A New or Improved Apparatus for Giving Notice of Leakage or Escape of Gas from Gas Pipes or the like.
Year: 1889

page_text: Date of Application, 30th July, 1889
Complete Specification Left, 29th Apr., 1890-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION
A New or Improved Apparatus for Giving Notice of Leakage or
Escape of Gas from Gas Pipes or the like.
I PHILIPPE ANTOINE LEON EXUPÈRE of 71 Rue Turbigo Paris in the Republic
of France Scale Manufacturer do hereby declare the nature of this Invention to be
as follows:-
:-
This Invention relates to an apparatus for giving notice by means of an audible or
other signal of leakage or escape of gas from the pipes or burners after the gas is
turned off at the meter or main. With this object I employ a box or chamber with
flexible or elastic sides and place this box or chamber in communication with the gas
pipes in such a manner that the elastic or flexible side or sides of the box move in
response to any fluctuation or reduction in the pressure of the gas and bring into
action electric or other mechanism which rings a bell or otherwise gives notice of the
reduction of the pressure resulting from leakage or from an escape of gas through a
burner which may have been accidentally left open for example.
In the construction of an apparatus according to my Invention I provide a flexible
chamber of circular form for example with one or both sides made of thin corrugated
metal. One side of this chamber is attached by a screwed gland or flanged nut to a
hollow support through which gas is conducted to the interior of the chamber by
means of a nozzle provided with a contracted opening so as to prevent any sudden
inrush of gas on sudden opening or closing of the cocks. This nozzle may also act
as a stop limiting the inward movement of the free or moveable side of the chamber.
This side of the chamber is formed or provided at its centre with a flat part or plate
which when there is no pressure of gas in the apparatus bears against a suitable stop
such as the above mentioned nozzle. At the side of the chamber there is suspended a
carefully balanced lever provided with a screw by means of which it can be adjusted
relatively to the flexible side of the chamber and at the side of this lever there is
suspended a second lever similarly balanced and provided at its extremity with an
adjustable plate or arm carrying two pins one of which is made of non conducting
material. This second lever is electrically insulated from the support and the two
pins are situated one on each side of the first lever the adjustable plate enabling the
amount of play of the said lever between the pins being regulated according to the
amount of sensitiveness required in the instrument. Springs are provided which tend
to retain both levers in the normal or zero position when there is no pressure in the
chamber.
The chamber is emptied or relieved of pressure by means of a three way cock, which
when in one position places the chamber in communication with the gas pipe and in
another position places it in communication with the atmosphere. The plug of this
cock may also be provided with an eccentric cam or projection which operates a spring
or other contact maker and disconnects the instrument from the battery when the gas
is cut off from the chamber.
This apperatus being placed near the meter, for example or between the main cock
or valve and the burners, automatically gives a signal when the pressure falls below a
certain limit depending on the adjustment of the instrument. For this purpose the
three way cock must be turned so as to admit the gas to the flexible chamber which
expanding under the pressure causes the first lever to oscillate and come in contact
with the insulating pin on the second lever. The circuit of a battery or other source
of electricity connected to the first lever through the contact maker and the support
is thus opened and the alarm apparatus is held out of action but in case the pressure
diminishes owing to leakage, accidental opening of a burner or other cause the side of
the chamber returns towards its original position and the first lever immediately or

page_text: after an interval dependent on the adjustment, comes in contact with the conducting
pin on the second lever and by thus closing the circuit of the battery brings the alarm
or signalling apparatus into action.
The levers may be suspended so as to oscillate in planes perpendicular to or at right
angles with the side of the chamber in the latter case the movements of the side are
transmitted to the first lever by a sleeve attached to the side and provided with a
helical or inclined slot engaging with a radial pin on the axis of the first lever the
free end of which is provided with an adjustible screw which when the chamber is
expanded makes contact with the second lever and closes the circuit. These are
merely given as examples of the construction of apparatus operating according to my
Invention. The mechanism may be enclosed in a suitable case having a glass plate
on one side if required and provided with a suitable union for connecting it to the gas
pipe and having binding screws for connecting it to the wires of the battery and of
the electric hell or other alarm or signalling apparatus. This alarm or signalling
apparatus may be of any ordinary or suitable construction and in large establishments
the contact makers and alarm apparatus controlled by a number of flexible chambers
connected with different parts of the gas pipes and operating as hereinbefore described
may be collected in the managers office or other convenient position.
Dated this 30th day of July 1980
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
A New or Improved Apparatus for Giving Notice of Leakage or
Escape of Gas from Gas Pipes or the like.
I, PHILIPPE ANTOINE LÉON EXUPERE of 71 Rue Turbigo, Paris in the Republic
of France, Scale Manufacturer 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 an automatic apparatus for giving notice by means of
an audible or other signal of leakage or escaps of gas from the pipes or burners.
With this object I employ a box or chamber with flexible or elastic sides and place
this box or chamber in communication with the gas pipes in such a manner that the
elastic or flexible side or sides of the box move in response to any fluctuation or
reduction in the pressure of the gas and bring into action electric or other mechanism
which rings a bell or otherwise gives notice of the reduction of the pressure resulting
from leakage or from an escape of gas through a burner which may have been
accidentally left open for example.
And in order that my said Invention may be fully understood 1 shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheets of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents in front elevation & partly in
section an example of apparatus according to this invention.
Figure 2 represents the apparatus in vertical section the section being taken through
the axis of the flexible chamber and Figure 3 shows the apparatus partly in elevation
and partly in vertical section.
Figure 4 represents the apparatus in plan the case being in section on a line level
with the centre.
Figures 5, 6, 7 and 8 represent certain essential details hereinafter described.
This apparatus is provided with a metal box or chamber A constructed with
extremely thin sides a al corrugated in order to render them as flexible as possible.
The metal employed in its construction is preferably red copper or other suitable metal
stamped or embossed to the required shape.
This box is fixed in a case B of suitable form by means of a gland or screwed boss y
screwed into a hollow support S attached to the back of the outer case B and com-

page_text: municates through a nozzle or nipple with a tube T which is in communication with
the gas pipes through a union or branch piece provided with a tap or cock R admitting
gas to the interior of the box A.
A fine or capillary passage is formed in the nozzle a compelling the gas to enter
the metal box or chainber A slowly and preventing the violent strain on the chamber
that might otherwise result from a sudden inrush of gas on the sudden opening of the
tap. The lover hereinafter described is thus caused to act slowly on the lever l' in
place of with a sudden jerk. The nozzle is moreover screwed on in such a manner
as to enable its rounded extremity to be adjusted in contact with the side a¹ of the
chamber A when the interior of the latter is at atmospheric pressure. The side a¹
consequently always returns to the same point when the chamber is emptied of gas
this fixed starting point constituting the zero of the apparatus.
The side a of this chamber is formed with a flat projecting plate or surface b which
acts upon the balanced lever 1 figs. 1 and 7 hereinbefore referred to the said lever
being pivotted at o on a plate attached to the case B. The lower or free end of
this lever engages between two pins on an adjustable plate p (fig. 8) attached to the
insulated and balanced lever pivotted on the same plate C (figs. 1 and 6).
Between the lever and the flat part 6 of the side of the chamber there is a
screw v which enables the point of contact to be accurately adjusted.
is
This screw is situated below the fulcrum or axis of oscillation of the lever and an
opening is formed in the plate C so as to enable the screw to come in contact with the
flat surface bereinbefore referred to the parts being so adjusted that the lever
caused to oscillate by the movements of the side a¹ of the chamber A and its lower or
free extremity is thereby displaced to a corresponding extent. A spring rattached to
the plate C presses slightly on the lever so as to constrain it to partake of all the
movements of the side of the chamber resulting from either increase or decrease in
the pressure.
On the axis of the insulated is placed a small pulley n pressed by a spring
attached to an insulated pillar 7 and so adjusted as to exert sufficient pressure to cause
the balanced lever to remain in the position to which it may have been moved by
the increase or decrease of the pressure of the gas acting on the lever 1.
The lever carries the adjustable plate p hereinbefore referred to which is capable
of being adjusted on a centre and carries two pins forming a fork one pin being of
ivory or non-conducting material and the other pin being of platinum for example.
The extremity of the lever is situated between these pins and makes or breaks
the electric contact according as it is in contact with the platinum pin or with the
ivory pin.
The plate p being capable of adjustment by turning somewhat stiffly on its centre
the horizontal distance between the contacts can be regulated so that contact is not
made until the required decrease of pressure, which may be as small as possible, has
taken place.
A
The lever communicates through the body of the apparatus with a binding
screw B¹ connected with one of the poles of a battery the lever being similarly
conected by the spring ¹, conductor e, pillar and insulated binding screw B.
bell and an interrupter are provided in the circuit of this battery. The two binding
screws B1 B2 may both be insulated. In this case the first is connected to the mass
by means of a special commutator connected to the apparatus. This commutator is
formed by a large spring E attached to the binding screw B' and a cam f on the plug
of the tap or cock R controlling the supply of gas to the chamber A.
Under normal conditions when the gas tap is closed the large spring E does not
touch the casing and the current does not pass through the apparatus but when the
plug of the tap is turned to admit the gas the cam f moves the spring and places
it in contact with the case as indicated in Figure 1 thus enabling the current to enter
the apparatus.
The cock or tap R is constructed with 3 ways or passages so as to admit gas to
the elastic chamber A in one position and to place the said chamber in communication
with the atmosphere when in another position in which the gas is turned off

page_text: consequently the chamber is emptied of gas at each operation and the side a¹ and
levers and return to their original or zero position.
The apparatus for giving notice of escape of gas being thus constituted is con-
nected with the gas pipes preferably near the meter unless it is employed in a very
large supply in which case it is placed at the side of each main cock.
.
The action of the apparatus is as follows assuming that the gas is turned off at
the burners as well as at the meter or main supply cock and the cock R of the
connection is open. The act of opening this cock makes the contact which admits
the electric current to the apparatus. The pressure of the gas contained in the pipes
expands the chamber A and causes its sides a and a¹ to bulge outwards. One of these
sides (a) being fixed the whole of the movement takes effect at the opposite side (a¹)
which actuates the lever and this lever moves the lever by pressing on the ivory
pin. This condition is maintained so long as the pressure of gas remains constant
and as the circuit is open between the levers and the bell or other alarm apparatus
remains silent.
In the contrary case tha is to say if there is a leakage or if the gas has not been
properly turned off at a burner the loss of pressure resulting from the escape of
gas is immediately felt in the chamber A. which tends to contract. The lever
moving with the side a of the chamber now quickly makes contact with the platinum
or conducting pin on the lever i which has the effect of closing the circuit and
ringing the bell until the commutator tap is turned off in order to stop the alarm and
attend to the escape.
The distance traversed by the lever in moving from the platinum pin to the ivory
pin on the plate p carried by the lever can be regulated as required by turning this
plate upon its centre (Figure 3). By these means the alarm can be adjusted to
ring at any desired degree of diminution of pressure and this adjustment can be
effected at any time according to the capacity of the pipes. Moreover there is a
certainty that the alarm will always be given at a predetermined loss of pressure
because owing to the slight escape provided for by the construction of the tap R the
chamber is emptied of the gas which it contained and the levers and return to the
zero position after each alari.
Figures 9, 10 and 11 of the accompanying drawings illustrate a modified arrange-
ment of the parts of the apparatus as hereinafter explained. In this case the levers
in place of moving in a direction perpendicular to the side a of the chamber A move
in a direction parallel to the said side. This arrangement simplifies the construction
without prejudice to the accuracy of the indication given or to the sensitiveness of the
apparatus.
The transmission of movement from the side a to the lever is effected not by a
flat surface (b) as in the arrangement herein before described but by a sleeve or plate
provided with a helical or inclined slot (figure 11) engaging with a radial pin g on
the axis of the lever 1.
The lever is arranged behind the lever and oscillates on a centre lower than the
centre of oscillation of the lever on the plate being maintained between two
elastic and insulating pressures.
This lever is actuated by an adjustable screw p
carried by the lever the contact being capable of adjustment by means of the screw
so as to enable the point of contact to he regulated as hereinbefore described.
