or orifices I provide in the guide piece, two of which commu-
nicate with the auxiliary, and one with the main burner. The lower
end of the sliding tube I attach to a diaphragin or broad base acted
upon by the pressure of the gas in such a manner as to maintain the
tube in its lowest position at certain degrees of pressure. At this stage
one of the sets of apertures in the tube communicates with the corrc-
sponding orifice in the guide piece, the auxiliary flame has only a very
small quantity of gas supplied to it, and the main burner not communi-
cating with the gas pipe remains unlighted. Upon the sliding tube
beginning to rise owing to an increase of pressure the remaining
apertures in its side are made to communicate more or less fully with
their corresponding canals in the guide piece, so that an additional
quantity of gas is supplied to the auxiliary, and a small quantity only to
c
.

page_text: .
the main burner. The diminutive auxiliary flame having by this means
been increased at once shoots up, passes through the openings in the
double casing, and ignites the gas issuing from the main burner. By
the continued rise of the tube the third aperture in the side of the tube
which had remained partly closed is placed in full communication with
the main burner, whilst the other apertures in the tube are put out of
communication with the orifices corresponding to them in the guide
piece, and by this means the auxiliary flame is extinguished. Upon
the pressure of the gas being reduced again the tube redescends, the two
sets of apertures and orifices corresponding to one another in the tube
and guide picce respectively are again brought face to face with each
other and gas is once more admitted to the auxiliary burner, which is
thence relighted by the main flame. When the tube resumes its lowest
position the communication between the main burner and the tube is
shut off and the main flame extinguished. Gas is then supplied to the
auxiliary burner through one set of apertures and orifices only, and the
auxiliary flame is consequently reduced again to a diminutive size.
al
In order to adjust the pressure of gas required for lighting and
extinguishing the two burners I connect a set of adjustable levers with
the diaphragm or broad base, upon which the tube is fitted. These
levers I place in connection with one another by means of a set of links
or other suitable appliances, and to each of the levers I attach a balance-
weight in such a manner as to cause its center of gravity to be shifted
by every change in the correlative position of the levers, which is
effected by the rising and falling of the diaphragm. Thus at the lowest
position of the tube the aggregate force of the weights is brought to
bear upon it.
As the tube rises the pressure of the weights decrcases
owing to the shifting of their centers of gravity, and this pressure is
reduced to its lowest limit at the moment the diaphragm and tube have
been raised to their highest position and the main flame is fully lighted.
By this means the loss of gas pressure due to the efflux of gas through
the main burner is fully compensated and prevented from impeding the
full rise of the tube at a certain gas pressure, and by the same means
the tube is kept in its highest position and the main flame kept alight,
even though there should be a fall in the gas pressure.
At the stage at which the extinction of the main flame is wanted the
reduced force of the weights is sufficient to overcome the gas pressure
under the diaphragm and cause the tube to redescend. As the efflux
A 2.

page_text: of
gas from the main burner decreases the gas pressure beneath the tube
increases and so does the force of the balance weights owing to the
shifting of their centers of gravity, and thus as soon as the gas pressure
is so far reduced as to cause the tube to redescend the tube is at once
forced down to its lowest position, at which the auxiliary burner is
relighted and the main flame extinguished.
For the levers described a set of concentric or excentric wheels may
be substituted, or else a rope or chain sliding over a pulley and loaded
at various places with weights, or other appliance suitable for effecting
a shifting of the centers of gravity may be used or employed in lieu of
the levers.
With a view to regulate the consumption of gas by cach burner I
provide beneath the slide tube a disk, which is kept floating in the gas
by means of a membrane or other flexible material so as to be her-
metically held in a position in which it may both stem and be acted
upon by the current of gas. To this disk I fit a cone which works
within the tube communicating with the burner. By means of a hole
made in the cone, disk, or membrane a certain quantity of gas is allowed
to pass, and as the pressure and counter-pressure beneath and above the
disk vary the position of the cone in relation to the burner is likewise
varied or shifted in such a manner as to permanently secure the access
of an equal quantity of gas to the burner..
In those cases in which the lighting gear of the apparatus con-
structed according to my Invention is not required I adapt the last
arrangement as an independent regulator to any kind of gas conduit in
connection with one or more burners.
I also regulate the consumption of gas by means of a set screw,
wedge, pin, or other suitable appliance inserted in a canal connecting.
the space above with the space below the disk so as to increase or reduce
the size of the passageway, as the case may be, and thereby adjust the
quantity of gas to be admitted to the burner. And the same arrange-
ment may likewise be applied directly to the holes in the cone, disk, or
membrane herein-before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Theodore Dann in the Great Seal Patent
Office on the 7th December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
THEODORE DANN, of 43, Cowley Road, North Brixton, in the County of
Surrey, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of June, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Joseph Theodore Dann, Her special
licence that I, the said Joseph Theodore Dann, my executors, admi-
nistrators, and assigns, or such others as I, the said Joseph Theodore
Dann, 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,
excrcise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR LIGHTING, EXTINGUISHING,
AND REGULATING GAS FLAMES," a communication, to me from abroad by
Michael Flürscheim, of Gaggenau, in the Empire. of Germany, Manufac-,
turer, and Leopold Baumeister, of Gaggenau, in the Empire of Germany,
Engineer, upon the condition (amongst others) that I, the said Joseph
Theodore Dann, my executors or 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 Joseph Theodore Dann, 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 and accompanying Sheet of Drawings:-
This Invention has for its object to substitute for the method of
lighting and extinguishing gas flames by hand, as practised at present,
a new system of lighting, and (extinguishing these flames by self-action,
4

page_text: and simultaneously regulating the consumption of gas by cach burner.
To this effect I provide in close proximity to each burner of the usual
kind, herein-after called the main burner, an additional burner, by pre-
ference of smaller proportions, herein-after called the auxiliary burner,
which I enclose in a double casing fitted around the main burner, and
having its sides perforated alternately in such a manner as to admit
sufficient air while shutting out the draught.
Upon the auxiliary burner I maintain a flame varying in proportion
according to the successive stages of ignition. It is of diminutive size
while the main burner is extinguished; it assumes a larger proportion
as soon as a certain pressure is put on the gas; it is reduced to nil or
extinguished when the main flame is fully lighted; as the gas pressure
decreases, it is relighted by the main flame; and, lastly, at the
extinction of the main flame it is brought down to its original minute
size.
In order to cause the two flames to pass through these various stages
I provide a tube communicating constantly with the gas pipe, and
sliding within a guide [picce connected with both burners. Within the
side of the tube I make three sets of apertures, corresponding to three
canals or orifices I provide in the guide piece, two of which com-
municate with the auxiliary and one with the main burner. The lower
end of the sliding tube I attach to a diaphragm or broad base, acted
upon by the pressure of the gas in such a manner as to maintain the
tube in its lowest position at certain degrees of pressure. At this stage
one of the sets of apertures in the tube communicates with the cor-
responding orifice in the guide picce, the auxiliary flame has only a very
small quantity of gas supplied to it, and the main burner not com-
municating with the gas pipe remains unlighted. Upon the sliding
tube beginning to rise owing to an increase of pressure the remaining
apertures in its side are made to communicate more or less fully with
their corresponding canals in the guide piece, so that an additional
quantity of gas is supplied to the auxiliary and a small quantity only to
the main burner. The diminutive auxiliary flame having by this means
been increased at once shoots up, passes through the openings in the
double casing, and ignites the gas issuing from the main burner. By
the continued rise of the tube the third aperture in the side of the tube,
which had remained partly closed, is placed in full communication with
the main burner, whilst the other apertures in the tube are put out of

