IM- PROVEMENTS IN APPARATUS FOR REGULATING THE PRESSURE OF GAS
Year: 1861

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IM-
PROVEMENTS IN APPARATUS FOR REGULATING THE PRESSURE OF GAS."-A con-
munication from abroad by Henri Girond, of Paris, in the Empire of
France.
Sealed the 31st October 1861, and dated the 30th May 1861.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
30th May 1861.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR REGULATING THE PRESSURE OF GAS," a com-
munication from abroad by Henri Girond, of Paris, in the Empire of France,
to be as follows:-
This Invention relates to a peculiar construction and arrangement of self-
acting electric apparatus for regulating the pressure of gas in mains or service
pipes, and consists in the use of two separate pieces of apparatus working in
conjuction with each other, the one piece of apparatus being placed in some

page_text: central position in the locality supplied by the works, whilst the other is
situate at the place where the gas is manufactured. The first-mentioned
piece of apparatus consists of a float manometer or pressure guage, the needle
or indicator of which is so constructed that one of its branches dips into one or
other of two vessels containing mercury whenever the pressure varies in the
slightest degree from its regulated or desired amount. Two conducting wires
connected severally to the vessels of mercury extend to the gas works, and the
needle of the manometer being in communication with one of the poles of a
battery, the other pole of which is in connection with earth, it follows that
each time the pressure varies, one of the branches of the needle enters into one
of the vessels of mercury, and establishes an electric communication with the
gas works. The second piece of apparatus placed at the gas works consists of a
hydraulic valve placed on the mouth of the main, which conducts the gas from
the gas-holder, such valve being opened or closed by an arrangement of
wheelwork actuated by a weight and double gearing. Two electro-magnets,
attached one to each wire, are so adjusted' in the apparatifs as to act upon the
starting or reversing lever of the wheelwork, and according as one or the
other of these magnets is excited, the lever will be brought into two opposite
positions, or will remain in a central position, when both magnets are un-
excited, and the valve will be either elevated, depressed, or held stationary
accordingly. By a slight modification of the manometer it may be transformed
into a commutator, in which case one conducting wire only in place of two
would be required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
30th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gen-
tleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of May, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fourth year of Her reign,
did, for Herself, Der heirs and successors, give and grant unto me, the said
John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I,
the said Jolm Henry Johnson, my executors, administrators, or assigns,

page_text: 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 Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN APPARATUS FOR REGULATING THE PRESSURE OF GAS," a com-
munication from abroad by Henri Girond, of Paris, in the Empire of France,
upon the condition (amongst others) that I, the said John Henry Johnson,
my executors or administrators, by an instrument in writing under my hand
and seal, or under the land and seal of one of them, 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 John Henry Johnson, do hereby declaro
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:
The said Invention relates to a peculiar construction and arrangement of
O self-acting apparatus for regulating the pressure of gas in mains or servico
pipes, and consists in the use of two separate apparatus working in conjunction
with each other, the one piece of apparatus being placed in some central
position in the locality supplied by the works, whilst the other is situate at the
place where the gas is manufactured. The first-mentioned piece of apparatus
consists of a float or pressure guage or indicator, the needles of which are so
constructed that one of their branches dips into one or other of two vessels
containing mercury, or establishes in any equivalent manner an electric contact
whenever the pressure varies in the slightest degree from its regulated or
desired amount. Two conducting wires connected severally to the vessels of
mercury or contact surfaces, as the case may be, extend to the gas works,
and the needle of the indicator being in communication with one of the poles
of a battery, the other pole of which is in connection with earth, it follows
that each time the pressure varies one of the branches of the needles esta-
blishes an electric communication with the gas works. The second piece of
5 apparatus placed at the gas works consists of a hydraulic valve or regulator
placed on the mouth of the main, which conducts the gas from the gas-holder,
such valve being opened or closed by an arrangement of wheelwork actuated
by a weight and double gearing. Two electro-magnets, attached one to each
wire, are so adjusted in the apparatus as to act upon the starting or reversing

page_text: lever of the wheelwork, and according as one or the other of these magnets is
excited, the lever will be brought into two opposite positions, or will remain in
a central position when both magnets are unexcited, and the valve will be
either elevated, depressed, or held tationary accordingly. By a slight
modification of the pressure indicator it may be transformed into a com-
mutator, in which case one conducting wire only in place of two would be
required.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheets of Drawings hereunto annexed,
the same letters of reference indicating corresponding parts throughout all
the corresponding Figures.
Figure 1 on Sheet 1 of the Drawings represents the apparatus which is
intended to be established at the place where the gas is manufactured; it
consists of a bydraulic valve and equilibrium bell. Figure 1, a represents the
apparatus, which is to be placed in some central position in the locality sup-
plied by the works. It consists of a pressure indicator and regulator, which
regulates by the aid of electricity the position of the hydraulic valve at the
works. Figure 2 is a plan of Figure 1; Figure 3 represents a plan of the
battery employed, and Figures 4 and 5 represent in vertical section and plan
a modified form of equilibrium bell capable of moving the valve by the return
of the gas. itself, thereby dispensing with wheelwork and electric agency, as
herein-after described.
Figures 1, 2, and 3 on Sheet 2 of the Drawings represents respectively.a
front and side elevation and plan drawn to a scale of one-half the full size of
the reversing contact pieces shown in Figures 4 and 5 of the same Sheet..
Figures 4 and 5 represent two vertical sectional views of the apparatus, showing
the gas pressure indicators and the reversing contacts, as well as the three-
way cock which receives the return gas; and Figures 6, 7, and 8 represent
respectively a front elevation, a plan, and a side elevation of the wheelwork,
drawn to a scale of half the real dimensions. So soon as the valve of the.
gasometer is opened the gas will arrive by the pipe A (Figure 1, Sheet 1)
underneath the inverted vessel or chamber B, which is supported at four
From this chamber the gas
points in its circumference in the water tank C.
passes inside the suspended bell D in order to become distributed through the
mains by passing down the pipe E. The bell D is a cylindrical vessel closed
at its upper end, and suspended from an oscillating beam or lever overhead.
When it is lowered by the movement of the lever, so as to rest upon the
pipe E, it establishes a bydraulic joint or seal, when the gas will no longer pass

page_text: into the mains; and in order to prevent the entrance of air through the
aperture in the vessel B, through which the rod of the bell D works, this rod
is itself provided with a water joint or seal, as shewn. When the bell D is
elevated the gas escapes by the triangular openings made therein, the
aggregate area of which should be equal to the area of the mouth of the
service main. In the locality. where the consumption of gas is greatest, a
small pipe of not less than one inch bore (the diameter of the bore being
greater in proportion to the length of the pipe) is connected to the main.
This pipe extends to the gas manufactory, and is in communication with an
indicator F, when the gas remains in a stagnant condition or state of rest, so
that any variation of pressure in the locality supplied is instantly indicated at
the works by a species of concussion or commotion in the column of gas in the
pipe, but unattended by any great displacement. The float of the indicator
thus receives a slight movement, which is transmitted to tho pulley of a
reverser G placed above it. This pulley carries two needles or indicators,
which communicate with the two poles of the battery L, and slide over a
metallic dial, which is divided into two semicircles insulated from cach other
by a thin strip of ivory. A conducting wire connects the upper semicircle
and the wheelwork I forming the return wire, whilst the lower semicircle com-
municates with earth. The wheelwork is provided with a lever actuating a
bevel wheel reversing gear which drives a wheel, of which the nut of the screw
forms the pivot, so that this wheel turns first in one direction and then in the
contrary direction according to the position of the bevel gearing, which is
determined by the position assumed by the lever under the influence of two
electro-magnets. When the gas in the locality to be lighted is at the proper
pressure, the two needles of the reverser rest upon the strip of ivory, in which
position the apparatus will remain at rest. If the indicator of the pressure of
the return gas in the small pipe descends, the left-hand needle will rise on to
the upper semicircle, and the right-hand needle will descend on to the lower
semicircle, thereby closing the circuit. The current of electricity now elevates
a detent, which arrests the fly wheel of the gearing or wheelwork, and at the
same time so acts upon the reversing gear as to cause the screw spindle to
descend and open the gas valve. If, on the other hand, the indicator rises,
the reversing gear is acted upon in the contrary direction, and the gas valve is
closed. Should the return pipe be extended to the gas works, a Daniell's
battery of six cells may be used; but this number should be augmented if,
for the purpose of reducing the length of the pipe, the indicators and their
accessories be situate in the locality to be lighted; for, in that case, the wire
will be carried to the gas works, and connceted to the gearing placed by the

