Year: 1898

page_text: CHARLES WILLIAM SCOTT CRAWLEY, 16, Red Lion Street, Clerkenwell, E.C.,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
I will describe my invention as applied to maintaining constant the voltage of
a dynamo, driven by a steam engine.
In the circuit to be kept constant is an instrument of the nature of a voltmeter,
the needle of which works between two stops, which makes contact on one stop
when the voltage is too high, and on the other when it is too low.
A moving part is kept in constant motion by some external means, such as the
machinery itself, or a separate motor.
When the needle touches the high stop it closes a circuit, and throws the
moving part into gear with a shaft, causing it to rotate in one direction.
When the needle touches the low stop it similarly causes the shaft to rotate in
the opposite direction; when it touches neither stop the shaft is at rest.
The shaft has a screw thread cut on it and carries a nut which is not allowed
to rotate but has a longitudinal motion only along the shaft depending on which
way the shaft is revolving.
The nut acts through any suitable gear on the expansion valve of the engine,
and thus keeps the voltage constant.
Should the voltage fall very much, the nut approaches the end of the shaft, it
then throws a second continuously moving part into gear with suitable mechanism
for increasing the exciting current, until the voltage rises a little above the
normal. The second continuously moving part only remains in gear as long as
the nut is close to the end of the shaft.
It is preferable that the nut after throwing this second gear into action shall
break the circuit of the high side of the voltmeter till the nut goes back and
lets it out of gear again.
In the same way if the voltage rises so high that the nut approaches the other
end of the shaft, it throws the second continuously moving part into gear with the
exciting current mechanism, and causes it to move in the opposite direction, and
diminish the E.M.F. till it is a little too low. It is preferable to break
the circuit of the low stop, the same as the high.
The action is therefore as follows. There is a fine adjustment acting on the
expansion valve, by means of the nut, and when the voltage has got so high or
so low as to be out of the range of this adjustment, a second coarse adjustment
is thrown into gear which slightly over adjusts.
The coarse adjustment then stops and the fine adjustment comes into play
again.
I do not confine myself to this particular method of working, but may coarse
adjust on any variable which affects the voltage, and fine adjust on any other, or

page_text: may both fine and coarse adjust on the same variable. For example, the fine
adjustment may act on a rheostat of small resistances in the field circuit, and the
coarse adjustment on another rheostat in the same circuit.
Although the above description refers to regulation of voltage only, I do not
confine myself to this, but may apply the same method to maintain any other
property of running machinery constant by means of this double adjustment,
actuated in opposite directions according as the property to be controlled is above
or below the normal.
I, CHARLES WILLIAM SCOTT CRAWLEY, 16, Red Lion Street, Clerkenwell, E.C.,
Electrical 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 apparatus for maintaining constant the speed or other
property of running machinery and comprises the improvements hereinafter
indicated.
I will describe my invention as applied to maintaining constant the voltage of
a dynamo, driven by a steam engine.
In the circuit to be kept constant is an instrument of the nature of a voltmeter,
the needle of which works between two stops, which makes contact on one stop
when the voltage is too high, and on the other when it is too low.
A moving part is kept in constant motion by some external means, such as
the machinery itself, or a separate motor.
When the needle touches the high stop it closes a circuit, and throws the
moving part into gear with a shaft, causing it to rotate in one direction.
When the needle touches the low stop it similarly causes the shaft to rotate in
the opposite direction; when it touches neither stop the shaft is at rest.
The shaft has a screw-thread cut on it and carries a nut which is not allowed
to rotate, but has a longitudinal motion only, along the shaft depending on which
way the shaft is revolving.
The nut acts through any suitable gear on the expansion valve of the engine,
and thus keeps the voltage constant.
Should the voltage fall very much, the nut approaches the end of the shaft,
it then throws a second continuously moving part into gear with suitable mechan-
ism for increasing the exciting current, until the voltage rises a little above the
normal. The second continuously moving part only remains in gear as long
as the nut is close to the end of the shaft.
It is preferable that the nut after throwing this second gear into action shall
break the circuit of the high side of the voltmeter till the nut goes back and lets
it out of gear again.
In the same way if the voltage rises so high that the nut approaches the other
end of the shaft, it throws the second continuously moving part into gear with
the exciting current mechanism, and causes it to move in the opposite direction,
and diminish the E.M.F. till it is a little too low. It is preferable to break the
circuit of the low stop, the same as the high one.
The action is therefore as follows:-There is a fine adjustment acting on the
expansion valve, by means of the nut, and when the voltage has got so high or

