Year: 1886

page_text: [Communicated from abroad by CHARLES FRANCIS BRUSH, of Cleveland, Ohio, United
States of America, Electrician.]
I, HERBERT JOHN HADDAN, of 67, Strand, in the County of Middlesex, Civil
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 improvements in automatic electric-current governors or
regulators, and has for its object the automatic control and regulation of the strength
of the current in an electric circuit in which the current strength is subject to
variations due to variations in the speed of the armature of the dynamo electric
machines, or to varying resistances in the circuit owing to an increase or decrease of
work or of the number of translating devices included therein, or to other or both of
the causes specified.
The invention consists in the combination, with an electric circuit, of a series of
resistances and means actuated by the varying current strength in the circuit for
automatically switching into an electric circuit the series of resistances (some or all of
them) in multiple arc with each other.
The invention further consists in combination of parts and features of construction,
as will be hereinafter described, and pointed out in the claims.
In the accompanying drawings, Figure 1 is a view in side elevation of one form of
electric-current governor embodying the invention, only one of the wire resistances
being shown in detail, the remaining resistances being illustrated in dotted lines.
Fig. 2 is a detached view partly in section and partly in end elevation, illustrating by
dotted lines the position assumed by the parts in the simultaneous adjustment of the
series of contact-rods. Fig. 3 is a detached view in perspective of one of the tubular
holders, contact-rod, and a portion of the armature. Figure 4 illustrates the governor

page_text: applied to the circuit of a dynamo-electric machine for automatically controlling the
magnetic field of the machine to govern and control the current in the working circuit ;
and Figs. 5, 6, 7, 8, 9, and 10 illustrate modifications.
A represents a frame, which may be made of cast-iron, wood, or other material, and
of any desired shape and form. It is provided at its upper end with the top portion
or forwardly-projecting flange, A³, from which are suspended the operating parts of
the governor.
A A³ are binding posts secured to the top of the frame, and insulated therefrom by
insulating washers A. To the binding-posts are detachably connected, by the screws a,
the ends of the circuit B, which for convenience of reference, I will designate as the
"main" circuit.
B¹ represents a long electro-magnet, the opposite ends of the conductor, comprising
its helix B, being permanently secured to the binding posts A² A³, whereby the
electro-magnet B is included in the main circuit and energized by the current flowing
therein.
C represents a series of armatures located at a considerable distance below the broad
pole-piece b of electro-magnet B', in order to insure a practically uniform pull of the
magnet on the armatures throughout their entire range of movement, and thereby
cause a slight increase or correspondingly slight decrease in the strength of the magnet
to attract or release the armature. The armatures are each supported, as represented
in Fig. 2 on a strip, C, of wood or other insulating material fastened to the frame
underneath the ledge C³, which latter is formed on the frame itself, the strip C¹ and
the ledge C being located at such distance apart as to form a groove within which the
ends of the armatures are inserted. The insulating-strip C³, fastened to the under side
of the ledge (3, operates to insulate the armatures from the frame. The inner end of
each armature is provided with a hole or depression, c³, in which is received a pin or
stud, fastened to the strip C³, which serves to retain the inner end of the armature
against lateral or endwise displacement, and allow the armature to be supported on the
edge of its downwardly-curved rear end and rock thereon, and thus be subjected
to only the minimum amount of friction in its operation. The outer or free ends of
the series of armatures rest on a bar or strip, D, of wood or other insulating material,
and hence are retained at an equal distance from the pole of the magnet B¹, and are
retained against lateral displacement by the guide-pins d². The bar or strip Dis
journalled between the depending arms d of the bracket D¹ by the pivotal bearing D',
to allow the strip to be slightly rotated on its axis for a purpose which will be herein-
after explained. To the free end of each armature is fastened a depending tubular
holder, E, which is closed at its lower end, and contains in its lower portion a spiral
spring e. Within the holder is inserted a contact-piece or rod, E', which is preferably
made of carbon, but may be made of any other suitable material. Contact-piece E¹ is
a straight rod, preferably cylindrical in cross-section, and loosely fits within the tubular
holder and rests upon the spiral spring e, contained therein. That portion of the
tubular holder extending above the armature is cut away so as to form a semicircular
bearing e¹, against which rests one side of the projecting end of the contact piece or
rod E. To the lower portion of the tubular holder is secured one end of a wire
spring E2, which extends upwardly and passes through an elongated slot, E³, in the
armature, the upper end of the spring being bent laterally and then forwardly and
around in front of the contact-rod, the straight ende bearing against the contact-rod
and forcing it into contact with its semicircular seat or bearing e¹. The spring E³ is
sufficiently strong to force the contact rod against its seat or bearing el with sufficient
force to securely clamp the contact rod and retain it in its proper adjustment. On
each tubular holder is fastened a hook, e, on which is suspended a weight, e¹, for the
purpose of adjusting the armature, so that it will respond to a predetermined pull of
the magnet. Instead of a weight, an adjustable spring might be connected with the
holder for this purpose. Above the series of contact rods is located a rod, bar, or
cylinder, F, which is preferably made of carbon although any other suitable electric
conductor might be used for this purpose. Carbon is the preferred material for the

page_text: series of contact rods and the main contact bar or rod F, because of its well-known
great refractory qualities, good conductivity, and the fact of its cheapness enabling the .
