improvements in and relating to Continuous Current Dynamo Electric Machines and Electro-motors.
Year: 1887

page_text: Date of Application, 2nd Sept., 1887
Specification Accepted, 4th Oct., 1887
improvements in and relating to Continuous Current Dynamo
Electric Machines and Electro-motors.
I, RANKIN KENNEDY, of the Electric Lamp Works, 115 Woodside Road, Glasgow,
Lanarkshire, Electrical Engineer do hereby declare the nature of my said invention and
in what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement in writing, reference being had to the accompanying
Sheet of Drawings and to the letters and figures marked thereon, that is to say :-
This Invention has reference to improvements in and relating to continuous current
dynamo electric machines and electro-motors suitable for electric lighting, motive
power and other purposes; and comprises a new or improved arrangement of their
electro-magnets armatures and fittings; and consists mainly in the use of two or more
armatures so that when one breaks down or fails the other may be immediately used,
and thus ensure the continuous working of the dynamo and prevent the possibility of
the failure of light in the installation.
According to my invention I arrange the electro-magnets so that two independent
magnetic fields are produced by one field magnet coil of wire, and thus enable two
rotating armatures to be worked in one machine, either together or separately. I also
by my improvements can obtain three independent magnetic fields by employing two
electro magnets or coils of field magnet wire, or four magnetic fields by employing
three electro magnets, and so on in any multiple, thus producing magnetic fields by a
less number of electro-magnets; or stronger magnetic fields by employing the same
or an additional number of electro magnets to the fields, constructed or arranged
according to the improvements of my invention.
And in order that my said invention and the manner of performing or carrying the
same into effect or practice may be properly understood, I have hereunto appended an
explanatory Sheet of Drawings representing my improvements as applied to a
continuous current dynamo-electric machine or motor, showing my arrangement of
single electro field magnet, and three electro field magnets respectively as applied in
this double armature machine. In these Drawings the same reference letters are used
to indicate corresponding parts in all the Figures where shown. Figures 1 and 2 are
side and end elevations respectively partly in section, of a double armature continuous

page_text: current dynamo electric machine, also applicable as a motor, fitted with my improved
arrangement of single electro-magnet A, A', as used to produce the magnetic field to
excite the two rotating armatures B b, B¹ b. While Figure 3, is a plan corresponding
to Figure 1. Figures 4 and 5 show a side elevation and plan respectively of a
continuous current dynamo electric machine or electro-motor, to a smaller scale than
shown in Figures 1 to 3, and showing how three electro-magnets A, A' can be
arranged according to my improved system to produce stronger magnetic fields than
in the arrangement shown in Figures 1 to 3, to excite the rotating armatures B b, B'b,
for generating the electric current. While Figures 6 and 7 show detailed elevations
of the lower pole pieces C, C¹, of the two arrangements shown in Figures 1 to 3 and 4
and 5, respectively, which are essentially the same as the upper pieces and show these
separate from the machine.
Referring to the arrangement shown in Figures 1 to 3 of these Drawings in which
one electro-magnet A, A³, is used to produce two magnetic fields and two
armatures B b, B¹ b, are used, which may be worked either together or separately.
According to my improvements, I arrange a field electro magnet A, A¹, consisting of
a vertical malleable-iron cylindrical core surrounded with coils of wire, between the
rotating armatures B 6, B₁ b, of the dynamo, and place the pole pieces C, C' above
and below the armatures B, B¹, to form the magnetic field (and poles at S and N)
round the circumference of the rotating armatures. The lower piece C forms the
foundation of the dynamo and is secured to any suitable foundation by the snugs and
bolts c, while the lower end of the core A of the field magnet A, A', is keyed or other-
wise secured through an eye at c' in it. This pole piece is shown detached in
elevation in Figure 6. The upper pole piece C¹ is formed similar to the lower C
except that it requires no snugs c and is keyed or otherwise secured in an equivalent
manner on the upper end of the core piece A, through a central eye (", all parallel
and vertical over the lower pole piece C having the polar ends N, 8, of the
lower projecting upwards and those S, N, of the upper projecting downwards
over the armatures B b, B¹ b, and bored out truly to just clear the outer circum-
ference of the coiled armature B b, B¹ b. Each armature is composed of a
spindle B, B', with an enlarged boss or arms in the centre, on which is secured the
cylindrical or ring coils 6 of the armature preferably formed of a core of laminated
ring plates and wound with insulated copper wire outside the full length of the
poles S, N, of the blocks C C³. Each spindle B or B¹ of the armature is carried in
journal bush bearing brackets C secured to the lower block C of the dynamo, and
has on one side overhung the driving pulley C, and on the other side the commu-
tator 61, having the collecting brushes & carried on the usual swivelling studs and
frame 63, all substantially in any usual manner. The field magnet A, A', which is
preferably cylindrical or bobbin shaped, may be wound with wire in any of the well-
known shunt, series, or compound methods. This arrangement of dynamo electric
machine or motor admits of either working one or both of the armatures B b, B¹ b,
for generating the electric current, making sure of one being available for lighting
should the other fail.
Referring to the arrangement shown in Figures 4 and 5, this shows two outer field
magnets A A³ mounted beyond the armatures B B' and having the pole pieces C, C³,
extended with eyes c³, c³, at their outer ends to carry the cores A¹ of these coils.
This arrangement gives a double magnetic and stronger field for each armature,
whether one only or both of the armatures B, B₁, or fields are worked. And three
independent magnetic fields might be produced by employing two magnets and
three armatures, that is adding an armature beyond either of the field magnets
A' or A'; and four fields by employing three field-magnets and four armatures and
80 on.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
T
T

page_text: arrangement and combination of the parts so that two independent magnetic fields are
produced by one electro-magnet, or three fields by two, or four fields by three, and so
on, with only one extra armature, all substantially as herein described in reference to
and shown in the accompanying Drawings.
Second. In continuous current dynamo electric machines or electro motors, the
combination of two armatures with one electro or field magnet, all substantially as
herein described in reference to and shown in Figures 1 to 3 of the accompanying
Drawings.
Third. In continuous current dynamo electric machines or motors, the combination
of two armatures with three field magnets, all substantially as herein described in
reference to and shown in Figures 4 and 5 of the accompanying Drawings.