IMPROVEMENTS IN ELECTRO MAGNETIC INDUCTION MACHINES."
Year: 1881

page_text: LETTERS PATENT to Henry Wilde, of Manchester, in the County of
Lancaster, for an Invention of "IMPROVEMENTS IN ELECTRO MAGNETIC
INDUCTION MACHINES."
PROVISIONAL SPECIFICATION left by the said Henry Wilde at the Office
of the Commissioners of Patents on the 5th February 1881.
HENRY WILDE, of Manchester, in the County of Lancaster.
IN ELECTRO MAGNETIC INDUCTION MACHINES."
"IMPROVEMENTS
My Invention consists in a method of constructing electro magnetic induction
machines with multiple armatures for producing electricity, by which their power
and efficiency are greatly increased.
.
In this improvement the metal wheels or discs in which the armitures are
mounted are slit in a radial direction towards the centre of each iron armature.
The armatures are also slit in a radial direction towards their centres, and are
fixed in the wheels in such a position that the slits in the wheels and the slits in
the armatures coincide or extend into each other.
The ends of the electro magnets are terminated by iron pole pieces of circular or
other suitable form, and are of such a diameter or width that when the spaces
between the cores of the electro magnets are equal to the diameter of the magnets,
the said pole pieces are about one half larger in diameter, or wider than the
diameter of the cores of the electro magnets.
The pole pieces at the ends of the electro magnets are slit radially towards the
centre of the cores.
The revolving iron cores are of the same diameter as the cores of the electro
magnets, and are armed with pole pieces which fit in recesses in the brass wheels
In which they are mounted.
These pole pieces are about one sixth less in diameter or width than the pole
pieces on the electro magnets, so that when the armitures revolve before the
magnets, the rear edges of their polar faces are leaving the pole pieces of one set of

page_text: magnets, while the front edges of the polar faces of the armatures are at the
centres of the pole pieces and cores of the adjoining set of magnets.
The electro magnets of the machine may be excited either by the current from a
separate sinall machine, or by one or more armature coils of the same machine, and
in order to avoid the destructive spark on the commutator when the direct current
is used for external work, and the circuit is from any cause or by accident
interrupted or broken, an electro magnet excited by the major current actuates a
shunt which short circuits the current through the machine till the external circuit
is reestablished.
The intermittent direct current from the machine may be made approximately
uniform by transmitting it through the coils of a large electro magnet placed in the
external circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Wilde in the Great Seal Patent Office on the 3rd August
1881.
HENRY WILDE, of Manchester, in the County of Lancaster.
IN ELECTRO-MAGNETIC INDUCTION MACHINES."
"IMPROVEMENTS
My Invention consists in a method of constructing electro magnetic Induction
machines with multiple armatures for producing electricity, by which their power
and efficiency are greatly increased.
In this machine the metal wheels or discs in which the armatures are mounted are
slit in a radial direction towards the centre of each iron armature. The armatures
are also slit in a radial direction towards their centres in the usual manner, and are
fixed in the wheels in such a position that the slits in the wheels and the slits in
the armatures coincide or extend into each other.
The iron pole pieces at the ends of the electro magnets are of such a diameter or
width, that when the spaces between the cores of the electro-magnets are equal to
the diameter of the magnets, the said pole pieces are about one half larger in
diameter, or wider than the diameter of the cores of the electro-magnets. The
pole pieces at the ends of the electro-magnets are slit radially towards the centre of
the cores.
The radial slits in the pole pieces of the electro-magnets and in the
wheels in which the armatures are mounted, prevent adverse or counter electric
currents circulating in the machine, and enable the electro-magnets to be more
readily excited by their own residual magnetism.
The revolving iron cores or armatures are of the same diameter as the cores of
the electro magnets, and are armed with pole pieces which fit in recesses in the
brass wheels in which they are mounted. These pole pieces are about one sixth less
in diameter or width than the pole pieces on the electro-magnets, so that when the
armatures revolve before the magnets, the rear edges of their polar faces are leaving
the pole pieces of one set of magnets, while the front edges of the polar faces of the
armatures are at the centres of the pole pieces and cores of the adjoining set of
inagnets.
The electro-magnets of the machine may be excited either by the current from a
separate small machine, or by one or more armature coils of the same machine, in
the manner described in the Specifications of Letters Patent granted to me in 1863,
1865, and 1867, and numbered 3006, 2762, and 842, respectively. In order to
prevent the destructive spark on the commutator when the direct current is used
for external work, and the circuit is from any cause or by accident interrupted or
broken, an electro-magnet is placed in any convenient position, and is excited by
the major current in order to actuate or release a switch, which shunts or short
circuits the current through the machine till the external circuit is re-established.
The intermittent direct current from the machine may be made approximately
continuous by transmitting it through the coils of a large electro-magnet placed in
the external circuit.
Fig. 1 represents a disc in which the armatures are mounted, and Fig. 2 shows
an electro-magnetic induction machine with the wheels, armatures, and magnets in
section.
a, a, are the wheels or discs made of brass or other non-magnetic metal, and they
are slit in a radial direction towards the centre of each armature; b, b, are the
armatures armed with the pole pieces b', b¹, the slits in which coincide with the
slits in the wheels. The pole pieces are fitted in recesses in the brass wheels a, and
are retained with their slits in the proper positions by means of screw pins 6²;
c, c, are the electro-magnets armed with pole pieces d slit radially, as shown in

page_text: Fig. 1, and about one half larger in diameter than the diameter of the cores, while
the pole pieces 61, 61, are about one sixth larger in diameter than the armature
cores.
Having stated the nature of my Invention, and described the manner of
performing the same, I declare that I claim,-
1. The method of arming the electro magnets and armatures of electro-magnetic
induction machines in the proportions, substantially as shown and described.
2. The method of preventing counter electric currents in the pole pieces of the
electro-magnets of electro-magnetic induction machines, substantially as shown and
described.
3. The use of an electro-magnet placed in the major circuit of an electro
magnetic induction machine to prevent sparks on the commutator when the circuit
is broken, substantially as described.
In witness whereof, I, the said Henry Wilde, have hereunto set my hand and
seal, this Second day of August, One thousand eight hundred and eighty