A NEW AND IMPROVED RHEOMETRIC REGULATOR FOR GAS BURNERS. AND IMPROVED RHEOMETRIC REGULATOR FORNER
Year: 1872

page_text: LETTERS PATENT to Henry Giroud, of Paris, Department of Seine,
in the French Republic, Merchant, for the Invention of "A NEW
AND IMPROVED RHEOMETRIC REGULATOR FOR GAS BURNERS.
AND IMPROVED RHEOMETRIC REGULATOR FOR GAS BURNERS.
PROVISIONAL SPECIFICATION left by the said Henry Giroud at the
Office of the Commissioners of Patents, with his Petition, on the
28th June 1872.
I, HENRY GIROUD, of Paris, Department of Seine, in the French
Republic, Merchant, do hereby declare the nature of the said Invention
for "A NEW AND IMPROVED RHEOMETRIC REGULATOR FOR GAS BURNERS," to he
as follows:
My improved regulator applicable to a single gas burner differs front
other regulators inasmuch that they regulate the pressure, whereas
mine regulates the quantity, wherefore I term it "The Rheometric
Regulator," or otherwise "The Rheometer."
A

page_text: My apparatus produces this rheometric action independently of
variation of the initial pressure as of variation of the final outlet orifice.
I obtain this result by the interposition on the current of a diaphragm
of any form, the weight of which causes a constant differential pressure
constant as the weight itself. This constant differential pressure acts on
a special orifice, itself constant; and these are the two elements of the
independent rheometric action above mentioned, the character and
effects will be theoretically demonstrated hereafter.
I will now proceed to describe the improvements the subject of this
Invention, reference being had to the accompanying two Sheets of
Drawing, on which-
Fig. 1 represents full size a vertical section of a glycerine rheometer,
as patented by me in the year 1870, under the No. 315, with the addition
of the conical needle A over the cap. The arrows show the direction of
the current.
The addition of the cone A renders the cross bar B useless, because
the two cones are sufficient to guide the movements of the cap, and
because the limited stoppage of the ascensional motion can be either
taken on one or the other cone. And in certain cases it may be useful
to have recourse to the two cones for correcting the action of the
variations of the initial pressure.
Fig. 2 represents the same apparatus provided only with a cone A
fixed over the cap.
This arrangement renders useless the stem C, Fig. 1, and the lower
union D, Fig. 1.
The setting up of the apparatus thus becomes easier, the introduction
of the glycerine no longer requires any preparation, and the bottom F,
Fig. 2, can easily receive a thread screw of any size.
The stem, C, Fig. 3, can be held in a cross bar placed in B, as in
Fig. 1. The complete cap with its guide is represented in Fig. 3.
A projecting part can be left in the centre of the cover and the.
simple contact of the receiver or bell with this projection is sufficient to
meet the action of the cone.
Figure 4 represents a dry rheometer, that is, with optional con-
sumption. The essential amelioration which distinguishes this arrange-
ment from that specified in my previous Patent, consists in the fact

page_text: that the solid A bears whatever is cennected with the supplementary
passage of the gas by a lateral conduit independent of the diaphragm B.
It is in this same solid part that the cylinder C, C, is made.
The manipulation and construction become thereby easier.
The apparatuses are smaller in size, especially in height..
The key of the lateral conduit is casily worked; in the Drawing it.
is formed with a screw, by screwing or unscrewing which the same
effect is obtained as if the space open for the passage of the gas round
the disc were modified. This screw can be replaced by an ordinary tap
or any suitable device.
The disc may be provided with a lower guide or with a weight forming
counterpoise. The cone can be fixed over the disc, as in Fig. 4, or
below, as in my previously patented arrangement. Every cone might
even be rendered useless by utilizing the mere contact of the disc
against the central projection of the cover. The two cones can also be
left as in Fig. 1.
In all the arrangements, the cone can be supplied by a body of any
form whatever. It matters little whether the receiver and the disc are
made of copper, aluminium, or if they are tinned like the other pieces,
or coated by the galvano-plastic, or any other process; or, in short, if
they are covered with a light metal leaf like gold, silver, tin, plate,
nickel, &c.
The reservoir or basin and its cover can be made of any kind of metal,
such as cast iron, tin, or some alloy. The choice to be made among
these different combinations depends on the nature of the gas, and
on the corrosive properties that it may borrow from its chemical
composition.
my regulator exercises or not a rheometric action.
Any apparatus constructed according to the arrangements I have.
specified fixes the consumption to a quantity that never changes, neither
through the variations of the initial pressure within the ordinary limits of
practice, nor through the substitution of a burner of one kind to a burner
of another kind, provided that in this latter case the initial pressure be
2