page_text: communication with the orifices corresponding to them in the guide
piece, and by this means the auxiliary flame is extinguished. Upon the
pressure of the gas being reduced again the tube redescends, the two sets
of apertures and orifices corresponding to one another in the tube and
guide piece respectively are again brought face to face with each other,
and gas is once more admitted to the auxiliary burner, which is thence
relighted by the main flame. When the tube resumes its lowest position
the communication between the main burner and the tube is shut off,
and the main flame extinguished. Gas is then supplied to the auxiliary
burner through one set of apertures and orifices only, and the auxiliary
flame is consequently reduced to a diminutive size.
In order to adjust the pressure of gas required for lighting and
extinguishing the two burners I connect a set of adjustable levers with
the diaphragm or broad base upon which the tube is fitted. These.
levers I place in connection with one another by means of a set of links
or other suitable appliances, and to each of the levers I attach a balance
weight in such a manner as to cause its center of gravity to be shifted
by every change in the correlative position of the levers, which is effected
by the rising and falling of the diaphragm. Thus at the lowest position
of the tube the aggregate force of the weights is brought to bear upon
it. As the tube rises the pressure of the weight decreases, owing to the
shifting of their centers of gravity, and this pressure is reduced to its
lowest limit at the moment the diaphragm and tube have been raised to
their highest position and the main flame is fully lighted. By this
means the loss of gas pressure due to the efflux of gas through the
main burner is fully compensated, and prevented from impeding the full
rise of the tube at a certain gas pressure; and by the same means the
tube is kept in its highest position and the main flame kept alight, even
though there should be a fall in the gas pressure.
At the stage at which the extinction of the main flame is wanted the
reduced force of the weight is sufficient to overcome the gas pressure
under the diaphragm, and cause the tube to redescend. As the efflux
of gas from the main burner decreases the gas pressure beneath the
tube increases, and so does the force of the balance weights owing to
the shifting of their centers of gravity; and thus as soon as the gas
pressure is so far reduced as to cause the tube to redescend, the tube is
at once forced down to its lowest position, at which the auxiliary
burner is relighted and the main flame extinguished.

page_text: For the levers described a set of concentric or excentric wheels may
be substituted; or else a rope or chain sliding over a pulley and loaded
at various places with weights or other appliance suitable for effecting
a shifting of the centres of gravity may be used or employed in lieu of
the levers.
With a view to regulate the consumption of gas by cach burner I
provide beneath the slide tube a disk which is kept floating in the gas
by means of a membrane or other flexible material, so as to be hermet-
ically held in a position in which it may both stem and be acted upon
by the current of gas. To this disk I fit a cone which works within the
tube communicating with the burner. By means of a hole made in the
cone, disk, or membrane, a certain quantity of gas. is allowed to pass;
and as the pressure and counter pressure beneath and above the disk
vary, the position of the cone in relation to the burner is likewise varied
or shifted in such a manner as to permanently secure the access of an
equal quantity of gas to the burner..
In those cases in which the lighting gear of the apparatus constructed
according to my Invention is not required, I prefer to adapt the last
arrangement as an independent regulator to any kind of gas conduit in
connection with one or more burners.
I also regulate the consumption of gas by means of a set screw,.
wedge, pin, or other suitable appliance inserted in a canal connecting
the space above with the space below the disk, so as to increase or
reduce the size of the passage way, as the case may be, and thereby
adjust the quantity of gas to be admitted to the burner; and the
same arrangement may likewise be applied directly to the holes in the
cone, disk, or membrane, herein-before described.
DESCRIPTION OF DRAWINGS.
In the accompanying Sheet of Drawings I have shown in Figures 1,
2, and 3 a longitudinal section of a self-lighting apparatus constructed
according to my Invention, representing the sliding tube and the
organs connected therewith in three different positions, as will appear

