Improvements relating to Electro-motors and to the Transformation and Distribution of Electric Currents.
Year: 1891

page_text: Date of Application, 30th June, 1891
Complete Specification Left, 30th Apr., 1892-Accepted, 11th June, 1892
PROVISIONAL SPECIFICATION.
Improvements relating to Electro-motors and to the Transformation
and Distribution of Electric Currents.
I, FRIEDRICH WILHELM LAHMEYER, Electrical Engineer, of Neue Mainzer-
strasse 68, Frankfort on the Main, Germany do hereby declare the nature of my
invention to be as follows:-
The present invention relates to the use of high tension electro-motors in which
the field magnets are excited by a low tension current, produced in a second winding
of the armature. Such a motor is also a transformer, inasmuch as it converts the
high tension current into a low tension current for its own use.
By utilizing the low tension current produced in this manner, also for the
purpose of illumination, I may obtain a very simple system of distribution specially
adapted for some industrial districts. In this system the high tension energy may
be employed either in the shape of continuous currents or in the shape of rotary
phase currents.
The low tension winding of my high tension electro motor may also give off a
rotary phase current, in which case three or more symmetrically situated points of
The system
the armature winding are provided with drag rings and drag springs.
of distribution is therefore arranged as follows:
The high tension collecting bars of the central or generating station supply high
tension energy to the large motors situated in the different factories of the district,
this being done in the case of continuous currents by means of two conduits and in
the case of rotary phase currents by means of two or more conductors. The axle
of each motor gives off motive power, and the low tension armature winding of the
motor gives off low tension energy, which may be applied both for illumination
and for the propulsion of small electro-motors. Or the low tension energy may be
employed for charging accumulators, or for supplying ordinary transformers.
To provide that the low tension current has everywhere a constant pressure, the
secondary terminals of all these high tension motors may be connected by a
compensating or equalizing conduit, or a network of conductors.
The high tension terminals of all the combined motors and transformers may
likewise be connected by a conduit or a network of conductors, in order to facilitate
the regulation of the said motors for constant speed.
The network of high tension conductors may at the same time supply energy to
arc lamps and glow lamps in series, which would, for instance, be suitable for the
illumination of railways.
Dated this 25th day of June 1901
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Electro-motors and to the Transformation
and Distribution of Electric Currents.
1, FRIEDRICH WILHELM LAHMEYER, Electrical Engineer and Managing
Director of the Company W. Lahmeyer & Cie., of Neue Mainzerstrasse 68,
Frankfort on the Main, Germany, 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 present invention relates to the use of high tension electro-motors, in which

page_text: the field magnets are excited by a low tension current, produced in a second winding
of the arinature. Such a motor is therefore at the same time a transformer, inas-
much as it converts the high tension current into a low tension current for its
own use.
By utilizing the low tension current produced in this manner, also for the purpose
of illumination, I obtain a very simple system of distribution specially adapted for
some industrial districts. In this system the high tension energy may be employed
either in the shape of continuous (direct) currents, or in the shape of rotary phase
currents, inasmuch as my well-known high tension electro motor need only be
provided with collecting rings and suitable circuit connections, in order to work it
with Haselwander's rotary phase currents.
The low tension winding of my high tension electro motor may also give off a
rotary phase current, in which case three or more symmetrically situated points of
the armature winding are connected with collecting rings and springs. The system
of distribution is therefore arranged as follows:
The high tension collecting bars of the central or generating station supply high
tension energy to the large motors situated in the different factories of the district,
this being done in the case of continuous currents by means of two conduits, and in
the case of rotary phase currents by means of three or more conductors. The axle
of each motor gives off motive power, and the low tension armature winding of the
motor gives off low tension energy, which may be applied both for illumination and
for the propulsion of small electro-motors. Or the low tension energy may be
employed for charging accumulators.
To provide, that the low tension current has everywhere a constant pressure, the
secondary terminals of all these high tension motors (also called motive power and
light dynamos, or motor generators) may be connected by a compensating or
equalizing conduit, or a network of conductors.
In the accompanying drawings,
Fig. 1 represents a system of electric distribution embodying my invention.
The high tension conductors are represented by thin lines and the low tension
conductors by thick lines. Instead of double conductors in the case of direct
currents, or instead of three conductors in the case of multiphase currents, the
drawing shows only single lines.
H. S indicates the high tension collecting bars of the central station. H N is
the network for distributing the high tension current. KL are the motive power
and light dynamos (or motor generators) serving at the same time to produce
mechanical power and low tension electricity. NN are the low tension conductors.
It is evident, that ordinary transformers, which do not produce mechanical
power, and ordinary low tension electromotors, which do not generate electric
currents, may likewise be included in this system. U represents such a
transformer.
K represents an ordinary electromotor, A. a battery of accumulators.
If the high pressure terminals of the different motor generators are connected
with one another by a network, and the low pressure terminals by another network,
a'special advantage is obtained, as regards the regulation of the machines to a
constant number of revolutions of their axles; for, assuming that in this case, the
number of revolutions of one motor generator falls below the normal speed, the low
tension network will also supply current to this machine and accelerate its motion.
The high tension network may also be used for supplying current to arc lamps
and to glow lamps connected in series, which arrangement would be suitable for
lighting roads along railways. In the drawings R represents such a series of arc
lamps and glow lamps.
The low tension network may be used directly for supplying current to lamps and
to small electromotors, as well as for exciting the magnets of the motor generators.
Fig. 2 represents separately one of the motor generators forming part of this
system of current distribution; H indicates the high tension conductors coming
from the central station, as well as the high tension winding.

page_text: A represents the armature, R, the driving belt mounted on the pulley which is
keyed on the shaft giving out the motive power, N indicates the low tension winding
and the conductor for the low tension energy produced by the motor generator,
which energy is utilized according to the diagram (Fig. 2) for electric lighting, but
may also be employed (as mentioned above) for driving a small electromotor.
From the above description it follows, that this very simple system of current
distribution lends itself to a great variety of applications.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is: : ---
1. An electric machine, which combines, or which is adapted to produce in
combination, the following features:
a, receiving high tension current and conducting it into a motor winding of its
armature.
b, giving out motive power through its shaft.
c, carrying on its armature a low tension winding which acts as a current
generator and supplies current for exciting its own field magnets as well as
for lighting the neighbouring district (or feeding an external circuit),
substantially as described.
2. In a system of electric distribution, two or more light and power dynamos or
motor generators as described receiving high tension current from a central station
and connected with a common network of conductors by means of low tension
terminals or couplings, substantially as described.
Datele cu ca
F. W. LAHMEYER,
By Fairfax & Wetter,
433, Strand, London, Agents.
F. W. LAHMEYER,
By Fairfax & Wetter,
433, Strand, London, Agents.