Improvements in the Regulation of Dynamo Electric Machines.
Year: 1887

page_text: Date of Application, 10th May, 1887.
Specification Accepted, 21st June, 1887
COMPLETE SPECIFICATION.
Improvements in the Regulation of Dynamo Electric Machines.
We, ENOS TOLAND HIGHAM and DANIEL HIGHAM, residents of Philadelphia,
Pennsylvania, United States of America (No. 2165 East Cumberland Street) Lumber
Merchants, do hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
Our Invention relates to the automatic regulation of dynamo electric machines for
the production of a constant current in a circuit of varying resistance with the most
economical consumption of power in proportion to the work done by the dynamo.
The object of our Invention is to simplify and render more effective this regulation
of the dynamo and of the motive power engine, and this object we attain by causing the
dynamo electric machine itself to control the motive power engine, as fully described
hereinafter.
On the accompanying drawings, we have illustrated the devices which we prefer
to use for carrying our Invention into effect.
Fig. 1, represents a side view, illustrating in elevation, a dynamo electric machine
and driving wheel provided with compensating and regulating devices whereby the
dynamo is caused to govern the motive power engine.
Fig. 2, represents a reverse view of the driving wheel of the engine and of the pulley
of the dynamo, taken on a section through the said driving shaft and the armature
shaft of the dynamo; and Fig. 3, represents a vertical section on the line x-x,
Fig. 2.
Our Invention may be applied to any construction of series-wound dynamo electric
machines. On the accompanying drawings we have shown only one well known
form, for the sake of illustration.
A, is the dynamo electric machine, the armature shaft of which is connected by
a belt or gearing directly to a wheel, D, or its equivalent. This wheel, D, may be
mounted on, but must be free to turn independently of, the driving shaft, E, of the

page_text: motive power engine. This shaft, E, may, however, be any shaft which is driven
from the engine.
Keyed or otherwise secured to the shaft, E, is a two-armed lever, F, the opposite
ends of which are connected to the wheel or pulley, D, by means of springs, G, the
connection of the latter with the levers being such as to give a compensating leverage
for the varying tension or stretch of the springs, as hereinafter described.
We prefer to provide the springs with suitable adjusting devices at the points of
connection with the wheel or pulley, as shown in the drawings.
The eccentric, H, which through its strap, h¹ and eccentric rod, H³, controls the
cut-off or other valve of the steam engine, turbine, or other motive power engine,
is hung by its arm, h, to a pin, i, on the lever F, as shown in the drawing. This
eccentric, H, has a slot, e, through which the driving shaft, E, freely passes. At right
angles, or nearly so, to the slot, e, is another slot, d, in which works a pin, d², carried
by the wheel or pulley, D. In the present case, we have shown this piñ, d', as
passing freely through a curved slot in one arm of the lever, F, simply because the
relative positions of the parts shown in the drawing has necessitated it.
The means we prefer to provide for compensating for increasing and decreasing the
tension of the springs, due to the varying stretch of the latter, consists in the
construction of the lever, F, so that the points of connection of the springs with
the two arms of the lever will be nearer to or further away from the fulcrum or centre
of the latter as the tension of the springs increases or diminishes.
As shown in Figs. 1, and, 2, one end of each spring is connected to the extreme
end of each arm of the lever, F, by means of a flexible but inelastic strap, g, and each
arm of the lever is formed with a curved face, f, of the character illustrated in the
drawing, so that as the changing relative positions of the wheel or pulley and the
lever, F, vary the stretch of the springs, the leverage of the lever, F, will correspondingly
vary, as illustrated in Figs. 1, and 2.
In Fig. 1 the springs are shown stretched to their full extent, and the leverage
correspondingly reduced, while in Fig. 2, the springs are shown unstretched, and the
leverage correspondingly increased.
It will thus be seen that the curved faces can be so shaped as to give a uniform
pull of the springs on the wheel, no matter what may be the position of the lever, F.
In other words, the pull exerted by the springs between the driving shaft of the
engine and the shaft of the armature is, by the means described, rendered uniform at
all times.
The operation of the above described devices is as follows
Suppose the dynamo to be adapted for supplying current for a circuit of forty
electric arc lamps, and suppose it to be running with twenty of the lights in circuit, the
relative positions of the lever, F, and pulley of the regulating device will be towards
that shown in Fig. 1, and the eccentric will be in a position to work the cut-off to
supply a correspondingly small amount of steam. The magnetic retarding effect of
the poles of the dynamo on the armature will be balanced by the effective exertion of
the springs G.
If now the twenty additional lights be thrown into circuit, the first effect in the
dynamo circuit will be a reduced current, and consequently, the magnetic retardation
of the armature will be diminished and the load on the motive power engine decreased.
At the regulating device the effect of this reduction of engine load will be the
contraction of the springs, G, and consequent corresponding increase in the throw of
the eccentrics (as shown in Fig. 2) to supply a greater amount of motive fluid to the
engine.
The speed of the engine and of the dynamo armature will thus be increased until
the current in the dynamo circuit is increased to the normal point and the magnetic
retardation of the armature is again increased in consequence, to equal the tension of
the springs of the regulating device.
Thus it will be seen that as the pull of the springs between the shaft, E, and the
periphery of the wheel, D, is constant in its different positions, the magnetic
retardation of the armature must also be constant under its different speeds, and as

page_text: the magnetic retardation of the armature is the result of the current, the current must
be constant.
Having now particularly described and ascertained the nature of our said Invention,
and in what manner the same is to be performed, we declare that what we claim is :-
1. The combination of the dynamo shaft and engine shaft, with a spring connection
between the two, and devices controlling the supply of motive fluid to the engine,
with a compensator for the springs, substantially as and for the purpose herein before
set forth.
2. The combination of the dynamo electric machine and driving shaft, with a lever
fast to the shaft, a wheel loose from the shaft, and springs connected at one end to the
wheel and having at the other end a connection with the lever, varying the leverage
of the latter in proportion to the varying tension of the springs, substantially as
hereinbefore set forth.
3. The combination of a dynamo electric machine and driving shaft, with a lever
fast to the shaft, a wheel loose from the shaft, an eccentric controlled by the wheel
and lever to operate the valve of the motive power engine, and springs connected at
one end to the wheel, and having at the other end a connection with the lever, varying
the leverage of the latter in proportion to the varying tension of the spings,
substantially as hereinbefore set forth.
4. The combination of a dynamo electric machine and driving shaft, with the
wheel loose on the shaft, a lever fast thereto and having inclined bearing faces, with
an eccentric operated by the wheel to control the engine valve, and springs connected
to the wheel and having a strap connection with the inclined faces of the lever, all
substantially as hereinbefore specified.
D
1
1007
DAY, DAVIES, & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicants.