IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES AND ELECTRIC MOTORS AND IN THE MEANS OF STORING THE ENERGY OF THE ELECTRIC CURRENT
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Thomas Parker and Paul Bedford
Elwell at the Office of the Commissioners of Patents on the 20th June 1882.
THOMAS PARKER of Coalbrookdale in the County of Salop, and PAUL BEDFORD
ELWELL of Wolverhampton in the County of Stafford. "IMPROVEMENTS IN
DYNAMO-ELECTRIC MACHINES AND ELECTRIC MOTORS AND IN THE MEANS OF
STORING THE ENERGY OF THE ELECTRIC CURRENT."
Our improvements in Dynamo-Electric Machines relate, firstly to the armature,
the object being to reduce the useless portion of the inductor and to screen it from
inverse magnetic action. We effect this object by building the armature of square
or oblong longitudinal section, similar in outward appearance to the rim of a fly-
wheel, so that the two sides of this rim and also the face can be embraced by the
field magnets. The inductor consists of one long copper bar, which may be made
for convenience in several sections, forming a continuous spiral round the rim of
the armature but not entirely covering the rim, and connected at intervals to sections
of the commutator cylinder. The core of the rim is of a non-magnetic substance,
such as vulcanite or cardboard covered with an iron casing, around which the
spiral copper bar passes, the latter being properly insulated from the iron. Strips
of iron are placed between each spiral turn of the copper inductor, which strips are
in contact with the iron casing above mentioned but insulated from the inductor.
The armature, formed as above described, is carried upon a disc or cylinder of non-
conducting material mounted upon a shaft in the ordinary manner. Several of
these armatures may be mounted upon the same shaft. For currents of very low
resistance we use a copper ring or cylinder instead of the spiral bar, aforesaid, and
this ring entirely covers the irou casing
Our Improvements in Dynamo-electric machines relate, secondly, to the mode of
collecting the current from the revolving armature, and consist as follows:-
A groove is turned in the face or circumference of the commutator cylinder, which
is formed of segments in the usual manner, and two rollers, each formed of two
discs of copper with a spring between the discs, are fixed upon opposite sides of
the commutator with their outer edges bearing against the sides of the groove.
The opposite edges of these rollers may turn also in similar grooves cut in two
solid rollers.

page_text: By the method last described we reduce the friction (caused by using brushes or
bars in the usual manner) and secure a perfect and constant contact requiring
very little attention.
According to our invention the commutator may be formed by an alternative
method to that described, in which case instead of making a cylinder with sections
of copper or brass connected at intervals with the spiral bar on the armature, we
make a disc of copper or brass and mount it upon a ball-and-socket joint which
slides upon the armature spindle. The disc is formed of such diameter as will
enable it to touch the copper spiral rod when pressed sideways upon the spindle.
Upon the opposite side of the armature is placed a second disc of equal diameter but
having a large hole in its centre through which the spindle can work without touching
the disc. This second disc is attached firmly to the first disc by means of distance
pieces and pins passing through spaces in the boss of the disc or wheel which carries
the armature, and this boss is set on one side of the armature so as to leave free that
part of the spindle which passes through the centre of the armature for the ball-
and-socket joint to slide upon. The two discs are insulated from each other and
the first one has an arm attached to the centre extending outwards horizontally in
a line with the spindle of the armature. The distance between the inside edges of
the two discs is about an eighth of an inch more than the thickness of the
armature, so that when the horizontal arm is pressed out of line with the spindle
of the armature the two discs each come in contact with the copper spiral upon
exactly opposite sides of the spindle, and as the latter rotates it carries the two
discs with it by friction, and by fixing a guide to the end of the horizontal arm
to keep it in one position, a perfect rolling motion is effected between the discs
and the armature rim. The current may be carried away from one disc and
brought back to the other through the end of the horizontal arm.
This arrangement of commutator is specially suitable for low tension currents as
it lessens considerably the resistance of the armature.
Our improvements in Electro-motors consist in causing an electro-magnet to
rotate between the poles of a fixed electro-magnet, or coils of wire without any
iron shell, and reversing the current of the internal inagnet at each point when its
lines correspond to the lines of the outside shell or coils. The revolving magnot
with its coils forms a complete disc and presents the minimum resistance against
the atmosphere.
By this means, the vanishing magnetism and current, and the current entering
the coils of the rotating magnet, are made to spend their inductive effect in
increasing the magnetism of the outer coil, and greatly increase the economy and
efficiency of the motor. Several magnets may be set radially upon the spindle.
Our invention as it relates to the means of storing the energy of the clectric
current consists as follows:-A number of strips of lead foil inch inch or
1 inch wide, according to the thickness of the intended plates, are coiled or folded
in a zig-zag form and placed in a crate or skeleton box, made of strips of dried
wood soaked in parafiue and dovetailed together, the end of each strip of lead foil
being carried to the top of the plate to form the pole. The interstices of the coil
are then filled up with oxide of lead or sulphate of lead. This forms one plate
which is developed in the usual manner and may be multiplied, as desired.