parts to be renewed or replaced at a small expense.
The rod or cylinder F is journalled at its opposite ends on adjustable screw-points f,
so that it may be easily removed when necessary, and may be readily rotated so as to
present a fresh surface for the series of contact rods to engage with whenever any
portion of the surface of the cylinder F becomes uneven or unduly worn or burned away.
As herein before stated, the bar or strip D, on which rest the free ends of the series
of armatures, is journalled between the brackets d. The object of this is to provide
for the simultaneous adjustment of all the contact-rods of the series, which result is
effected as follows: By pressing on the thumb piece G, attached to the lower edge of
the strip or bar D, and moving its lower edge rearwardly, its upper and forward
edge G¹, will be moved forwardly and engage each one of the spring arms E³, and
simultaneously retract the entire series, and thus operate to release the clamping arms
or fingers from their contact rods, as shown by dotted lines in Fig. 2, and allow the
contact-rods to be forced upwardly by their spiral-spring supports within the holders
into contact with the main contact bar or cylinder F. This operation is quickly
performed and simultaneously adjusts the contact rods so that their outer ends will be
in alignment with each other, or, in other words, the main contact bar F forms a
straight and an even gage against which the ends of the several contact-rods are forced
simultaneously, and thus brought into perfect alignment with each other. The position
of the parts in effecting this operation is illustrated in Fig. 2. The next operation is to
simultaneously separate the contact rods a very slight but a uniform distance from the
main contact rod or cylinder F, which is effected as follows, reference being had to
Fig. 2 After the spring clamps have been retracted and the contact-rod clamp
disengaged by the action of the edge G¹ of the oscillating bar or strip D, the lower
edge of the latter is pulled outwardly, as shown by the dotted lines in Fig. 2, which
operates to move the upper edge rearwardly, and cause the forward edge G¹, to
engage the under side of all the armatures and lift them a slight distance, as repre-
sented by dotted lines in Fig. 2, the effect of which is to slightly raise each one of the
tubular holders and contact-clamps carried thereon, and, as the ends of the contact
rods rest against the cylinder F, they will be held stationary while the tubular holders
are raised, and hence the several clamps or arms will each be moved upwardly on its
contact-rod and form a new point of engagement therewith. This having been done,
the edge G of the bar or strip D is moved outwardly again allowing the armatures
to descend and carry with them their contact-rods, and thus separate the ends of the
latter a very slight distance from the surface of the main contact bar or cylinder F.
As all the armatures are moved exactly the same distance in effecting the adjustment
of the contact-rods, the ends of the latter will all be equally distant from the main
contact-cylinder. Springs F¹ attached to the bracket arms, engage the adjustable strip
or bar D and prevent it being accidentally displaced. I have already called attention
to the fact that the armatures are located at quite a distance from the pole-piece of the
long electro-magnet, in order to insure a uniformity of pulling action of the magnet
on the armature. This distance of separation may be varied as occasion may require
by the following means: the electro-magnet is preferably secured in a permanent
manner to the top A¹ of the frame. The bar or strip D, which serves as a support for
the outer or free end of the armatures, is journalled in the arms of the bracket D¹,
which latter is made vertically adjustable in the following manner. To the top of the
frame are secured the screw-rods H, one at each end, which extend downwardly and
form guides for the cross-bar H₁ of the bracket, thereby enabling the latter to be
vertically moved thereon. On each one of the screw rods is placed a nut, H*, the
periphery of which constitutes a sprocket-wheel H³. An endless chain H, engages
the two sprocket wheels H. By moving the chain on one direction bracket Dis
raised and the series of armatures moved toward the pole of the electro magnet, and
by moving the chain in the opposite direction the bracket is lowered and the armatures
moved away from the pole of the magnet; hence all of the armatures of the series may

page_text: be simultaneously adjusted with relation to the pole-piece of the electro-magnet, which
adjustment is convenient to adapt the apparatus to the automatic control and regulation
of electric currents of different strength. On the pole-piece of the magnet-is secured
a strip, h, of wood or other suitable insulating material, which serves as a spacing strip
and as a stop for the armatures.
