Improvements in the Attachment of Pole Pieces to the Armatures of Dynamos.
Year: 1897

page_text: Date of Application, 14th Sept., 1897--Accepted, 13th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in the Attachment of Pole Pieces to the Armatures
of Dynamos.
I, WILLIAM HUMPHREY WHEATLEY, of the Firm of Wheatley and Mackenzie,
Engineers and Patent Agents, of 40 Chancery Lane, in the County of London,
do hereby declare the nature of this invention a communication to me from
Allgemeine Elektricitäts-Gesellschaft, of 22 Schiffbauerdamm, Berlin, in the
Empire of Germany-and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The usual method of arranging pole pieces on the armatures of dynamos consists
in cutting three or more pole piece projections in the main plate. This method
of construction has however important disadvantages in the production of the
armature and in the erection of the dynamos.
The object of this invention is to obtain pole pieces which may be drawn out
sideways and having a special attachment to the main plates. The following
advantages are thereby attained: (1) The pole pieces, the bobbins and the
periphery can be separately and simultaneously prepared. (2) The pole pieces
can be easily inserted in the periphery at the place of erection. It is thus possible,
without exceeding the limit for railway transport, to increase the diameter of
the wheel by twice the height of the pole pieces. (3) To change single bobbins
in the field magnet it is not necessary to move aside the armature, that is, the
frame, as by the removal of a pole piece the bobbin to be changed is made
accessible. (4) By the use of detachable double wedges specially secured, the
pole pieces can be quickly and easily fastened in and detached from the periphery
of the wheel.
In the accompanying drawing Figs. 1 and 2 show a portion of the armature
periphery with inserted pole pieces in side view and in section. Figs. 3 and 4 show
the shape of the main plates and the pole plates. Figs. 5-7 show the double
wedge.
The pole plates a are clamped together in a block by rivets; the main plates b
are united by bolts into a ring or circle so that the pole pieces and the ring may
be regarded as fixed parts. The foot d of the pole plate a is so shaped that the pole
plate may be inserted in the groove e cut in the main plate b. On the accom-
panying drawing these grooves are dovetail shaped. The fastening of the inserted
pole pieces a with the coils e is effected by double wedges g h Figs. 5-7, the
securing of which is effected by means of pins f located in slots along the wedges
and which are clinched or screwed therein.
In erecting the dynamo the coils e are first placed on the pole pieces a a, then
the latter are inserted sideways into the dovetail groove c of the main plate b
and the safety pins f are clinched or screwed after insertion and adjustment of
the wedges gh.

page_text: 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
I claim is
1. A detachable attachment arrangement for pole pieces characterised by main
plates (b) with grooves (c) corresponding to similarly shaped feet (d) of pole
plates (a) of the pole pieces for insertion therein.
2. With the attachment arrangement for pole pieces the use of double wedges (g h)
and pins (f) for securing the wedges, which pins lie in a common slot in the
wedges and are suitably clinched or screwed at the ends.
3. The improvement in the attachment of pole pieces substantially as described
with reference to the drawings.
1007
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.