IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Year: 1883

page_text: LETTERS PATENT to William Phillips Thompson of the Liverpool and London
Agency for Foreign Patent Solicitors 6. Lord Street Liverpool in the county
of Lancaster Civil Engineer for an Invention of IMPROVEMENTS IN DYNAMO
ELECTRIC MACHINES a communication from Robert J Sheehy' a person
resident in the City, County and State of New York United States of America
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 25th September 1888.
WILLIAM PHILLIPS THOMPSON of the Liverpool and London Agency for Foreign
Patent Solicitors, 6 Lord Street Liverpool in the County of Lancaster, Civil
Engineer "IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES."-A communication
from Robert J. Sheehy, a person resident in the City, County and State of New
York, United States of America."
This invention relates to the art and practice of economically converting the
energy of mechanical force into that of electrical currents.
It has for its object to increase the efficiency of the so-called dynamo-electrio
machine, especially such forms as are employed in the production of currents of
large volume and high intensity. It concerns in this connection the methods of
utilizing the magnetic field, of economically maintaining the magnetic intensity, of
applying the power to rotate the armatures, of adapting the armature-conductors
to the requirements of the external circuit, and of maintaining a uniform current
throughout any given circuit.
In general the more important features of the improved machine constituting the
subject-matter of this invention may be enumerated as follows :—
First, for the purpose of generating currents economically the machine is
constructed with a number of field pole-pieces arranged in a series of alternating
polarities, and provided with intermediate armatures between adjacent pole-pieces,
and exterior armatures against the outer faces of exterior pole-pieces
Secondly, the fields of the several armatures are maintained by means of the
currents generated in said outer armatures, employing one or both as may be
required.

page_text: Thirdly, the driving power is communicated from a main Shaft to the
independent armature-shafts through the medium of friction gearings which may
be independently operated.
Fourthly, mechanism is provided whereby the length of all of the conductors in
each of the several bobbins of any armatures may be simultaneously increased or
reduced to compensate for changes in the conditions of the external circuit ; and
Fifthly, means are provided for automatically operating said mechanism for
varying the length of the conductors in the armature bobbins when the normal
strength of current is disturbed, thereby so altering the electro-motive force and
internal resistance of said armature, as to restore the normal strength of current
generated.
For the purpose of regulating the volume or strength of the current generated in
each armature independently of the remainder, the several coils of each armature
are constructed in such a manner that a greater or less portion of the wire
constituting the same may be employed at will, thus varying the total amount of
active inductive wire in the circuit.
The manner in which this end is accomplished consists in placing upon each
armature-shaft, a disc of non-conducting material, such for example as compressed
paper, carried upon the face of a metallic supporting plate, and in mounting thereon
a number of radial series of contact-points.
The successive contact-points are electrically connected by conductors with the
successive layers or groups of layers of the insulated wire constituting the bobbins
of the armatures.
An electro-magnetic motor of any suitable construction is included in the external
circuit of each armature of the generator and arranged to revolve a shaft under
the influence of an electric current of increasing strength, and to allow the same to
be revolved in the opposite direction through the influence of a weight when the
current traversing the coils of the motor decreases in strength.
Upon the shaft is formed a continuous thread along which a corresponding
threaded traveller is caused to move in one direction or the other according to the
direction of revolution of the shaft. A forked lever is operated by the traveller.
This lover is pivoted about its centre and also forked at the opposite end which
embraces a collar on the armature shaft and sliding thereon on a feather or key.
The other end of the collar engages the short arms of a series of levers which serve
to close the circuits between the opposite contact points. A series of levers are
pivoted at points equidistant from each other round a collar rigidly fixed to the
shaft. Each of these levers is moreover so constructed that the extremity of its
long arm which is preferably insulated from the lever itself may be swung outward
from the centre of the shaft in the plane of the radial series of contact points.
In front of each radial series of contact-points and extending parallel thereto, is
a guide-rail supported at each end from the disc by arms extending through the
metallic supporting plate but insulated therefrom. Each guide-rail is provided
with a movable collar or traveller upon which is carried a circuit closer.
The circuit-closers each consist of a wheel having four teeth or projections, two
of which diametrically opposite each other are of slate or other suitable non-
conducting and non-inflammable material. This four-armed wheel is pivoted at
Its centre to a resilient arm of conducting material, rigidly supported from and in
electrical connection with the carrier. The conducting teeth or prongs of the
wheel have their extremities rounded and are constructed to fit into recesses
formed in the faces of each of the contact-points.