I I represent resistances, only one being illustrated in Fig. 1 the others of the series
being represented by dotted lines. Each one of the resistances is preferably composed
of German-silver wire of small gage, which is first coiled into a spiral and then
stretched, one end of the wire being attached to a hook, i, fastened to the pivoted end
of the armature, from which point the wire is carried down and attached to a hook i¹,
fastened to the insulated bottom I of the frame, and from thence the wire is carried
upwardly and attached to a hook, fastened to the strip or bar D, and from thence
it extends downwardly, and its opposite end is fastened to a hook, ³, secured to the
bottom piece I', of the frame. All of the hooks are soldered to or otherwise
electrically connected with the copper wire J or other suitable electrical conductor.
By making the resistance in the spiral form and stretching the spirals and then
fastening them in the manner shown and described I secure the following advantages:
When the resistances become heated and expanded, the spring action of the spiral con-
ductors operates to take up and compensate for the slack in the wire, and prevents it
from sagging and making contact with the frame or any other one of the resistances
of the series. Again, by winding the wire into the form of a spiral, and then stretching
it as described, a great length of wire is disposed within a comparatively small spaco,
and each coil is subjected to the colling action of the air, and thus, the heat
generated in the resistance by the current is rapidly radiated. The zigzag
arrangement of the resistances also allows the apparatus to be brought into
comparatively small compass and thus require but little space for its accommodation
in use.
The conductor J, with which is connected one end of each resistance of the
entire series, is electrically connected with the conductor J which leads and is
permanently secured to the binding post J', while a conductor, J³, is connected at
one end to the other binding post J³, and its other end is connected to the pivotal
scrow f. Both of the pivotal screws f, which support the main contact cylinder or
rod F, are insulated from the bracket by the insulating-washers g. Thus it will be
observed the conductor J is electrically connected with one end of each resistance of
the entire series, while the conductor J¹ is electrically connected with the main contact
bar or cylinder F.
Having described the construction and arrangement of the several parts of one
form of electric-current governor embodying my invention, I will now describe its
operation when used for controlling the volume of current in the external or working
circuit of a dynamo-electric machine by automatically varying the intensity of the
magnetic field in which the armature rotates to compensate for varying resistance
in the external or working circuits of the dynamo.
The broad principle of automatically regulating the strength of the current in the
main circuit of a dynamo by automatically controlling and varying the intensity of
the magnetic field of the dynamo-machine is fully set forth and illustrated by other
forms of current governors in Letters Patent granted to me as follows: No. 2003
of 1878, and No. 1835 of 1881 and hence need not be elaborated here.
In Fig. 4 I have represented the improved current governor included in the circuit
of a dynamo-electric machine. L represents the field-of-force magnets of the dynamo ;
L', the armature; L³, the armature-shaft; I, the commutator. The helices of the
field magnets are connected in series, one end of the conductor N being connected
with the commutator-brush M, and the other end to the binding-post M', which forms
one terminal of the machine. The other binding post or terminal, M³, is connected
with the other commutator-brush M. To the binding posts or terminals M¹ M³ are
connected the two ends of the external or working circuit B. In the working circuit
is included the current governor, the circuit being severed and the ends secured to the
binding posts A² A². As the ends of the helix of the electro-magnet B¹ are connected

page_text: to the binding posts A² A the electro-magnet B' will thus be included in the main
circuit and energized by the current flowing therein. The binding post J³ is connected
with the binding post or terminal M¹ by the conductor K, and the binding post Ja is
connected with the commutator brush M, or a binding-post electrically connected with
the commutator-brush M by the conductor K'. Thus there is provided abnormally-
open shunt-circuit around the field of force magnets, one end of the shunt-circuit
connected with the binding-post M³, and leading by the conductor K to the binding-
post J, and from thence by the conductor J¹ to the main contact-rod or bar F. The
other end, K, of the shunt is connected to the commutator-brush M, or a binding
post electrically connected therewith, and the binding-post J2 of the current governor,
and by the conductor J' is connected with one end of each one of the series of
resistances, the latter being electrically connected with the series of independent
contact rods by the series of armatures. The shunt-circuit is thus open between the
main contact-rod F and the series of small contact rods E', the space between the
main and independent contacts being very slight, as illustrated in the drawings.
