IMPROVEMENTS IN GOVERNORS FOR CONTROLLING STEAM ENGINES OR OTHER MOTORS
Year: 1884

page_text: I PETER WILLIAM WELLANS of Thames Ditton in the County of Surrey Engineer
do hereby declare the nature of my invention for "IMPROVEMENTS IN GOVERNORS
FOR CONTROLLING STEAM ENGINES OR OTHER MOTORS" 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 governors for controlling steam or other motors and
consists especially in improvements on a governor formerly invented by me but
now well known.
I will describe first the improved governor as I now prefer to construct it and
will afterwards point out the features of novelty which are the object of my present
Patent application.
My improved governor is caused to operate by an electric current derived from
a dynamo driven by the motor. The governor consists of a solenoid through the
coils of which the electric current flows. Within this solenoid there is a core
suspended by a helical spring. The core is connected by a rod to an equilibrium
valve which is contained within the hollow rod of a piston working in a hydraulic
cylinder. From this piston rod there is again suspended a double piston throttle
valve regulating the flow of steam or other fluid to the motor.
The equilibrium valve mentioned above consists of a tube with two pistons
upon it and water is admitted as hereinafter described to the spaces between these
pistons and the valve controls the passage of the water to and from the hydraulic
cylinder.
In order that the valve may move with but little friction, each of the valve
pistons is reduced to a pair of discs or flanges upon the cylindrical body of the
valve; it is only at its upper and lower ends that each piston comes into contact
with the hollow piston rod within which it works.
The throttle valve connected with the hydraulic piston takes the form of a
double piston working in a cylinder.
The inlet for the steam or fluid passing to the motor, is by passages through the
walls of this cylinder and so it enters the space between the two parts of the
double piston valve; from thence it escapes by apertures in the pistons and so
passes on by the open ends of the valve cylinder to the steam or feed pipe of the
motor.
In its mean working position the upper piston of the throttle valve partially
covers the passages by which the steam enters the valve cylinder.
If the current through the coils of the solenoid should increase the throttle valve
descends thereby closing the steam admission passages to a greater extent. On
the other hand should the current become less the throttle valve is raised and the

page_text: passages for the admission of steam to the motor will be wider opened, whereby
the speed of the motor will be increased, the dynamo will be driven at a higher
speed and the falling off in current will be compensated.
If however the current in the circuit should more or less completely fail as
would result from the breakage of the circuit wire then, in place of the ports being
wider opened for the admission of steam to the motor, these ports are entirely
closed, this is effected by the lower portion of the double piston of the throttle
valve which by the higher rise of the solenoid core and consequently of the throttle
valve is caused to cover the ports in the throttle valve cylinder. There is only one
position of the throttle valve in which it allows fully steam to pass to the motor.
If from this position the throttle valve descends the ports are partially closed by
the upper piston of the throttle valve.
If on the other hand the throttle rises from this position, then again the ports
are closed by the lower piston of the valve.
In order that my said invention may be most fully understood and readily
carried into effect, I will proceed to describe the drawing hereunto annexed.
DESCRIPTION OF THE DRAWING.
The drawing shows a vertical section of a governor constructed in accordance
with my invention.
a is the cylindrical coil or bobbin of the solenoid through which the current to
be regulated passes. The bobbin a surrounds a brass tube b which forms a part of
the frame of the apparatus. For the purpose of adjustment the coil a can be
moved a short distance longitudinally upon the tube b by means of the adjusting
screws c.
At the upper end of the tube b there is a cover c¹, through which a screw stem d
passes. The stem d¹ serves for the suspension of the helical spring d, and by the
nut d the point of suspension can be raised or lowered. e is the solenoid core; it
is cylindrical and of soft iron; the spring d passes down within it to a hook at its
lower end, the stem of the hook is screwed.into the closed end of the core and a
rod fis connected to it. The rod f serves to suspend the hydraulic equilibrium
valve g-this valve is contained within the hollow rod h¹ of the hydraulic piston h
the upper end of the hollow rod h¹, into which the rod ƒ enters, serves as the outlet
for the water from the hydraulic cylinder, and it is conveniently arranged so that,
the water may be led away by a flexible pipe attached at the nozzle h².
is the hydraulic cylinder and the entrance for the water under pressure
which serves to give movement to the throttle valve, this water passes through the
side of the cylinder into the cavity h³ enclosed between the two ends of the
piston h and the walls of the cylinder; from this cavity the water passes by radial
passages to the cavity g¹ of the valve. between the two valve pistons.
g and g are respectively the upper and the lower valve pistons, each of them,
as will be seen, consists simply of a pair of rings or flanges upon the tubular body
of the valve. The construction of the valve pistons in this manner is important
for if the pistons were cylindrical from top to bottom the friction of the valve in
moving would be very much greater. In the position in which the valve is
represented in the drawing the upper piston is covering the ports in the side of
the rod h¹, and the lower piston is similarly covering ports he in the side of the rod.
If the valve be lowered the ports and will both be opened, water will then be
able to flow from the central cavity of the valve through the ports to the upper
side of the piston and also from the under side of the piston through the ports *
and so to the outlet at 2. If the valve g be raised the action is in all respects
similar except that now water passes from the central cavity of the valve by the
ports to the under side of the cylinder and escapes from the upper side of
the piston by the ports he to the outlet at 2, the piston consequently rising.
The throttle valve consisting of the pistons partakes of the movements of the
hydraulic piston with which, through its rod it is connected.

