Improvements in Dynamo Electric Machines.
Year: 1897

page_text: Date of Application, 2nd Jan., 1897--Accepted, 27th Feb., 1897
Improvements in Dynamo Electric Machines.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of London, and EDUARD FRIEDRICH HERMANN
HEINRICH LAUCKERT of 63 Maryon Road, Old Charlton, in the County of
Kent, Electrical Engineers, 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 the construction of the armatures of disc form
employed in dynamo electric machines, as we shall describe referring to the
accompanying drawings.
Figure 1 is a front view of part of the armature, without the coils on it.
Figure 2 is a front view of part shewing two adjacent coils.
Figure 3 is a section of the armature on a radial arm.
The central part of the armature according to this invention consists of two
discs D D of non-magnetic material keyed side by side on the armature shaft A.
The circumference of each of these discs is made with ratchet teeth, the teeth
of the one disc sloping in the one direction, those of the other disc sloping in the
opposite direction. Instead of two separate non-magnetic discs, the central portion
which is keyed to the armature shaft may be constructed of a single disc having
fixed on its periphery two parallel rings of non-magnetic material in which the
ratchet teeth are cut.
Two outer rings R R of the same thickness as the discs and of non-magnetic
material are made with internal ratchet teeth oppositely sloped. Between each
disc or inner ring and the corresponding outer ring, that is to say, that ring in the
same plane with it, a number of iron strips 1 insulated from each other of width
equal to the thickness of one of the discs or rings are placed in bundles between
the slopes of the teeth of D and of the corresponding ring R so that the strips
stand at right angles to these slopes from which they are insulated, each bundle
being inclined to a radius. In like manner bundles of iron strips are placed
between the slopes of the teeth of the disc D¹ and the ring R¹. The bundles thus
placed are inclined in opposite directions thus holding the rings which are bolted
together firmly in position relatively to the discs.
The bundles I and I¹ may have the strips all parallel as shewn at v leaving
triangular vacuous spaces v³ which might be filled in with wood or other material
or it might be with a number of iron strips of different length forming a stepped
wedge piece, as shewn at v². Instead of using any wedge piece or filling material
the strips constituting the bundles might diverge as shewn at 3 by opening them
apart at one end of the bundle and filling the spaces with suitable cement. The
coils C are fixed on the discs D D' and rings R R¹ by clips P P screwed
respectively on the disc and rings. The empty spaces forming the inside of the
bobbins may be filled in with wood or other suitable material, which is kept in
place by the clips P and Pl. The magnet pole pieces between which the coils
revolve are indicated at M M.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
An. armature for a dynamo electric machine consisting of two discs fixed on the

page_text: shaft and having oppositely sloped ratchet teeth, two rings having internal ratchet
teeth oppositely sloped separated from the discs by bundles of iron strips bearing
perpendicularly against the slopes of the teeth, and coils fixed on the discs and
rings by suitable clips, substantially as described.
Dated this 2nd day of January 1847
ABEL & IMRAY,
Agents for the Applicants.