It will now be evident that when the collar is moved forward towards the lug
to which the levers are pivoted, the short arms of the levers will be pressed
outward, and the long arms forced toward the centre of the shaft, thereby bringing
the circuit-closers into contact with the innermost contact-points. When on the
other hand the collar is moved in the opposite direction the long arms of the levers
will be carried outward by means of the force exerted by the springs combined
with the centrifugal force occasioned by the rapid revolution of the armature

page_text: Shaft. As the arms are carried outward the circuit closers make connections
between the successive contact-points and the guide-rails. The rails which
correspond with the diametrically opposite armature coils are electrically connected
with each other by conductors.
The object of this regulating mechanism is to maintain a constant uniformity in
the strength of current traversing the external circuit. The operation of the
device is as follows:-The circuit-closers are in contact with the inner circular
range of contact-points which as already described are connected with the inner
terminals of the innermost groups of conductors of the respective bobbins to which
they correspond. This is the condition best suited to the development of currents
of high electro-motive force. If now, for any reason, the resistance of the external
circuit is diminished, the strength of current in the circuit will be proportionally
increased. This will operate the motor, to withdraw the collar and allow the
outward movement of the levers. The circuit-closers on leaving the inner circular
series of contact-points and making connections with the second series, eliminate
from the main circuit the inner group of conductors. This simultaneously reduces
the electro-motive force of the current generated and the internal resistance of the
machine. If the strength of current is still excessive the circuit closers are still
further advanced and the length of wire in the armature still further decreased.
Ultimately the condition is reached in which the original strength of current is
again established throughout the circuit. On the other hand if the strength
of the current generated falls below the predetermined point, the motor-shaft
is rotated in the opposite direction by means of the weight and the convolutions
are reintroduced.
For the purpose of adjusting the motor to respond to currents of any required
strength, it is preferred to attach the cord supporting the weight to a conical drum
in such a manner that the weight will exert a greater retarding influence upon the
shaft at the start than thereafter to prevent action of the regulator in response to
slight diminutions of resistance or variations of speed of the machine. To prevent
the circuit-closers from remaining at positions intermediate between two contact-
points, there is mounted upon the motor-shaft an arm carrying at its extremity
a pyramidal wedge in connection with adjustable tension-cluten consisting of two
resilient arms or springs normally so far separated as to allow the cam to enter the
space between them, but not to allow it to pass between without separating them
still farther. This renders the movement intermittent.
For the purpose of allowing this shaft to be revolved freely in the reverse
direction, the springs are hinged and held in position by another spring.
A modification of the device employed for cutting the successive layers of bobbin
wire out of circuit may be used, the object of which is to combine a commutator
with the device for varying the length of the armature conductors, and thereby
dispense with the commutator placed at the opposite extremity of the armatures.
It consists in constituting each of the pivoted levers a conductor and pivoting
them in a non-conducting support. An annular series of metallic contact-segmenta
surrounds these levers one of which is adjacent to and in electrical connection with
each of said segments. The brushes will then at any time be in electrical
connection with the outer terminals of opposite bobbins. Assuming that the
inner terminals are connected together directly and that the connections between
opposite guide-arms have in this instance been severed, corrents will be collected
by said brushes, which will depend in strength upon the positions of the circuit-
closers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson in the Patent Office on the 25th March
1884.
"
WILLIAM PHILLIPS THOMPSON of the Liverpool and London Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, in the county of Lancaster, Civil
Engineer IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES" A communication
from Robert. J. Sheehy a person resident in the city, county, and state of New
York, United States of America.
This invention relates to the art and practice of economically converting the
energy of mechanical force into that of electrical currents.
It has for its object to increase the efficiency of the so-called dynamo-electric
machine, especially such forms as are employed in the production of currents of
large volume and high intensity. It concerns in this connection the methods of
utilizing the magnetic field, of economically maintaining the magnetic intensity,
of applying the power to rotate the armatures, of adapting the armature-conductors
to the requirements of the external circuit, and of maintaining a uniform current
throughout any given circuit.
In general the more important features of the improved machine constituting the
subject-matter of this invention may be enumerated as follows :—
First, for the purpose of generating currents economically, the machine is
constructed with a number of field pole-pieces arranged in a series of alternating
polarities and provided with intermediate armatures between adjacent pole-pieces,
and exterior armatures against the outer faces of exterior pole-pieces.
Secondly, the fields of the several armatures are maintained by means of the
currents generated in said outer armatures, employing one or both as may be
required.
Thirdly, the driving power is communicated from a main shaft to the
independent armature-shafts through the medium of friction gearings which may
be independently operated.
Fourthly, mechanism is provided whereby the length of all of the conductors in
each of the several bobbins of any armature may be simultaneously increased
or reduced to compensate for changes in the conditions of the external circuit :
and,
Fifthly, means are provided for automatically operating said mechanism for
varying the length of the conductors in the armature bobbins when the normal
strength of current is disturbed, thereby so altering the electro-motive force and
internal resistance of said armature, as to restore the normal strength of current
generated.
In the accompanying drawings, Fig. 1 is an elevation, and Fig. 2 a plan of the
compound dynamo-electric generator, or bank of generators. Fig. 3 is a longitudinal
view mostly in section of one of the armatures, showing the commutator mechanism,
the mechanism for varying the length of armature-conductors, and the motor for
automatically actuating the same. Fig. 4 is a face view of the commutator
employed in conjunction with each armature Fig 5 is an end view of the
apparatus for varying the length of said armature-conductors. Fig 6 is a
modification of the improvements consisting of a combination of a commutator
with the mechanism for varying the length of armature conductors, and Fig 7.
is a detached view of one of the cores of the armature bobbins. Similar letters of
reference are applied in the serveral figures to the same parts.
Referring to the drawings, A¹ A' represent two electro-magnets, with yokes B¹

page_text: and B respectively.
The pole-pieces of these electro-magnets are shown at
C¹ C³ C³ and C* respectively. Each of the pole-pieces C consists of a block of iron
having a longitudinal semi-circular recess c formed in each side thereof. The
helices of the electro-magnets are connected together in one electric current, the
winding being in such directions that under the influence of the current the
polarization of the alternate pole-pieces will be opposite. Thus for example, that
of C¹ will be north, that of C³ south, etcetera. Within each of the cylindrical
openings formed by the confronting recesses c, made in the extensions C¹ C² C³
and C, as also within each of the recesses formed in the outer surfaces of the two
extreme pole-pieces C¹ and C, is placed a cylindrical armature D. The outer
armatures D¹ and D" are each provided with a field of force created by the pole-
piece Cupon one side only, whereas the three intermediate armatures D2 D3 and D*
are each provided with fields of force created by a pole-piece upon each side. The
former therefore revolve in a field of one polarity, while the latter revolve through
two fields of opposite polarity.
Against the extremities of each pole-piece C is secured an iron plate E, which
serves to extend the magnetic field over the ends of the armature bobbins as they
are revolved in proximity to that extension. A standard F preferably of non-
magnetic metal is secured to each of the plates E at the ends of each armature,
and within said standards are formed suitable journal-boxes f for receiving the
respective ends of the armature-shaft d.
The armatures D are independently connected through their shafts & with a
horizontal shaft G extending in a direction at right angles therewith. The
horizontal shaft G carries a pulley g, by means of which a rotary motion may be
communicated thereto from any suitable source of power. The rotary movement
of the shaft G is communicated to the armatures D respectively, by means of
beveled friction wheel H and I of compressed paper mounted upon the shaft G
and the individual armature-shafts d. It is preferable also to so construct the
friction-wheels H that they may be independently disengaged from their respective
armature wheels I, at will. This is accomplished by connecting each of the
wheels H to the shaft G by a convenient spline and feather attachment, which
permits a horizontal movement of the same to and from the friction wheels I. In
the sleeve h', of each of the friction wheels H, is formed an annular groove h³ for
receiving the two-semi-circular prongs jj of a forked lever J. The levers J are
each pivoted at a point in a manner allowing the extremities of the prongs jj to
be moved longitudinally along the shaft G, carrying therewith the friction wheel H.
At the remote extremity of each lever J is formed a slot k for receiving a pin k¹
carried upon a cam-lever K. By means of this system any desired number of the
armatures may be actuated.
