Improvements in Electromotors.
Year: 1890

page_text: Date of Application. 25th Aug., 1.90
Complete Specification Left, 23rd May, 1891-Accepted, 15th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Electromotors.
I, ALEXANDER SIEMENS of 12, Queen Anne's Gate, Westminster in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to an improved construction of dynamo electro motors,
applicable more particularly in cases where the motor is required to drive in either
direction and also to work with variable speed or power such for example as in
working winches, cranes etc.
For this purpose the motor is arranged with its armature shaft either in a
vertical or a horizontal position, and is connected to the working machine either
directly or by toothed or other gearing. The connection may be made through an
intermediate shaft coupled thereto in such a manner as to allow of a slight amount
of end and side play, in order to obviate the necessity of accurate adjustment
relatively to the working machine.
The commutator brushes may consist of a number of metallic fingers, arranged
side by side, which are pivotted at one end to a fixed pivot while the other ends
are pressed upon the commutator by helical springs connecting the two opposite
sets of fingers together at an intermediate point of their length, but so that they are
insulated therefrom.
The windings of the field magnets and of the armature, are connected to the
main circuit through switches and resistances by means of which the speed
power and direction of rotation of the motor can be controlled in the well
known way.
The levers of these switches may be interlocked if required.
In order to prevent the motor being injured by an excess of current in the event
of its movement being arrested by overloading it with work, a permanent resistance
may be provided in the main or armature circuit.
Dated this 25th day of August 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electro Motors.
I, ALEXANDER SIEMENS, of 12 Queen Anne's Gate, Westminster, in the
County of Middlesex, Civil 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 :-
This invention relates to an improved construction of dynamo electro motors
applicable more particularly in cases where the motor is required to drive in either
direction and also to work with variable speed or power such for example as in
working winches, cranes, etc.
For this purpose the motor is arranged with its armature shaft either in a
vertical or a horizontal position, and is connected to the working machine either
directly or by toothed or other gearing. The connection may be made through an
intermediate shaft coupled thereto in such a manner as to allow of a slight amount
of end and side play, in order to obviate the necessity of accurate adjustment
relatively to the working machine.
The commutator brushes may consist of a number of metallic fingers arranged
Price dl

page_text: side by side, which are pivotted at one end to a fixed pivot while the other ends are
pressed upon the commutator by helical spings connecting the two opposite sets of
fingers together at an intermediate point of their length but so that they are
insulated therefrom.
The windings of the field magnets and of the armature are connected to the main
circuit through switches and resistances by means of which the speed, power, and
direction of rotation of the motor can be controlled as illustrated by the accompanying
diagram.
A indicates the armature, B' B2 the commutator brushes, and C the coils of the
field magnets of an electro motor geared to the barrel D of a winch. L is the
handle of a lever which has on it two conducting plates E E² insulated from one
another, arranged to slide over and make contact with two inner segments F¹ F2
and two outer segments G1 G2 each of which is divided into a number of insulated
parts connected to a series of resistances R¹, R2. There is also an extended outer
segment H with which either E' or E2 makes contact when the other is over the
divided segments G2 or G¹. The lever K of a carbon break switch carries a
roller on which the cam shaped end of the lever L comes to bear when the
lever is in middle position, thus separating the carbons M and throwing the motor
out of circuit. When the lever L is in the position shewn, the course of the
current is M, K, C part of the resistance R₁, G¹, E, F, B', A, B², F2, E², H,
through a permanent resistance R to -, the motor being thus caused to turn in the
one direction with more or less power according as the lever L is moved more or
less over, cutting out more or fewer of the resistances R'.
When the lever is moved over beyond its middle position the direction of the
current through the armature A is reversed causing the motor to turn in the
opposite direction.
In order to prevent the motor being injured by an excess of current in the event
of its movement being arrested by overloading it with work, a permanent resistance
may be provided in the main or armature circuit.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
In an electro motor, connecting the windings of the field magnets to the main
circuit through switches and resistances whereby the speed, power and direction of
rotation can be varied.
1100.1 la
M
1901
ABEL & IMRAY,
Agents for the Applicant.