page_text: somewhat stronger than that required by the burner chosen to make
the consumption already mentioned.
r
I have previously stated that all the regulators hitherto known or
used are regulators of pressure, they all derive from the system in-
vented by Clegg" at the birth of gas engineering, and the following
are the principal differences that distinguish my rheometer from that
system..
It is essential in Clegg's regulator that the atmospheric pressure acts
upon the receiver.
It is essential in mine that this pressure does not act on the
receiver.
It is essential in Clegg's regulator that the gas current after having
passed through a modifiable orifice (as, for instance, in a conical valve)
to penetrate under the receiver shall flow from thence directly to the
burners.
It is essential in my apparatus that the gas current be submitted to
two distinct actions, the successive order of which is indifferent. These
two actions are exercised the one by the fixed or immovable orifice
pierced in the receiver, and the other by the modifiable orifice of the
conical valve.
As the order of succession in which these two orifices are arranged
is indifferent, it results that in my apparatus the cone can be placed
either on or under the receiver, as in the annexed Drawing. When it
is above the receiver the cone is set to form valve in the hole pierced
in the centre of the cover.
I would here observe that this last arrangement is entirely incom-
patible with Clegg's regulator, in which it would be both unrealizable
and purposeless; while, on the contrary, in my apparatus this same
arrangement in no way changes either the action or the working of the
instrument. To ascertain this perfect identity it is only necessary to
examine the two following theoretical figures, in which to simplify the
matter I represent the receiver by a disc, as in the dry rheometer,
then the annular space necessarily existing between the disc and the
cylinder that contains it plays the part of the guaging orifice bored
in the receiver. The direction of the current is shown by the arrows:

page_text: and it necessarily follows that the conc opens or closes the diaphragm
in such a way as to realize this situation, notwithstanding the variations
of P.
In the system of Fig. 6 if p changes " according to the equation (2)
changes to the same extent, and the cone opens or closes the diaphragm 5
in such a way as to preserve to the pressure p' the constant value which
it must have.
In short, in the two systems the effects are the same on each side of
the diaphragm round the cone, Thus,―
In Fig. 5 under the diaphragm P is variable.
In Fig. 6 under the diaphragm p" is variable.
In Fig. 5 above the diaphragm P" is constant.
In Fig. 6 above the diaphragm p¹ is constant.
1
If now we look at Clegg's system it will be seen that without the
modifications that I have brought to it neither the relations of pressure 1
not the fixation of volumo that I realize could be obtained.
It is true that these material modifications consist only,-
1°. In closing the apparatus with a cover, that is, in having a flow
into a closed vessel in which is effected a guaging independent of the
variations of the atmospheric pressure.
2°. In boring a hole in the receiver.
But the simplicity of these modifications increases instead of diminish-
ing the distance that separates my rheometer from Clegg's regulator,
if the practical usefulness of the two systems is brought into con-
sideration.
In the preceding I have neglected the small actions of the pressures
on the cone itself. To keep an account of them mechanically the two
systems might be combined and two cones be used, at the same time,
one below and the other above the disc.
2
2
.
An essential feature of the apparatus described in the Specification to 3
my Letters Patent of 1870, No. 315, is the cap pierced with a hole by
which the outflow of the gaseous fluid takes place under a constant
differential pressure. This differential pressure changes with the weight
of the cap, the diameter remaining the same.

