Improvements relating to Armatures for Dynamo Electric Machinery.
Year: 1896

page_text: Date of Application, 5th Feb., 1890
Complete Specification Left, 5th Nov., 1896-Accepted, 12th Dec., 1896
Date
7000
Complete Specification Left, 5th Nov., 1896-Accepted, 12th Dec., 1896
Improvements relating to Armatures for Dynamo Electric
Machinery.
We, P. R. JACKSON & CO., LIMITED, Steel Manufacturers, and JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,
Salford, in the County of Lancaster, do hereby declare the nature of this invention
to be as follows:-
Our invention relates to armatures for dynamo electric machinery and has for
its object to provide improved means for preventing movement of the armature
wires or bars relatively to the armature core.
Hitherto it has been customary for this purpose to slot out a groove or grooves
in the core and to insert therein driving keys of fibre, wood or other vegetable
materials all of which are unsuitable for this purpose, in consequence of their being
subject to considerable heat. Metal keys have the disadvantage when inserted in
the said slots or grooves of setting up eddy-currents, even when the said keys are
insulated from the core plates. A further disadvantage of this method of driving
is that owing to the slots a series of small air gaps are produced between the
core and the pole-pieces of the dynamo, the magnetic field being thereby
affected.
By our invention we avoid these disadvantages and at the same time we entirely
prevent any movement of the wires.
According to our invention we drill a series of holes in the armature core in
pairs, into which we drive metal staples of a U-shape, the bridges of the staples
being parallel to the armature wires. The said staples are preferably made of
hard German silver, though iron or steel staples may be used, the latter have
however a prejudicial effect upon the magnetic field. The staples may be made of
bent wire of either round or rectangular cross section, or they may be punched out
of plates. The latter method has the advantage that the staples offer a flat surface
to the armature wires. Pieces of insulated material may be inserted, if desired.
between the bridge of the staple and the core, and the staples may be entirely
insulated from the core although this precaution is we believe unnecessary; in any
case however the staples must be insulated from the armature wires. The staples
are preferably placed immediately under the armature binding wires so that
they are not liable to be thrown out of position by centrifugal force or other
cause.

page_text: Improvements relating to Armatures for Dynamo Electric
Machinery.
We, P. R. JACKSON & Co., LIMITED, Steel Manufacturers, and JOSEPH
SLATER LEWIS, Engineer, both of Salford Rolling Mills, Hampson Street,.
Salford, in the County of Lancaster, 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:-
Our invention relates to armatures for dynamo electric machinery and has for its
object to provide improved' means for preventing movement of the armature wires
or bars relatively to the armature' core:
Hitherto it has been customary for this purpose to slot out a groove or grooves
in the core and to insert therein driving keys of fibre, wood, or other vegetable
materials all of which are unsuitable for this purpose, in consequence of the heat to
which they are subjected when the machine is running and their liability to absorb
moisture. Metal keys in such grooves or slots are objectionable owing to the eddy
currents set up therein even when the said keys are insulated from the core plates.
A further disadvantage of this method of driving is that owing to the slots a series
of small air gaps are produced between the core and pole-pieces of the dynamo, the
uniformity of the magnetic field being thereby effected.
By our invention we avoid these disadvantages and at the same time we entirely
prevent any movement of the wires.
According to our invention we drill a series of holes in the armature core in
pairs, into which we drive metal staples of a U-shape the bridges of the staples
being parallel to the armature wires, or we may use half staples or T-shaped nails
with heads having the same wire bearing surface as the staples.
In the accompanying drawing
Figure 1 is a side elevation and
Figure 2 an end elevation of an armature core having driving arrangements
according to our invention.
Figures 3 and 4 shew half staples or T-shaped nails for use instead of complete
staples.
The staples A are preferably made of hard German silver, though iron or steel
staples may be used, the latter have, however, a prejudicial effect upon the
magnetic field. The staples may be made of bent wire of either round or
rectangular cross section, or they may be puuched out of plates. The latter
method has the advantage that the staples offer a flat surface to the armature
wires. The staples may be cut in half either before or after placing in position so
that two L-pins are formed as shewn in Figure 3. Pieces of insulating material
may be inserted if desired, between the bridge of the staple and the core, and the
staples may be entirely insulated from the core although this precaution is we
believe unnecessary, in any case however the staples must be insulated from the
armature wires. Instead of staples T-shaped nails with heads' häving the same
wire bearing surface as the staples may be used, such a nail is shewn for example
in Figure 4. The staples or nails are preferably placed immediately under the
armature binding wires so that they are not liable to be thrown out of position by
centrifugal force or other cause.
Although we have herein shown our invention applied to a drum armature we do
not restrict ourselves in this respect as it may be employed with other descriptions
of armature if desired.

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 :-
The combination with an armature core, of U-shaped staples or L-shaped or
T-shaped nails insulated or not from the core, for preventing movement of the
armature wires or bars, substantially as described.
Dated this 5th dose of Nazember 1806
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicants.