Improvements in Regulators for Dynamo Electric Machines.
Year: 1895

page_text: Date of Application, 28th Dec., 1895
Complete Specification Left, 28th Sept., 1896-Accepted, 7th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Regulators for Dynamo Electric Machines.
We, P. R. JACKSON & Co., LIMITED, Steel Manufacturers, and JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,
Salford, in the County of Lancaster, do hereby declare the nature of this invention
to be as follows:--
This invention has reference to regulators for dynamo electric machines of the
class in which the magnets are wholly or partially energized by a coil joined as a
shunt to the armature. The regulation, of dynamos of this class is usually
accomplished by varying a resistance which is in series with the said shunt coil,
the amount of said resistance depending on the position of an arm or contact maker
which is controlled by the regulating mechanism.
The chief feature of our invention consists in the means we provide for moving
the above mentioned arm or contact maker. Anothef feature of our invention
which however is not essential to the working consists in the means for stopping
the movement of the arm or contact maker when the same reaches its limiting
positions.
According to our invention we provide a shaft in operative connection with the
arm or contact maker and arrange so that when the shaft is rotated in one direction
the arm is moved so as to increase the resistance in series with the shunt coil and
when the shaft is rotated in the other direction the said resistance is decreased.
For rotating the shaft we provide a bevel wheel secured thereto and adapted to
engage with one or other of two bevel wheels secured to a continuously rotating
shaft perpendicular to the first shaft. This second shaft we will call the motive
shaft. In proximity to the bevel wheel on the said first shaft is provided a
magnetising coil joined as a shunt to the armature, the current flowing in said coil
causing the said bevel wheel to assume a fixed magnetic polarity. On the motive
shaft two coils are provided so arranged that when the current is flowing in one of
the coils the two bevel wheels on said shaft have different polarities the polarity of
each being reversed when current flows in the other coil. Under these conditions
when one of the coils is energised the bevel wheel on the first shaft is attracted
and engaged by one of the bevel wheels on the motive shaft and repelled by the
other, being thus rotated in one direction. When the second coil is energised the
polarities of the bevel wheels on the motive shaft being reversed the bevel wheel
on the first shaft is attracted by the opposite bevel wheel on the motive shaft and
is thereby turned in the opposite direction. It will be observed therefore that
the direction of motion of the first shaft and consequent variation in the resistance
depends upon which of the two coils on the second shaft is energised. These two
coils are joined as a shunt to the armature of the dynamo and arranged so that
one or other of the said coils is brought into circuit depending on the rise or fall
in the potential on the terminals of the dynamo. Devices for this purpose are
well known and need not here be further described.
In order to prevent the arm or contact maker hereinbefore described being
forced too far when near the extremities of its travel, we arrange that such arm
shall break the circuit of the magnetising coils on the shafts as soon as all the
resistance has been cut out or inserted in the shunt circuit of the dynamo.
The coil on the first shaft mentioned above may be arranged to be in series
with either of the coils on the second shaft or may be placed in a separate circuit
if desired.

page_text: The bearings of the first shaft are arranged so that the shaft can move laterally
to allow the bevel wheel thereon to engage with one or other of the bevel wheels
on the motive shaft.
We do not confine ourselves to the precise method hereinabove described for
carrying our invention into effect, for example, the two shafts may be inclined at
any suitable angle, and we do not restrict ourselves to the use of a bevel wheel for
communicating the motion from one shaft to the other as other forms of gearing
may be adopted.
Dated this 28th day of December 1895
W. P. THOMPSON & Co.,
31, High Holborn, London, W.C., Patent Agents for the Applicants.
Improvements in Regulators for Dynamo Electric Machines.
We, P. R. JACKSON & CO., LIMITED, Steel Manufacturers, and .JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,
Salford, in the County of Lancaster, de 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 :-
This invention has reference to regulators for dynamo electric machines of the
class in which the magnets are wholly or partially energized by a coil joined as a
shunt to the armature. The regulation of dynamos of this class is usually
accomplished by varying a resistance which is in series with the said shunt coil,
the amount of said resistance depending on the position of an arm or contact maker
which is controlled by the regulating mechanism.
The chief feature of our invention consists in the means we provide for moving
the above mentioned arm or contact maker. Another feature of our invention
which however is not essential to the working consists in the means for stopping
the movement of the arm or contact maker when the same reaches its limiting
positions.
In the following description reference is made to the accompanying drawing
which illustrates somewhat diagrammatically a convenient form of our improved
regulating device and the manner of connecting the same to the dynamo to be
regulated.
A. is the armature of the dynamo to be regulated B the external or lamp circuit,
C the shunt field magnet coil. D, D', D. are resistance coils connected
between adjacent contact blocks E, E.. with which one end of an arm or bridge
piece makes electrical contact the other end of said arm making a sliding
electrical contact with a bar G. H is the magnetizing coil of a relay which is
joined as a shunt to the armature A. The plunger H' of coil H is pivotally
connected to the tongue J pivoted at J' which tongue makes contact with the
upper or lower of two stops J2 J3 according as the potential difference at the
terminals of and current in the coil H is above or below the normal. When
the current in the coil is normal the tongue lies midway between the stops making
contact with neither of them. A spring H2 and weight J are preferably provided
for adjusting the relay to work with a given potential. The bar F is provided
with a nut engaging with a screw threaded shaft K which is mounted in
bearings K' K2 arranged so that the shaft can move a small distance laterally, for
this purpose the bush of the lower bearing K2 may be made with lateral play in
its supporting bracket it will be sufficient however in the case of the upper bearing
if the journal of the shaft loosely fits therein. L is a magnetizing coil surrounding
the bottom portion of the shaft K and at the end of said shaft is secured a bevel
w beel K³. M is a shaft mounted at right angles to the shaft K and provided with

