IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Year: 1887

page_text: Date of Application, 21st July, 1887...
Complete Left, 13th Apr., 1888
Complete Accepted, 18th May, 1888
I JOSEPH PLATT HALL of Gorse Bank Werneth Oldham in the County of
Lancaster Electrical Engineer do hereby declare the nature of said Invention for
IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES, to be as follows:-
My improvements relate to the Invention for which Letters Patent No. 9582
dated July 24, 1886 were granted to me.
In carrying my present improvements into effect I cast the bedplate the standards
for carrying the pedestals and the keeper together in one piece and I form each core
of the magnet of one piece of wrought iron the core embracing that portion on which
the wire is wound which is preferably circular in section and also the upper portion
or pole piece which may be of any form desired. Holes are bored through the keeper
portion of the bed plate to receive the ends of the magnet cores which are preferably
slightly reduced in diameter to form a shoulder which rests upon the bed and I make
the cast iron keeper of such section that its resistance is not greater than that of the
wrought iron parts of the circuit.
The magnet cores can be conveniently wound with wire and then afterwards
placed in the holes in the keeper prepared for them and secured in position by a screw
or screws or equivalents.
I prefer to use an armature of the drum pattern such as the Gramme or Siemen s.

page_text: I JOSEPH PLATT HALL of Gorse Bank Werneth Oldham in the County of
Lancaster Electrical 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 :-
My improvements relate to the Invention for which Letters Patent No. 9582
dated July 24th 1886 were granted to me.
In carrying my present improvements into effect I cast the bedplate the standards
for carrying the pedestals and the keeper together in one piece and 1 form each core
of the magnet of one piece of wrought iron the core embracing that portion on which
the wire is wound which is preferably circular in section and also the upper portion
or pole piece which may be of any form desired. Holes are bored through the keeper
portion of the bedplate to receive the ends of the magnet cores which are preferably
slightly reduced in diameter to form a shoulder which rests upon the bed and I make
the cast iron keeper of such section that its resistance is not greater than that of the
wrought iron parts of the circuit.
The magnet cores can be conveniently wound with wire and then afterwards placed
in the holes in the keeper prepared for them and secured in position by a screw or
screws or equivalents.
I prefer to use an armature of the drum pattern such as the Gramme or Siemens.
And in order that my Invention may be fully understood and readily carried into
effect I will describe the accompanying four Sheets of Drawings reference being had
to the figures and letters marked thereon.
Figure is a perspective view of a dynamo electric machine embodying my present
improvements.
Fig. 2 is a side view of the machine omitting some of the details shown in Fig. 1.
Fig. 3 is an end view of Fig. 2 and
Figs. 4 to 9 are detail views of parts of the machine.
In constructing my improved dynamo electric machine I prefer to cast the bedplate a
the standards for carrying the pedestals b and the keeper c all in one piece together
as shown in the detail views Figs. 4 and 5 but I sometimes combine the standards
with the pedestals and cast them together in one piece 61 separate from the bedplate
see Fig. 6. I form each core of the magnet in one piece see Figs. 7, 8, and 9 of
wrought iron and this one forging comprises the end d which fits into a hole e
see Figs. 4 and 5 formed to receive it in the keeper c the core f on which the
magnetising coil is wound and the pole piece 9 which is bored out to receive the
armature shown in Figs. 1, 2 and 3. The pole pieces g I make of any suitable form
but I prefer to use the shape shown by the three views Figs. 7, 8, and 9 of which
Fig. 8 is a transverse section taken on the line A B Fig. 7 and Fig. 9 is an end view
of Fir 7.

page_text: The core falso may be made in any form desired but I prefer to make it circular
and with the end part d also circular but slightly smaller so as to form a shoulder
which rests on the upper side of the keeper c. I so proportion the keeper c and
joints where the magnet legs d go into the keeper that there is no increase in the
magnetic resistance of the circuit except the air space where the armature wire works
I secure the magnet legs d in the holes e by screws has shown in Fig. 2 or other
suitable means.
.
By the above described arrangement I obtain a very powerful magnetic field as the
magnetic lines of force generated in the cores f by the magnetising coils pass directly
through wrought iron pole pieces where there are no joints to magnetise the armature
the cast iron part of the circuit being the keeper and the points of contact large the
minimum amount of resistance is offered to the magnetic lines of force.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is-
1.-A dynamo electric machine having each magnet, comprising the core and pole
piece, formed in one piece of wrought iron and let into a bedplate of cast iron as
described.
2. The construction combination and arrangement of parts embodying my
improvements in dynamo electric machines substantially as herein described and as
shown on the Drawings hereunto annexed.
Dated this 12th day of April 1888.
H. B. BARLOW,
17, St. Ann's Square, Manchester,
Agent for Applicant.
H. B. BARLOW,
17, St. Ann's Square, Manchester,
Agent for Applicant.