IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES FOR ELECTRIC LIGHTING
Year: 1881

page_text: "
LETTERS PATENT to James Edward Henry Gordon of Dorking, in the County
of Surrey, for an Invention of IMPROVEMENTS IN DYNAMO-ELECTRIC
MACHINES FOR ELECTRIC LIGHTING."
PROVISIONAL SPECIFICATION left by the said James Edward Henry
Gordon at the Office of the Commissioners of Patents on the 6th January
1881.
JAMES EDWARD HENRY GORDON, of Dorking, in the County of Surrey.
"IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES FOR ELECTRIC LIGHTING."
This Invention has for its object improvements in dynamo electric machines for
electric lighting.
My improved dynamo electric machine is designed to maintain a large number of
independent lights; also so that the efficient working of the machine and the
maintenance of the lights may not be interfered with by increasing or diminishing
the number of lamps in operation from time to time.
My machine is also designed with a view to simplicity in construction, efficiency
in working, and facility for examination and repair.
My machine consists of a number of discs or wheels mounted upon an axis which
is driven at a high speed. The wheels or discs carry at their periphories cylindrical
bobbins of insulated wire arranged with their axes parallel to the axis of the
machine and equidistant from it. They are each wound upon an iron core generally
tubular, and are converted into electro magnets by permanent connection with a
direct current exciting machine; the magnet coils may be combined in "series "
or "quantity," or in whatever combination of them bests suits the exciter used.
The polarity of the magnets is such that the poles on each side of a given pole, and
the one opposite to it are of contrary polarity to itself. The moving parts of the
exciting machine are preferably upon the same axis with the wheels or discs
mentioned above.
The reason for placing them on the same axis is that the revolving part of my
machine being heavy acts as a fly wheel, and keeps the speed of the exciter uniform
In spite of irregularities in the motor.
Between the wheels or discs other cylindrical bobbins of insulated wire are
rranged; their axes are also parallel with the axis of the machine, and they are

page_text: carried by stationary brackets fixed to the frame. They have cores consisting pre-
ferably of a bundle of iron wires, though a slit tube might be used.
When used for the production of high tension currents, such as are required for my
iridium lamps, they are wound with fine wire. 0079 inch is one of my standard sizes
though not the only one for use with my lamps, and the bobbin is divided by a
number of insulating discs like the secondary of a Rhumkorf induction coil. A
tube of ebonite or other insulator is placed between the core and the conducting
wire. The insulating discs are usually made of card and attached to the ebonite
tube as follows:-Two tubes, one of which will just fit over the other, are taken,
and the outer one cut into short lengths. Ebonite ends are made for the bobbin
and screw on to the inner tube. Holes are made in the discs which the inner tube
will just pass through. One ebonite end is screwed on, then a short length of such
tube slid on, then a dise, then another length of tube, then another disc, and so on,
and all are tightened up by screwing on the second end. Thus in case of the coil
heating there is no cement to melt and spoil the insulation.
The induction bobbins are arranged so that the ends of the cores of the moving
electro magnets pass very close to their ends. From each of these stationary
bobbins a separate circuit may be led away to supply a lamp with the alternating
currents induced in it by the rapidly passing electro magnets, or for lamps of larger
size two, three, or more bobbins may be employed to supply a single_lamp; large
and small lamps may be worked on the machine simultaneously.. Except at the
two ends of the machine each induction bobbin is influenced at both its extremities
by the electro magnets, and in the end sections substantially the same effect is
obtained by using shorter bobbins, coupling them in pairs and connecting the
exterior ends of the two cores of each pair by an iron plate...
In large machines, say those for 200 to 500 lamps, the shaft is very long, and
one or more intermediate bearings may be introduced besides the end bearings.
To make room for these it will be necessary to omit three or four stationary coils
from one of the rings.
To allow the exciting current to pass these bearings the shaft at these points may
be made a little thicker, and channels drilled in it for the conducting wires.
Thus my improved dynamo-electric machine is composed of stationary induction
bobbins of cylindrical form, influenced at each of their ends (except as already
mentioned) by moving electro magnets. The moving magnets have also the form
of cylindrical bobbins and pass the stationary bobbins end to end. The coils of the
magnet bobbins at each of their ends come into close proximity with the coils of
the induction bobbins, and so a maximum effect is obtained.
The magnetization of the moving bobbins is entirely independent of the lamp
circuits, and the lamp circuits are numerous and independent the one of the other,
and powerful and weak circuits can be maintained simultaneously..

page_text: 16
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Edward Henry Gordon in the Great Seal Patent Office
on the 5th July 1881.
JAMES EDWARD HENRY GORDON, of Dorking, in the County of Surrey.
IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES FOR ELECTRIC LIGHTING."
This Invention has for its object improvements in dynamo electric machines for
electric lighting.
My improved dynamo electric machine is designed to maintain a large number
of independent lights; also so that the efficient working of the machine and the
maintenance of the lights may not be interfered with by increasing or diminishing
the number of lamps in operation from time to time.
My machine is also designed with a view to simplicity in construction, efficiency
in working, and facility for examination and repair.
My machine consists of a number of discs or wheels mounted upon an axis, which
is driven at a high speed. The wheels or discs carry at their peripheries cylindrical
bobbins of insulated wire arranged with their axes parallel to the axis of the
machine, and equidistant from it. They are each wound upon an iron core, either
solid or tubular, and are converted into electro magnets by permanent connection
with a direct current exciting machine; the magnet coils may be combined in
"series" or "quantity," or in whatever combination of them best suits the exciter
used. The polarity of the magnets is such that the poles on each side of a given
pole and the one opposite to it are of contrary polarity to itself. The moving parts
of the exciting machine are preferably upon the same axis with the wheels or disos
mentioned above.
The reason for placing them on the same axis is that the revolving part of my
machine being heavy acts as a fly wheel, and keeps the speed of the exciter uniform
in spite of irregularities in the motor.
Between the wheels or discs other cylindrical bobbins of insulated wire are
arranged, their axes are also parallel with the axis of the machine, and they are
carried by stationary brackets fixed to the frame. They generally have cores,
consisting preferably of a bundle of iron wires, though a slit tube might be used.
Mechanically it is more convenient to employ a split tube, but electrically, the wires
are better.
When used for the production of high tension currents, such as are required for
my 1 irridium lamps, they are wound with fine wire. 0079 inch is one of my standard
sizes, though not the only one for use with my lamps. This size is suitable when
the highest tension is desired. It is also suitable for a machine with small coils
where the required length of wire can only be obtained by reducing the section.
For lower tensions or for larger machines I employ sizes from 01 to 03 of an inch.
These sizes are suitable for my irridium lamps. The bobbin is divided by a
number of insulating discs like the secondary of a Rhumkorf induction coil. A
tube of ebonite or other insulator is placed between the core and the conducting
wire. The insulating discs are usually made of card, and attached to the ebonite
tube as follows:-Two tubes, one of which will just fit over the other, are taken,
and the outer one cut into short lengths. Ebonite ends are made for the bobbin,
and screw on to the inner tube. Holes are made in the discs, which the inner tube
will just pass through. One ebonite end is screwed on, then a short length of such
tube slid on, then a disc, then another length of tube, then another disc, and so on,
and all are tightened up by screwing on the second end. Thus in case of the coil
heating, there is no cement to melt and spoil the insulation.
The induction bobbins are arranged so that the ends of the cores of the moving
electro magnets pass very close to their ends. From each of these stationary
bobbins a separate circuit may be led away to supply a lamp or lamps with the
alternating currents induced in it by the rapidly passing electro magnets, or for
lamps of larger size two, three, or more bobbins connected in series or quantity or

