Improvements in Dynamos.
Year: 1898

page_text: Date of Application, 19th May, 1898-Accepted, 6th Aug., 1898
COMPLETE SPECIFICATION.
Improvements in Dynamos.
I, GUSTAV UNTERBERG, of 92A, Fabrikstrasse, Cannstatt, in the Empire of
Germany, Mechanician, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention for improvements in dynamos relates to a new dynamo, which
on account of its lightness and the considerable useful effect resulting from the
lines of force being applied to the very best advantage, is especially suitable for use
in places where these qualities are necessary or desirable.
In the accompanying drawing, Fig. 1 is a vertical section in the direction of the
axis of a dynamo constructed according to this invention and Fig. 2 is a vertical
section taken at right angles to Fig. 1.
In the suitably constructed bearings a and b of the frame A, is mounted the
shaft c of the dynamo, one end of which is furnished with a driving pulley. On
the shaft c, the armature d formed and wound after the fashion of a gramme-
ring is fixed, in the usual manner to radial arms.
The core of this ring is composed of separate rings of good, soft wrought iron,
around which the armature windings are placed in separate divisions adjoining
one another,
The free ends of the windings are directed to the commutator e and are firmly
fastened in the segments thereof by the screws e¹.
An important departure in a dynamo constructed according to this invention is
that horse-shoe cores are not made use of in any way, but that the winding is
applied only to a thin sheet iron spool, which in its turn, surrounds the greater
portion of the periphery as well as the side-surfaces of the ring-armature. In
this way, the special use of horse-shoe cores becomes superfluous, these to a certain
extent being replaced by the core of the ring armature.
The spools and fl, the forms of which are to be seen from Fig. 2, are made of
suitable strong sheet iron and have a special internal bottom or lining also of sheet-
iron which with the addition of the indispensably necessary space for free running,
approaches in form the whole periphery of the armature and likewise its side
surfaces. The angles formed by the tray-shaped bottom or lining above and below,
can as a matter of course not be made use of in the winding but must be balanced
by the straight walls f¹¹ and fill of the coils.
The form of the frame, of the bearings, or the fixing of the ring armature to the
shaft or other constructional details are of no importance as regards the essential
feature of the invention.
The dynamos built or wound according to this invention can be applied for the
production of continuous or alternating currents or in the three phase system of
currents for producing a rotary magnetic field.
The tray-shaped spools almost entirely surrounding the fixed field magnets,
induce in the most intense degree, the armature-windings affected by the magnetic
field produced by them, and a dispersion of the magnetic lines of force is entirely
avoided. Through the avoidance of any loss of force in this respect, the useful

page_text: effect or good quality of the machine is decidedly increased, and beyond this its
use is less dangerous or more agreeable, as delicate electrical measuring instru-
ments installed in proximity are not caused to deviate.
A further great advantage of the machine consists in its exceeding lightness as
compared with dynamos of hitherto known construction.
The weight of such a machine compared with one of those formerly in use and
doing equal work is about two thirds.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. A dynamo, the distinguishing feature of which is that special horse-shoe
cores are avoided and that the armature is almost entirely enveloped on its
periphery as well as its side surfaces by two spools made of thin sheet iron and
furnished with a tray-shaped lining, whereby, with the application of a suitable
coil-winding, the armature core to a certain degree replaces the usual horse-shoe
cores and notwithstanding the lightness of the machine a very considerable useful
effect is obtained.
2. The improvements in dynamos substantially as described with reference to
the drawings.
Dated this 17th day of May 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.