page_text: Figures
anu o are respectively a longional section and a noNV.
elevation of an apparatus constructed according to my Invention and
designed for indoor or generally private use.
Figure 9 is a longitudinal section of the apparatus used for regulating
the flame, to be adapted to ordinary burners or gas fixtures; and
Figure 10 is a horizontal section of the plug a, a', Figure 7.
In all these views indentical parts, portions, or organs are denoted by
identical letters of reference. -
:
In the apparatus shewn in Figures 1, 2, 3, 4, 5, and 6, a is a plug or
joint, by means of which the apparatus is fitted to the pipe of the street
lamp for the lighting and extinction whereof it is to be used; . is an
iron casing with a recess c at its bottom. Instead of being made of
solid iron this casing may consist of two sheets of iron plate placed
inside one another, and of which the interior one forms the inside of tho
recess. This recess or groove c is filled with mercury to about three-
quarters of its depth. By means of an iron casing or float & dipped' in
the mercury
the gas
is shut off hermetically. On the casing b'a cover e
is mounted, upon which the guide piece fis screwed. To the top of the
float d a tube g-made of a suitable hard metal is attached. The top end:
of this tube consists of a solid head piece h, and the tube g itself is so
fitted into the guide piece fas readily to slide up and down without,
allowing any gas to pass between. the sides. Within the side of the
sliding tube g three sets of holes w, l, and, are pierced at three different
places, and in connection with the lowest of these holes % circular
recesses are provided. Within the guide piece f a longitudinal canal i̇
is made parallel to the central canal in which the tube g slides, and the
two canals communicate with one another by means of the transversal-
orifices ¹ and 1, which are closed up from without by means of the
adjusting screws 2 and 12. Above the head picce h the central canal is
enlarged so as to allow of this head piece passing up and down. To the
top of the guide piece f immediately above the central canal the burner
pipe m is fitted, whilst the lateral canal i is surmounted by a small bent
pipe n, the opening of which is diminutive. Thus m is the main, and n
the auxiliary burner pipe. Both are enclosed in two hoods or casings o¹, o²,
superposed to one another, and furnished with small alternating air
holes H, H, in such a manner as to secure a constant supply of air, and
yet keep out every draught from the interior of the hoods. At the top
I

page_text: of this double hood or casing o', o², a double opening W is made for the
burner proper and for the igniting flame proceeding from the auxiliary
burner to pass through.
To the top of the float d, and diametrically opposite to one another,
two supports p, shewn in Figure 5, are fitted. In some cases I prefer to
attach these supports to a cross stay instead of connecting them with
the sliding tube. The supports pass through the top of the casing e,
and are attached to the hoop q which encircles the guide picce f, and is
connected with the lever arms q', q2. To the cover e of the casing ba
support is attached, having a semicircular top in which the conical
ends of the set screws 7, 7¹, enter, as shewn in Figure 4, so that the
horizontal axis of this support and of the screws forms the fulcrum of
the lever arm q'. This lever arm has a fork at its end in which the
cranked lever u moves freely upon a spindle u³, and a balance weight v
is attached to the top of the cranked lever u. The lower end of the
lever u is fork-shaped. Upon the cover e a horizontal arm t is mounted,
which has a groove at its end for a movable arm or limb t' to slide to
and fro, the position of which is adjusted by a set screw 2 travelling in
the aforesaid groove. To the extremity of the limb t'a long pin ♬ is
fixed, which slides freely in the forked end of the lever u.
To the lower surface of the float d an annular plate d' is attached,
between which and the end of the tube g a packing ring g' is fitted.
Around the annular plate d' a diaphragm 6, made of an animal
membrane, of leather, thin metal, or any other flexible material, is
hermetically attached. This diaphragm carries a circular metal plate 6º,
upon which the plug y, by preference of conical shape, is fixed. This
plug y moves freely within the lower open end of the tube g or within
the ring g', to either of which it may be adapted. It is perforated by. a
series of holes, the size of which corresponds to the size of the thin
metal plate 62, upon which the pressure of the gas acts directly, whilst
both these holes and the weight of the thin plate together are in their
turn proportionate to the quantity of gas to be consumed. Through
the pressure exerted beneath, and the counter pressure acting above the
thin plate 62, the conical plug y is kept in its proper position, so that
according as the pressure increases or decreases the area of the opening
of the tube g is reduced or enlarged, and by this means both the flame
and the consumption of gas are preserved at a uniform rate, irrespective
of the pressure at which the gas enters the apparatus,

