Improvements in Controllers for Electric Motors.
Year: 1896

page_text: Date of Application, 11th Feb., 1896-Accepted, 11th Feb.. 1897
COMPLETE SPECIFICATION.
Improvements in Controllers for Electric Motors.
1. JAMES DEVONSHIRE, Secretary of The British Thomson Houston Limited
of No. 38 Parliament Street, Westminster, London (a communication to me from
abroad by William B. Potter, Electrical Engineer, of Schenectady in the State
of New York, United States of America) 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 controllers for electric motors, and has for its object
to so arrange a controller that it may be adapted to give a greater number of
combinations by which the speed of the motor may be regulated than has
heretofore been the case. I also combine with the controller, mechanism by
which in its ordinary operation it may be actuated from its lowest to its highest
position, giving the motors a certain number of changes or commutations, and
by then throwing a switch the manual operation may be repeated, combining
the motors in different manners and giving different rates of speed; so that
before the switch for this purpose, which I shall call an "auxiliary switch," has
heen thrown and after it has been thrown, the manual operation of the controller
is identical, but the results in the combinations of the motors are different.
It
In the operation of electric railways where the same road is run within a city
and outside of it in suburban or interurban transportation, it is sometimes a
convenience to have cars which may with the ordinary operation of the controller
run up to a certain limit of speed, for instance, 20 miles an hour. Where the
same car, however, is to be used outside of the city a much higher rate of speed
is often practicable, and the car should be properly equipped to obtain it.
is the object of the combination of apparatus shown in this application to
accomplish this result, by combining with the controller the auxiliary switch to
which I have referred in the statement of invention; so that when the car comes
to a station upon the outskirt of the city (the power-house or car-barn being
commonly so located) the switch may be thrown, and the controller will then
operate the motors at a higher rate of speed than before. By preference I so
locate this switch that it may not be operated by the motor-man in the ordinary
use of the car, my object in so doing being to place beyond his control the
means of obtaining higher speeds as herein pointed out, so that should the car
for any reason be delayed, it will not be possible for the motorman in charge
to run at a dangerous rate of speed or a speed higher than that permitted within
the city streets.
I bave illustrated my invention as applied to the now well-known form of
series-parallel controller used in electric railways of the type running at Bristol,
England. I have also illustrated it in combination with a peculiar form of
reversing switch, which, however, is not of my invention. I have further illus-
trated it as applied to an equipment of four motors upon a car. It is possible
to use other combinations and other types of apparatus than the ones described,
and still be within the purposes of my invention; which consists, broadly, in the
combination of a number of motors, means for regulating the motors from rest to
a certain speed, and an auxiliary switch or other means for so changing the
combination of the motors that they may range from rest to a certain other
higher speed than the one first named without effecting any change in the
controlling apparatus itself.

page_text: I have illustrated my invention in the accompanying drawings; in which
Fig. 1 is a diagram showing the circuits upon one end of an electric car; the
reversing switch, controlling switch and auxiliary switch all being shown as
developments of cylindrical switches.
Figs. 2, 3, 4 and 5 are the motor combinations, all to be more particularly
pointed out hereinafter, and
Fig. 6 is a side elevation of the auxiliary switch, to which I have referred, with
part of the car wall in section.
I have illustrated the four motors with their armatures connected so as to
revolve in the drawings in the same direction. As ordinarily mounted however,
and as is well known in the art, adjacent armatures upon the same truck revolve
in opposite directions, and are so geared to the wheels as to give proper direction
of rotation to them. My object in illustrating them, as pointed out, is to make
the construction entirely clear and readily understood.
In Fig. 1 the motor armatures are numbered A' to A respectively and the
fields to F respectively. K is the controller, the contacts of which are shown
in plane. The fixed contacts are numbered respectively from 1 to 10. RS is
the reversing switch, provided with movable contacts C C C arranged in rows,
the middle set of contacts being cross-connected. This, however, is not of my
invention. The resistances are indicated diagrammatically, the series resistance.
at R, and the shunt resistance by which the fields of the motors are weakened for
the highest speed are lettered respectively R¹ to R. The fixed contacts upon the
reversing switch are numbered 11 to 18 and 11 to 18 respectively and the leads
from the controller and reversing switch are numbered to correspond with the
contacts upon those switches with which they respectively connect. One other
lead numbered 19 is employed. The auxiliary switch S is also provided with
movable contacts D' D2 D3, arranged in rows, and fixed contacts 20 to 31, 49
and 50 respectively.
The particular construction of the auxiliary switch is illustrated in Fig. 6,
wherein S is the switch and D2 the middle set of contacts. W is the side or wall
of the car and H is a key by which the switch ir manipulated through the opening
in the side of the car, it' being provided with a square shaft like a clock-winding
mechanism.
The particular combinations of the motors are as illustrated in Figs. 2 to 5. In
Fig. 2 the motors are shown in series between the trolley T and the ground.
The resistances are not shown in the combinations diagrammatically illustrated,
inasmuch as their office is well understood. In Fig. 3 the motors are shown
connected in two groups in multiple of two each in series, corresponding to the
position shown by the dotted lines X-X upon the controller K. These are the
two running positions of the motors with the auxiliary switch S in that one of its
two positions to be hereinafter referred to as the slow speed position; that is, in;
the case illustrated, in the position when the contacts 25, 26 and 29, 30 are upon
the movable contacts D or with the movable contacts thrown to the left in Fig. 1.
When, however, the switch is thrown to the right in Figure 1 thus occupying the
right hand or high speed position, and the contacts 20 to 23, 49 and 5 are upon
the movable contacts of the series D' and the contacts 24 to 31 are at the same
time upon the movable contacts of the series D3, then the motors are combined as
shown in Figs. 4 and 5; that is to say, in multiple series with an equalizer across
the connections between the armatures A' A' and the fields F F3, while Fig. 5
shows all four motors in multiple between the trolley and ground, which is the
position adapted for the highest speed.
With the motors grouped as shown in Fig. 2 the circuit is as follows:
Eatering in Fig. 1, from the trolley 1, to contact 1, by cross-connection to
contact 2, then through the resistance R, from the resistance by the lead 5,
connecting with the lead 18, to contact 18 upon the reversing switch RS, the fixed
contacts of which are supposed to be respectively upon the rows of contact-
plates Caud C, passing by the contact-plate, from contact 18, to contact 17, by

page_text: the lead 17 and the lead 32, to the armature A'. Through that armature by the
lead 33, to the lead 16, to contact 16, by the contact-plate in the row C, to
contact 15, by the lead 15 and the lead 35, throngh the field F', by the lead 34,
contact 26 upon the switch S, thence to contact 25, the switch being assume to
be in its left hand or slow speed position, or with the fixed contacta 25 and 26,
29 and 30 upon the movable contact of the series D³, thence by the lead 25, to the
lead 18 to contact 18 upon the reversing switch, by cross-connection to
contact 16, thence by the lead 16ª and the lead 40, to the armature A³, thence
through the armature, by the lead 41, to the lead 17, from the lead 17", to
contact 17, by cross-connectiou to the contact 15, by the lead 15 and the lead 43,
to the field F, through that field by the lead 42, to the lead 8, thence to contact 8,
by the cross-connection upon the controller K to contact 6, by the lead 6, to the
lead 14, by the lead 14, to contact 14, to contact 13, by the lead 13 to the lead 36,
to the arinature A2, through that armature, by the lend 37 to the lead 12, to
contact 12 on the reversing switch, contact 11, by the lead 11 and the lead 39 to
the field F, through that field, by the lead 38 to the lead 19, by the lead 30
to contact 30 on the switch S, to contact 29, by the lead 29 and the lead 14° to
contact 14, by cross-connection to contact 12, by the lead 12 and the lead 44, to
the armature A, through the armature A to the lead 45, to the lead 13", by
cross-connection to contact 11", by the lead 11ª and the lead 47 to the field F,
through field F, by the lead 46 to the lead 9, and by the lead 48 from the lead 9.
to ground.
It will be readily understood that the contacts upon the controller K co-operating
with the contacts 2 to 5 respectively control the resistance R and that when the
contact 4 cross-connection to the contact 5 touches its relative contact-plate on
the cylinder K the resistance R is cut out, when the motor will take the position
shown in Fig. 2.
When however the contacts 1 to 10 of the cylinder K have reached the position
indicated by the line X--X, so that the resistance R has been entirely cut out, the
motors are in the position shown in Fig. 3.
The circuits in this case are as follows:-Contact 1 brings in the circuit from the
trolley T and the current then passes immediately to the contact 5, and also to
the contact 6. Following the line from contact 5 it passes by the lead 5 to the
lead 18, then to contact 18, to contact 17, by the lead 17 to the lead 32, through
the armature A', by the lead 33 and the lead 16, to contact 16, thence to
contact 15, by the lead 15, to lead 35, through field F, by the lead 31 to
contact 26 upon the switch S, to contact 25, to lead 18, thence to contact 18, by
cross-connection to contact 16, to lead 16" by the lead 40 to the armature A³, by
lead 41 to lead 17, to contact 17, by cross-connection to contact 15, by the
lead 15 and the lead 43, through the field F³, by the lead 42 and the lead 8, to
contact 9, and by the lead 9 and the lead 48 to ground.
The other path of the current in this combination is from the contact 6 upon the
controller, by the lead 6 to the lead 14, contact 14 upon the reversing switch,
contact 13, by lead 13 and lead 36, to the armature A through the armature, by
the lead 37 to lead 12, contact 12, contact 11, by lead 11 and lead 39 to field F,
through that field, by lead 38 to lead 19, by lead 30 to contact 30 upon the
switch S, contact 29, by the lead 29 to lead 14, contact 14 upon the reversing
switch, contact 12, by lead 12ª and lead 44 to armature A', through that armature
to lead 45, to lead 13 upon the reversing switch, contact 11, lead 11, and lead 47,
through the field F by lead 46, to lead 9, and by that lead to lead 48, to ground,
forming the other path of the combination, as shown in Fig. 3.
When the switch S is, however, thrown to the right hand or high speed position
so that the contacts 20 to 23, 49 and 50 are upon the contacts of the series D',
and the contacts 24 to 31 are upon the contacts of the series D, the combination
shown in Fig. 4 is that first effected by the controller K, and afterwards the
combination shown in Fig. 5.
It is to be understood, of course, that the controller K is brought to the off

page_text: position before the switch S is thrown, as this switch carries, in the operation of
the car, the entire current, and it is not designed to interrupt the circuit at the
switch at any time, that office being performed by the controller. In this position
the paths of the current are as follows, it being assumed that the controller K is so
far advanced that the contact 5 has touched its relative contact-plate, and therefore
that the resistance R is entirely cut out.
Entering from the trolley T the current passes to the contact 1 and thence by
cross-connection to contact 5, thence by the lead 18, to contact 18 upon the
reversing-switch to contact 17, by the lead 17 and lead 32 through the armature A',
by the lead 33 and the lead 16 to the contact 16, thence to contact 15, by the
lead 15 to the lead 35, through the field F, by the lead 34 to contact 26 upon the
switch S, to contact 27, to the lead 8, to contact 8 upon the controller, by cross-
connection to contact 6, by the lead 6, to lead 14, contact 14 upon the reversing
switch, to contact 13, to the armature A., passing thereto by the lead 36, thence
by the lead 37 and the lend 12 to contact 12, to contact 11, by the lead 11 and
lead 39 to field F2, thence by the lead 38 to lead 19 and lead 30, to contact 30,
contact 31, by the lead 31 to the lead 9, by the lead 9 and lead 48 to ground; thus
passing in series through the armatures A and A' and their respective fields, as
shown in the upper half of Fig. 4.
The other path through the remaining motors is through lead 5 from contact 5,
but instead of passing to the right through the lead 18 as in the circuit just traced,
it passes to the left to the lead 24, to contact 24, to contact 25, thence to
contact 18, by cross-connection to contact 16", thence to lead 16" and lead 40,
through the armature As, by lead 41 and lead 17° to contact 17ª, by cross-connection
to contact 15 by lead 15" and lead 43, through the field F3, by the lead 42, lead 8,
to contact 8, by cross-connection to contact 6, by the lead 6 and the lead 28 to
contact 28 upon the switch S, contact 29, by the lead 29, and the lead 14" to
contact 14, by cross-connection to contact 12, by the lead 12", and the lead 44
to the armature A, through that armature, by the lead 45 and the lead 13" to
contact 13, by cross-connection to lend 11, by lend 11" and the lead 47, through
the field F by the lead 46, lead 9, lead 48 to ground, forming the circuit shown
in the lower half of Fig. 4. The equalizer N, Fig. 4, is thrown across the ground
terminals of the fields F, F, and may be traced as follows:-
By the lead 34, from the termina! of the field F, contact 26 on the switch S,
contact 27, by the lead 27, to lead 8, and by that lead and the lead 42 to the
terminal of the field F³.
Referring now to Fig. 5, the connections for this figure will be upon the
line X-X of the controller K, and the paths of the current are as follows:-
Entering from the trolley T the current passes to contact 1, and then by the
various cross-connections, either contact-plates or contact, to contact 5, thence by
the lead 5 to the lead 18, by the lead 18 to contact 18, thence to the contact 17 to
the lead 17, and by the lead 32 through the armature A', by the leads 33 and 16
to contact 16, contact 15, by the lead 15 and the lead 35, through the field F1, by
the lead 34 to contact 26 upon the switch S, to contact 27, to the lead 8, to
contact 8 upon the controller, by cross-connection to contact 9 and by the lead 9
and lead 48 to ground.
Another path of the current is from contact 5 upon the controller, by the lead 5,
passing to the left at the point B, by the lead 24, contact 24 upon the switch S,
contact 25, by the lead 25 and the lead 18", to contact 18ª, then to contact 16, by
the lead 16 and the lead 40, through the armature A³, lead 41 and lead 17", to
contact 17, by cross-connection to contact 15", by the lead 15 and the lead 43,
through the field F³, by the lead 42 and the lead 8 joining the path of the current
from the motor 1, thence to contact 8 upon the controller, and by cross-connection
contact 9, by lead 9 and lead 48 to ground.
The paths for the other two motors start from contact 6 upon the controller,
which it will be noticed, is cross-connected to contact 5 by the cross connection
between the two contact plates.

page_text: Starting from contact 6 the current proceeds to the point C, lead 6, thence
passing to the right by the lead 14 to contact 14 upon the reversing switch, contact 13,
by the lead 13 and lead 36, through the armature A', by the lead 37, and lead 12,
contact 12, contact 11, by the lead 11 and lead 39, through the field F, by the
lead 38 to lead 19, by lead 30, to the contact 30, to contact 31 by the lead 31, to
lead 9, and by that lead and lead 48 to ground.
Starting from point C again, the current passes to the left along the lead 6,
thence down the lead 28 to contact 28 upon the switch S, contact 29 by lead 29 to
lead 14 contact 14" upon the reversing switch, by cross-connection to contact 12,
by the lead 12 and lead 44, through the armature A', by lead 45 and lead 13, to
contact 13, to contact 11, by lead 11° and lead 47, through the field F, by the
lead 46 to lead 9, by that lead and lead 48 to ground thus putting the four motors in
multiple between the trolley and ground, as in Fig. 5.
The office of the resistances R to R is to shunt the motor fields and thereby
obtain a higher rate of speed than is due to the full magnetization, by weakening
the fields in ways well known in the art. During the first operation of the
controller, or when the switch S is in its first or "slow speed" position, as already
described, these resistances are not employed, and their contacts are opened upon
the switch S. By tracing the circuits it will be found that if the resistances were
used in this position, they would not act to shunt the fields only, but would also in
part shunt the armature of the motors or act as a direct shunt around the notors
to ground, and thus would throw the apparatus out of halance, as would be well.
understood.
With the controller cylinder K turned to its extreme position when the
contacts 1 to 10 occupy the position indicated by the line Y Y, Fig. 1, and with the
switch S in its "slow speed" position, that is when the contacts 25, 26 and 29, 30
are upon the movable contacts of the series D³, the remainder of the fixed contacts
of the switch S being open-circuited as hereinafter explained, the motors then being
in the position shown in the Fig. 3; the circuit is as follows:
Entering at the trolley T the current passes to the contact I, and then by various
cross-connection between contact-plates in the cylinder K to the contact 5 and to
the contact 6. Following the circuit from the contact 5 it passes by the lead 5 to
the lead 18, by the lead 18 to the contact 18, thence to the contact 17, to the
lead 17, and by the lead 32 through the armature A¹, by the lead 33 and 16 to
contact 16, contact 15, by the lead 15 to the point D where the circuit divides as
follows: Proceeding further along the lead 15 to the point thence by the shunt
resistance R', by the lead 49 to the contact 49 and, if the short circuiting contact
of the series D₁ was in contact with the fixed contacts 49, 23 and 22, the circuit
would be continued to the contact 22, by the lead 10 to the contact 10 and by cross-
connection between the corresponding contact plates on the cylinder K to the
contact 9 and from thence by the lead 9 and 48 to the ground G. It is thus
evident that were the short circuiting contacts D' of the switch S in contact with
the fixed contacts 22, 23 and 49 the current from the trolley after traversing the
armature A would pass directly to the ground thus shunting or short circuiting the
field F, through the resistance R'.
Returning now to the point D the other circuit is by the lead 35 through the
field F, by the lead 34 to contact 26 upon the switch S, to contact 25, to lead 18ª,
thence to contact 18, by cross-connection to contact 16, by lead 16" and by the lead 40
to the armature A³, by lead 41 to lead 17ª, to contact 17, by cross-connection to
contact 15, by the lead 15 to the point where the circuit divides one path being
through the shunt resistance R³ by the lead 20 to contact 20 of switch S; if now
the short circuiting contact of the series D' covered the three fixed contacts 20, 21
and 50 the current would pass by means of this contact of the series D' to the
contact 21 and by the lead 21 to the lead 7, thence by the lead 7 to the contact 7
and by means of the cross-connections on the cylinder K to the contact 9, thence
by the leads 9 and 48 to ground, a series of connections which obviously short
circuits the field through the resistance R³.

page_text: Returning now to the point the circuit is as follows: From the current flows
by the lead 15 to the lead 43, by the lead 43 through the field F, by the
lead 42, and the lead 8 to contact 8 by cross-connection on the cylinder K to
contact 9, and by the lead 9 and the lead 48 to ground.
The other part of the current in this combination, always supposing that the
contacts of the series D' of the auxiliary switch S touch the fixed contacts 20 to 23,
49 and 50, is as follows: From the contact 6 on the controller K, by the lead 6 to
the lead 14, contact 14 upon the reversing switch contact 13 by lead 13 and
lead 36, to the armature A, through the armature by the lead 37 to lead 12,
contact 12, contact 11, by lead 11 to the point 2 where the circuit divides. In one
direction the circuit is from the point through the resistance R' and by the
lead 23 to contact 23, to contact 22 by means of the short circuiting plate of the
series D' of the switch S, by lead 22, and the lead 10 to contact 10 of controller K,
by cross-connections between controller. plates on the cylinder to contact 9, and
finally by lead 9 and 48 to ground thus shunting or short circuiting the field F
through the resistance R'. This path also short circuits the motor A* F* as will
now be seen in precisely the same manner as the path through the resistance R
would short circuit the motor A³ ³ were the auxiliary switch S in the "slow
speed position with the contacts 20 to 23, 49 and 50 covered by the short
circuiting contacts of the series D'.
