IMPROVEMENTS IN DYNAMO-ELECTRIC MOTORS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Carl Kesseler at the Office of the
Commissioners of Patents on the 22nd November 1880. A communication
from Ernst Kuhlo, of Stettin, in the German Empire.
CARL KESSELER, of 53, Mohrenstrasse, Berlin, W., in the Empire of Germany,
Civil Engineer and ratent Solicitor. "IMPROVEMENTS IN DYNAMO-ELECTRIC
MOTORS." A communication from Ernst Kuhlo, of Stettin, in the German Empire.
The purpose of this Invention is to continuously cause the attraction of an
electro-magnet to act upon a conductor or transmitter of power without interrupting
the current, and thereby preventing a cessation of the power for a single moment.
This is perfectly attained by an arrangement bereinafter set forth of three electro-
magnets placed opposite a certain number of armatures which are mounted upon a
wheel.
By means of the contact arrangements forming one part of the Invention, it is
rendered possible that the current shall not leave one electro magnet before another
has come into contact, so that consequently one electro-magnet must always be in
activity.
Now as the electric current passes through bodies with inconceivable rapidity,
it is possible to cause these electro magnets to be electrical and non-electrical
many hundred times in a second, and if this power be caused to act innumerable
times in every second upon a long lever, it is clear that even a comparatively
small power will overcome a great weight in a short time, it is therefore quite
feasible to perform a great amount of work at very little expense.
An apparatus constructed according to this Invention consists of three electro-
magnets arranged in proximity to an iron wheel which is free to revolve around its
axis, said wheel being provided preferably with eleven iron armatures mounted
upon its periphery.
The contact mechanism employed consists of a case made of insulated material
of 33 metal pieces separated from each other by saw cuts, and of a metallic arm
which is mounted upon the axle of the said wheel.
This arm is at about the centre of its length moveable on a hinge, so that a
copper roller placed upon the end of the arm may always be pressed upon the
contact pieces herein before mentioned by means of a suitable spring.
The metallic arm is provided with an aperture near the axle of the wheel, into
which aperture a projection fixed upon the axle of said wheel takes. The aperture
ED 137

page_text: is just so much larger than the projection that the arm is capable of a lateral
movement equal to the width of one contact piece.
The insulated contact pieces are in three series, connected with each other by
copper conducting wires in such a manner that the three series are insulated from
each other.
The conducting wires are arranged in such a manner that if the contact pieces
were numbered there would be electric connection between 1 and 4, 7, 10, 13, 16, 19,
22, 25, 28, & 31, also between 2 and 5, 8, 11, 14, 17, 20, 23, 26, 29, & 32, and
further between 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, & 33.
The end of each of the three copper wires is connected with the coil of one of the
electro magnets herein before referred to, so that each of the electro-magnets is
connected with one series of contact pieces; the opposite ends of the wire coils of
said electro magnets are connected with one pole of a battery. The other pole
thereof is in electrical connection with the copper roller above described, by being
connected with any suitable part of the apparatus.
The action of the apparatus is as follows:-Supposing that series 1 of the contact
pieces is electrically connected with the coil of the first electro magnet, the series 2
with the coil of the second one, and series 3 of the contact pieces with the coil of
the third electro magnet, then if the copper roller be placed upon the first contact
piece, the current will pass through the coil of the first electro magnet, render the
latter magnetic, and cause it to attract the armature which is nearest to it.
This causes the wheel to revolve till the said first armature stands centrally to
the first electro magnet.
Now as the roller upon the axle of the wheel is forced to participate in this
movement, it will touch the next contact piece before the armature is quite central
to the electro magnet; thus the current is momentarily divided and causes the
second electro magnet also to be magnetic, which therefore receives the tendency to
rotate the wheel in the same direction (to the right), because the second armature
is in close proximity to it. In the next moment, however, the roller no longer
touches the first contact piece but only the second one, and the undivided current
acts upon the electro-magnet until the corresponding armature stands centrally to
it and the roller touches the third contact piece. Thereby the third electro-magnet
becomes magnetic, the second ceases to act, and the next armature is brought
opposite to the third electro-magnet. Then the first magnet comes into action
again and so on, so that one magnet is always in action. If the wheel with the
armatures is to move in an opposite direction (in this case to the left), it will only
be necessary to rotate the arm upon the wheel round the the moveable piece at its
end. The roller will then touch the contact pieces as above described but in an
opposite order, and the wheel is revolved towards the left.
As, however, can be very easily moved on the piece at its end, it is only
necessary to give to the wheel a slight impulse to the right or left and then to make
contact, and the wheel will continue to revolve in the same direction.
The number of armatures depends on the size of the wheel and the diameter of
the iron cores of the electro magnets, but the number of the contact pieces is always
three times that of the armatures.
Electro magnets may also be used which, besides having the iron core, may
have an iron tube or shell outside the coils, so as to economize the number of
armatures.
This motor can be used for transmitting any kind of motion, for example, the
motion of a weather cock; in this instance it would only be necessary to attach the
rod of the weather cock to the arm carrying the contact roller, so that this arm
participates in the rotation of the weather cock.
The ends of the three contact series may be connected with line wires as occasion
may require.
At the terminal station a system of electro magnets exactly like that above
specified and of as small dimensions as possible, but without the contact arrange-

page_text: ment may be placed, as the contact mechanism is attached to the rod of the
weather cock.
An index may be connected with the axle of the wheel.
As the wheel must always follow the movements of the arm, the index, when
once placed in the direction of the weather cock, will always correspond with it.
This principle may also be applied to transmit the indications of any kind of
pointer, such as the index or hand on a pressure gauge, or of an indicator for the
level of any liquid, and so forth.