Improvements in the Arrangement of Field Coils of Shunt Motors for use with Storage or other Batteries and Method of Connect- ing such Coils with the Batteries.
Year: 1897

page_text: Date of Application, 1st Feb., 1897
Complete Specification Left, 1st Nov., 1897-Accepted, 18th Dec., 1897
Improvements in the Arrangement of Field Coils of Shunt Motors
for use with Storage or other Batteries and Method of Connect-
ing such Coils with the Batteries.
I, THOMAS HUGH PARKER, of the Manor House, Tettenhall, near Wolverhampton in
the County of Stafford, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
Hitherto, in using electro-motors in conjunction with storage or other batteries, it
has been the practice to employ series-wound motors, in consequence of there being
no efficient means for maintaining a constant electro-motive force at the terminals of
the field coils of shunt wound motors whilst the electro-motive force is varied at the
armature terminals.
Now, this invention has for its object to facilitate the employment of a shunt-
wound motor used in conjunction with storage or other batteries, by providing means
whereby the electro-motive force at the terminals of the field coils may be maintained
constant while the electro-motive force at the armature terminals is varied.
According to this invention, the field magnets are wound in sections, and a
corresponding number of sets of storage or other battery cells are used. Four sections
of coils, and four sets of cells each set containing six, will be found a convenient
arrangement. The terminals of each set of cells are connected with the terminals of
a corresponding section of the coils, so that each section of the coils is excited by one
set of cells only, and a constant electro-motive force is thus maintained at the terminals
of the coils. The armature circuit is independent of the circuits of the shunt coils;"
and thus, without varying the electro-motive force at the terminals of such coils, (a)
all the sets of cells may be connected in series with the armature, when the highest
electro-motive force is required at the armature terminals, or (b) if a less electro-
motive force is required at the armature terminals, the sets of cells may be arranged
in two pairs of which the cells of each pair are in series, but of which the two pairs are
in parallel, or (c) if a still lower electro-motive force is required at the armature
terminals, all the sets of the cells may be arranged in parallel. The alteration in the
arrangement of the sets of cells are effected by means of a multiple switch, as will bé
readily understood.
I have mentioned a particular number of shunt coils and sets of battery cells, for
the sake of clearness of description as well as to indicate a convenient application of
the invention; but it will be obvious that the arrangement inay be varied considerably
without departing from the nature of the invention, which consists in connecting the
batteries in sections with sections of field coils respectively, independently of
the armature circuit, whereby a constant electro-motive force is maintained at the
terminals of the field coils, whilst the arrangement of the sets of cells may be varied to
vary the electro-motive force at the armature terminals,

page_text: The means above described for facilitating the employment of a shunt-wound motor
in conjunction with storage or other batteries, enable the motor to be utilized as a
dynamo when a vehicle to which it is applied is running downhill. In such case,
therefore, the motor may be utilized in charging the batteries, and it acts also as a
brake.
Improvements in the Arrangement of Field Coils of Shunt Motors
for use with Storage or other Batteries and Method of Connect-
ing such Coils with the Batteries.
I, THOMAS HUGH PARKER, of the Manor House, Tettenhall, near Wolverhampton in
the County of Stafford, 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:-
Hitherto in using electro-motors in conjunction with storage or other batteries, it
has been the practice to employ series-wound motors, in consequence of there being
no efficient means for maintaining a constant electro-motive force at the terminals of
the field coils or shunt-wound motors whilst the electro-motive force is varied at the
armature terminals.
Now, this invention has for its object to facilitate the employment of a shunt-wound
motor, used in conjunction with storage or other batteries, by providing means
whereby the electro-motive force at the terminals of the field coils may be maintained
constant while the electro-motive force at the armature terminals may be varied without
unnecessary waste of power.
According to this invention, the field magnets are wound in sections, and a
corresponding number of sets of storage or other battery cells are used. The terminals
of each set of cells are connected with the terminals of a corresponding section of the
coils, so that each section of the coils is excited by one set of cells only, and a
constant electro-motive force is thus maintained at the terminals of the coils. The
circuits of the shunt coils are independent of the armature circuit; and thus,
without varying the electro-motive force at the terminals of such coils, (a) all the
sets of cells may be connected in series with the armature, when the highest electro-
motive force is required at the armature terminals, or, (b) if a less electro-motive
force is required at the armature terminals, the sets of cells may be arranged in two
or more divisions of which the cells of each division are in series, but of which the
divisions themselves are in parallel, or, (c) if a still lower electro-motive force is
required at the armature terminals, all the sets of cells may be arranged in parallel.
The alterations in the arrangement of the sets of cells are effected by means of a
multiple switch, as will be readily understood.
In order that the invention may be clearly understood, I will proceed to describe
the same by way of example, with reference to the accompanying drawings, which
illustrate the application of the invention in a case in which four sections of field
coils are used and four sets of battery cells, each set, containing six.
In figure 1, the sets of cells are shewn as all connected in series with one another
in relation to the armature; in figure 2 the sets of cells are shewn as arranged in
two pairs, of which the sets of each pair are in series with one another in relation to
the armature while the two pairs are in parallel; and, in figure 3 all the sets of cells
are shewn as arranged in parallel with one another in relation to the armature.
The

