Improvements in Governors for Motive Fluid Engines.
Year: 1888

page_text: Date of Application, 25th Aug., 1888
Complete Specification Left; 27th May, 1889-Accepted, 29th June, 1889
PROVISIONAL SPECIFICATION.
Improvements in Governors for Motive Fluid Engines.
I, JOHN SMITH RAWORTH of 112 Belvedere Road, Lambeth, in the County of
Surrey, Engineer do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved construction of Governor whereby the speed
of a motive fluid engine such as a steam engine is maintained nearly uniform under
varying loads and varying steam pressures.
With my improved Governor it is not necessary that with an increased load, the
speed of the engine should be permanently decreased, as is the case with an ordinary
centrifugal Governor.
In carrying out my invention I use any of the ordinary forms of centrifugal
Governor carried by a spindle driven by the engine at a higher speed than it is
intended the Governor shall revolve at.
The connection between this spindle and the centrifugal part of the arrangement is
not positive, but is by friction caused by the pressure of the Governor balls or some
part in connection therewith upon the aforesaid spindle or a dise or pulley attached
thereto.
•
It will be seen therefore, that when the said spindle is caused to revolve the
centrifugal portion also revolves with it, until such a speed is attained that the Governor
balls or parts in connection therewith have attained such a speed as to relax their hold
upon the said spindle, disc or pulley.
It therefore becomes impossible to drive this centrifugal Governor at a higher
speed than that for which it has been previously adjusted, and as the driving
spindle is set to run at a speed considerably in excess of the normal speed of the
Governor, it follows that when the engine is running at about its proper speed the
centrifugal Governor will always be kept revolving at one definite rate.
The regulation of the valves, be they throttle valves or expansion valves of any kind,
is done by the engine itself in the act of gaining or losing speed. The centrifugal
Governor revolving at a definite speed merely acts as a fulcrum.
For the apparatus to actuate the said valves I use any well known balance motion,
as for instance, the "Jack in the Box," or a screw revolving inside a nut which also
revolves. A description of this latter motion will serve as an illustration.
I arrange a screw to be constantly driven in one direction by the engine, and a nut
upon this screw also driven in the same direction by the centrifugal Governor. It is
obvious therefore, that so long as the screw is driven by the engine and at the same
speed as the nut is driven by the centrifugal Governor, the position of the nut upon
the screw will not vary.
Should however, the engine from any cause decrease in speed the nut will travel
along the screw and by means of levers or other equivalent devices, actuate the valve
and give the engine more steam.
Should however, the engine increase in speed the nut would travel in the other
direction, and cut off a portion of the steam.
Dated this 95th day of Ammuust 1888