page_text: The part of the apparatus just described, consisting of the thin plate 6º,
the plug y, and the organs connected therewith, acts as a regulator of
the flame and simultaneously as a receptacle of gas, inasmuch as the
quantity of gas consumed at a uniform rate per hour must naturally be
known, if once the number of hours be fixed during which the lamps
are to remain lighted. Therefore this part may also be employed
independently of my apparatus, for common burners or in connection
with any kind of gas fittings. If employed for this last-named purpose,
the organs alluded to are inserted in a small casing, which may be fitted
to any gas fixture in a place corresponding to a single flame. In
Figure 9 such a fitting is shown in a vertical section. In this case the
annular plate d' forms the top part or cover of the casing. At the top
of this plate there is a small tubes furnished with screw threads for the
burner pipe to be screwed upon. The annular plate d' is screwed
tightly into the casing 6, the lower part of which is furnished with
interior screw threads by means of which it may be screwed upon the
gas pipe or fitting.
The quantity of gas to be consumed is regulated within certain limits
by means of the screw r, or by any other suitable appliance, so that
the deeper this screw enters the less gas will be admitted, and vice
versa.
The mode of ignition and extinction of the main flame and the
auxiliary flame is shewn at three several stages in Figures 1, 2, and 3.
In Figure 1 the various organs are placed in the position they will
occupy during the daytime, or generally when the main flame is not
lighted. At this stage the gas enters through the joint a beneath the
float d into the casing 6, and thence proceeds to the pipe g. All the
openings in the sliding tube 9 are now shut off by the solid parts of
the sides of the guide piece f, save the holes k, which communicate with
the transversal opening in the guide piece. Therefore it is obvious
that the gas can only pass through these apertures and into the longi-
tudinal canal i and the auxiliary pipe 22. This gas being ignited on tho
auxiliary burner n a small flame is kept up, which is adjusted by the
screw in such a manner that it may be brought to a diminutive size
and made almost invisible. This auxiliary flame keeps itself up as long
as the main flame is not lighted, and the double hood o¹, o², protects it
from every blast of wind, as herein-before explained.
n.

page_text: In Figure 2 the second stage is illustrated at which the main flame is
ignited. Upon the pressure of the gas at the works, and thence within
the pipe, being raised towards nightfall, or at such other time as may be
thought proper for the purpose of lighting the street lamps, the float d
is raised some distance, but not high enough to cause its bottom edge to
emerge from the mercury, by which the gas is hermetically shut off.
As the float d is lifted the tube grises, the orifice k then remains in
communication with the opening ¹ in the side of the guide piece, and
the hole is brought opposite the canal /, whilst, the top of the orifices w
is placed in communication with the opening beneath the burner pipe m,
by which means some gas is allowed to enter the main burner. At this
stage all the three sets of orifices are in communication with their
burners. The quantity of gas passing into the auxiliary burner n
through the orifices k, k¹, is increased by that which enters through the
openings, . The auxiliary flame being thence increased in size shoots
up through the openings W of the two hoods o¹, o², and upon touching
the main burner m ignites the gas, which proceeds through the same,
While this is going on the float d, and along with it the tube g, continuc
their upward movement, and during their progress the moment arrives
when the openings ¹ and are completely cut off from their corre-
sponding orifices in the tube g, whilst the top orifices w are set entirely
free for the gas to pass through them. At this stage, which is illustrated
in Figure 3, the main flame has risen to full size; and the auxiliary one
has been extinguished. As soon as the pressure is reduced again the
float d, and along with it the tube g, descends again, the orifices k, k', l, l';
are again brought opposite to one another, as shewn in Figure 2, and a
double current of gas passes again through the burner pipe n and lights
itself at the main flame. As the float d and the tube g resume their
lowest position; shown in Figure 1, the orifices w and are shut off
again, and no more gas passing then into the pipe m the main flame is
extinguished, and the auxiliary one being fed.only through the set of
orifices k, k¹; is reduced to its minimum size.
Instead of the sliding tube g being arranged in the manner shewn in
Figures 1, 2, and 3, a stationary tube may be fixed to the cover e of
the casing b, and a movable tube connected with the float d be so fitted
around the stationary one as to slide up and down, according as the gas
pressure increases or decreases. In this case the orifices may, with
slight changes, be made to work in a manner similar to the one herein-

page_text: before described, and the compensating gear may be fitted to the sliding
tube directly. Morcover to consolidate the supports p, p, shewn in
Figure 5, they may be joined together by means of cross stays con-
nected with the sliding tube, whereby all undue shaking or vibration
is obviated, and greater efficiency imparted to the apparatus:
In order to enable the main flame being lighted instantaneously, as
soon as a certain degree of pressure is reached, and extinguished with
the same rapidity as soon as a certain reduction in the pressure has
taken place, I regulate the working of the apparatus by means of the
variations effected in the position of the shifting weights s and v, and of
the limb t, which is fixed by means of the set screw t², Figures 1, 2, 3,
and 4. The object of the shifting weights is to load the float d according
to the degree of pressure desired for the ignition of the main flame
The adjustment of the position of the cranked lever u by means of the
set screw is accessory to the loading of the float d, and to the fixing of
the degree of pressure; but its principal object is to determine and fix
the difference between the varying degrees of pressure required for
ignition and extinction. If the apparatus be so regulated as to require
a certain gas pressure to lift the float d along with all the organs con-
nected with it, then, whilst the hoop q with its arm q² carrying the
weights is lifted, the arm q' pivoting upon the screws ¹, ¹, descends,
and in doing so causes the spindle u¹ connected with the lever u to con-
vert its slanting position into a vertical one by the aid of the movable
limb by which the fork u is supported.
The-working of this adjusting and regulating gear is as follows:-As
soon as the gas begins to issue from the main burner the pressure
beneath the float d diminishes, and a further increase of pressure is
required to effect a complete ignition, and prevent the float d from
liaving its upward movement arrested before the main flame is fully
ignited, and the auxiliary one fully extinguished. By the changing
positions of the lever the lighting of the main flame once begun is
completed forthwith. This object is achieved by the change in the position
of the arm u¹, which becomes more erect as the float d begins to rise,
and by which the decrease of the pressure beneath the float is compen-
sated, and a decrease in the counter pressure brought about. At the
stage shewn in Figure 1 the arm u¹ produces the fullest counter pressure.
In Figure 2 this arm is placed in a vertical position, is is conscquently
at its dead point. It then produces no further counter pressure, and the

page_text: reduced pressure beneath the float d is sufficient to raise it to its full
height, and so to complete the ignition. At this stage the arm u¹ changes
its vertical position for one slanting to the right, as shewn in Figure 3,
and by the pressure of its weight depresses the lever arm q', and
raises the arm q' until the main flame is fully ignited.
By means of the screw the cranked lever u may be fixed at any
angle, in accordance with the requirements of the case, so as to occupy
a horizontal position at the dead point of the weight v, as shewn in
Figure 2, or to fall below or rise above this position, as illustrated in
Figures 1 and 3. According to the angle at which this lever is fixed
the difference between the gas pressure for igniting and the one for
extinguishing the main flame'adjusts itself. For instance, the more the
arm u¹ inclines to the right the more counter pressure the weight v
exercises as against s, and the more it assists in keeping up the position
of the tube g, so that the pressure below the float d must be reduced
more and more before the weights and the float d can overcome the
force of the counterweight, and the float and the tube can be made to
redescend and extinguish the main flame. By the adjusting gear shewn
in the accompanying Sheet of Drawings, I am, thus enabled to draw a
line between the pressure required for extinguishing and that required.
for lighting the lamps, that is to say, to regulate the pressure at which
the whole or part of the lamps of a district are to be extinguished, inde-
pendently of the pressure at which they are to be lighted.
In the act of extinguishing the lamps the working of the regulating
gear is the reverse of what it is in lighting. As the float d descends
the decrease in the efflux of gas increases the pressure beneath it, and
without the working of the lever ua further decrease of the pressure
would have to take place in the pipe before the float d could descend
completely, so as to put the main flame out altogether. It is precisely
by the action of the lever u that this inconvenience is obviated. As the
arm u¹ approaches its dead point it exercises less and less counter-
pressure against the weight 8, therefore this weight presses upon the
float with increased force, and hastens its descent; and as soon as the
dead point is passed the downward motion of the float is completed, the
weight v assisting in producing this effect.
I do not mean to confine mitself to the nontioulan ama u manasti

