Improvements in Electro Motors.
Year: 1890

page_text: Date of Application, 14th May, 1890
Complete Specification Left, 14th Feb., 1891-Accepted, 11th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Electro Motors.
I, HENRY FREEMAN, 1, Rappart Road, Seacombe, Cheshire, Estate Agent, do
hereby declare the nature of this invention to be as follows:-
A circular plate of metal. Mounted thereon, either vertically or horizontally, a
series of electro-magnets. A shaft of iron, brass, or steel, is keyed or fastened
through the centre of the plate, each end of the shaft is turned down to form a
bearing to revolve in suitable supports. Those supports to be mounted upon a
suitable bed-plate.
The electro magnets are constructed of lengths of iron tube, with an iron bottom,
in the centre of the iron bottom, a core of iron is fixed. A bobbin of wood or any
other suitable material, of length equal to the depth of the tube is then wound with
wire, a portion of the top end of the bobbin is reserved and wound with another
wire. The bobbin is inserted in the tube, allowing the iron core to come through
the centre, and there secured.
Moving upon the shaft is a toothed wheel carrying armatures, corresponding with
the number of electro magnets carried upon the plate. Mounted upon the supports
that carries the shaft a series of pawls are arranged to fall into the teeth of the
toothed wheel, to prevent the toothed wheel from returning in one direction. Fixed
upon the plate that carries the electro magnets is a commutator constructed of any
hard material which is a non-conductor of electricity in which are cut three narrow
grooves, in which grooves are inserted three pieces of platinum, to fit in and fill up
the grooves, the whole having a smooth, level surface.
A lever with platinum attached to the end, is caused to move backwards, and
forwards, by the motion of the machine. The lever is formed of two pieces of metal,
joined together, by a suitable material, which is a non-conductor of electricity and
screwed into position.
On the end of the shaft projecting through the plate, are two rings of metal, with
a non-conductor of electricity between, and also separating them from the shaft.
Resting against these rings, and fastened to the bed-plate, are two springs for
conveying an electrical current to the machine.
The working of the apparatus is as follows
An electric current is caused to pass through one of the springs attached to
the bed-plate, and resting against one of the rings on the shaft. From there
it passes along a wire, to the lever of the commutator. When the lever is in
the cores.
contact with the first piece of platinum in the first groove, it allows the electric
current to pass along a wire to the electro magnets and there passes along the
wire in the lower portions of the bobbins, and from thence it leaves the machine
by the second ring on the shaft and the spring attached to the bed plate.
This causes the iron cores to be magnetized, and the iron tubes, forming the
exterior of the electro magnets, also to be magnetized, but with opposite poles to
The magnetism thus induced in the electro magnets, causes an attraction
between the electro magnets, and the armatures upon the toothed wheel, but as the
toothed wheel cannot be moved backwards, on account of the pawls on the supports
dropping into the teeth, the electro magnets, with the plate, and shaft, and all that
are fastened to them are drawn towards the armatures. Just before the electro
magnets have reached the armatures, a projecting piece of metal, on the toothed
wheel, catches the lever of the commutator, as it moves forward with the plate, and
moves the end of the commutator from the platinum in the first groove, to the
platinum in the second groove. This causes the electrical current to be diverted
from the lower parts of the bobbins in the electro magnets, and passes from the

page_text: platinum in the second groove, to the wire round the top parts of the bobbins in
the electro magnets but in an opposite direction to that in which it passed round
the lower parts of the bobbins.
This causes the destruction of the residue of magnetism left in the electro
magnets, so that the armatures are at once released from the attraction to the
electro magnets. A spiral or any other suitable spring, attached to the toothed
wheel at the one end, and the other end to the plate carrying the electro magnets,
draws the toothed wheel, with the armatures, away from the electro magnets,
forward a regulated distance.
Just before the toothed wheel has reached its regulated distance, another metal
projection on the toothed wheel, moves the end of the lever of the commutator
back to the platinum in the first groove, when the electro magnets are again drawn
towards the armatures, and so the machine continues to revolve.