The construction of the armature which it is preferred to employ in this
connection, consists of an annular series of coils L' to L of insulated wire,
surrounding the armature shaft d. Each of the coils L is constructed with a hollow
rectangular core M of soft-iron, and these cores are, for convenience, constructed
in four sections m¹ m³ m³ and m* (see Fig 7). The sections m are constructed to
fit together in the manner shown in Fig 7, with their edges projecting slightly
beyond the opposite sides of the coils, and forming tenons n which fit into corre-
sponding apertures n¹ formed in a series of horizontal girders N. The girders N
are supported at their respective extremities by means of two soft-iron cylinder
beads and O¹ affixed to the armature-shaft d. Suitable radial lugs o are formed
upon the inner surface of each cylinder head O and O¹ to which the girders N are
bolted. For the purpose of surrounding the coils L to as great an extent as
possible with inductive metal, a plate P of soft-iron is placed longitudinally
beneath each coil L, and is supported at either end in grooves o¹ o¹, also formed in
the inner face of the heads O and O'. A sufficient space is preferably left between
the surfaces of the coils L adjacent to the heads O and O', as also between the coils
and the longitudinal plates P, to allow a free circulation of air for the purpose of
cooling the machine.

page_text: The inner terminal of each coil L of each armature is connected with the inner
terminal of the diametrically opposite coil in a manner to be hereinafter described.
The outer terminal of each coil is connected with an individual segment ¹²
to of a commutator R, carried at one end of each armature-shaft d and
revolving therewith. The commutators R each consists of a metallic disc S secured
to the armature-shaft d and faced upon one side with compressed paper or other
suitable insulating material, as shown at 8. The curved segments 717" etcetera,
are secured to the iron supporting disc S by suitable studs 8' which serve to
separate the segments from the disc and allow air to circulate between the two, and
prevent false connections from being established between adjacent plates through
the accumulation of metallic dust from the commutator.
The segments 171 etcetera, are thus arranged upon the lateral face of the
commutator, and forming rings concentric with the axis of the shaft d, as shown in
Fig 4. In each ring there are two segments placed diametrically opposite each
other, and the spaces intervening between the adjacent ends are occupied by
The complete
projections 8 of non-conducting material extending from the disc 8.
rings thus formed, are relatively so arranged that the insulating segments ³
succeed each other at regular angular distances.
In the drawings, the commutator is shown with four complete rings comprising
eight sections corresponding to the eight coils L' to L of wire in the armature,
with which they are respectively connected. The position of the commutator, with
reference to the polar extensions C, is such that during the period in its revolution
when a current of a given direction is being generated in any given inductive coil,
as for example L³ of the armature, the outer terminal of that coil will be connected
through its commutator-segment with one of the collecting brushes T¹. The
inner terminal, as before mentioned, is connected with the inner terminal of the
diametrically opposite coil L, and the outer terminal of the latter to the
diametrically opposite segment 2 of the commutator and collecting brush T*. At
the moment however, that the current ceases to be generated in the coils L' and Lo,
or becomes too weak to be of service, the connections with the brushes T¹ and TË
are severed by the intervention of the non-conducting segments &³. At the instant,
or immediately before the connections of any given coil are severed, the connections
of the next succeeding coil are completed with the same contact brushes. The
current is thus at all times collected from a constant amount of inductive wire.
The commutator-brushes T and T are supported at the respective extremities of
an arm &* which is supported at its centre upon a collar 85 surrounding the shaft d,
and constituting a journal in which the arm may be rocked. A clamp 8 is fastened
to, but insulated from each extremity of the arm 8, and in these clamps the
contact-brushes are held in their required positions by means of set-screws 87. The
angular position of the arm may be manually adjusted as required for the purpose
of bringing the brushes in the proper positions relative to the commutator-segments.
For the purpose of preventing the occurrence of electric discharges or sparks
between the brushes T¹ and T and the successive commutator-segments when the
circuit between the same is interrupted, a series of contact-segments t' to t³ and
independent contact-brushes T and T are employed for short-circuiting the
successive coils immediately before, or at the instant their connections with the
brushes T¹ and T are severed. The segments t¹ to t³ are preferably arranged in
an annular series at the back of the disc S and are supported by lugs extending
therefrom. The outer terminal of the armature coil is connected with the
segment t¹, the corresponding terminal of coil L³ with the segment t, and so on, in
regular succession.
