Improvements in Dynamo-electric Machines or Motors.
Year: 1888

page_text: Improvements in Dynamo-electric Machines or Motors.
We, PATRIOK JAMES CHARLES and LUTHER HANSON both of North Bridge
Electrical Works, New Bank, Halifax, in the County of York, Electrical Engineers,
and ROBERT HENRY FOWLER of the Steam Plough Works, Leeds, in the same
County, Engineer, do hereby declare the nature of this invention to be as follows:-
In a certain class of dynamo-electric machines as commonly employed the excita-
tion of the field magnets is obtained by winding the iron coro or cores with copper
wires in the form of helices one of which is usually of high and the other of low
resistance.
According to this invention we use instead of the low resistance wire helix, a
sheet or sheets of metal of the required sectional area, wound around the iron core in
the form of a roll, each convolution of which covers the entire length of the core or
limb of the magnet.
By this means we are enabled to bring the conductor into closer proximity to the
iron of the magnet and obtain a greater radiating surface than is possible by using
wire in the form of a helix, thereby increasing the efficiency of the magnet. In order
to allow of ventilation and to get rid of heat, the metal sheet may be perforated or
may take the form of gauze.
ic 1 1000

page_text: We, PATRICK JAMES CHARLES and LUTHER HANSON both of North Bridge Electrical
Works, New Bank, Halifax, in the County of York, Electrical Engineers, and
ROBERT HENRY FOWLER of the Steam Plough Works, Leeds in the same County,
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 :-
In a certain class of dynamo electric machines as commonly employed the excita-
tion of the field magnets is obtained by winding the iron core or cores with copper
wires in the form of helices one of which is usually of high and the other of low
resistance.
According to this invention we use instead of the low resistance wire helix, a
sheet or sheets of metal of the required sectional area, wound around the iron core
in the form of a roll, each convolution of which covers the entire length of the core
or limb of the magnet.
By this means we are enabled to bring the conductor into closer proximity to the
iron of the magnet and obtain a greater radiating surface than is possible by using
wire in the form of a helix, thereby increasing the efficiency of the magnet.
In order that our said invention may be fully understood and readily carried into
effect we will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a section of the field magnets of a dynamo-electric machine or motor
constructed in accordance with our invention. Figure 2 is a transverse section on
the line A B in Figure 1. a, a, are the magnet cores; they are magnetically con-
nected by the iron base b and c c are their pole pieces. Between the pole pieces there
is as usual the cavity in which the wound armature rotates. dd are sheets of copper
wound around the magnet cores in the form of a roll each turn covering the entire
length of the core. The sheet metal is insulated by means of paraffined paper or calico,
vulcanised fibre or in other usual manner. The roll is connected up by folding over
the end of the sheet and soldering or rivetting thereto a flat copper conductor of
sufficient sectional area and this is coupled in series between one of the collecting
-brushes and one of the terminals of the machine. ee are the higher resistance shunt
coils, these are as usual of insulated wire; their ends are connected with the terminals
of the machine each to each. These coils e are preferably outside the roll d as
shown but the roll might be on the outside.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. A dynamo electric machine or motor with a field magnet wound with a roll of
sheet metal connected in series and each turn covering the whole length of the core
and also wound with wire coils connected as a shunt substantially as described.
2. Our improvements in dynamo electric machines or motors substantially as
described.