With this arrangement the apparatus being constructed with the fewest possible
parts, certain supports, cocks, springs and the like which tend to render the construction
complicated being dispensed with is reduced to its most simple form. The elastic
chamber, the gas tap, commutator etc. are the same as in the arrangement herein before
described.
The foregoing descriptions are merely given as examples of the mode of carrying
out the invention in practice, the dimensions forms and details of construction may
be modified according to circumstances and the apparatus being combined or not
with an independent interrupter or circuit breaker. This circuit breaker may be
placed on the alarm apparatus or at any other suitable point. For example in a large
establishment divided by means of cocks or valves all the interrupters and bells or

page_text: alarm apparatus can be collected together in one room (Managers room for example)
where they would show whether the gas had been properly turned off and give notice
of the existence of any escape or leakage of gas.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is:-
1. A metallic box or chamber with elastic or flexible sides enabling mechanism
suitable for actuating an electric bell or other signal to be brought into action under
the influence of a diminution of the internal pressure so as to disclose the existence
of an escape of gas from the pipes employed in supplying gas for domestic or other
consumption the said box or chamber being connected with the pipes and operating
substantially in the manner herein before set forth.
2. In apparatus for giving notice of escape of gas the combination of a metallic
box A having flexible or elastic sides a and a¹ with levers and for the purpose of
making an electric contact under the influence of a diminution of pressure resulting
from an escape of gas and actuating a bell placed in the electric circuit of the said
apparatus substantially as hereinbefore described with reference to the accompanying
drawings.
3. In apparatus for giving notice of escape of gas the mode of connecting the
box or chamber A to the supply tube T by means of a gland or nut y carrying a
nozzle with a capillary passage for the purpose of preventing a sudden inrush of
gas and regulating the action of the apparatus substantially as hereinbefore described
with reference to the accompanying drawings.
4. In apparatus for giving notice of escape of gas the arrangement of the box or
chamber A with two sides a and a one side being fixed and the other moveable the
latter normally bearing against a fixed point or stop which may be formed by the
extremity of the nozzle the said fixed point constituting the zero of the apparatus
substantially as hereinbefore described with reference to the accompanying drawings.
5. In apparatus for giving notice of escape of gas the arrangement of the balanced
lever maintained in contact with the side a of the box or chamber A in combination
with the balanced lever for the purpose of producing an electric contact under the
influence of a diminution of pressure in the said box or chamber substantially as
herein before described with reference to the accompanying drawings.
6. In apparatus for giving notice of escape of gas, in combination with the levers /
and the arrangement of the adjustable pivotted plate p attached to one of the said
levers and serving to regulate the time in which the contact is to be established for
the purpose of actuating the bell when any given reduction or loss of pressure is
obtained substantially as herein before described with reference to the accompanying
drawings.
7. In apparatus for giving notice of escape of gas the arrangement of the threeway
tap or cock for the admission of gas with one passage opening to the atmosphere
enabling the parts of the apparatus to return to their initial position when the gas
inlet is closed that is to say causing the apparatus to return to the zero point after
reference to the
each operation substantially as hereinbefore described with
accompanying drawings.
8. In apparatus for giving notice of the escape of gas the arrangement of the
gas cock or tap R in combination with the eccentric part or cam fand a spring E so
as to enable the said tap to act as a commutator the action of which is rendered
dependent on the position of the gas cock or tap substantially as herein before
described with reference to the accompanying drawings.
9. In apparatus for giving notice of escape of gas the arrangement of the levers /
and vibrating on axes arranged perpendicularly or at right angles to the side a¹ of
the box or chamber the movement being obtained with the aid of a sleeve or plate bl
provided with a helical or inclined slot acting on a pin g connected to the lever /
which also carries the adjustable device p attached to the said lever substantially

page_text: as hereinbefore described with reference to Figures 9, 10 and 11 of the accompanying
drawings.
10. The general arrangement and combinations of parts constituting the apparatus
for giving notice of escape of gas substantially as hereinbefore described with
reference to Figures 1 to 8 of the accompanying drawings.
11. The general arrangements and combinations of parts constituting the apparatus
for giving notice of escape of gas substantially as herein before described with
reference to Figures 9 to 11 of the accompanying drawings.
Dated this 29th day of April 1890.
J. H. JOHNSON & Co.,
Agents.