page_text: I propose to utilsie this latter peculiarity to construct rheometers
working only under the night pressure, which is always stronger than
that of the day. For this purpose it is only necessary to give to the
cap sufficient weight to equilibrate the day pressure, and to add to the
apparatus a valve which closes under this pressure, and opens directly
it is exceeded. Subject to the condition of not rendering the valve
tight I can then in the morning lower all the public lamps to a mere
glimmer by a simple change of pressure without interfering with the
supply to private establishments, while in the evening I may in a
moment set all the lamps fully alight without the intervention of lamp-
lighters. These effects may even be made partial or successive within a
same district.
The Drawings, Sheet II., show the manner in which the valve above
mentioned may be joined with my ordinary glycerine rheometer.
In Fig. 1 the valve is formed by the bell or receiver A quite inde-
pendently of the rheometric cap B. The receiver A weighs, for example,
14 grammes, its diameter is 30 millimetres, so that its section is 7 square
centimetres. In these conditions an initial pressure of 20 centimetres
will be required in order that the receiver A may be in equilibrium on
the fixed cone C on which it rests. In this state the flow around the
cone C is still insufficient to keep a light at the burner.
Directly the initial pressure exceeds 20 millimetres in the hypothesis
the receiver A is uplifted, and the gas precipitates itself under the
rheometric cap to set it in operation. As to the receiver A, were it not
for the counterpressure established above it, it would come against the
rheometric cap, but it is restrained by this compression, and takes upon
the cone C such a position that whatever may be the differential pressure
which upholds it it may permit the passage of the volume fixed by the
rheometric cap..
Daylight having arrived, directly the initial pressure is lowered to
19 millimetres the bell or receiver valve A falls back on the cone, and
automatically reduces the light at the burner to the smallest jet.
D
Fig. 2 shows two rheometers set the one above the other, the first
enclosing the receiver valve A, and the second the rheometric cap B.
•
Fig. 3 is another arrangement in which the rheometric cap and the
receiver valve are united and placed in a single and same basin con-
taining as usual glycerine. In this case it is the total weight of the

page_text: receiver A and of the cap B united which has to be taken into con-
sideration, because the receiver valve no longer fulfils any rheometrical
functions, as in Figures 1 and 2.
Lastly in Fig. 4 there is no receiver valve. It is a simple ball D
which is brought back by an inclined plane upon the orifice, into which
enters the cone of the rheometric cap. The weight of the ball and that
of the cap estimated in a column of water are equal. Suppose this
weight to be 25 millimetres, so long as there is not 25 millimetres of
initial pressure the ball almost entirely closes the orifice of passage, and
the burner remains only just alight. As to the rhcometic cap it rests
at the bottom of the basin and remains immovable. Directly the initial
pressure exceeds 25 millimetres the ball is driven up the inclined plane,
the rheometric cap rises, the point of the cone prevents the ball from
coming back on the orifice, and if the burner employed does not need
more than 4 millimetres to consume the guaged volume it is only
requisite that the initial pressure should rise to 30 millimetres to cause
the burner to give its fullest flame.
These arrangements are specimens which may be summed up
thus
1°. Rheometric valve independent of the cap, and enclosed in a single
basin, Fig. 1, or in two separate basins, Fig. 2.
2°. Non-rheometric valve dependent upon the cap, and placed beneath
this latter, as at Fig. 3, as above it, as at Fig. 4.
With the addition of the valve my rheometer may be said to be an
auto-extinguisher or auto-lighter. It thus permits the lamps to be closed
so that the action of the wind need no longer be dreaded.
SPECIFICATION in pursuance of the conditions of the Letters ratent,
filed by the said Henry Giroud in the Great Seal Patent Office on
the 28th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
GIROUD, of Paris, Department of Seine, in the French Republic,
Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of June, in the
year of our Lord One thousand eight hundred and seventy-two, in the

page_text: thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Giroud, Her special licence,
that I, the said Henry Giroud, my executors, administrators, and assigns,
or such others as I, the said Henry Giroud, my executors, adininistrators,
and assigns, should at any time agree with, and no others, from time to
time and 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 Ireland, the Channel Islands, and Isle of
Man, an Invention for "A NEW AND IMPROVED RHEOMETRIC REGULATOR FOR
GAS BURNERS," upon the condition (amongst others) that I, the said Henry
Giroud, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Giroud, 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 :—
My improved regulator applicable to a single gas burner, patented
under the No. 315, A.D. 1870, differs from other regulators inasmuch
that they regulate the pressure, whereas mine regulates the quantity,
wherefore I term it "The Rheometric Regulator," or otherwise "The
Rhicometer."
My apparatus produces this rheometric action as independently of
variation of the initial pressure as of variation of the final outlet orifice.
I obtain this result by the interposition on the current of a diaphragm
of any form, the weight of which causes a constant differential pressure,
constant as the weight itself; this constant differential pressure acts on
a special orifice, itself constant, and these are the two elements of the
independent rheometric action above mentioned, the character and effects
of which will be theoretically demonstrated hereafter.
I will now proceed to describe the improvements the subject of this
Invention, reference being had to the accompanying Sheet of Drawing.
I.

page_text: to penetrate under the receiver shall flow from thence directly to the
burners.
It is essential in my apparatus that the gas current be submitted to
two distinct actions, the successive order of which is indifferent. These
two actions are exercised the one by the fixed or iminovable orifice a
pierced in the receiver, and the other by the modifiable orifice of the
conical valve.
As the order of succession in which these two orifices are arranged is
indifferent, it results that in my apparatus the cone can be placed either
on or under the receiver, as in the annexed Drawing. When it is above ]
the receiver the cone is set to form valve in the hole pierced in the
centre of the cover.
I would here observe that this last arrangement is entirely incom-
patible with Clegg's regulator in which it would be both unrealizable
and purposeless. While on the contrary in my apparatus this same ]
arrangement in no way changes either 'the action or the working of the
instrument. To ascertain this perfect identity it is only necessary to
examine the two following theoretical figures in which to simplify the
matter I represent the receiver by a disc as in the dry rhcometer, then
the annular space necessarily existing between the disc and the cylinder a
that contains it plays the part of the guaging orifice bored in the receiver.
The direction of the current is shown by the arrows.
The two burners are supposed to have the same consumption.

page_text: between two pressures, the difference of which is constant.
In fact, let
us suppose the apparatus to be in equilibrium, if it be so it is because
there will be equality of action between the forces acting from the
bottom upwards and between those acting from the top downwards..
These forces are:—

page_text: If now we look at Clegg's system it will be seen that without the
modifications that I have brought to it neither the relations of pressure
nor the fixation of volume that I realize could be obtained.
It is true that these material modifications consist only,-
1°. In closing the apparatus with a cover, that is, in having a flow
into a closed vessel, in which is effected a guaging independent of the
variations of the atmospheric pressure.
2º. In boring a hole in the receiver.
But the simplicity of these modifications increases instead of diminish-
ing the difference between my rheometer and. Clegg's regulator, if the
practical usefulness of the two systems is brought into consideration.
In the preceding I have neglected the small actions of the pressures
on the conc itself. To ascertain them mechanically, the two systems
might be combined and two cones be used at the same time, one below
and the other above the disc.
A theoretical study of the neglected perturbations or commotions
would demand a knowledge of the manner in which the gas flows round
the disc and the cone. It is certainly not the same here as for a con-
sumption through a thin partition or an adjutage; it is probable that it
is something analogous to an outflow through capillary slits. To study
this thoroughly it would even be necessary to consider according to the
mechanical theory of heat, the heat absorbed or transferred in the
changes of pressure of the gas, but not only would such a study be of
little practical use, but would be very difficult to calculate. It will
therefore be evident that in practice it would be difficult to distribute
the regulating action exactly between the two cones, because if one of
the cones first exercises this action, it does so completely, and the other
then serves only as a guide.
Comparison between the two systems of regulators applicable to a
single humou