page_text: bevel wheels N, O said shaft is continuously rotated in the direction shewn by a
belt driving a pulley M on the shaft or by other suitable means. P, Q are coils
surrounding the shaft M and adjacent to the bevel wheels N, O above-mentioned.
The shafts K, M and wheels K³, N, O are made of magnetic material and are.
magnetized when currents are caused to flow in the coils L, P, Q. R is a pivoted
lever adapted normally to connect with a contact R' and S is a similar lever having.
a corresponding contact S'.
The electrical connections are as follows. The shunt fieldmagnet coil C is.
connected between one terminal of the dynamo and bar G and the first block E of
the series of contact blocks E, E'
is connected to the other terminal of the
dynamo. The shunt circuit of the dynamo is therefore completed through coil C,
bar G, bridge piece F, and one or more of resistances D, D¹.
depending
on the position of the bridge piece F. If the bridge piece is in contact with
block E none of the resistances will be in circuit. To prevent accidental interruption
of the shunt circuit by reason of a failure of contact by bar F, the bar G is
connected to the last block of the series E, E¹. . as shewn. The relay tongue J
is connected to one terminal of the armature A the other terminal of which.
is connected through coil L and either coil P, contact S¹ and switch lever S to.
contact J2 or, coil Q contact R' and switch lever R to contact J*.
The action of the device is as follows:-
If the potential difference at the terminals of the dynamo rises, the current in
the coil H is increased, and the plunger H' is pulled down, thereby causing the
relay tongue J to make contact with the stop J2. A current will therefore flow
through the switch S S¹ and coils P and L. We will assume that the shaft M is
driven in the direction shown by the arrow and that the direction of current in the
wire is such that the circulation of current in the coil L imparts a north magnetic
polarity to the bevel wheel K³, the current flowing through coil P will therefore
cause the bevel wheel N to acquire south magnetic polarity and the bevel wheel O
to acquire north magnetic polarity, hence the bevel wheel K³ will be attracted by
the bevel wheel N and repelled by the bevel wheel O being driven by the former
in such a manner that the shaft K has a righthanded rotation imparted to it which
causes the bridge piece F to move along so as to increase the number of resistance
coils D D¹
included between itself and the contact block E. The resistance
in the shunt circuit will therefore be increased, and the electromotive force of the
dynamo lowered until the potential difference at the terminals and the current in
coil H becoming normal the relay tongue J is brought to its central position
breaking the circuit through the coils P and L. If the potential difference of the
terminals of the dynamo decreases the current in the coil H also decreases and the
plunger H' rises, causing the tongue J to make contact with the lower stop J'.
A current will therefore flow in the switch R R' and in the coils Q and L and
since the coil Q is wound in the opposite direction to the coil P the polarities of
the bevel wheels N and O will be reversed. Hence the bevel wheel K³ being
attracted by the bevel wheel O and repelled by the bevel wheel N will be driven
in the opposite direction and the bridge piece caused to move so as to cut out
resistance coils from the series D D'.... thereby decreasing the resistance in
the shunt circuit. The electromotive force of the dynamo will therefore increase
until the potential difference is normal upon which the relay breaks the circuit
through the coils L and Q. It will be seen from this description the direction of
rotation of the shaft K depends upon which of the two coils P and Q of the second
shaft is energised.
In order to prevent the bridge piece F from being forced too far when near
the extremities of its travel the levers R and S are arranged so as to project into
the path of said bridge piece, hence as soon as all the resistances DD'.
have
been inserted, the bridge piece F strikes against the lever S and breaks the
circuit through coil P. If on the other hand coil Q is energised and all the
resistances D D¹.... are cut out the bridge piece F meets the lever R and
breaks the circuit through the said coil.

page_text: Although we have herein described a very convenient apparatus for the purpose
of carrying out our invention in practice we do not confine ourselves to the precise
arrangements hereinabove described. For example, the coil L may be arranged in
a separate shunt circuit instead of being connected in series with the coil Por Q
also the shaft M may be inclined at any suitable augle to the shaft K instead of
being perpendicular thereto, and other forms of gearing than bevel wheels may be
used for communicating the motion from the one shaft to the other.
Furthermore coils such as P and Q may be provided on the shaft K and a coil
similar to coil L placed on the shaft M in which case the magnetic polarities of
wheels N and O will be constant while that of the wheel K³ will be varied in
accordance with the movements of the relay tongue.
The relay is shown diagrammatically in the drawing and we wish it understood
that we contemplate using any description of relay suitable for our purpose.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed we declare that what we
claim is :-
1. A regulating device wherein a rotary motion is imparted to a shaft from a
continuously rotating adjacent shaft, in different directions according as one or
other of two electromagnetic coils on one of the shafts is energized, substantially
as described.
2. For dynamo electric machines a regulating device constructed and operating
as described with reference to the accompanying drawing.
Dated this 28th day of September 1896.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicants.