Improved System of Electro-dynamic Propulsion.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improved System of Electro-dynamic Propulsion.
We, LEON ROSENFELD, CONSTANTIN ZELENAY, and JULIEN DULAIT, Engineers,
all of Charleroi, in the Kingdom of Belgium, do hereby declare the nature of this
invention to be as follows:
The object of this invention is to provide an improved construction of the
inducing and induced elements in the polyphase current system of electro-dynamic
propulsion, in which the induced element or armature suspended from the
vehicle is influenced parallel to the inducing element or field magnet without
any other corelation thereto than the energy produced in the inter-air-space,
the said improved construction being intended to obviate the chief disadvantage
of the system, which lies in the insufficiency of the inter-air-space, by rendering
it much more adequate, without diminishing the effect of the magnetic flux to
be applied to the armature by which the vehicle is propelled.
Hitherto the minimum adequacy of the inter-air-space has been indispensable
for obtaining, with a given weight of copper, for the ampere-turns of the field
magnet, a magnetic flux applying sufficient energy to the armature for the
propulsion of the vehicle as, with the existing arrangements it was not possible
tc increase the value of the inter-air-space without diminishing its energy
in the same proportion so that in order in this case to maintain the same energy
of the magnetic flux, considerable increase in the weight of the copper would
be suggested as necessary.
As, moreover, the minimum
"
value" of the inter-air-space renders this system
of propulsion, if not impossible at least very difficult in practice, in consequence
of the jolting of the vehicle possibly happening at the moment of the contact
between the field magnet and armature with all its disastrous consequences it
becomes necessary to increase the "value" of the inter-air-space considerably.
Now, this increase of the actual "value" of the inter-air-space, which is about
3 millimeters to nearly four times its value, say to 12 millimeters, without
increasing the weight of the copper whilst preserving an energy equal to the
magnetic flux is realisable, y means of a special arrangement of the pole pieces
of the armature and of the field magnet, as illustrated in the accompanying
drawing.
Fig. 1 is a transverse section of the new construction of the armature and of
the field magnet. the winding being arranged in the form of a drum.
Fig. 2 is a similar section, with the winding arranged in the form of a ring.
Fig. 3 is a plan view showing the winding arranged partly in drum and partly
in ring form.
Fig. 4 being a side elevation showing diagrammatically the rheostat for start-
ing in connection with the armature.
The realization of the invention, that is to say, maintaining the same energy
in an inter-air-space four times larger than the ordinary is chiefly due to the
enlarging of the pole surfaces without increasing the section of the iron portion

page_text: which carries the copper winding, in order to excite the radiation of lines of
force in the direction of the width, so as to compensate the loss of force experienced
in the direction of the height of the inter-air-space by its extension in width.
In practice, the arrangement carried out in conformity with the particulars
given above can be suitably effected in the following manner:
The magnetic metal or iron in the field magnet as well as in the armature
consists preferentially of thin plates or laminations of sheet iron joined together
and is applied in two parts, the one part a being composed of a series of thin
longitudinal plates either in the form of a rectangular bar either endless or in
interrupted sections throughout its course and on which the series of consecutive
pole pieces which forms the other part is placed. These, likewise, constitute
a collection of thin plates joined together but cut out in T form, the side
extensions cc of which are considerably widened, whilst the vertical paten has
only a sufficient section for the passage of the magnetic flux corresponding to a
single induction. The plates of the longitudinal bar, as well as those of the
pole pieces, are joined together by means of rivets or bolts.
The longitudinal parts a of the field magnet and of the armature are fitted
into braces". e of which that belonging to the field magnet forms part of the
foot placed cross-wise, whilst those belonging to the armature are suspended by
means of adjustable rods, to the axle h of the vehicle. The pole pieces are
bound very tightly to the longitudinal bars and thus solidly combined therewith,
and retained on the one hand in the "braces" by adjustable tie-rods and on
the other against the pole pieces, by lugs & cast in one piece with the plates and
serving at the same time for bringing the extremities of these together.
In this arrangement the longitudinal bars a in the form of joined plates
chiefly serve to facilitate the passage of the lines of force produced by the
current running through the copper windings, which may be in either of the
so-called drum and "ring" forms as preferred.
66
"
In Fig. 1 the winding is formed as a drum and in this case the copper
surrounds the patens of the pole pieces, whilst in Fig. 2 the winding is repre-
sented in ring form, in which case the copper is wound on the longitudinal bar.
The windings are situated in both cases in the spaces formed by the gaps
between the pole pieces, where they are arranged flat as shown in Fig. 3.
The armature closely connected with the vehicle may be made in a single
piece; but it is preferably constructed in several, by reason of the special advan-
tages accruing from this arrangement in its application to tractional purposes.
The control of the vehicle that is to say, the starting, relaxation of speed,
stopping, in other words, the putting into action or the suspension of the action
of the magnetic flux is carried out in the manner generally adopted in connection
with polyphase motors, that is to say, through the medium of a rheostat o, the
coils of which are connected with the windings of the armature belonging to
the system, as shown diagrammatically in Fig. 4 for a triple phase system, for
example, in which the rheostat wires as well as the windings of the armature
and of the field magnet are shown in thick, thin and dotted lines. Under these
conditions, according to the position given by the conductor to the rheostat
elements, the arrangements for which may be selected from the numerous known
varieties of these apparatuses with a view to securing the desired effect, the
currents induced in the windings or m of the sectioned propeller will be very
powerful or very feeble or absolutely void in conformity with the motion to be
applied to the vehicle.
Based on these conditions, the system of polyphase current propulsion, which
has the considerable advantage of dispensing with all connecting parts between
the propeller and the inducing conductor, meets all the requirements of satis-
factory working without presenting any of the disadvantages which have hitherto
rendered this system impracticable and it may without any further hesitation be
brought into practical use.
From the effects above described in the system of tangential traction, by the

page_text: arrangement of widened pole pieces, it follows that this system may be employed
with corresponding advantages to alternating current motors with the view of
increasing their power without the addition of copper windings.
Dated this 14th day of July 1899
Improved system of Electro-dynamic Propulsion.
We, LEON ROSENFELD, CONSTANTIN ZELENAY, and JULIEN DULAIT, Engineers,
of Charleroi, in the Kingdom of Belgium, 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: —
The object of this invention is to provide an improved construction of the
inducing and induced elements in the polyphase current system of electro-dynamic
propulsion, in which the induced element or armature suspended from the
vehicle is influenced parallel to the inducing element or field magnet, without
any other co-relation thereto than the energy produced in the inter-air-space
the said improved construction being intended to obviate the chief disadvantage
of the system, which lies in the insufficiency of the inter-air-space, by rendering
it much more adequate, without diminishing the effect of the magnetic flux to
be applied to the armature by which the vehicle is propelled.
Hitherto the minimum adequacy of the inter-air-space has been indispensable
for obtaining, with a given weight of copper, for the ampere-turns of the field
magnet a magnetic flux applying sufficient energy to the armature for the
propulsion of the vehicle as, with the existing arrangements it was not possible
to increase the "value of the inter-air-space without diminishing its energy
in the same proportion so that in order in this case to maintain the same energy
of the magnetic flux, a considerable increase in the weight of the copper would
be suggested as necessary.
"
As, moreover, the minimum value of the inter-air space renders this system
of propulsion, if not impossible at least very difficult in practice, in consequence
of the jolting of the vehicle possibly happening at the moment of the contact
between the field magnet and armature with all its disastrous consequences, it
becomes necessary to increase the value of the inter-air space considerably.
Now, this increase of the actual value of the inter-air space, which is about
3 millimeters, to nearly four times its value, say to 12 millimeters, without
increasing the weight of the copper whilst preserving an action equal to the
magnetic flux, is realisable, by means of a special arrangement of the pole pieces
of the armature and of the field magnet, as illustrated in the accompanying
drawing.
Fig. 1 is a transverse section of the new construction of the armature and of
the field magnet, the winding being of the drum type.
Fig. 2, is a similar section, the winding being of the ring type.
Fig. 3, is a plan view showing the winding partly of the drum and partly of
the ring type.
Fig. 3, and 3b, are respectively a section and plan view of a varied form of
construction of polar pieces, . and Fig. 4, a side elevation showing diagram-
matically the rheostat for starting in connection with the armature.
The realisation of the invention, that is to say, maintaining the same energy
in an inter-air space four times larger than the ordinary is chiefly due to the

page_text: enlarging of the pole surfaces without increasing the section of the iron portion
which carries the copper winding in order to excite the radiation of lines of
force in the direction of the width, so as to compensate the loss of force experienced
in the direction of the height of the inter-air-space by its extension in width.
In practice the arrangement carried out in conformity with the particulars
given above can be suitably effected in the following manner:-
The magnetic metal or iron in the field magnet as well as in the armature
consists preferentially of thin plates or laminations of sheet iron joined together
and is applied in two parts the one part a being composed of a series of thin
longitudinal plates either in the form of a rectangular bar either endless or in
interrupted sections throughout its course and on which the series of consecutive
pole pieces b, which forms the other part is placed. These likewise, constitute
a collection of thin plates joined together but cut out in T form, the side
extensions c c of which are considerably widened, whilst the vertical paten has
only a sufficient section for the passage of the magnetic flux corresponding to a
single induction. The plates of the longitudinal bar, as well as those of the
pole pieces, are joined together by means of rivets or bolts.
The longitudinal parts a of the field magnet and of the armature are fitted
into braces e of which that belonging to the field magnet forms part of the
foot placed crosswise, whilst those belonging to the armature are suspended, by
means of adjustable rods g to the axle of the vehicle. The pole pieces are
bound very tightly to the longitudinal bars and thus solidly combined therewith,
and retained on the one hand in the braces by adjustable tie-rods and on
the other against the pole pieces, by lugs k cast in one piece with the plates and
serving at the same time for bringing the extremities of these together.
Instead of making the polar pieces of a series of plates cut out in T form and
joined together after being placed, with the flat sides side by side vertically
one against the other, as shown in Fig. 1, 2, and 3, they may be formed by super-
posing two series of rectangular plates 6 of different lengths, bent at right angles,
and suitably joined together by bolts or rivets as shown in Fig. 3, and 3b.
This is a more economical form of construction.
In this arrangement, the longitudinal bars « in the form of joined plates
chiefly serve to facilitate the passage of the lines of force produced by the
current running through the copper windings, which may be in either of the
forms shown as preferred.
In Fig. 1, the winding is of the drum type and surrounds the patens of the
pole pieces, whilst in Fig. 2, the winding is of the ring type in which case the
wire is wound on the longitudinal bar.
The windings are situated in both cases in the spaces formed by the gaps
between the pole pieces, where they are arranged flat as shown in Fig. 3.
The armature closely connected with the vehicle may be made in a single
piece; but is preferably constructed in several, by reason of the special advan-
tages accruing from this arrangement in its application to tractional purposes.
The control of the vehicle, that is to say, the starting, relaxation of speed,
stopping, in other words, the putting into action or the suspension of the action
of the magnetic flux is carried out in the manner generally adopted in connection
with polyphase motors, that is to say, through the medium of a rheostat o, the
coils of which are connected with the windings of the armature belonging to
the system, as shown diagrammatically in Fig. 4 for a triple phase system, for
example, in which the rheostat wires as well as the windings of the armature,
are shown in thick, thin and dotted lines. Under these conditions, according
to the position given by the conductor to the rheostat elements, the arrangements
for which may be selected from the numerous known varieties of these apparatus
with a view to securing the desired effect, the currents induced in the windings
or m of the sectioned propeller will be very powerful or very feeble or absolutely
void in conformity with the motion to be applied to the vehicle.
Based on these conditions, the system of polyphase current propulsion, which

page_text: has the considerable advantage of dispensing with all connecting parts between
the propeller and the inducing conductor meets all the requirements of satis-
factory working without presenting any of the disadvantages which have hitherto
rendered this system impracticable and it may without any further hesitation be
brought into practical use.
From the effects above described in the system of tangential traction by the
arrangement of widened pole pieces, it follows that this system may be employed
with corresponding advantages to alternating current current motors with the
view of increasing their power without the addition of copper windings.
Having now particularly described and ascertained the nature of our invention
and in what manner the same is to be performed, we declare what we claim is:-
1. In the polyphase current system of electric traction, without any other
relation between the induced element or armature suspended to the vehicle and
the inductor or field magnet extending along the track, than the sliding magnetic
field, the construction of the field magnet and of the armature in such a manner
as to realise, with the same quantity of winding copper, a distribution of the
magnetic flux rendering possible a corresponding increase in the adequacy of
the inter-air-space without any decrease in the energy of ordinary conditions.
2. Method of carrying out the construction described above distinguished by
the widening of the surface of the pole pieces without increase ci the section
carrying the winding, in such a manner as to recover through the increase in
width of the extent of the inter-air-space, the loss arising from the height of
the latter.
3. An apparatus in accordance with the form of construction described above,
distinguished by the employment of a series of pole pieces consisting of collec-
tions of sheets or plates joined together in T form with very considerably widened
side extensions on a bar likewise consisting of joined sheets or plates and suitably
fitted into braces the whole firmly bound together by means of adjustable tie-rods,
equally for the field magnet as for the armature.
4. The varied form of the polar pieces distinguished by two series of thin
plates of variable lengths, bent at right angles and suitably superposed for being
put together by rivets or bolts.
Dated this 3rd day of March 1900.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.