A Removable Combination Magnet and Coil for Electric Generators and Motors.
Year: 1899

page_text: Date of Application, 15th May, 1899
Complete Specification Left, 14th Sept., 1899-Accepted, 4th Nov., 1899
PROVISIONAL SPECIFICATION.
A Removable Combination Magnet and Coil for Electric Generators
and Motors.
We, CHARLES HENRY CUTTING and GEORGE HAWKINS CUTTING, Constituting
the Firm of Cutting Bros., Electrical Engineers, Parliament Works, Parliament
Street, Derby, do hereby declare the nature of this invention to be as follows;-
This invention is a removable combination field magnet and coil for electric
generators and motors. It will be specially suited to generators and motors of
the square or circular construction in the bi-polar and multi-polar types. By this
invention the field magnet and coil complete can be removed from the outside of
the generator or motor without the removal of any part of the yoke or armature.
The removable magnet may be made of wrought iron or be a steel casting. The -
magnet is so formed as to carry the magnetising coil which forms a part of the
combination. The magnet is provided with a flange for fixing same to the yoke
of the machine.
Dated this 12th day of May 1899
1
CHAS. H. CUTTING,
GEORGE H. CUTTING.
A Removable Combination Magnet and Coil for Electric Generators
and Motors.
We, CHARLES HENRY CUTTING. and GEORGE HAWKINS CUTTING, Parliament
Works, 165, Parliament Street, Derby, in the County Borough of Derby, Elec-
trical 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:-
-
According to this invention, we provide a removable combination field magnet
and coil for electric generators and motors. These field magnets are so con-
structed as to carry their magnetizing coils without the aid of separate bobbins,
the wire being insulated from the magnets but wound directly thereon. These
magnets can each be provided with a flange. Such flange is fixed on the outside
frame by means of screws passing through the flange into the frame or yoke of
the machine.
In this frame or yoke suitable openings are provided of sufficient size to admit
the free passage of the magnet with its coil, the flange resting on the frame
outside on a suitable surface prepared for it. These openings may be round,
square or oblong.

page_text: It may sometimes be found more convenient to remove the combination field
magnet and coil laterally instead of externally. In this case we divide the yoke
into two parts, Q, Q, (see Figures 4, 5, 6, & in drawings) and in such wise that
the direction of the dividing line D, D, Fig. 4, runs parallel with the direction
of the lines of force, and in such wise also that, on the removal of one portion of
the said yoke, the field magnets can be removed laterally (see Fig. 6). In order
to secure such removal of the combination field magnet and coil the division of
the yoke takes place across the holes in which the field magnets are to be fixed,
so that part of the extremity of the magnet core is embraced by one part of the
yoke and part of it by the other (see Figures 4 and 6). When the said hole is
circular the division of the yoke is made to cut through the centre of the hole;
when however, the hole is square or oblong the division may be arranged to cut
across any convenient part of the said hole that will allow both the free admission
and the removal of a field magnet with its coil. When the yoke of the machine is
divided the flange on the removable field magnet may be used for a double pur-
pose, namely, for the fixing of the field magnet to the yoke and for the holding
together of the two divisions of the yoke, and both these by means of screws
passing through the flange into the yoke (see Fig. 4).
When a flange is used for the fixing of these two yoke pieces, one part of the
divided yoke may be removed without disturbing either the field magnets or the
other part of the yoke, (see Figures 6 and 7) and this may be performed simply
by taking out the screws from that side of the yoke which is to be removed, and
from that side only.
In the drawings we have shewn two suitable ways of using the combination
field magnet and coil, but we do not limit ourselves to these as precisely shewn,
Fig. 1 is an elevation of a removable field magnet, but without its coil.
F, F, is the flange.
S, S, the space to be occupied by the magnet coil.
Fig. 2 is an elevation of a removable field magnet together with its winding.
Fig. 3 is a section of a combination magnet and coil fitted in the frame of an
electric generator or motor.
Q, Q, shows in section part of the frame or yoke.
C, C, is the magnetizing coil.
F, F, is the flange.
B, B: the flat surface upon the outside of the frame on which the flange rests.
P, is the polar face.
Fig. 4 is a plan showing two parts of a yoke divided for the reception of a
combination field magnet and coil and held together by screws through the
flange Fat extremity of field magnet the flange extending to both sides of the
dividing line of yoke.
D, D, is the dividing line.
Q, Q, are the two sides of the divided yoke.
Fig. 5 is an end elevation showing poles of combination magnets and coils in
position in a divided yoke.
F, F, the flanges.
C, C the magnet cores with their magnetizing coils.
P, P the polar faces.
Q-the yoke.
Fig. 6 is a plan showing one side only of a divided yoke, with two flanged field
magnets F, F, still held in position, although the other part of the yoke as shown
in Fig. 7 has been removed.
Fig. 7 is a plan showing the other side of the yoke when removed laterally
from its counterpart, its screws having been taken out for that purpose.
This form of construction offers the following advantages:-
:-
It expidites, by simplyfying, the process of manufacture of electric generators
and motors. For example,-The field magnet core with its flange and polar face
can be cast in one piece if required.

page_text: The usual coil bobbins can be dispensed with since no support for the winding
is necessary beyond what is provided on the magnet itself.
When a magnet core is placed in its position from the outside of the frame of
generator or motor it can be withdrawn in the same way without the necessity
of removing either coil or polar face.
When it is thought necessary to provide a divided yoke the combination field
magnet and coil can, when the retaining screws are removed from one side, be
drawn out of its position laterally.
By the adoption of the combination field magnet and coil the after examination
of individual parts of a machine is greatly facilitated, as for example, when repairs
are necessary or for other purposes.
This method facilitates the removal of an armature, especially from a machine
of the square or circular type, seeing that after the field magnets have been
removed the armature can be lifted out of its bearings without the necessity of
having either a horizontally divided yoke or separately fixed standards, for the
bearings; and the same advantage is gained in the placing of an armature in its
bearings in the first place, since the finished field magnets with their coils can
be placed in position after the armature has been properly placed.
The outside flange above described has the advantage of providing a magnetic
contact of more than usual area, while at the same time leaving the field magnet
itself not necessarily dependent on the hole in the yoke for either its mechanical
support or magnetic contact, but magnets may be fitted without the said flange.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:
1. In the construction of an electric generator or motor the use of a detachable
combination field magnet and coil as shown and described.
2. In the construction of an electric generator or motor the use of a field magnet
which together with its magnetizing coil can be placed in its normal position or
withdrawn therefrom externally in a direction at right angles with the shaft as
shown and described.
3. In the construction of an electric generator or motor the use of a field
magnet which together with its magnetizing coil can be placed in its normal posi-
tion or withdrawn therefrom laterally in a direction parallel with the shaft as
shown and described.
4. In the construction of an electric generator or motor the use of a field
magnet provided with a flange for fixing the magnet externally as shown and
described.
August 1800
CHARLES HENRY CUTTING,
GEORGE HAWKINS CUTTING.