Improvements in Dynamo Electric Machines and Motors.
Year: 1892

page_text: PROVISIONAL SPECIFICATION.
Improvements in Dynamo Electric Machines and Motors.
WENCESLAS CAMILLE RECHNIEWSKI, Electrical Engineer, 98 Rue d'Assas,
Paris, France, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to obtain a dynamo electric machine from
which two different voltages can be obtained, for example 100 volts and 200 volts,.
and so arranged that it can be accomplished by a simple change of connections.
When employed as a motor such a machine would have two speeds for the same
voltage at its terminals which is very convenient in many applications such as.
for tramways, driving machine tools etc.
Fig. 4 shows the magnetic arrangement of the machine.
Ordinarily the machine is of 4 poles NS. N S (Fig. 3) and supplied with 4 brushes
but by reversing the exciting current of one of the field magnets by simply changing
the connections, the machine can be specially changed into one of two poles in
which case two brushes only are used, the others lifted off the collector and the
electro motive force of the machine is hereby doubled (Fig. 4).
The magnetic disposal which I have adopted presents for a two pole machine an
advantage over the ordinary design of such machines the opening a a in the fields N
and S diminishes the reaction of the armature on the fields and therefore diminishes
the exciting current required.
The same change of electromotive force can be effected in a similar way in most.
other shapes of multipolar machines.
The shape of the field magnets is here chosen in view to apply this system to
inductors made of sheet iron plates and of toothed armatures.
Fig. 5 shows how with a single stroke, it is possible to punch out from a sheet of
given dimensions, the lamination of the fields with a minimum of waste.
The sheet for the field magnets, when leaving the punching machine has the
piece b attached to its back, which afterwards is cut off with shears, as shewn by
the dotted line.
The machine ready for use is shown in Fig. 1 and 2.
Having described the nature of my said invention, and in what manner the said
is to be performed, I declare that what I claim is :
1. The combination of the magnetic circuits as above described, permitting the
transformation of a 4 pole machine into one of 2 poles, or more generally the trans--
formation of a 2n pole machine into one of n poles, thereby doubling their electro
motive force.
2. The use in 2 pole machines of field magnets of the form described in Fig. 3,
with fields N and S separated by an open space a. a, which thus diminishes the
importance of the armature reactions.
3. The use of field magnets-the shape of which is described in the figure-
which reduce to a minimum the waste of materials when such field magnets are
obtained by punching sheet iron plates.
Dated this Twenty-third day of April A.D. 1892.

page_text: COMPLETE SPECIFICATION.
Improvements in Dynamo Electric Machines and Motors.
I, WENCESLAS CAMILLE RECHNIEWSKI of 98 Rue d'Assas, Paris, France,
Electrical Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The object of this invention is to obtain a dynamo electric machine from
which two different voltages can be obtained, for example 100 volts and 200 volts,
and so arranged that it can be accomplished by a simple change of connections.
When employed as a motor such a machine would have two speeds for the same
voltage at its terminals which is very convenient in many applications such as for
tramways, driving machine-tools etc
In the drawing left with my Provisional Specification I have shown how my said
invention may be carried into practice.
and
Figure 1 is a side elevation of my improved dynamo electric machine and motor.
Figure 2 is an end view thereof.
Figures 3 and 4 are details showing the magnetic arrangement of the machine
Figure 5 is a diagram showing how at a single stroke it is possible to punch out
from a sheet of given dimensions, the lamination of the fields with a minimum
amount of waste.
Ordinarily the machine is of 4 poles NS. NS (Figure 3) and supplied with
4 brushes but by reversing the exciting current of one of the field magnets by
simply changing the connections, the machine can be specially changed into one of
two poles in which case two brushes only are used, the others lifted off the collector
and the electro motive force of the machine is thereby doubled (Figure 4). The
magnetic disposal which I have adopted presents for a two-pole machine an advan-
tage over the ordinary design of such machines the opening a a in the fields N
and S diminishes the reaction of the armature on the fields and therefore diminishes
the exciting current required. The same change of electro motive force can be
effected in a similar way in most other shapes of multipolar machines.
The shape of the field magnets is here chosen with the view to apply this system
to inductors made of sheet iron plates and of toothed armatures.
The sheet for the field magnets, when leaving the punching machine has the
piece b attached to its back, which afterwards is cut off with shears, as shewn by
the dotted line.
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. The combination of the magnetic circuits as above described, permitting the
transformation of a 4-pole machine into one of 2 poles, or more generally the
transformation of a 2n pole machine into one of N poles, thereby doubling their
electromotive force.
2. The use in 2-pole machines of field magnets of the form described in Figure 3,
with fields N and S separated by an open space AA which thus diminishes the
importance of the armature reactions.
3. The use of field magnets the shape of which is shown in the drawing which
reduces to a minimum the waste of materials when such field magnets are obtained
by punching from sheet iron plates.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.