page_text: COMPLETE SPECIFICATION.
Improvements in Governors for Motive Fluid Engines.
I, JOHN SMITH RAWORTH, of 112, Belvedere Road, Lambeth, in the County of
Surrey, Engineer, 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 :-
My invention relates to an improved construction of Governor whereby the speed
of a motive fluid engine such as a steam engine can be maintained nearly uniform
under varying loads and varying steam pressures, this governor being such more-
over as to render it unnecessary that with an increased load, the speed of the
engine should be permanently decreased, as is the case with an ordinary centrifugal
governor.
In carrying out any invention I use any of the ordinary forms of centrifugal governor
carried by a spindle driven by the engine at a higher speed than it is intended the
governor shall revolve at.
The connection between this spindle and the centrifugal part of the arrangement
is not positive, but is by friction caused by the pressure of the governor balls or
some part in connection therewith upon the aforesaid spindle, or a disc or pulley
attached thereto.
It will be seen therefore, that when the said spindle is caused to revolve, the
centrifugal portion will also revolve with it, until such a speed is attained that the
governor balls or parts in connection therewith have attained such a speed as to
relax their hold upon the said spindle, disc or pulley.
It therefore becomes impossible to drive this centrifugal governor at a higher
speed then that for which it has been previously adjusted, and as the driving
spindle is set to run at a speed considerably in excess of the normal speed of the
governor, it follows that when the engine is running at about its proper speed the
centrifugal governor will always be kept revolving at one definite rate.
The regulation of the valves, be they throttle valves or expansion valves of any kind,
is effected by the engine itself in the act of gaining or losing speed. The centrifugal
governor revolving at a definite speed merely acts as a fulcrum.
For the apparatus to actuate the said valves I use any well-known balance motion
as for instance: the "Jack in the box," or a screw revolving inside a nut which also
revolves. A description of this latter motion will serve as an illustration.
I arrange a screw to be constantly driven in one direction by the engine, and a nut
upon this screw also driven in the same direction by the centrifugal governor. It is
obvious therefore, that so long as the screw is driven by the engine and at the same
speed as the nut is driven by the centrifugal governor, the position of the nut upon
the screw will not vary.
Should however, the engine from any cause decrease in speed the nut will travel
along the screw and by means of levers or other equivalent devices, actuate the valve
and give the engine more steam.
Should however, the engine increase in speed the nut would travel in the other
direction, and cut off a portion of the steam.
In the accompanying drawing,
Fig. 1 is a side elevation partly in section, of my improved governor.
Fig. 2 is a partial view taken at right angles to Fig. 1. shewing the bar and its
attachments whereby motion is communicated from the revolving fly-wheel to the
spindle.
a is the driving shaft which receives motion from the pulley a², this pulley is
driven by a belt from the shaft of the engine the speed of which is to be governed.
A toothed wheel may be substituted for this pulley, if desired, or the shaft a' may
be coupled direct to the shaft of the engine. The driving shaft a¹ which at one
end is provided with a screw thread, carries a bevel wheel 61 that drives another
Level wheel 6. This wheel 62 is connected by means of a hollow shaft b with a

page_text: pulley c; this pulley transmits motion to a fly wheel by the friction between
it and weighted levers d¹ pivotted to the fly wheel, and pressed against the pulley
by the action of the springs c³, the tension of these springs can be regulated by
the screw and nut d, the flywheel in its turn transmits motion through a
pillar carried by it and a cross-bar e to a spindle that is arranged within
the hollow shaft 68 and carries at its lower end a small bevel wheel e. This bevel
wheel is geared with another bevel wheel f¹ which runs loose upon the driving
shaft a and carries with it in its rotation the nut f* which is threaded upon the
screw a on the driving shaft a'. g' is a lever for actuating the throttle valve or
for influencing the expansion gear; a fork on this lever enters a groove formed
in the surface of the nut f so that end wise motion of the nut will be communicated
to the end of the lever.
The bevel wheel 61 is made larger in diameter than the wheel 2 so that the pulley c¹
may always be driven at a velocity slightly in excess of that which is required
in the flywheel c². The flywheel c' may advantageously be carried on a roller or ball
bearing as she wn.
It is obvious that with the arrangement described whenever the driving shaft a¹ and
the nut are revolving at exactly the same speed there will be no traverse or end wise
motion of the nut and no alteration in the position of the lever g¹.
Should however the engine from any cause decrease in speed, the nut will travel
along the screw and by means of the lever and attached mechanism will actuate the
distributing valve and give more steam as herein before mentioned.
As soon however as the flywheel c² revolves at a speed at which the centrifugal
force of the weighted levers d is sufficient to overcome the tension of the springs c
the said levers will relax their hold upon the periphery of the pulley c¹ and enable the
fly wheel to recover its normal velocity; the centrifugal governor thus practically
revolves at one definite rate.
If the engine should increase in speed the nut will travel in the other direction and
cut off a portion of the steam.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
The combination of parts forming a governor which will tend to maintain an
absolutely uniform speed irrespective of the load on the engine and irrespective of
variations in the steam or other motive fluid pressure within the limitation of the
power of the engine substantially as hereinbefore described.
Dated this 25th day of May 1889
JOHN S. RAWORTH.
W. Lloyd Wise,
Applicant's Agent.