page_text: side of the gas exit valve. It is convenient to adopt this arrangement in
order to have a more rapid transmission of the indications than could be
obtained from the gas when the distance between the locality lighted and the
works is considerable. When the return pipe is used extending from the
centre of the locality lighted to the gas works, the wheelwork or gearing and
electric current may be both dispensed with, the gas valve D being then
actuated directly by the return gas itself. For that purpose the slight modifi-
cation of the equilibrium bell M shown in Fig. 4 may be adopted, but this
will entail the use of a return pipe of five inches bore, which will considerably
increase the expense of the apparatus.
I will now proceed to describe the wheelwork illustrated by Figures 6, 7, 8,
and 9, on Sheet 2 of the Drawings. This wheelwork is driven by a weight
acting directly upon the drum or barrel A. The movement of this barrel is
transmitted by the toothed wheels to the spindle B, and thence to the fly
wheel C, the speed of which may be at the rate of one half to two revolutions
per second, as required. Upon the axis of the fly wheel is placed with very
slight friction the rod D, connected to this axis by a spring E, and serving to
stop the wheelwork, when on turning with the fly wheel it encounters the
rod F. The fly wheel will then make a quarter or a half backward revolution;
which movement is necessary for disengaging the sliding reversing clutch G,
and holding it in a position suitable for receiving the impulse imparted to it
by the rod at the moment of the passage of the electric current. The rod F
works on the axis d, which carries a bar of soft iron T, attracted by the
electro-magnets c and f. The upper end of the rod F slides freely in a slot
in the piece g, which limits its forward and backward movement. The spring h
tends constantly to bring back the rod Fagainst the pivot i so soon as the
electric current ocases its action. The screw spindle I is connected at its lower
end with the equilibrium bell, and at its upper extremity with the balance
lever of the gas valve or regulator D (see Figuro 1, Sheet 1), in such a
manner as to be incapable of turning, and the nut J of the screw is fitted to
turn freely in a suitable opening in the frame, being maintained therein by a
shoulder placed above it, and by a nut K and counter-nut L below it. Upon
the shoulder is fitted a stop which serves to ensure the rotation of the nut
with the wheel M. The spindle B carries two bevel wheels N, O, shown more
clearly in the enlarged detail (Figure 9), both of which gear into the bevel
wheel P. The wheels N and O are both loose upon the spindle B, but either
of them may be coupled therewith by bringing the clutch G in contact with one
or the other of them. This clutch slides freely along a feather on the spindle,
and consequently turns with it. It is provided with suitable teeth or projec-

page_text: tions R on each side, which interlock into corresponding recesses or notches
formed in the bosses of the wheels N and O, thereby causing one or other of
these wheels to be carried round by and rotate in the direction of the spindle B.
The two shoulders S serve to prevent the wheels from coming out of gear.
By this arrangement the wheel P will be rotated in either direction according
to the position of the clutch G, and by transmitting its motion to the wheel M
and nut J, will cause the rod or screw spindle I to rise or fall accordingly.
The movement of the clutch G is effected by the rod H, which works on the
spindle b, and is provided at its lower end with a permanent steel magnet c¹,
and is maintained in a vertical position by means of the springs 1, m, carried
on the ends of the cross bar or arm a fixed to the rod H. Supposing a posi-
tive electric current to be passing through the electro-magnets c, f, the rod F
by being drawn back will release the stop D, when the wheelwork will be
set in motion. At the same time the electro-magnets p, o, will become
excited, and will move the permanent magnet c' to the right, for example,
which motion, by imparting a corresponding movement to the rod H, will cause
the clutch G to be moved towards the left or bevel wheel N, which will be
set in motion and will rotate the wheels P and M in such a direction as to
cause the screw spindle or rod I to ascend. Should a negative current pass
through the electro-magnets, the magnet c¹ will be moved to the left, and the
clutch, by bringing the bevel wheel O into action, will reverse the motion of the
wheels P and M, and will cause the spindle L to descend. The rod F will in
both cases be acted upon as the plate or armature T consists simply of a
piece of soft iron.
I shall now proceed to describe the pressure indicators and reversors,
reference being bad to Figures 1, 2, 3, 4, and 5 on Sheet 2 of the Drawings.
As in nearly all gas manufactories the gas is supplied at two different pressures
during the night, it will be advisable to have two separate indicators, into either
of which the gas and electric current can be readily directed. For this purpose
a suitable chamber or box is used, in the lower compartment of which is securely
fitted a three-way cock A (Figures 4 and 5), which receives the return gas
by the branch B, and directs it by the branches C, C, to one or the other
of the two small pressure indicators D, D¹. According as the rod fixed to the
key of the cock is in the positions shewn in dotted lines A, E, or A, E', if it
be in the central position A, E", the gas is shut off entirely. Upon a pro-
longation of the plug of the cock is fitted a wooden disc F, turning freely with
it in a circular aperture in the back of the case, and carrying two copper
strips or blades, which form a communication for directing the electric current
of the battery alternately to either of the two contacts 1, 2, situate in the

