IMPROVEMENTS IN ELECTRO-MOTORS OR DYNAMO-ELECTRIC MACHINES
Year: 1885

page_text: I ANTHONY RECKENZAUN of 8 Osborne Road, Forest Gate, London, E. in the
County of Essex, Engineer, do hereby declare the nature of my Invention for
IMPROVEMENTS IN ELECTRO-MOTORS OR DYNAMO-ELECTRIC MACHINES, to be as
follows:-
My Invention has mainly for its object the production of a novel type and
improved construction of, field magnets, which are laminated or built up of thin
bars or plates, thus ensuring the advantages of rigidity, simplicity and efficiency,
combined with small weight of material.
With wrought iron cores of Dynamo Machines it is usual to make a joint
between the cores and the yoke of a field magnet in order to save expense in
forging and to facilitate the placing of wire coils In a well designed Dynamo
Machine there should be little or no magnetism at the neutral part of the field
magnets usually called the "yoke." In order to prevent the formation of magnetic
poles at the joint before mentioned-the yokes are made of large sectional area,
and their contact surfaces are made as true as possible; this however involves
a considerable amount of accurate work without entirely obviating the formation
of poles where not required, and the weight of these yokes is objectionable with
Electro Motors intended for locomotive purposes.
Now according to my present Invention I propose to make the core and yoke of
the field magnet continuous; that is to say, I bend the iron bar similarly as in a
horse shoe magnet and slip the wire coils on the iron cores, and fix the pole piece
-which, in Dynamos and Motors should be rather large-to the free ends of the
horse shoe shaped core. Said free ends are arranged in the position relatively to
the armature, where they exert their greatest power, or, in scientific terms, where
the greatest number of magnetic lines of force is desirable.
It is well known that laminated cores, or wire cores, are more effective than solid
masses of iron, for the production of Electro Magnets; but, there is a difficulty in
rendering such a divided field magnet core sufficiently rigid. Now, I obtain with
my present method of construction as herein described, a rigid and at the same time
light field magnet made of thin bars or plates; the laminated horseshoes forming
the core proper, having through the free ends, holes to receive well fitting bolts.
The segments for the polar extensions are also made of thin bars or plates with
corresponding holes at the ends. I thus build up the field magnet by taking horse

page_text: shoe shaped plates or bars alternately with concentric pole segments, so that there
will be an air space between the horse shoes equal in width to the thickness of a
pole segment; and, between the pole segments air spaces equal in width to the
thickness of the bars of which the horse shoe cores are made. Through the holes
at the ends of the horseshoes and the segments I place a bar or bolt, and screw the
plates aforesaid together; hence, along that part of the structure where the ends
meet, there will be a thick mass of metal, and this mass of metal occurs just at the
place where it can have its maximum useful effect upon the enclosed armature,
which in this case is of cylindrical form, as described in the Specification of my
Patent, Number 5031; the pole segments forming a partial cylinder surrounding
said armature.
In order to give increased rigidity to the structure above described, I place upon
the first and last-and also if necessary upon intervening polar segments, non-
magnetic rings with holes to receive the bolts holding the plates of the field magnet
together; said rings may form part of the bracket or bearing carrying the armature
spindle. The ends of the polar segments I make also, to project, forming pointed
poles.

page_text: improvements in Electro motors or Dynamo Electric machines.
I, ANTHONY RECKENZAUN of 26 Paternoster Square, London 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 :-
My Invention has mainly for its object the production of a novel type and
improved construction of field magnets which I laminate or build up of thin bars
or plates thus ensuring the advantages of rigidity, simplicity and efficiency com-
bined with small weight of material.
With wrought iron cores of dynamo machines it is usual to make a joint between
the cores and the yoke of a field magnet in order to save expense in forging and
to facilitate the placing of wire coils upon such cores. In a well designed dynamo
machine there should be little or no magnetism at the neutral part of the field
magnets usually called the yoke. In order to prevent the formation of magnetic
poles at the joint, the before mentioned yokes are made of large sectional area and
their contact surfaces are made as true as possible. This however involves a
considerable amount of accurate work without entirely obviating the formation of
poles where they are not required, and the weight of their yokes is objectionable
with electro motors intended for locomotive purposes.
Figure 1 of the accompanying drawings is an end view and Figure 2 a side view
of a machine constructed according to my Invention. Figure 3 is a separate end
view of the field magnets. Figure 4 is an end view of another forin of machine
and Figure 5 another form of field magnet.
According to this Invention and with special reference to Figures 1, 2 and 3
I make the core and yoke continuous that is to say I bend the iron bar A. similar to
a horseshoe magnet the legs being by preference splayed more or less as shewn and
I slip the wire coils on the iron cores or wind them theroon in the lathe and I fix
the pole pieces B which in dynamos and motors should be rather large, to the free
ends of the horseshoe shaped core the said free ends are arranged in the position
relatively to the armature where they exert the greatest power, or, in scientific
terms, where the greatest number of magnetic lines of force is desirable.
It is well known that laminated cores or wire cores are more effective than solid
masses of iron for the construction of electro magnets but there is a difficulty in
rendering such a divided field magnet core sufficiently rigid. Now I obtain with
my present method of construction as herein described a rigid and at the same
time light field magnet, made of thin bars or plates as shewn in Figure 2, the
laminated horseshoes forming the core proper having through the free ends holes to
receive well fitting bolts C. The segments B for the polar extensions are also as
shewn in Figure 2 made of thin bars or plates with corresponding holes at the ends
I thus build up the field magnet by taking horse-shoe shaped plates or bars A
alternately with concentric pole segments B so that there will be an air space
between the horseshoes A equal in width to the thickness of a pole segment B;
and between the pole segments B there will be air spaces equal in width to the
thickness of the bars A of which the horseshoe cores are made. Through the holes

page_text: at the ends of the horse shoes A and segments BI place a bar or bolt C and screw
the plates aforesaid together; hence along that part of the structure where the
ends meet there will be a thick mass of metal, and this mass of metal occurs just
at the place where it can have its maximum useful effect upon the enclosed
armature which in this case is of cylindrical form (and for which I may suitably
use the one described in my Patent Specification N° 5031 of 1883) the pole
segments forming a partial cylinder surrounding said armature.
In order to give increased rigidity to the structure above described I place upon
the first and last polar segment B (and if necessary at intervening polar segments)
nonmagnetic rings D with holes to receive the bolts holding the plates A of the
field magnet together; said rings may as shewn form part of the bracket or bearing
carrying the armature spindle. The ends of the polar segments I make also to
project forming pointed poles N. S.
Figure 4 is an end view of another form of machine with upright field magnet
and Figure 5 an end view of another form of field magnet.
In order to save wire and as no air spaces are needed between the horseshoe
pieces I may bring them close together at that part where the wire is coiled round
them and do away with the distance pieces shewn at the yoke ends Figure 3.
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
First. The manufacture and use of field magnets constructed of a number of
horse shoe magnets lamince or plates without yoke pieces, in combination with
intermediate or alternate segmental pole piece plates all held together by through
bolts so that intermediate air spaces are formed substantially as set forth.
Second. The manufacture and use of field magnets constructed of a number of
horseshoe magnet lamince or plates without yoke pieces in combination with inter-
mediate or alternate segmental pole piece plates, all held together by through bolts
so that intermediate air spaces are formed the said bolts also connecting the field
magnets and pole pieces with a non magnetic ring or ring bracket at each end
substantially as set forth.
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