The two contact-brushes T and T are respectively carried in brackets forming
extensions of the clamps 8. Those brushes are in direct electrical connection with
each other through a conductor l, and a resistance coil To may be included for the
purpose of dimishing [sic] the strength of current traversing said conductor.
The positions of the respective segment t and segment to which any given
terminal is connected, are so arranged, relatively to their respective contact-brushes,.

page_text: that immediately upon or before the segment passes from beneath the brush T
or T the corresponding segment t will be brought into contact with the brush T*
or T. The force of the residual current in the armature coil will thereupon be
expended in the circuit of the conductor l.
For the purpose of regulating the volume or strength of the current generated
in each armature independently of the remainder, the several coils of each armature
are constructed in such a manner that a greater or less portion of the wire
constituting the same may be employed at will, thus varying the total amount of
active inductive wire in the circuit.
The manner in which this end is accomplished consists in placing upon each
armature-shaft d at the end of the armature D away from the commutator R, a
disc U of non-conducting material, such for example as compressed paper, carried
upon the face of a metallic supporting plate Us, and in mounting thereon a number
of radial series of contact-points u. Any requisite number of individual contact-
points may be contained in the radial series, but each series is preferably
constructed with the same number, and the consecutive contact-points are arranged
at equidistant intervals from each other, and the inner ones of all the series the
same distance from the centre of the dise U.
The successive contact-points u are electrically connected by conductors u³ with
the successive layers or groups of layers of the insulated wire constituting the
bobbins L of the armatures D. Thus beginning at the centre of the bobbin, the
inner contact-point u of any given radial series is connected with the inner group
of convolutions of that armature bobbin which is in the same axial plane therewith;
the second contact-point from the centre is connected with a second group of
convolutions in the same armature bobbin; the third contact point likewise with a
third group, and so on. The same construction is followed out with reference to
each bobbin and its radial series of contact-points.
For the purpose of automatically determining the amount of wire which shall
be rendered operative at any given time, and thus controlling the strength of the
current transmitted to the external circuit, the following means are made use of
for simultaneously placing any of the contact-points in all the series in electrical
connection with the corresponding contact-point of the diametrically opposite
Beries; and automatically determining which set of contact-points shall thus be
connected, by means of the strength of the current in the external circuit. An
electro-magnetic motor V of any suitable construction is included in the external
circuit of each armature of the generator and arranged to revolve a shaft v in the
direction indicated by the arrow under the influence of an electric current of
increasing strength, and to allow the same to be revolved in the opposite direction
through the influence of a weight v¹ when the current traversing the coils of the
motor decreases in strength.
Upon the shaft is formed a continuous thread along which a corresponding
threaded traveller is caused to move in one direction or the other according to
the direction of revolution of the shaft. The two prongs w of a forked lever W
extend upon opposite sides of the traveller and are loosely jointed thereto by
means of the transverse studs vs projecting from the traveller, through elongated
slots w' formed in the extremities of the respective prongs. The lever W is
pivoted at a point w³, and is forked at the extremity remote from the shaft v in a
manner similar to that described with reference to the lever J, as shown at w³ w³.
The prongs w³ and w* embrace a collar X surrounding the armature-shaft & and
longitudinally movable upon a feather a. An annular groove a³ is formed at one
end of the collar X, into which groove the extremities of the fork-prongs w³ w
extend. This construction permits the collar to revolve with the shaft & and at
the same time affords a permanent lateral connection with the lever W. The
extremity of the collar X remote from the groove engages the short arms of a
series of eight levers Y, which serve to close the circuits between the diametrically
opposite contact-points u, in a manner hereinafter described. The levers Y are
respectively pivoted at points equidistant from each other to annular lugs y formed

page_text: upon a collar y¹, which collar surrounds the shaft and is rigidly attached thereto.
Each of the levers is moreover so constructed that the extremity of its long arm y³
which is preferably insulated from the lever itself by an intervening block y³ of
compressed paper or other suitable insulating material, may be swung outward
from the centre of the shaft d in the plane of the radial series of contact-points u
to which it corresponds.
Directly in front of each radial series of contact-points u, and extending parallel
thereto, is a guide-rail u¹ supported at each end from the diso U by arms u
extending through the metallic supporting plate U but insulated therefrom. Each
guide-rail u¹ is provided with a movable collar or traveller u³ upon which is carried
a circuit-closer U hereinafter described. A slot y' is formed in the extremity of
each arm y³ of the levers Y, through which slot extends a stud u³ formed upon
each of the travellers u³.
