IMPROVEMENTS IN GAS GOVERNORS
Year: 1880

page_text: LETTERS PATENT to William Cowan, of Edinburgh, in the County of Mid
Lothian, North Britain, for an Invention of "IMPROVEMENTS IN GAS
GOVERNORS."
PROVISIONAL SPECIFICATION left by the said William Cowan at the Office
of the Commissioners of Patents on the 8th December 1880.
WILLIAM COWAN, of Edinburgh, in the County of Mid Lothian, North Britain.
"IMPROVEMENTS IN GAS GOVERNORS."
This Invention relates to improvements in gas governors, and has for its object
the application of means whereby the action or influence of the inlet pressure on
the superficial area of the base of the cone may be neutralized, and the governing
agency of the instrument be undisturbed by changes of the initial pressure.
The Invention applies to governors in which the bell is sealed by water in a tank,
and the inlet orifice is regulated by a conical plug and valve seat.
In applying the Invention there is placed on the exterior of the roof of the
governor bell a tank capable of being charged with water, glycerine, or other
suitable liquid, hereinafter called the water tank, and which may in some cases be
annular, the central chamber being closed at the top. This tank moves up and
down along with the governor bell to the outside of the roof, of which it may either
be fixed, or upon which it may simply rest. Into this water tank, whether annular
or not, there dips a bell which does not move, but is fixed to and suspended by a
cross bar or other suitable means. This moving tank with the fixed bell forms a
water slide like that of some gaseliers.
Into this fixed bell pressure from the inlet of the governor is introduced by
means of a pipe connecting the two, and as the area of the fixed bell corresponds
with the area of the base of the governor cone, it follows that the influence of the
initial pressure upon the latter will under all circumstances be balanced by an
equivalent effect produced on the former. When increased inlet pressure on the
base of the cone would tend to force it upwards, and so by lightening the bell
derange the pressure the governor was loaded to maintain, the same influence
exerted over a similar area above the roof of the governor bell will prevent the
action referred to taking place, and the adjusted pressure will therefore not be

page_text: disturbed. In like manner, when diminished inlet pressure would, by its less
supporting influence on the base of the cone, tend to increase the weight of the
governor bell, and so to derange the outlet pressure, the reduction of support to the
cone will be accompanied by a corresponding diminution of the pressure above
the roof of the governor bell, with the result that the perfect equilibrium will
remain unaffected.
In constructing governors according to this Invention, the changes introduced
would be wholly exterior, and in no way interfere with the principle or internal
arrangements of the gas governors most commonly in use. The object is to correct
by simple means applied to the exterior certain inherent defects which are known
to exist in most gas governors.
To avoid the necessity for lengthening the pillars of a governor constructed or
altered according to this Invention, the usual cross bar may be made with a ring in
the centre, through which the moving tank may pass up and down. Upon the
upper side of this ring two or more smaller pillars may be fixed, and on the top of
these there may be a disc or cross bar, to which the roof of the fixed bell may be
attached and from which it will hang downwards into the water of the moving
tank.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Cowan in the Great Seal Patent Office on the
8th June 1881.
WILLIAM COWAN, of Edinburgh, in the County of Mid Lothian, North Britain.
"IMPROVEMENTS IN GAS GOVERNORS."
This Invention relates to improvements in gas governors, and has for its object
the application of means whereby the action or influence of the inlet pressure on
the superficial area of the base of the cone may be neutralized, and the governing
agency of the instrument be undisturbed by changes of the initial pressure, and is
applied to governors in which the bell is sealed by water in a tank, and the inlet
orifice is regulated by a conical plug and valve seat, as shown in the accompanying
Drawings, Fig. 1 being a sectional elevation of an ordinary gas governor with my
Invention applied; Fig. 2, a plan of the disc attached to the top of the small pillars
of the instrument; Fig. 3, a plan of the cross bar and ring hereinafter to be
described, and Fig. 4, a sectional elevation of part of the apparatus, showing the
arrangement more particularly applicable when constructing new governors.
The Invention consists in placing on or attaching to the exterior of the roof of
the governor bell A a tank B capable of being charged with water, glycerine, or
other suitable liquid, hereinafter called the water tank, and which in some cases
may be annular, the central chamber C being closed at the top. This tank moves
up and down along with the governor bell, to the outside of the roof of which it

page_text: may be either fixed, or upon which it may simply rest. Into this water tank,
whether annular or not, there dips a bell D which does not move, but is fixed to
and suspended by a disc E, cross bar, or other suitable means. This moving tank
with the fixed bell forms a water slide, like that of some gaseliers.
Into this fixed bell gas and consequently pressure from the inlet F of the
governor is introduced by means of a pipe G connecting the two, and as the area
of the fixed bell D corresponds with the area of the base of the governor cone H
it follows that the influence of the initial pressure upon the latter will under all
circumstances be balanced by an equivalent effect produced on the former. When
increased inlet pressure on the base of the cone H would tend to force it upwards,
and so by diminishing the effect of the weight of the bell derange the pressure
the governor was loaded to maintain, the same influence exerted over a similar
area [that is, the area of the fixed bell D] above the roof of the governor bell A
will prevent the action referred to taking place and the adjusted pressure will
therefore not be disturbed. In like manner, when diminished inlet pressure would
by its less supporting influence on the base of the cone H tend to increase the
effect of the weight of the governor bell and so to derange the outlet pressure, the
reduction of support to the cone will be accompanied by a corresponding diminution
of the pressure above the roof of the governor bell, with the result that the perfect
equilibrium will remain unaffected.
To avoid the necessity for lengthening the pillars I, I, of a governor constructed
or altered to this Invention the usual cross bar J, J, Figs. 1, 3, and 4, may be made
with a ring K in the centre, through which the moving tank B may pass up and
down. Upon the upper side of this ring two or more suitable pillars L, L, may be
fixed, and on the top of these there may be a disc E, Figs. 1 and 2, or a cross bar,
to which the roof of the fixed bell may be attached, and from which it will hang
downwards into the liquid in the moving tank.
The moving tank is not necessarily annular, but may be sometimes so made in
order to reduce the constant weight the governor bell will have to carry.
The pipe G, instead of being arranged as shown [it being shown in this manner
simply for the sake of perspicuity] may be carried up from the inlet F of the
governor close to the side of the fixed tank N, and from thence up by the sides of
the pillars I and L to the top of the fixed bell, or in any other convenient
manner.
Instead of the foregoing arrangement the cone H may be pierced vertically
through its centre and suspended by a tube or pipe T, which extends from the
bottom of the cone to the inside of the central chamber C of the annular moving
tank, but in this case the top of the central chamber must be open, or the top U
may be closed and the pipe T extended, as shown in dotted lines, and caused to
project a little above the top U and in the fixed bell D. The pipe is divided at or
about the point S and a cup and ball joint interposed, so that while there is a free
passage for the gas to pass from the underside of the cone to the fixed bell D the
joint permits the cone to swing freely and accommodate itself to its seat. When
this arrangement is adopted it will be necessary to reduce the area of the fixed
bell by the area of the orifice of the pipe conveying the gas from under the cone to
the fixed bell.
In cases where the governor bell is suspended by a cord passing over a wheel,
one end of the cord being fastened to the governor bell and the other connected to
a rod whereon counterpoise weights are hung, the Invention may be applied by
having two stationary bells, one fixed on each side of the cross bar, and two water
tanks attached to the governor bell, the combined area of the tops of the two bells
being equal to the bottom of the cone.
The dotted lines O and P, Fig. 1, show the limits to which the governor bell can
either ascend or descend, while the dotted line Q shows the lowest position of the
top of the moving tank, so that the fixed bell will be at all times sealed. R shows
a number of segmental flat rings of metal that may be placed on the top of the
governor bell, but the loading or unloading may be effected by any well known

page_text: or suitable method, that produced by the weight of water admitted to a tank on
the top of the governor bell being in my opinion the best.
In constructing governors according to this Invention the changes introduced
may be wholly exterior and in no way interfere with the principle or internal
arrangement of the gas governors most commonly in use. The object is to correct
by simple means applied to the exterior certain inherent defects which are known
to exist in most gas governors.
Having now described and particularly set forth the nature of this Invention,
and the manner in which the same is or may be used or carried into effect, I would
observe in conclusion, that I do not restrict or confine myself to the precise details
or arrangements that I have described or referred to, as variations may be made
therefrom without deviating from the principles or main features of this Invention,
but what I consider to be novel and original and therefore claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is,-
Firstly. The tank B, either annular or otherwise, placed on or attached to the
governor bell, and as herein described and shown on the Drawings.
Secondly. In a gas governor, the combination with the governor bell A and the
rising and falling tank of the fixed bell D, arranged as and for the purpose described
and shown on the Drawings.
Thirdly. In a gas governor, the combination with the rising and falling tank B
of the fixed bell Ď, provided with a pipe G connected with the inlet of the governor,
as and for the purpose herein described and shown on the Drawings.
Fourthly. In a gas governor, the combination of the rising and falling tank B,
cross bar J, constructed with a ring K, the pillars L and connecting disc or cross
bar E, arranged as and for the purpose herein described and shown on the
Drawings.
Fifthly. The application of the apparatus mentioned in the foregoing claims to
existing gas governors.
In witness whereof, I, the said William Cowan, have hereunto set my hand
and seal, this Third day of June, in the year of our Lord One thousand
eight hundred and eighty one.
WILLIAM COWAN. (L.S.)