page_text: upper compartment of the case. This communication with the contacts is
effected through the copper plates, which form the feet of the contact appa-
ratus, the two plates H, H, (shewn more clearly in Figures 1, 2, and 3,)
communicating also with the battery, whilst the plates J. J', communicate
with the wheelwork for actuating the gas valve.
In the Drawings the gas is supposed to be entering the indicator D, and
the electric current to be passing through the contact apparatus 1, placed
above it. If the key of the cock be brought to the position A, E, the gas
and the electric current will simultaneously change their course, the one being
directed into the indicator D, and the other passed through the contact 2..
On bringing the key of the cock into the central position A, E, the gas will
be entirely shut off, and the electric circuit will be interrupted. Upon each
float of the indicators is fixed rigidly a vertical rod or spindle, which slides
freely through a hole made in each cover at K. On the upper end of each
rod is a headed pin, round which is wound a cord, which actuates the contact
mechanism above, provision being made for adjusting the needles M and N
to the position indicated by zero when the floats are acted upon by the proper
gas pressure, or when it is desired to vary the pressure. The pullies L of the
contacts, and by which they are actuated, are composed of ivory or other non-
conducting material, and its axis is made in two parts, as shewn in Figure 2,
cach part communicating through its bearings or supports with one of the
wires of the battery. For this purpose the copper plates upon which these
bearings or supports are fixed are each in communication with the plates
II, H from each half of the axis the current passes through the needles.
The needle M is for this purpose fixed to the collar or flange P by means of a
piece of ivory, and it is connected to the collar Q by two screws which are not
in contact with the collar P. These two needles are provided at their extre-
mities with small platinum points, which, when the pulley turns on its axis,
rub over the surface of the copper circle R, secured by screws to the support S.
In order to render this friction as slight as possible, two adjusting screws are
tapped into the pulley, and cause the needles to bear upon the circle with the
exact amount of friction necessary. This circle has four saw cuts made in it
at the points T, T, and T', T', which cuts are filled with slips of ivory smoothed
off flush with the surface, so as to offer no resistance to the passage of the
needle points over them. The two small sections of the circle are in com-
munication with each other by means of a wire a, which extends also to the
plate J, and thence to the wheelwork, whence it returns to the plate J', which
is itself in communication with the lower portion of the circle by the wire b.
The upper portion of the circle R may be placed in communication at will,