As the lever of the commutator is passing from the first groove to the second, it
touches the platinum in the second groove, before contact with the platinum in the
first groove is actually broken, and as the length of wire is much less which passes
round the tops of the bobbins in the clectro magnets than round the bottom parts,
the electric current, commences to be diverted from the first groove, although the
contact is not yet broken.
This reduces the induced electric spark. A direct wire in connection with the
third groove leads the electrical current, away from the machine by the same ring
on the shaft, and spring on the bed-plate, as from the first and second grooves.
The induced electrical spark from the second groove is reduced by the lever
touching the third groove before leaving the second.
Dated this Thirteenth day of May 1890.
HENRY FREEMAN.
COMPLETE SPECIFICATION.
Improvements in Electro Motors.
I, HENRY FREEMAN, of 1, Rappart Road, Seacombe, in the County of Chester,
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 :-
This invention relates to certain improvements in electro-motors having for their
principal object the construction of an electro-motor in which the electric current
shall be more economically employed than in motors hitherto generally known.
To this end the electro-magnets through which the rotation of the motor is
effected are so arranged and connected that they shall operate simultaneously
during such rotation and not in succession as in some machines heretofore
constructed.
The manner in which I carry my invention into effect may be described with
reference to the accompanying drawings, in which,
Figure 1 is an end elevation of the machine, partly in section;
Figure 2 is a side elevation thereof, part being broken away;
Figure 3 is an end view looking the reverse way from Figure 1, and showing
the electric connections, parts of the machine being removed;
Figure 4 is an enlarged view, partly in section, of a portion of the pawl
mechanism shown in Figure 1;
Figure 5 shows the switch arrangement and the various electric connections for
operating the machine.
b
A. A are two rigid standards supported upon any suitable base. B is the motor
shaft mounted in bearings 6 upon the standards. C is a circular plate of metal
rigidly secured to the shaft and by preference provided with a peripheral flange C.
DD are a series of electro-magnets arranged equidistantly round the flange C¹
of the plate C to which they are firmly secured. Each of the electro-magnets is

page_text: composed of an iron tube d, closed end d¹ and core d², and of a bobbin d³ and coil
of insulated wire d. The tube, closed end and core are all in electric connection
and form as it were the core of a horse-shoe magnet. The coil d' is mounted upon
the bobbin d³, which is of non-conducting material and surrounds the core d² serving
to magnetize both the core and the tube. The tubes d are split as at d' in order
to prevent the circulation of induced currents round them.
In my Provisional Specification I described an arrangement consisting of a
toothed wheel carrying a series of armatures and mounted loosely upon the motor
shaft, the said wheel being so engaged by a series of pawls mounted upon the fixed
framework of the machine as to be capable of rotation in one direction only. I
have since found however that a better result is obtained by reversing this arrange-
ment, that is, by making the wheel a fixture and so arranging and mounting the
armatures and pawls that they are capable of rotation about the wheel in one
direction. Instead of using a toothed wheel and pawls I prefer to employ a wheel
with a smooth or slightly serrated periphery in conjunction with a series of friction
pawls. This arrangement is shown on the drawings.
E is a wheel or circular disc which is in this case provided in duplicate, one being
placed at each side of the circular plate C. Both discs are firmly secured to the
adjacent standards A as at a, and each is provided with an annular flange E'
preferably smooth (or only slightly serrated) on both its inner and outer peripheries.
F are the armatures, one for each electro-magnet. Each armature is carried by
a pair of arms F, which project inwards past the inner sides of the flanged discs E E¹
and are each provided with a pair of friction pawls F2 F2, Figure 4, arranged one
on each side of the adjacent flange E¹. These pawls each consist simply of a pair
of projections so arranged as to bear forcibly against the faces of the flanges
whenever (during the working of the machine) the adjacent electro-magnet operates
to draw the armature towards it. The movements of the armatures away from
their respective electro-magnets are controlled by adjustable stops F³, which may
be conveniently mounted upon the closed ends of said magnets, being insulated
therefrom as at F4.
It will thus be seen that if the current be passed round all the coils D D (these
being so connected as hereinafter described that they are for all practical purposes
energized simultaneously) the magnets will be magnetised and tend to draw their
respective armatures towards them. This they cannot do however as the pawls F² F
bind upon the flanges of their respective friction wheels. The electro-magnets with
their supporting plate C are consequently drawn towards the armatures and the
shaft partly rotated. As soon as the armatures make contact with the poles of
their respective magnets (or, it may be, before actual contact) the current through
the coils is reversed as hereinafter described, the magnets are thereby demagnetised
and the armatures are drawn away from them by means of the armature springs F³,
as shown in Figure 1. The said springs are secured at one end to the inner ends
of the pawl arms carrying the armatures, and at the other end they are attached to
the tubes d of the electro-magnets or to some part moving therewith, the pull of
the springs being in a direction more or less tangential to the flanges E', so that
they draw the pawls and their arms round the flange of the wheel, this movement
being arrested however by the armatures coming in contact with their limiting
stops F3, F. As soon as this contact occurs, the current round the coils is again
reversed, the magnets attracted to the armatures and the shaft partially rotated as
before, the above cycle of operations being repeated continuously.
In my Provisional Specification I described the bobbins as being wound at their
upper ends with a second wire, through which the reverse current was caused to
pass for the purpose of demagnetising the cores d² and tubes d. My further
experiments have however shown me that this current is insufficient to thoroughly
demagnetise the cores and tubes (unless the latter be of very soft iron) and I now
wind each of the bobbins with only one wire and cause the reverse current to pass
through the entire coil as hereinafter described, the electric connections of the coils
being modified accordingly.

page_text: In my Provisional Specification I also described a switch lever which was
mounted upon, and moved with, the plate carrying the electro-magnets, the switch
lever being operated by mechanical means during each successive partial rotation
of the plate and rearward stroke of the armatures, and the current being conveyed
to the magnets by means of a suitable series of insulated contact rings moving with
the shaft, and a corresponding number of contact brushes mounted upon the
framework of the machine. I have since found however that it is more advan-
tageous to control the movements of the switch lever entirely by electro-magnetic
means and I am thereby enabled to mount the lever and its operating devices upon
the machine framing or on some other part not rotating with the magnets, the various
contact rings and brushes, with the lever and connections, being adapted to suit this
altered arrangement, which may now be described in detail.
N¹ N2 N3 N4 N5 are a series of insulated contact rings mounted upon and rotating
with the shaft B. 01 02 03 04 05 are a similar series of insulated contact brushes
bearing upon the peripheries of said rings and mounted in any suitable manner
upon one of the standards A. P is the switch lever aforesaid which in this instance
is supposed to be mounted upon a fixed bed located conveniently to the motor.
1, 2, 3, 4, 5, are insulated electric conductors connected respectively with the
rings N1 N2 N3 N4 N° and passing to various points upon the motor as
follows: 2 is the conductor whence the current is led to the terminal d³ of
one of the coils d', passing thence in succession through all the coils until it
reaches the further end of the last coil as at d whence it passes by the conductor 4
into the corresponding contact ring N4. The conductor 1 is connected by
means of two branches 1 and 1 with two insulated contacts G H respectively,
said contacts being mounted upon one of the armatures or on some part movable
therewith. One of these contacts G is adapted to bear against the adjacent
armature adjusting screw F³ when the armature is drawn away from its magnet,
said adjusting screw being connected by means of the conductor 3 to the contact
ring N³. The contact H is connected with a spring arm H¹, which, when the
armature carrying said contact is drawn towards or against its magnet, makes
contact with an insulated contact piece J connected by the conductor 5 with the
contact ring N³. The contact piece J may be conveniently mounted upon the
closed end of the adjacent magnet.
The switch lever P is pivoted at P and carries two insulated armatures Q R¹
fixed one on each side of it and placed directly opposite the poles of two electro
magnets QR. The switch lever carries 6 contact studs, U V W X Y Z, three
being fixed on each side of the lever. Two of the studs, W Z, are in electric
connection with the lever, and the other four are insulated therefrom, as shown at u,
v, x and y. U U³, V¹ V², W¹, X¹ X², Y¹ Y and Z are 6 pairs of insulated
contact springs arranged opposite the contact studs U V W X Y Z respectively,
in such manner that, when the three studs at one side of the lever are in contact
with their respective springs, the contact of the three other studs with their springs
is broken. The eight springs adjacent to the contact studs U V X Y are all
insulated one from the other and are each connected to an electric conductor, as
hereinafter described. The contacts W₁ and Z' are, however, merely formed
double in order to ensure a better contact with their studs, the two members of
each pair Wand Z' being connected to a common conductor.
S is a third electro magnet, opposite the poles of which is an armature S¹
mounted upon a spring arm S2 which is attached to a standard S. The distance of
the armature from the electro magnet is adjusted by means of an insulated adjusting
screw S³.
P2 is an arm carried by the lever P and adapted to bear against the outer face of
the armature S' when the lever is drawn over in one direction (towards the left),
the bearing end of the said arm being provided with an insulating piece, as
shown at 13.
T is a battery or other source of electric current. T1 and T2 are two terminals
connected with the battery.

page_text: The terminals T1 and T2 are also connected by various insulated conductors with
the lever P (through its supports P'), electro magnets Q, R, S, standard S4, contact
springs U1, U2, V, V, W, X', X, Y, Y2 and 2, and the brushes 0' 02 03 04
and . The arrangement of the various conductors and other connections will be
readily understood by describing the operation of the machine, which is as
follows:-
:-
This
Assuming the lever P to be placed in its right hand position, the contact studs X
Y and Z will then make contact with their respective springs, the armature R¹ will
rest against the poles of its magnet R and the armature S₁ will be held, by means
of its spring arm S², against the adjustable stop S3 and out of contact with the
poles of its magnet S. The current from the battery now passes through the
terminal T2 along the wire 1° to the brush O¹, through the contact ring N¹, and
the wires 1 and 1ª to the contact G on one of the armatures of the machine.
contact resting against the armature adjusting screw F³, the current passes through
said screw and its metallic support, along the wire 3, through contact ring N³,
brush O³ and wire 3ª, round the electro magnet Q, along wire 3b, and through the
contact spring Z', stud Z, lever P, lever support P4 and wire 7 to the terminal T¹,
whence it re-enters the battery T, thus completing the electric circuit round the
coil of the magnet Q. The latter, being energised, draws over the lever P to the
left, causing the studs U V and W to make contact with their respective springs,
and the armature S₁ to be placed in contact with the poles of its magnet S, by
means of the lever arm P2. The movement of the lever also breaks the circuit
round the electro magnet. Q and through the brush O', so that the magnet Q is
demagnetised when the lever has been drawn towards it.
The current now flows from the terminal T2 along the wires 1° 1d, contact
spring V2, stud V, spring V₁ and wires 2b and 2º, to the brush 02, thence through
the ring N2 and wire 2 to one of the coils of the electro magnets on the machine,
as at d in Figure 3. Thence it passes round the coils in succession, and away at de
by the wire 4 and contact ring N₁. Thence it flows through the brush O¹, wire 4ª,
standard S4, spring arm S2 and armature S¹, to the exterior metallic tube of the
electro magnet S. The latter is electrically connected by a binding screw S³ with
the wire 4 of the magnet coil, so that the current flows from the aforesaid tube,
through the screw S, round the coil of the magnet S, along the wires 4 and 4°
through the contact spring U₁, stud U, spring U2 and wires 6 and 6, to the
terminal T' and battery T. The circuit is now completed round the machine coils and
round the electro magnet S, and, consequently, the machine magnets D are drawn
towards their armatures F, as before described, contact being thereby broken at G, F³;
and contact made between the spring arm H' on one of the armatures F and the
adjacent contact J. The current now passes from the terminal T, through the
wire 1, brush O¹, ring N¹, wires 1 and 1 to the armature contact H, Figure 3.
Thence through the contacts H' and J and along the wire 5, to the ring No, whence
it passes, by the brush 05 and wire 5, round the electro magnet R, and then
through the wire 5, spring W₁, stud W, lever P, lever support P and wire 7 to
the terminal T', thus completing the circuit through the electro magnet R and
drawing over the lever to its right-hand position again. The movement of the
lever breaks the circuit through the machine coils and through the coil of the
electro magnet S, also relieving the armature S' from the pressure of the lever
arm P2. The poles of the magnet S, however, being of comparatively hard metal,
retain sufficient magnetism to hold the armature S₁ in contact with the poles of its
magnet after the withdrawal of the arm P2, and in defiance of the tension of its
spring arm S2. The magnets D also retain sufficient residual magnetism, after the
breaking of the circuit at V1 V2 to hold their armatures F in contact with their
poles, in defiance of the pull of the armature spring F³, these latter being designedly
made as weak as possible in order that they may offer a minimum amount of
retardation to the magnets as they move towards their armatures. The lever being
in its right hand position and the magnet S in contact with the armature S', as
aforesaid, the current now passes through the terminal T2, along the wires 1°, 1, 1°,

page_text: spring Y, stud Y, spring Y', wires 4d and 4°, round the coils of the electro
magnet S in the reverse direction to that which it took previously, and thence by
the wire 4, binding screw S³, armature S¹, spring arm S2, standard S and wire 4"
to the brush O. Thence it passes round the machine coils in the reverse direction
from that which it took previously, by way of the contact ring N4, wire 4, and
wire 2. From the wire 2, it flows through the contact ring N2, brush 02, wires 2"
and 2, spring X', stud X, spring X2 and wires 6 and 6 to the terminal T. This
reverse current demagnetises the machine magnets D and the magnet S. The
armature S' is thus drawn away from its magnet by the spring arm S2 and rests
again against its stud S³, while the machine arınatures F are drawn back against
their contact screws F³ by their respective springs F5. This completes the first
cycle of operations, during which the machine has been partially rotated a distance
equal to the distance between its magnet poles. The controlling arrangements are
now in their original position and the above cycle of operations is repeated until,
by the successive impulses imparted to the machine magnets, the driving shaft of
the machine has attained the required speed.
Theoretically, the reversal of the current in the machine magnets is not necessary,
as the breaking of the circuit alone should release the armatures and permit their
springs to withdraw them. It is, however, practically impossible so to construct
the magnets that they shall have no residual magnetism when the circuit is broken,
and hence the reversal of the current becomes almost a necessity.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
―
1. An electric motor, in which a series of electro magnets, capable of rotating
bodily about the motor shaft and of being alternately magnetised and de-magnetised,
have their poles arranged opposite a corresponding series of armatures, which are
held immovable during the successive energisings of the magnets, but receive a
limited amount of movement about the axis of the shaft and away from the magnets
during each successive demagnetisation of the same, all retrograde movement of
the armatures being prevented by a ratchet and pawl arrangement or its equivalent
as described, either the pawl or the ratchet, or their equivalents respectively, being
a fixture, whilst the complementary member of the device rotates with the shaft,
substantially as described.
2. In an electric motor, an electro magnet and magnet armature, both mounted
independently upon a common axis, in combination with devices, substantially as
described, whereby the magnet and armature alternately receive an impulse in the
same direction about said shaft, substantially as described.
3. The arrangement of contacts on the machine armature and magnet, in
combination with the automatically operated switch lever, and the various contacts
and electric conductors connected with the same, whereby the alternate forward
movements of the machine armatures and magnets are automatically controlled,
substantially as described.
Dated this 13th day of February 1891
HENRY FREEMAN.
Wm. P. Thompson & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.