page_text: disposition of the regulating gear shewn in Figures 1, 2, 3, and 4, as it
is obvious that the same end might be achieved by any other method
of regulation, either by means of levers, excentric wheels, or any
similar appliances, so long as the shifting of the center of gravity,
and by this means a corresponding variation in the degrees of pressure,
is effected.
In adapting the apparatus constructed according to my Invention to
private use or employing the same within public buildings, or generally
in cases where there is no great fluctuation of pressures, the appliance
herein-before described for the regulation of pressures may be dispensed
with, and the arrangement of the apparatus simplified. In these cases
the float & may be loaded with weights to a certain degree, which may
vary for different lamps, so that by turning on more or less the cock
connected with the meter or with a regulator some of the lamps may be
lighted or extinguished at one time, and some at another.
Instead of mercury I prefer in some instances to place the float d in a
bath of glycerine or other suitable liquid; in which event it would
become incumbent on me to increase the size of the apparatus con-
structed according to my Invention.
In the arrangement of the apparatus of which a longitudinal section
and an elevation are shewn in Figures 7 and 8 of the accompanying
Sheet of Drawings, I have obviated the various drawbacks connected
with the adaptation of diaphragms or membranes to private gas burners,
and which have not as yet been successfully contended with. Between
the lower plate d, beneath which the small regulator is fitted in the
same manner as in the arrangement shewn in Figures 1, 2, and 3, and
the upper plate d² I fix a circular membrane a, for which a diaphragm
made of a thin metal plate or any other suitable material may be
substituted. The lower part of this membrane or diaphragm is tied
round the base c. In this base an opening is provided into which a
plug or joint a is screwed from below through the bottom of the casing b,
whereby the base of the membrane is firmly attached to this bottom.
In this manner the membrane may be fastened or unfastened by a few
twists of the screw, and the whole apparatus be readily taken to pieces
even by an unexperienced hand. The joint a may either be screwed
directly upon the fixtures, or else, as shewn in Figures 7 and 10, it may

page_text: ..
pivot upon another conical plug a¹, which is screwed upon the fixtures.
Both joints are furnished with the requisite holes and orifices; those of
the one communicating with the casing b, and those of the other with
the gas pipes. The holes are so pierced that if the apparatus be turned
in one direction the holes coincide together, and the gas enters the
casing 6, whereas if it be turned in the other direction until it comes to
bear against a stop the gas is cut off, and can enter the casing 6 only
through a small orifice passing through both plugs or joints.
:
b
. In order to preclude every possible escape of gas I adopt the following
arrangement:-The canal e¹ passes from the casing 6 through the lid e
into the guide piece f, and joins a transversal canal h³, which commu-
nicates with the tube g. Another cross aperture 2 communicates with
the tube g opposite the canal h¹, and is connected with a canal e², which
leads into the open air. Another groove is turned upon the outside of
the tube g between the orifices w and 1. When the tube g is down this
groove is placed below the canals h¹ and h², and then the inside of the
chamber is shut off from the air. At the moment the ignition takes
place the groove ascends simultaneously with the tube, then the
canals h¹ and h² are placed in communication with one another, and the
air in, the casing is allowed to escape, thereby enabling the tube g to
complete its upward movement. When this is done the groove has
proceeded beyond the canals ¹ and ², and then the chamber bis again
shut off when the main flame is fully lighted, just as it was when the
flame was extinguished, and thus the chamber is made to communicate
with the outer air only at the moment the ignition takes place.
Having now described the nature of my said Invention, and illus-
trated the same in the accompanying Sheet of Drawings, I wish it to be
understood that I do not claim the use of automatic or self-acting con-
trivances in general for the spontaneous ignition and extinction of gas
flames, various such contrivances having been known and employed a
heretofore; but what I claim is,—
First. The use or employment of a sliding tube furnished with orifices
corresponding to a main flame, and an auxiliary or igniting flame, for
effecting the ignition of the main flame, and the extinction of the
auxiliary one upon being lifted by the increase of the gas pressure, and 3
for producing the opposite effect upon being depressed by a decrease of

page_text: diaphragm fitted with a joint or plug, as illustrated in the accompanying
Sheet of Drawings.
In witness whereof, I, the said Joseph Theodore Dann, have here-
unto set my hand and seal, this Fifth day of December One
thousand eight hundred and seventy-four.
Witness,
(L.s.) JOSEPH THEODORE DANN.
SAMUEL CHALLEN GREENFIELD,
59, Treherne Road,
Brixton,
S.W.