page_text: either with the wire a or with another wire c, in connection with an alarm or
signal bell, and thence returning to the lower portion of the circle.
In order to regulate the working of the contacts, it is necessary, first, to shut
the cock A by bringing the key into the vertical position A, E"; the two cocks d
of the indicators over them are then opened, when the floats will descend to the
point marked zero. By winding up the cord of the float rod round the pin f,
the right-hand needle will descend to the numbered graduation or division in
the lower part of the circle, which corresponds to the amount of pressure it is
desired to maintain. The moveable needle X is adjusted by hand to the zero
on the right of the dial. This needle, when the apparatus is in action, serves
to indicate the pressure under which the apparatus is working; the first
indicator may thus be adjusted to one degree of pressure, and the second
indicator to another degree of pressure. The whole having been thus adjusted,
and the upper portion of the circle in communication with the wire passing
through the two small sections u, u, if the key of the cock be brought in to tho
position A, E, the return gas will enter into the indicator D, and will raiso
its float, the pulley L of the corresponding contact 1 above it is turned
slightly, and the needles will approach the horizontal line drawn across the
diameter of the circle R. Supposing the pressure of the return gas be lower
than is desired, as the right-band needle touches the lower portion of the
circle, and the left-hand needle touches the per portion of the circle, the
circuit will be established. A negative current will pass through the wire to
the wheelwork, which effects the further opening of the gas valve. The
pressure in the locality will thus be increased, and a corresponding increase of
pressure will be imparted to the return gas, which causes the pulley to again
turn from right to left, until the needles are brought into a horizontal position,
when by one of the needles resting upon the slip of insulating medium inserted
into the saw cut in the circle above referred to, the apparatus will remain at
rest. If, on the contrary, the pressure becomes too great, the right-hand
needle will move into the section u, whilst the left-hand needle will come in
contact with the lower portion of the circle, the circuit will be again established,
and a positive current directed through the wheelwork, which closes, or
partially closes the gas valve. If the communication between the circle R
and the small sections or segments u be interrupted, and communication
means of an
established with the conducting wire of the electric bell
ordinary commutator Y, should any change of pressure by any chance take place
beyond the powers of the action of the wheelwork, the apparatus will cease
to operate, and the bell being sounded will call the attention of the attendants
or manager of the works. Thus by these arrangements the regulating of the

page_text: Light pressure is effected simply by bringing the lever or key Z (Figure 5) of
the three-way cock into the position A, E; and if the pressure is to be instantly
altered, this is effected by reversing the lever, and bringing it into the position
A, E'; and in the morning at those works which do not supply gas during the
daytime, the lever is brought into the position A, E". In order that the
wheelwork may operate with a regular speed, and produce the same amount
of motion in the same space of time in the gas valve, it is necessary that this
valve be maintained in a perfect state of equilibrium, which is accomplished in
the following manner:-A small bell M (Sheet 1 of the Drawings), of a
cylindrical form like the valve D, and of the same diameter, is fixed to the
bottom of the screw spindle of the wheelwork. The gas which is delivered in
the locality under various pressures, and which exerts upon the valve Da
variable effect from below upwards acts. in a similar manner upon the bell M,
into which it is directed by the small pipe S. The parts being all disposed
with a view to the preservation of the equilibrium, it is simply necessary to
apply a weight to one or the other side of the centre of the lever or beam; the
annular space T formed on the equilibrium bell is intended for the reception
of shot for this purpose. In works where several gasometers are employed,
it is necessary to attach to the right limb of the beam or lever a small plate,
which is destined to receive the particular weights required by each of the
gasometers as they are successively brought into use. In order to allow for
the variation in the weight of the moving parts arising from their different
degrees of immersion in the water, it is simply necessary to place vertically in
a vessel filled with water two rolls of metal of the thickness and form of the
immersed cylinder; then rolls are attached to the extremities of the beam or
lever. The modified form of equilibrium bell herein-before referred to
consists in placing round the equilibrium bell M, shewn in Figures 4 and 5
(Sheet 1), a concentric bell N, and in correspondingly increasing the diameter
of the outer vessel or tank R', and to enlarge the diameter of the return pipe,
and to cause it to open into the annular space surrounding the inner bell, as
shewn in the Drawings. If a sufficient weight be now placed upon the
bell N to balance any pressure of the return gas, it is obvious that if this
pressure varies, the gas valve will be raised or lowered until the original
pressure be re-established. The wheelwork and electricity may under such
circumstances be dispensed with, but it will be necessary in order to obtain
perfect accuracy that the equilibrium be perfect, and for that purpose it will be
advisable to suspend the balance lever or beam upon knife edges at its working
centres or points.
Having now described and particularly ascertained the nature of the said

page_text: Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is, the general construction, arrangement,
and combination of self-acting apparatus for regulating the pressure of gas, as
herein-before described and illustrated by the Drawings.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Twenty-ninth day of November, One thousand
eight hundred and sixty-one.
J. HENRY JOHNSON. (L.S.)