page_text: drawings are shewn in a diagrammatic form, for the sake of clearness and simplicity.
A A¹ A2 A³ represent the sets of battery cells, each set being shewn as containing six.
B is the armature, and C the field magnet system. The terminals a of the set of
cells A are separately connected by means of the leads b with a separate section of
field coils c; and the terminals a¹ a² and a³ of the sets of cells A¹ A² A³ are
correspondingly connected, each by means of leads 61 62 63, respectively, with separate
sections of field coils c¹ c² c³, and thus each section of coils c c¹ c² c³ is independently
excited by a separate set of cells, this being the case, as shewn by each of the figures,
whatever may be the arrangement of the sets of cells in relation to the armature.
each figure, also, the armature coils are shewn as connected with the positive
terminal a of the set of cells A, and with the negative terminal a³ of the set of
cells As, by means of the leads d d', respectively. In figure 1 the set of cells A' are
connected, by means of the leads e e¹ e², in series with the set of cells A2, and these
latter are, also, similarly connected, by means of the leads ff¹ f, in series with the
set of cells A¹, and these again are similarly connected, by means of the leads g g¹ g²,
in series with the set of cells A. In this case, therefore, all the sets of battery cells are
in series with one another in relation to the armature coils.
In
In figure 2 the set of cells A³ are shewn as connected in series with the set of
cells A2 similarly as in the case of figure 1, but the set of cells A² are
separated from the sets of cells A¹ and A, by means of the lead h which
directly connects the positive terminal 2 of the set of cells A2 with the lead d of the
armature coils. The sets of cells A¹ and A are connected together in series similarly
as shewn in figure 1, but are separated from the sets of cells A³ A2, by means of the
lead h¹ which directly connects the negative terminal a¹ of the set of cells A¹ with
the lead d¹ of the armature coils. In this case, therefore, the sets of cells A3 and A2
are in series with one another in relation to the armature coils, and the sets of
cells A and A are also in series with one another in relation to such coils, but the
sets of cells A' and A2 are in parallel with the sets of cells A¹ and A.
In figure 3 the negative poles of the sets of cells A A' A² are directly connected,
through the medium of leads iii, respectively, and lead k with which they all
connect, with the lead d¹ which connects the negative pole of the set of cells A³ with
the armature coils; and the positive poles of the sets of cells A³ A² A¹ are directly
connected, through the medium of leads 12, respectively, and lead m with which
they all connect, with the lead & which connects the positive pole of the set of
cells A with the armature coils. In this case, therefore, all the sets of cells are in
parallel with one another in relation to the armature coils.
I have shewn and described a particular number of shunt coils and sets of battery
cells, for the sake of clearness, as well as to indicate a convenient application of the
invention; but it will be obvious that the arrangement may be varied considerably
without departing from the nature of the invention, which consists in connecting the
batteries in sections with sections of field coils, respectively, independently of the
armature circuit, whereby a constant electro-motive force is maintained at
the terminals of the field coils whilst the arrangement of the sets of cells may be
varied to vary the electro-motive force at the armature terminals.
The means above described for facilitating the employment of a shunt-wound
motor in conjunction with storage or other batteries, enable the motor to be utilized
as a dynamo when a vehicle to which it is applied in running downhill. In such
case, therefore, the motor may be utilized in charging the batteries, and it acts also
as a brake.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is:-
Field coils of an electro-motor arranged in sections which are each separately
connected with a corresponding set of battery cells, independently of the armature
circuit, whereby each section of coils is separately excited by its corresponding set of
cells, and a constant electro-motive force is maintained at the terminals of the field

page_text: coils, whilst the arrangement of the sets of cells may be varied to vary the electro-
motive force at the armature terminals, substantially as described.
STEPHEN WATKINS
Wolverhampton Agent for the Applicant.