Now, so long as the shunt-circuit remains open, all of the current generated by
the machine will circulate in the external circuit and in the field-of-force magnets of
the machine; but in the event that the resistance in the working circuit is diminished
for any reason-as, for instance, by the switching out of electric lamps, motors or
other translating devices therefrom-the current in the main circuit becomes
abnormally strong, and operates to correspondingly augment the strength and pull
of the electro-magnet B', which in turn attracts the series of armatures. As it is a
mechanical impossibility to construct and arrange a series of armatures so that all
will respond to exactly the same pull of the magnet, or so that all will be exactly
equal in sensitiveness, it follows that when the electro-magnet B¹ is energized it will
cause the most sensitive armature of the series to respond and be raised, and thereby
cause its contact-rod E' to engage the main contact-bar F, the effect of which is to
close the shunt-circuit around the field of force magnets through one of the
resistances I, and thus divert a portion of the current developed by the dynamo from
the field-magnets, the amount thus diverted or shunted away from the field-magnets
being proportioned to the relative resistance of the shunt and the main circuit.
Should the amount of current thus shunted be insufficient to weaken the field-
magnets enough to decrease the current strength in the main circuit to correspond
to the decrease in the resistance interposed therein, the electro-magnet B¹ will attract
another one of the series of armatures, and thus automatically throw into the shunt-
circuit another resistance I in multiple arc with the resistance first switched in. In
the same manner will the electro-magnet B¹ continue to successively throw into the
shunt-circuit a sufficient number of the resistances in multiple arc with each other
to divert such an amount or proportion of the current generated by the machines
will operate to weaken the field-magnets to a point corresponding with the decreased
resistance in the working-circuit. On the other hand, any increase of resistance in
the working-circuit will operate to decrease the strength of the electro-magnet B¹
and cause the armatures of the series to successively drop and open circuit the
resistances I, and thereby increase the resistance of the shunt-circuit and divert more
current through the field-magnets, augmenting their strength until the strength of
the current developed by the machine shall correspond to the increased work or
resistance interposed in the main or working circuit. In view of the fact that each
one of the resistances of the series may be of any fixed or predetermined electrical
resistance, and that any number of such separate resistances may be arranged to be
thrown into the shunt circuit around the field-magnets in multiple are with each
other, and, further, that the armatures and contacts for automatically switching the
resistances into and out of the shunt-circuit are constructed and arranged to be
actuated by slight fluctuations in the strength of the current in the main or working
circuit, I am enabled to maintain a practically-uniform volume of current in the main
circuit, although the resistance therein is greatly varied, either by an increase or a
decrease of work interposed therein.

page_text: By manipulating the governor in the manner hereinbefore described all of the
series of contact points or rods may be simultaneously and uniformly adjusted with
respect to the main contact-bar, and when the surface of the latter becomes worn
unevenly by the continued contact and engagement of the small contact points or
rods therewith, a fresh and even surface may be readily presented by slightly
rotating the main carbon rod or bar on its journals.
While I have shown and described one form and construction of current governor
embodying my invention and one of its different applications, I do not restrict
myself to the particular use set forth nor to the particular construction and
arrangement of parts shown and described.
The main electro-magnet, instead of being constructed as a single magnet, as
shown, may consist of a number of separate and independent magnets O, included in
series with each other, as illustrated in Fig. 5; or a solenoid, O¹, may be employed
and each armature be provided with a core 02, entering the space O³ in the solenoid
as illustrated in Fig. 6.
Again, instead of using an endless chain and sprocket wheels for adjusting the
armature with respect to the pole of the magnet, I may use, and preferably shall use,
adjusting devices of the character illustrated in Fig. 7, in which o is a worm-rod
journalled in bearings o' on the main frame, one end of the rod having a hand-wheel, o¹,
attached thereto for rotating it. Worm o engages the worm-gears o² 0³. By rotating
the hand-wheel and worm the bracket may be readily raised or lowered and retained
in any desired adjustment.
Again, instead of employing a series of armatures, I may dispense with the armatures
and use a solenoid and adjust the main contact bar or rod as illustrated in Figs. 8 and 9.
In this modified form of construction P represents a solenoid included in the main
circuit, and P¹ its core, the lower end of which is secured to one end of a lever, P2, the
buter end of which is constructed with lateral arms p, between which is journaled the
main contact bar or rod F. Beneath the contact-bar F are located the series of tubular
holders E, each supporting its contact-rod E¹. Each holder E is supported in position
by an elastic strip 7, of conducting material, one end of which is attached to a flange
or strip, q, fastened to the frame and insulated therefrom, while the outer end of each
strip is fastened to one of the tubular holders. A spring-clamp is attached to each
holder for the purpose of clamping the small contact-rods, and an oscillating strip or
bar, D, is situated below the strip for simultaneously adjusting all the contact-rods by
first releasing all of the clamps and allowing all of the contact-rods to be forced
upwardly against the main contact bar or rod F, and then raising all of the tubular
holders and afterward lowering them to adjust all of the contact-rods E' evenly and
uniformly, as has been fully set forth. A bar R, of non-conducting material, attached
to a pivoted arm, R', rests upon the entire series of strips y, and serves as a stop for
each one and retains them in a uniform adjustment. When the current in the main
circuit is abnormally strong, the core of the solenoid will be raised and operate to
depress the main contact-bar F, and cause it to engage one or more of the contact-
points E' and automatically switch into the shunt circuit around the field-magnets some
or all of the resistances in multiple arc with each other, and thus weaken the magnetic
field of the machine to correspond with the decrease of resistance in the working
circuit, while an increase of resistance in the main circuit will operate to weaken the
strength of the solenoid and allow the spring R² to raise the main contact-bar, and
thereby switch out of the shunt-cireuit some or all of the resistances of the series and
divert more current through the field-magnets of the machine to cause the latter to
produce an increased amount of current proportioned to the increased amount of
resistance interposed in the working-circuit.
The main contact bar may be cylindrical or it may be square, octagonal, or of any
other form in cross-section. Instead of wire resistance I may use a series of carbon
resistances, and each may be made so that its resistance may be varied.
Again, instead of employing the series of contact-rods, tubular holders, and spring-
clamps, I may use carbon disks journaled in the free ends of the armature or elastic-

page_text: strips, and provide means for imparting a slight rotary movement to each disk every
time it is raised or lowered, and thus insure a uniform wear of its periphery.
Again, the main contact-bar may be journaled on adjustable screw-pivots, and one
of them be supported in a vertical slot, S, in the bracket, as illustrated in Fig. 10, the
bearing S being supported by a spring S. When all of the contact-rods have been
released and forced upwardly by their springs against the main contact-bar, one end
of the latter may be depressed slightly and then released and allowed to be raised by
the springs S. This operation will adjust the contact rods so that the space between
the series of contact-rods and the main contact-bar will gradually increase from one end
of the series to the other, and thus cause the contacts to be successively actuated from
one end of the series to the other.
Having now fully 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 ;-
1st. The combination with a series of resistances and a series of contacts connected
therewith, of a translating device constructed and arranged to actuate said contacts
and automatically and independently switch some or all of the resistances into an
electrical circuit in multiple arc with each other, substantially as set forth.
2nd. The combination, with a series of resistances and a series of independently-
movable contacts connected therewith, of a translating device for automatically and
independently switching some or all of the resistances into an electrical circuit in
multiple arc with each other, substantially as set forth.
3rd. The combination, with a series of resistances and a series of armatures con-
nected therewith, of a translating device for automatically and independently actuating
said armatures and switching some or all of the resistance into an electrical circuit in
multiple arc with each other, substantially as set forth.
4th. The combination with a system or series of resistances and a system or series
of armatures, each provided with a contact electrically connected with one of the
resistances, of a main contact, and a translating device for automatically and inde-
pendently actuating said armatures and switching some or all of the resistances into
an electrical circuit in multiple arc with each other, substantially as set forth.
5th. The combination, with an electro-magnet and a series of resistances, of a
series of armatures adapted to be actuated by the electro-magnet and automatically
switch some or all of the resistances into an electrical circuit in multiple arc with
each other.
6th. The combination, with a conductor forming a contact, of a series of inde-
pendently adjustable contacts and means for simultaneously adjusting the series,
substantially as set forth.
7th. The combination, with a series of armatures, each provided with a contact
adapted to be fed to compensate for wear, of means for simultaneously adjusting the
series of contacts, substantially as set forth.
8th. The combination with a series of resistances and a series of independently-
movable carbon contacts electrically connected therewith, of a translating device for
automatically and independently actuating said contacts and switching some or all
of the resistances into an electrical circuit in mutiple are with each other, substantially
as set forth.