Returning now to the point on the lead 11, the other circuit would be to
the lead 39 and thence through the field F, by the lead 38 to lead 19, by lead 30
to contact 30 upon the switch S, contact 29, by the lead 29 to lead 14º, contact 14*,
upon the reversing switch, contact 12" by lead 12 and lead 44 to armature A,
through that armature to lead 45, to lead 13, contact 13 upon the reversing
switch, coutact 11, lead 11 to the point where the circuit is again divided.
Proceeding through the resistance R, 'by the lend 50 to contact 50, to contact 21,
by lead 21 to lead 7, to contact 7, thence by cross-connection between contact
plates on cylinder K to contact 9, and then by leads 9 and 48 to the ground, the
current is provided with a shunt path short cireuiting the field F through the
resistance R*.
Returning now to the point the other path is by the lead 11, the lead 47,
through the field F, by the lead 46 to the lead 9, thence by the lead 48 to the
ground, thus completing the other path of the combination, as shown in the
Figure 3.
When however the switch S is in its "high speed" position, so that the motors
are combined as in the Figures 4 and 5, the resistances R, R, R and R' are
employed to obtain the highest speed, their circuits being closed by means of the
contact plates of the series D' of the switch S. It is also evident that the circuits
through these shunt resistances R', R, R³, R', are not closed on the controller K
until the series of fixed contacts 1 to 10 have reached the line Y Y at which point
the contacts 7 and 10 are in contact with their respective contact plates. With
the auxiliary switch S in its "high speed " position and the contacts 1 to 10 of the
controller at the line Y Y the motors occupying the position indicated in the Fig. 5
the circuit is as follows:-
Entering from the trolley T the current passes to the contact 1, and then by
various cross-connections either between contact plates or contacts, to contacts 5
and 6 respectively. Starting from the contact 5 the circuit passes by the lead 5
and the lead 18 to contact 18, to contact 17, by lead 17 and lead 32 to the
armature A', through the armature and by leads 33 and 16 to contact 16, to
contact 15, by lead 15 to point D where the circuit is divided, one portion of tho
current passing by lead 35 through the field F¹, by lead 34 to contact 26, to
contact 27, by lead 27 and lead 8 to contact 8, by cross-connection to contact 9,
and finally by leads 9 and 48 to ground.
Returning now to the point D the other path is by lead 15 to point r', through
the resistance R', by lead 49 to contact 49, to contact 22, by the leads 22 and 10

page_text: to contact 10, by cross-connection to contact 9 where the current unites with that
portion of the total current which has traversed the field F and proceeds by.
leads 9 and 48 to ground. It is thus clear that the field F is shuntel by the
resistance R' when the switch S and the controller K are in the positions above
indicated.
Returning now to the point B on the lead 5; the current follows the lead 5 and
the lead 24 to contact 24 of the switch S, to contact 25, by leads 25 and 18" to.
contact 18, to contact 16", by leads 16 and 40 to armature A³, through this
armature and by leads 41 and 17* to contact 17", to contact 15, by leads 15 and 43
to the point where the eirenit divides one part of the current passing by the
lead 43 through the field F3, by the leads 42 and 8 to contact 8 by cross-connections
to contact 9 and by leads 9 and 48 to the ground. Going back to the point
other path is through the resistance R³, by the lead 20 to contact 20 of the
switch S, to contact 21, by leads 21 and 7 to contact 7 by cross-connections.
between contact plates to contact 9 where the two paths again unite and the current
proceeds by leads 9 and 48 to the ground. By this combination of circuits the
field is shunted through the resistance R.
the
Returning now to the contact 6 on the controller the circuit is as follows:-
The current passes by the lead 6 to the point C where the circuit divides, one
path being by the lead 14 to contact 14, to contact 13, by leads 13 and 36 to the
armature A, through the armature and by leads 37 and 12 to contact 12, to
contact 11, by lead il to a point where the lead 39 branches at which point the
circuit is again divided one portion of the current passing by the lead 39 through
the field F, by leads 38, 19 and 30 to contact 30 on the switch S, to contact 31
and by leads 31, 9 and 48 to the ground. Going back to the point where lead 39
joins the lead 11, the current continues along the lead 11 to the point r, through
the resistance R2, by the lead 23 to contact 23 to contact 22, by leads 22 and 10
to contact 10, to contact 9 and by leads 9 and 48 to the ground thus shunting the
field F by means of the resistance R2.