page_text: Figure 1 shows a longitudinal section of a portion of a dynamo electric machine,
constructed in accordance with my Invention; Figure 2 shows an end elevation,
and Figure 3 a plan of portions of the machine.
a is a base plate, and standards a¹, a², carrying the main axis of the machine are
formed upon it; b is a stay connecting the standards, and serving to adjust the
position of intermediate frames, as hereinafter described; c is the main axis,
preferably of steel. Endway movement of the axis in its bearing is prevented by
adjustable screws abutting upon its ends.
Arrangements are to be made for rotating this axis at a high speed by any
suitable motor, and to prevent heating passages are provided in the bearings for
the circulation of water. In some cases the motor machine and the exciter may be
applied directly upon the axis c, and this is always advisable when a machine is
constructed for use in one place and to work always under the same conditions.
d, d, are brass wheels fixed upon the axis c; these wheels have cylindrical cavities
in their periphories in which the electro magnets are lodged; e, e, are the electro
magnets consisting of cylindrical bobbins of insulated wire wound upon cores of
soft iron; the thickness of the wire employed and the connections are such as will
best suit the exciter, and are regulated by well known rules.
Figure 4 shows full size and elevation, and Figure 5 a section of one of the
electro magnets; e¹ is the soft iron core; e², e², are stout brass ends; together they
form a reel which being wound full of wire is inserted into the cylindrical cavity
in the wheel & formed to receive it. The electro magnets e are secured to the
wheels d, d, by screws f, f, overlapping the ends e². The heads of screws are sunk
into the wheel and end plates. After the magnet coils are mounted the wheels d, d,
are turned at the sides to a flush surface, any projection of the cores being thus
removed. The exciter may be any continuous current dynamo electric machine
competent to develope a strong magnetism in the bobbins e.
Figure 6 is a side elevation, and Figure 7 is a section of one of the induction
coils; g¹ is the core; it is a tube of soft iron, or rather for convenience is two tubes,
one fitting tightly within the other. They are split longitudinally so as to leave
a gap of say 1/16 of an inch.

page_text: This core is inserted into a vulcanite tube g2 upon which the ends g³ of the
bobbin, also of vulcanite, are screwed. There are also intermediate discs g' of
cardboard dividing the bobbin into sections; they are kept properly spaced along
the bobbin by short tubes of vulcanite go fitting over the tube containing the core.
The bobbins are wound like the secondary of an induction coil, so that the course
of the wire may be traced through the bobbin from section to section from one end
of the bobbin to the other.
By this arrangement there is but little difference in potential between adjacent
convolutions of the insulated wire.
The bobbin when wound is enclosed in a vulcanite jacketting cylinder 96, and
then the whole is immersed in melted paraffin, until the air is displaced through
holes formed in the jacket from the interstices of the coils and escapes. This is a
usual operation in preparing induction coils. The jacket is secured to the ends by
angle pieces of brass not forming a continuous ring.
The induction bobbins g, g, are carried by frames h fixed upon the base plate.
These frames, which are of brass, are each made in two parts bolted together; they
have cavities formed in them for the reception of the bobbins g, which are secured
in their places by brass bands or straps h¹, as is represented in Figure 8. The bands
are insulated from the frames h by vulcanite washers inserted between the
screws h² and the bands or straps. The vulcanite jackets go have slits cut in their
edges so that when the bands or straps are applied over them they embrace the
coils tightly. The bobbins g being cylindrical are readily wound in the lathe, a
point of much importance when a great length of fine wire has to be wound.
As already mentioned each of the induction bobbins g is available by itself for
the maintenance of a lamp or lamps, or several bobbins may be coupled for the
supply of a lamp of larger size.
The induction bobbins may be used without cores.
In the machine shown by the Drawing, there are but two wheels d, and therefore
but one intermediate frame h. In machines provided with a third wheel there
would be naturally another intermediate frame h. In any case there are also two
end frames not shown by the Drawings, similar to the frames h but carrying by
preference bobbins of one half the length and coupled together in pairs, their cores
being connected by iron armatures, as is indicated in Figure 8, the coils of a pair
I prefer to place in the same circuit.
The frames h and the similar end frames are adjusted and securely retained in
their places by nuts b' upon the stays b, so as to avoid all risk of collision between
the electro magnets e and the bobbins g although the clearances are small.
i, i, are two insulated wheels of metal fixed upon the axis c; the current from
the exciting machine is conveyed to them by stationary brushes of wire bearing
upon their peripheries, and the wheels i, i, are connected by wires with the electro
magnets.
Having thus described the nature of my said Invention and the manner of
performing the same, I would have it understood that I claim my improved dynamo
electric machine for electric lighting, composed of stationary induction bobbins
and electric magnet bobbins mounted upon wheels, the said bobbins being
cylindrical or straight, and their axes parallel to the axis of the wheels, and so
arranged that as the wheels revolve the electro magnets are carried past the
induction bobbins end to end, substantially as herein described.
In witness whereof, I, the said James Edward Henry Gordon, have hereunto
set my hand and seal, this First day of July, in the year of our Lord One
thousand eight hundred and eighty one.
J. E. H. GORDON. (L.S.)