The circuit-closers U₁ each consists of a wheel u having four teeth or projections,
two of which, diametrically opposite each other, are of slate or other suitable non-
conducting and non-inflammable material. This four-armed wheel is pivoted at its
centre to a resilient arm u³ of conducting material, rigidly supported from and in
electrical connection with the carrier u³. The conducting teeth or prongs of the
wheel u have their extremities rounded and are constructed to fit into recesses u¹º
formed in the faces of each of the contact-points u. The insulating teeth or prongs
enter between adjacent contact-points and serve to prevent an electric discharge
from taking place between the adjacent points when the contact between one of
the conducting arms and one of said points is suddenly broken during the passage
of the wheel.
It will now be evident that when the collar X is moved forward toward the
lug y to which the levers Y are pivoted, the short arms of the levers will be pressed
outward, and the long arms y forced toward the centre of the shaft, thereby
bringing the circuit-closers into contact with the innermost contact-points. When
on the other hand the collar X is moved in the opposite direction, the long arms of
the levers will be carried outward by means of the force exerted by the springs Y¹
combined with the centrifugal force occasioned by the rapid revolution of the
armature-shaft. As the arms y³ are carried outward the circuit-closers U¹ make
connections between the successive contact-points u and the guide-rails u'. The
rails which correspond with the diametrically opposite armature coils are
electrically connected with each other by conductors 2.
The object of this regulating mechanism is to maintain a constant uniformity in
the strength of current traversing the external circuit. The operation of the
device is as follows: As shown in the figure, the circuit-closers Ū¹ are in contact
with the inner circular range of contact-points u, which as already described are
connected with the inner terminals of the innermost groups of conductors of the
respective bobbins to which they correspond. This is the condition best suited to
the development of currents of high electro-motive force. If now, for any reason,
the resistance of the external circuit is diminished, the strength of current in the
circuit will be proportionally increased. This will operate the motor, V to
withdraw the collar X, and allow the outward movement of the levers Y. The
circuit-closers U₁ on leaving the inner circular series of contact-points u and
making connections with the second series, eliminate from the main circuit the
inner group of conductors as already explained. This simultaneously reduces the
electro-motive force of the current generated, and the internal resistance of
the machine. If the strength of current is still excessive, the circuit-closers are
still further advanced, and the length of wire in the armature still further decreased.
Ultimately the condition is reached in which the original-strength of current is
again established throughout the circuit. On the other hand if the strength of
the current generated falls below the predetermined point, the motor-shaft vis
rotated in the opposite direction by means of the weight v³, and the convolutions
are reintroduced.
For the
Sum000
of odinsting the motor to respond to currents of any meanised.

page_text: strength, it is preferred to attach the cord supporting the weight to a conical
drum Z in such a manner that the weight will exert a greater retarding influence
upon the shaft at the start than thereafter to prevent action of the regulator in
response to slight diminutions of resistance or variations of speed of the machine.
It is desirable that the time intervening between the breaking of the circuit
with one contact-point u and the closing of the circuit with the next succeeding
point should be as small as possible. For the purpose of effecting this result, and
to prevent the circuit-closers from remaining at positions intermediate between
two-contact-points u, there is mounted upon the motor shaft van arm & carrying
at its extremity a pyramidal wedge 21 (see Figs 3 and 5). and in the path of its
revolution there is placed an adjustable tension-clutch 2 consisting of two resilient
arms or springs normally so far separated as to allow the cam ¹ to enter the
space between them, but not to allow it to pass between without separating them
still farther. This renders the movement intermittent.
The respective parts of the machine are so adjusted that one revolution of the
shaft will cause the circuit-closer U¹ to be moved from one contact-point u into
contact with the succeeding point. The resilience of the springs will be sufficient
to normally hold the pyramidal wedge z' and prevent the operation of the motor.
When, however, the current increases sufficiently to force the wedge through the
springs, the shaft will immediately complete one entire revolution, and the circuit
will be completed through the succeeding contact-point u. This operation is
repeated with every increase in the strength of the current which is adequate to
effect the operation.
For the purpose of allowing the shaft to be revolved freely in the reverse
direction, the springs are mounted upon a hinged support which is normally
held in an upright position by the spring 2 but which will be thrown backward,
and temporarily carry the springs out of the path of the wedge s¹ when the latter
strikes the springs upon the opposite side.
In Fig 6 there is shown a modification in the construction of the device employed
for cutting the successive layers of bobbin wire out of circuit. The object of this
modification is to combine a commutator with the device for varying the length of
the armature conductors, and thereby dispense with the commutator placed at the
opposite extremity of the armatures. It consists in constituting each lever Y a
conductor, and pivoting them in a non-conducting support. An annular series of
metallic contact segments to the surrounds the levers Y, one of which is adjacent
to and in electrical connection with each of said segments. The brushes Te and T7
will then at any time be in electrical connection with the outer terminals of
opposite bobbins.
Assuming that the inner terminals are connected together
directly, and that the connections between opposite guide-arms have in this instance
been severed, currents will be collected by said brushes, which will depend in
strength upon the positions of the circuit-closers U. This combined collector and
governor may be advantageously employed in conjunction with many of the
well-known forms of machine.
The bank of generators thus described may be regarded as a collection of
separate generators or as a single instrument, and the individual armatures may
be operated in series, multiple arc, or may be independently employed on separate
circuits.
Having thus described the nature of this invention and the manner in which it
is to be performed, as communicated to me by my foreign correspondent, I would
have it understood that I claim :-
1st. The combination, substantially as hereinbefore set forth, of an electro-magnet,
its pole-pieces, an armature moving within the field of magnetic force created
between the inner faces of said pole-pieces, and independent armatures moving
within the exterior field or fields created by the outer faces of said pole-pieces.
2nd. The combination, substantially as hereinbefore set forth, of two or more
electro-magnets, four or more pole-pieces thereof arranged consecutively with

page_text: alternating polarities, armatures moved within the fields of magnetic force created
between the confronting faces of the pole-pieces of the same or of adjacent electro-
magnets, and armatures moved within the fields created by the external faces of
the outermost pole-pieces.
3rd. The combination, substantially as hereinbefore set forth, of two or more
electro-magnets, their pole-pieces arranged consecutively with alternating polarities,
armatures moved within the intermediate fields between adjacent pole-pieces,
armatures moved within the exterior fields created by the outer faces of said pole-
pieces, and a magnetizing circuit the current within which is supplied by one or
both of the armatures moving within said exterior fields, for maintaining the fields
of all of said armatures.
4th. The combination, substantially as bereinbefore set forth, of two or more
separate armature-shafts, a friction wheel on each of said armature-shafts, an
independent shaft in motion, a corresponding number of friction wheels on said
independent shaft, and mechanism for independently engaging the friction wheels
on the independent shaft with those on the armature-shaft.
5th. The combination, substantially as herein before set forth, of two or more
separate armature-shafts, friction wheels mounted on said armature-sbafts, an
independent shaft in motion, friction wheels on said independent shaft, a forked
lever for independently sliding each of said friction wheels on said independent
shaft, and a cam-lever for locking said friction wheels upon said independent shaft
into and out of engagement with the friction wheels on the armature-shafts
respectively.
6th. The combination, substantially as hereinbefore set forth, of an armature
bobbin, a conductor disposed thereupon in several convolutions or layers of
convolutions, a series of contact-points respectively connected w ith the terminals
of each of said convolutions or layers of convolutions, and an automatic circuit-
closer making contacts with said contact-points, for the purpose of introducing
one or more of said convolutions or layers of convolutions into a circuit of
conductors.
7th. The combination, substantially as herein before set forth, of two bobbins
carried on either side of a central shaft, a radial series of contact-points for each
bobbin respectively connected to the conductors of said bobbins at different points
in their lengths, and travelling circuit-closers electrically connected together and
simultaneou-ly making contact with corresponding contact-points in the respective
radial series, for the purpose of connecting the conductors of one bobbin with
those of the other, and for simultaneously and equally varying the length of the
conductor in each.
8th. The combination, substantially as herein before set fortb, of an annular
series of bobbins, a commutator provided with conducting segments corresponding
to said bobbins and in electrical connection respectively with their outer terminals,
radial series of contact-points for each bobbin, said contact-points being
respectively connected with each of the conductors of said bobbins at corresponding
points throughout their lengths, and travelling circuit-closers for connecting
diametrically opposite bobbins through corresponding contact-points.
8
9th. The combination, substantially as hereinbefore set forth, of an annular
series of bobbins, a radial series of contact-points for each bobbin, the contact-
points of each series being respectively connected with the conductors of said
bobbins at corresponding points in their lengths, and travelling circuit-closers
for connecting diametrically opposite bobbins through the medium of said
contact-points.
10th. The combination, substantially as herein before set forth, of an annular
series of bobbins, commutator-sections connected to the outer terminals of said
bobbins, and means whereby the inuer terminals or corresponding points along the
lengths of the conductors constituting the diametrically opposite bobbins may be
connected together.

page_text: 11th. The combination, substantially as berein before set forth, of an annular
series of bobbins, a main line maintained in electrical connection with the outer
terminals of said bobbins through commutator mechanism, and means whereby
equal and corresponding fractions of the coils of such of said bobbins as are in
action may be introduced into or withdrawn from said main line, correlatively
with the changes in the strength of current traversing the same.
12th. The combination, substantially as hereinbefore set forth, of an annular
series of bobbins, mechanism for varying the lengths of the armature conductors in
action, and a motor whose movements are controlled by changes in the strength of
the current generated for actuating said mechanism.
13th. The combination, substantially as hereinbefore set forth, of an annular
series of bobbins, contact-points arranged in circular and radial series and revolving
simultaneously with said bobbins, travelling circuit-closers for each of said radial
series, and a motor operating under changes in the strength of current traversing
the main line for simultaneously actuating all of said circuit-closers.
14th. The combination, substantially as hereinbefore set forth, of an annular
series of bobbins, a radial series of contact-points for each of said bobbins, travelling
circuit-closers for each radial series, the diametrically opposite circuit-closers
being in electrical connection, a wedge collar for simultaneously actuating said
circuit-closers each to travel radially and make successive engagements with said
contact-points, and a motor operating intermittently to actuate said collar.
15th. The combination, substantially as herein before set forth, of contact-points
arranged in circular and radial series, circuit-closers travelling in the lines of said
radial series, each consisting of a wheel provided with four teeth, two opposite
teeth being of non-conducting and incombustible material, for intervening between
adjacent contact-points thereby preventing sparks and consequent deterioration.
16th. The combination, substantially as herein before set forth, of mechanism for
varying the length of the working conductor in an armature bobbin, a motor whose
movements are controlled by variations in the strength of current generated in
said working conductor, and mechanism for rendering the action of said motor
intermittent.
17th. The combination, substantially as hereinbefore set forth, of mechanism for
varying the length of working conductors in two or more armature bobbins, a
motor whose movements are controlled by changes of strength in the current
generated by said bobbins, and mechanism for rendering the action of said motor
intermittent when said variation is caused by an increase.
18th. The combination, substantially as hereinbefore set forth, of mechanism for
varying the length of working conductors in diametrically opposite armature
bobbins, a motor whose movements are determined by increases in the strength of
current generated in said bobbins, for actuating said mechanism to increase and
diminish the lengths of said conductors, and means whereby in dimishing [sic] the
length of said conductors the action of the motor is rendered intermittent.
19th. The combination, substantially as hereinbefore set forth, of mechanism for
varying the length of active conductor upon an armature, a moter actuated by
changes of the current generated by said armature, a motor-shaft, a pyramidal
wedge carried by said shaft and mechanism for retarding the passage of said wedge
in one direction only.
20th. The combination, substantially as hereinbefore set forth, of an armature, a
motor for varying the length of the active conductor upon said armature, a motor-
shaft, a pyramidal wedge carried by said shaft, springs permitting the passage of
said wedge between them in one direction, but with retarding influence, and a
shouldered lever carrying said springs, said lever being depressed by said wedge
when moving in the opposite direction for the purpose of allowing its free
passage.
21st. The combination, substantially as hereinbefore set forth, of an armature
generating electrical currents, a motor operating in opposition to a weight for

page_text: controlling through intermediate mechanism the strength of current generated by
said armature, a drum upon which the supporting cord of said weight is wound,
having a part of its surface conical for increasing the leverage necessary to wind
said weight for the purpose of opposing the action of the motor at certain times.
In witness whereof I the said William Phillips Thompson have hereunto set my
hand and seal this 24th day of March in the year of our Lord one thousand eight
hundred and eighty four.
W P. THOMPSON
(L.S.)