page_text: 15
Stan view of one 101 on my apparatus.
Figure 4 is a diagram showing the voltmeter connections.
a represents the voltmeter needle which plays between two stops and 61,
being the high stop and the low one. e is the motor which through the
screw and worm wheel e drives the two bevel wheels f and g continuously.
When the voltmeter needle a touches the high stop it closes the circuit h
(Figure 4) and when it touches the low stop bit similarly closes the circuit h¹.
The magnet as shown at i, in Figure 1 is of double pot form but two separate
magnets may equally well be used, and in this description I will refer to them
as though they were two separate magnets.
When the circuit h is closed, the magnet i is energized, attracting its armature j
and throwing the bevel wheel & into gear with the bevel wheel f. The shaft /
is thus rotated in one direction driving the screw-threaded shaft m in the same
direction by means of the forked driver n. The nut is thus moved longitu-
dinally, say towards the magnet i, and is prevented from rotating by reason of
engagement with the guide-rod p. The movement in this direction will put
the resistance into the field magnet circuit, as shown, by the brush q passing over
the stops r.
Just before the nut o reaches the end of its travel it comes into
contact with a pin s on a sliding bar t thereby moving the said bar in the same
direction. To this bar t is loosely connected a lever that is pivotally mounted
at the point. The distant end of the lever u is forked for engagement with the
disc u and throws the bevel wheel w into gear with the constantly rotating one g.
The result is that the nut o' mounted upon the screw-threaded shaft m' is similarly
longitudinally moved through the forked driver . This nut o operates the
coarse adjustment as for example by pulling the cord shown at a which may act
on the steam valve, a larger resistance, or other regulator. As soon as the nut o
has moved the lever u far enough to throw the wheel w into gear, an arm y rigidly
mounted upon the said lever u breaks the circuit at the point and the nut o
travels no further. As soon as the coarse adjustment has lowered the volts
slightly too much the needle a touches the stop b, the circuit is closed, the
magnet is energized, attracting its armature and thus the wheel is thrown
into gear rotating the screw-threaded shaft m in the reverse direction and return-
ing the nut o. As soon as the said nut o leaves the pin s, the wheel w is no
longer held in gear; the nut o' stops and the one o returns until the volts are
again normal. Similarly when the nut o has reached the end of its travel in the
opposite direction it comes into contact with the stop and throws the wheel w¹
into gear, then breaks its own circuit at 3 and the coarse adjustment continues
in gear until the volts are a little too high.
and are two strip springs between which the boss
located on the shaft /

page_text: rotates and which springs bring both wheels out of gear when no other force is
operating.
It is obvious that if it is desired to keep the current constant as for example in
arc electric lighting work, the needle or pointer a may be actuated by an ammeter
arrangement instead of a voltmeter, or, if speed is to be kept constant, by a speed
indicator or similarly by any other instrument which indicates the property
which is required to be kept constant.
In order to deal with sudden variations of load I sometimes introduce a second
pair of magnets between and w¹, these magnets being only actuated when a
very considerable variation takes place. I may accomplish this by mounting
the contacts and bon springs and having other contacts which are only made
if and bare moved through more than a given predetermined amount.
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. The combination, in a regulator, of a fine and a coarse adjustment, the
arrangement being such that when the range of fine adjustment is exceeded the
coarse adjustment is thrown and maintained in gear until the regulation is again
within the range of the fine adjustment, the fine adjustment meanwhile being
preferably inoperative substantially as set forth.
2. The automatic regulator for machinery constructed substantially as set
forth and illustrated in the accompanying drawings.
The L 1
T
1000
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.