page_text: is the cylinder of the throttle valve; it has steam inlets in its sides by
which the steam enters between the pistons k¹² the steam passes through
apertures in these pistons and so to the passage m leading to the motor, or the
direction of the flow of the steam may be reversed; it may enter the throttle
valve cylinder at the ends and escape by the apertures in the sides.
The valve as shown in the drawing is full open which is higher than the mean
working position. The increase of current in the circuit causing the solenoid core
to be drawn down will decrease the opening of the ports of the throttle valve;
similarly when the valve is near the mean working position the rise of the solenoid
core will increase the opening of the ports; but if the current should wholly fail
the piston will rise sufficiently high to entirely close the ports and the motor
driving the dynamo will consequently be stopped in time to prevent injury to the
mechanism which otherwise might probably result.
The governor hereinbefore described is especially applicable for the control of
engines driving dynamo machines for electric lighting or other purpose where the
power of the motor is entirely applied to the generation of electricity but it can also
be employed usefully in cases where much of the power of the motor is applied to
mechanical work and indeed in cases where the dynamo is of small dimensions and
is employed solely to generate an electric current, to operate the governor. Under
these conditions the governor will keep the engine to a constant speed so long as
the resistance remains constant in the circuit of which the solenoid forms a part.
It is not essential that the power to move the throttle valve should be obtained
by means of an hydraulic cylinder, it may for example be moved electrically by a
powerful solenoid.
It is not essential that the governor should be arranged vertically or its parts in
the same axial line this is usually convenient but nevertheless it may be otherwise
and by slight modification it may be adapted to work in a horizontal position.
The especial features of novelty in the arrangement which I have described
have reference to the construction of the throttle valve, the construction of the
hydraulic equilibrium valve g and the provision for adjustment in the position of
the solenoid coil a.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
(1). My improvements in governors for controlling steam engines and other
motors consisting in the use therein of a double piston throttle valve controlled by
an electric current passing in a solenoid coil substantially as and for the purpose
herein set forth.
(2). My improvement in governors for controlling steam engines and other
motors consisting in the employment therein of the equilibrium valve g which is
made to work with little friction by reducing each of its valve pistons to a pair of
discs or flanges substantially as described.
(3). My improvement in governors for controlling steam engines and other
motors consisting in the employment therein of a solenoid a adjustable in an axial
direction to regulate the distance to which its core enters when in a mean position
substantially as described.
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DOLL
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