An Improvement in or relating to Dynamos.
Year: 1889

page_text: Date of Application, 3rd Jan., 1889
Complete Specification Left, 3rd Oct, 1889-Accepted, 9th Nov., 1889
.
PROVISIONAL SPECIFICATION.
An Improvement in or relating to Dynamos.
I, GILBERT BETTELEY LÜCKHOFF, of 3 East-Nor Villas, Whitehorse Road, Croydon,
Surrey, Engineer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to construct a light cheap dynamo or electric
motor, having high commercial efficiency.
The improvements relate especially to the construction of armatures of iron in
strips of any desired shape laid on the armature core in any desired manner and
forming the periphery, said strips being fixed in position by catch pieces on them-
selves, or otherwise. The strips are insulated from the armature core and from one
another. The usual copper conductors (wire or strips) are laid between, or within
the iron strips and are held in position by the iron strips. The iron and copper
strips are joined together in parallel groups, each group acting as one single
conductor of electric current.
By this invention, the iron strips serve to conduct both the electric current and
the lines of force passing through the armature from pole piece to core and the reverse.
The electrical carrying capacity of the iron strips added to that of the usual copper
conductors gives a higher total carrying capacity and the output of the machine is
increased in the same proportion.
As the armature presents an almost continuous iron surface on its periphery and
it can be turned up true after the strips are laid on, the resistance of the air gap is
small, therefore the total resistance of the magnetic circuit can be made small and few
ampere turns will be required on the field magnets.
Dated this 3rd day of January 1880
H. GARDNER,
166, Fleet Street, London, Agent for the said Gilbert Betteley Lückhoff.
COMPLETE SPECIFICATION.
An Improvement in or relating to Dynamos.
1, GILBERT BETTELEY LUCKHOFF, of 214 Whitehorse Road, Croydon, Surrey,
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 :-
The object of this invention is to construct a light cheap Dynamo or Electric
Moter having high commercial efficiency.
The improvements relate especially to the construction of an armature in which
iron in strips of any desired shape are laid on the armature core in any desired
manner and forming the periphery, said strips being fixed in position by any suitable
means.
Figure 1 of the accompanying sheet of drawings represents a cross section of a
drum armature, illustrating several methods of arranging the iron and copper
conductors. Figure 2 is an external view.
Figure 3 is a longitudinal section of a drum armature showing one convolution.
Figure 4 is a perspective view of one strip, showing the manner in which it is
cut away to allow of same overbanging the enclosed copper conducting wires, as
shown at Figure 3.
Figure 5 is a perspective view of the iron conducting strips and shows the method
of coupling same.

page_text: -
A are the iron strips laid upon and insulated from the armature core B and from
one another. The usual copper conductors C (wire or strips) are laid between, or
within the iron strip A and are held in position thereby.
The iron strips A and copper conductors Care joined together in parallel groups,
each group acting as one single conductor of electric current, one or more wires Ci
being soldered at the ends at D, to compensate for the conductivity of the iron
strips A.
By this invention, the iron strips A serve to conduct both the electric current and
the lines of force passing through the armature from pole piece to core and the reverse.
The electrical carrying capacity of the iron strips A added to that of the usual
copper conductors gives a higher total carrying capacity and the output of the
machine is increased in the same proportion.
As the armature presents an almost continuous iron surface on its periphery it can
be turned up true after the strips and conductors are laid on and temporarilly bound
with bands, wedge pieces F or other equivalent devices being inserted between one
or more of the couples to secure them against disturbance by rotative force.
Recesses are formed in the turning for the reception of steel wire bands E
(insulated by mica or other non-conductor) which are passed over the heads of the
wedges and bind the whole in position permanently after the temporary bands are
taken off.
The resistance of the air gap is small owing to the close proximity of the field
magnets to the surface of the armature, therefore the total resistance of the magnetic
circuit can be made small and few ampere turns will be required on the field
magnets.
In Figure 1, I show examples of the different shapes or arrangements of the iron
strips and copper conductors. In example 1, the channel shape strips A are arranged
to look in the same direction, the conducting wires being laid in the trough of each
strip. In example 2, the strips are face to face and form a tube in which the wires
are laid. In example 3, the strips are arranged as in No. 2 but with a single solid
conducting wire, and in example 4 the conductor is a laminated one. No. 5 is similar
to No. 1 but with single solid conductors. In example 6 the iron strips consist
of simple flat bars, and the conductors are also flat, or in the form of ribbon.
In the drawings, I have shown my invention as applied to a drum armature but
it is equally applicable to other forms of armatures, such as ring or disc armatures, in
which cases the iron strips are always arranged nearest the field magnets.
By my invention, the insulation is perfect and durable owing to the facility with
which mica or other insulating material may be placed between the core and the
groups, also between the groups themselves. It also allows of thorough ventilation.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The employment in a Dynamo or Electric Motor of an armature in which iron
strips are separate or detached from the armature core from which they are insulated,
said.iron strips enclosing the copper conductors, the whole being secured in position
by wedge pieces and steel wire bands, or other devices, as described and substantially
as shown on the annexed drawings.
2. In Dynamos or Electric Motors, joining one or more copper conductors of each
group to iron strips, so that the. strips- become conductors both of electric current
and of the magnetic lines of force, as described..
H. GARDNER,
166, Fleet Street, London, Agent for the said Gilbert Betteley Lückhoff.