page_text: and enumerated in paragraphs I., II., III. and IV. of this Specification
substantially as set forth.
An essential feature of the apparatus described in the Specification
to my Letters Patent of 1870, No. 315, is the cap pierced with a hole
by which the outflow of the gaseous fluid takes place under a constant
differential pressure. This differential pressure changes with the weight
of the cap, the diameter remaining the same.
I propose to utilise this latter peculiarity to construct rhcometers
working only under the night pressure which is always stronger than
that of the day. For this purpose it is only necessary to give to the
cap sufficient weight to equilibrate the day pressure and to add to the
apparatus a valve which closes under this pressure and opens directly it
is exceeded. Subject to the condition of not rendering the valve tight
I can then in the morning lower all the public lamps to a mere glimmer
by a simple change of pressure without interfering with the supply to
private establishments, while in the evening I may in a moment set
all the lamps fully alight without the intervention of lamplighters.
These effects may even be made partial or successive within a same
district.
The Drawings Part II. show the manner in which the valve above
mentioned may be joined with my ordinary glycerine rheometer.
In Figure 1 (Part II.) the valve is formed by the bell or receiver A,
quite independently of the rheometric cap B. The receiver A weighs for
example 14 grammes, its diameter is 30 millimetres so that its section
is 7 square centimetres. In these conditions an initial pressure of
20 centimetres will be required in order that the receiver A may be
in equilibrium on the fixed cone C on which it rests. In this state
the flow around the cone C is still insufficient to keep a light at the
burner.
Directly the initial pressure exceeds 20 millimetres in the hypothesis
the receiver A is uplifted and the gas precipitates itself under the
rheometric cap to set it in operation. As to the receiver A were it not
for the counter pressure established above it, it would come against the
rheometric cap, but it is restrained by this compression and takes upon
the cone C such a position that whatever may be the differential
pressure which (upholds it, it may permit the passage of the volume
fixed by the rheometric cap.

page_text: Daylight having arrived directly the initial pressure is lowered to
19 millimetres, the bell or receiver valve A falls back on the cone and
automatically reduces the light at the burner to the smallest jet.
Figure 2 (Part II.) shows two rheometers set the one above the other;
the first enclosing the receiver valve A, and the second the rheometric
cap B.
Figure 3 is another arrangement in which the rheometric cap and
the receiver valve are united and placed in a single and same basin,
containing as usual glycerine. In this case it is the total weight of
the receiver A, and of the cap B united, which has to be taken into
consideration, because the receiver valve no longer fulfils any rheo-
metrical function as in Figures 1 and 2,
Lastly, in Figure 4 there is no receiver valve; it is a simple ball D,
which is brought back by an inclined plane upon the orifice into which
enters the cone of the rheometric cap. The weight of the ball and
that of the cap estimated in column of water are equal, suppose this
weight to be 25 millimetres, so long as there is not 25 millimetres of
initial pressure, the ball almost entirely closes the orifice of passage and
the burner remains only just alight. As to the rheometric cap it rests
at the bottom of the basin and remains immovable. Directly the
initial pressure exceeds 25 millimetres the ball is driven up the inclined
plane, the rheometric cap rises, the point of the cone prevents the ball
from coming back on the orifice, and if the burner employed does not
need more than. 4 millimetres. to consume the guaged volume it is
only requisite that the initial pressure should rise to 30 millimetres to
cause the burner to give its fullest flame.
These arrangements are specimens which may be summed up
thus-
1°. Rheometric valve independent of the cap and enclosed in a single
basin Fig. 1, or in two separate basins Fig. 2.
2°. Non-rheometric valve dependent upon the cap and placed beneath
this latter as at Fig. 3 (Part II.), or above it as at Fig. 4, Part II.).
With the addition of the valve my rheometer may be said to be an
auto-extinguisher, or auto-lighter. It thus permits the lamps to be
closed so that the action of the wind need no longer be dreaded.
i

page_text: I also claim as secured. to me by the hercin-before in part recited
Letters Patent,—
The use of rhcometers arranged substantially as herein-before described
and illustrated Figures 1, 2, 3 and 4 (Part II.) of the Drawing and for
the purposes hercin-before set forth.
In witness whereof, I, the said Henry Giroud, have hereunto.set my
hand and seal, this Twenty-fourth day of December, in the year
of our Lord One thousand eight hundred and seventy-two.
Witnesscs,
LOUIS ROBINS,
JEAN BAPTISTE GIRARD.
H. GIROUD.
(L.S.)