Returning now to the point C the other path of the current is as follows:-
By the leads 6 and 28 to contact 28 on the switch S, to contact 29 by leads 29
and 14 to contact 14, 10 contact 12", by leads 12 and 44 to armature A, through
the armature and by leads 45 and 13" to contact 13, to contact 11", by lead 11ª
to the point where the circuit divides as follows: One path is by the leads 11"
and 47 to the field F4, through the field, and by the leads 46, 9 aud 48 to ground.
The other path from the point r' is through the resistance R, by the lead 50 to
contact 50, to contact 21, by the leads 21 and 7 to contact 7, by cross-connection to
contact 9 and by lends 9 and 48 to ground, thus shunting the field F by means of
the resistance 1. It is thus evident that the switch S and the controller K in the
positions indicated the motors are grouped as shown in the Figure 5 each field
being shunted through its corresponding resistance, the highest speed of the enr
being thereby attained.
It will be observed from Figs. 1 and 6, that the contacts of the switch S are so
arranged that while the rows I, D' of contact-plates simultaneously touch the
contacts 24 to 31, 20 to 23, 49 and 50, the row of contacts D is spaced differently
from the others, the space between this row and the row D2 being greater than
between D and D2. By this means when the row D³ connects the contacts 25
and 26, and 29 and 30, the rows D' and D' open-circuit all of the other contacts,
and thus the resistances R' to R' will be open-circuited, as already pointed out.
I have descrit ed the device which I have invented as operating in one way, that
is, to so change the controller contacts and circuits that the speed of the motors
may be increased in the second position of the switch from that possible in the first
position. It is manifest that the reverse operation of the switch is also contemplated
in my invention and is to be included in the scope of the claims. It is also manifest
that I do not limit myself to the particular types of apparatus illustrated, as
switches of other forms might be used, and the combination may readily be

page_text: adapted to other forms of controlling apparatus than the ones illustrated without
affecting the essence of my invention, such modifications being readily apparent to
those skilled in the art.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me from
abroad, I declare that what I claim is :-
1. A controlling mechanism for electric motors, comprising a series-parallel
controlling switch having suitable circuits and contacts adapted to regulate the
motors from rest to a certain speed and an auxiliary switch adapted to modify the
circuits so that the controlling switch may regulate the motors from rest to another
or different speed.
2. A controlling mechanism for electric motors, comprising a series-parallel
controlling switch having contacts and connections adapted to regulate the motors
from rest to a certain definite speed, and in combination therewith an auxiliary
switch provided with contacts adapted to modify the circuits so that the controlling
switch may regulate the motors from rest to a higher speed than that of its first
operation.
3. In combination, an electric railway car, a plurality of motors upon the car, a
series-parallel controlling switch regulating the motors from rest to a certain speed
through series and multiple series positions, and an auxiliary switch modifying the
circuits of the controller so that by its operation after the auxiliary switch is
thrown the motors will be regulated through multiple series and multiple positions
from rest to a different speed from that possible with the first operation of the
controller.
4. In an electric railway car, in combination with a series-parallel controlling
switch, a circuit-modifying or auxiliary switch located out of the control of the
motor-man or other operative, adapted to change the combination of motors and
controlling circuits so that in one of the positions of the auxiliary switch the motors
may be run at one speed by the controller and in the other position thereof may be
run at a different speed.
5. A controlling mechanism for electric motors, comprising a series-parallel
controlling switch having suitable circuits and contacts for regulating the motors
from rest to a certain speed, and circuit-modifying means whereby the controlling
switch may regulate the motors from rest to a different speed.
Dated this 11th day of February 1896.
For the Applicant,
J. C. CHAPMAN,
70 Chancery Lane, London, W.C., Chartered Patent Agent.