9th. The combination with a series of resistances and a series of independently-
movable carbon contacts electrically connected therewith, of a main carbon contact
and a translating device for automatically and independently actuating the contacts of
the series and switching some or all of the resistances into an electrical circuit in
multiple arc with each other, substantially as set forth.
10th. The combination with a series of resistances and a series of independently-
movable contacts electrically connected therewith, of an adjustable conductor forming
a contact common to the series of contacts, substantially as set forth.

page_text: 11th. The combination with an electro-magnet, (one or more) of a series of
armatures for actuating a series of contacts and means for simultaneously and equally
varying the distance between the armatures and the electro-magnet, (one or more,)
substantially as set forth.
12th. The combination, with a series of contacts and devices for gripping or
clamping each contact, of means for simultaneously releasing all of the contacts from
their gripping or clamping mechanism, substantially as set forth.
13th. The combination, with a series of contacts, of means for simultaneously
adjusting and clamping all the contacts of the series.
14th. The combination with a series of contacts, of means for releasing all the
contacts, means for imparting equal and simultaneous adjustment to all the contacts,
and means for simultaneously clamping all the contacts, substantially as set forth.
15th. The combination with a series of independently-movable contacts, of a contact
common to the series, constructed and adapted to be adjusted so as to present different
surfaces to the action of the different contacts the series.
16th. The combination with a series of resistances and contacts electrically con-
nected therewith, of a translating device, and devices combined therewith, and the
-resistances for automatically and independently switching some or all of the resistances
into an electrical circuit in multiple arc with each other on the increase of current
strength in the circuit, including said translating device, substantially as set forth.
17th. The combination with a contact and an electro-magnet, of an armature and a
contact supported thereby and means for feeding the movable contact to compensate
for wear, said parts being constructed and arranged to either close the circuit by
the direct engagement of the contacts or open the circuit by their separation, sub-
stantially as set forth.
18th. The combination with a carbon contact and an electro-magnet, of a series of
armatures and a series of carbon contacts, and means for feeding the contacts of the
series to compensate for wear, substantially as set forth.
19th. The combination, with a main contact and an electro-magnet, of a series of
contacts adapted to engage the main contact and devices for clamping, feeding and
releasing the movable contacts substantially as set forth.
20th. The combination, with an armature, of a contact holder connected with the
armature, a spring for feeding the contact, and a clamping device for retaining the
contact in any desired adjustment, substantially as set forth.
21st. The combination, with an electro-magnet included in the circuit of an electric
generator and a series of resistances, of devices actuated by the electro-magnet for
automatically and independently switching one or more of the resistances into a shunt-
circuit in multiple are with each other on the increase of strength of the current in the
circuit including the electro-magnet, substantially as set forth.
22nd. The combination, with an electro-magnet included in the circuit of an electric-
generator and a series of resistances, of a series of armatures adapted to be actuated
by the electro-magnet and automatically switch some or all of the resistances into a
shunt-circuit in multiple arc with each other on the increase of the strength of the
current in the circuit including the electro-magnet, substantially as set forth.
23rd. The combination, with an electro-magnet included in the main or working
circuit of a dynamo electric machine, of a series of resistances and means actuated by
the electro-magnet for automatically and independently switching some or all of the
resistances in multiple arc with each other into a shunt-circuit around the field-magnets
of the dynamo-electric machine on an increase of current strength in the main or
working circuit, substantially as set forth.
24th. The combination with a holder or support, of a contact bar or rod detachably
secured in said holder and a spring for forcing the contact bar or rod outwardly from
its holder, and a spring actuated clamp connected with the holder and adapted to

page_text: engage the contact bar or rod and secure it in any desired adjustment, substantially
as set forth.
25th. The combination with an electro-magnet or solenoid and a series of arma-
tures, of a main contact and a series of contacts and means for simultaneously
adjusting the series of armatures with relation to the electro-magnet, substantially
as set forth.
26th. The combination with a rotary adjustable conductor constituting a main
contact, and a series of independently movable contact bars or rods, of a translating
device included in an electrical circuit and means combined therewith for automatically
and independently actuating some or all of said movable contacts, substantially as
set forth.
27th. The combination, with a rotary adjustable carbon bar or cylinder constituting
a main contact and a series of independently-movable carbon rods constituting con-
tacts, of a translating device and means combined therewith for automatically and
independently actuating some or all of said movable contacts, substantially as
set forth.
H. J. HADDAN.
Pp. Herbert & Co.,
67, Strand, W.C.,
Agents to Applicant.