Improvements relating to Apparatus for Producing Light by Means of Alternating Electric Currents.
Year: 1893

page_text: Date of Application, 4th Jan., 1893
Complete Specification Left, 31st July, 1893-Accepted, 2nd Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements relating to Apparatus for Producing Light by Means
of Alternating Electric Currents.
We, Sir DAVID LIONEL SALOMONS, Bart., of Broomhill, Tunbridge Wells, in
the County of Kent, and LAZARUS PYKE, of 34, New Tothill Street, in the City
of Westminster, Electricians, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object, to construct an apparatus for producing electric
illumination by means of the Geissler or glow effect, which apparatus shall be at
once compact, safe and readily applicable to existing electric lighting installations
served by alternating or pulsating currents.
To this end we combine in a special manner the following elements of
construction:
1. An induction coil or alternating current transformer.
2. A vacuum tube or vessel (or several tubes) suitable for producing the well-
known Geissler effect.
3. A pair of metallic contact pieces together with collar and cement filling, or
other suitable appliance, such as is or may be fixed to the glass bulb of an ordinary
incandescent lamp for the purpose of fixing the same to its holder and connecting
it with the source of electric energy.
These elements are arranged in two or more parts, and mechanically connected
together by any suitable means.
The primary winding of the transformer is connected with the said contact
pieces, and the secondary winding is connected with the vacuum tube or tubes
either directly or inductively.
As it is advisable, to economize space as far as possible, we prefer to employ in
this combination an induction coil or transformer of the Ruhmkorff type, but with
its secondary winding wire of iron, in order that it may approach more nearly in
converting power to the efficiency of a closed magnetic circuit transformer.
The said vacuum or Geissler tubes may form any desired device; when the
apparatus is required for advertising or allied purposes, it is convenient to construct
each tube as a letter or sign, so that a number of them can be readily made up into
the desired word or device.
Dated this 2nd day of January 1893.
FAIRFAX & WETTER,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements relating to Apparatus for Producing Light by Means
of Alternating Electric Currents.
We, Sir DAVID LIONEL SALOMONS, Bart. of Broomhill, Tunbridge Wells, in
the County of Kent, and LAZARUS PYKE, of 34 New Tothill Street, in the
City of Westminster, Electricians, 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 :---
The principal object of this invention is, to produce an apparatus for obtaining
electric illumination by means of the Geissler or glow effect, which shall be at
once compact, safe, and readily applicable to existing electric lighting installations
served by an alternating or pulsating current.

page_text: To this end, we employ in one or more parts, all being mechanically connected
together;
1. An induction coil or alternating current transformer;
2. A vacuum tube or vessel ;
3. A pair of contacts with a surrounding collar and cement filling, or other
appliance, such as is or may be fixed upon an incandescent lamp for the purpose of
fixing and connecting the same to its holder and the source of electric energy;
together with such materials as are required for holding the various parts together.
It is not necessary, that the various parts should be undetachable; they may
be more conveniently made detachable, and, if desired, interchangeable.
The primary winding of the transformer is connected with the said contacts, and
in the case of the secondary winding, the ends are either directly joined to the vacuum
tube or tubes, or inductively, as will be hereafter more fully described.
The vacuum tubes may form any desired device. If the apparatus is required for
advertising or allied purposes, it is usually convenient, to construct each tube as a
letter or other sign, and a number of tubes may thus be readily made up into the
desired form or signification.
In the accompanying drawings,
Fig. 1 is a section of an electric lighting combination embodying our invention
and illustrating the case in which the terminals of the secondary windings of the
transformers are directly connected with a vacuum tube ;
Fig. 2 is a horizontal section of the same;
Fig. 3 is partly an elevation and partly a section of a large apparatus representing
the case in which the secondary terminals are indirectly connected with several
vacuum tubes ;
Fig. 4 is a plan of the same;
Fig. 5 shows a glass cylinder forming part of the apparatus shown in Fig. 3;
Fig. 6 is an underside view of the socket piece A;
Fig. 7 is a vertical section of an ordinary incandescent lamp holder showing its
connection with the socket piece.
It is not essential, that the special features or arrangements shown combined in
one drawing, should always be so; for instance, the position of the iron mass or core,
the primary or the secondary winding, in relation to each other may be reversed,
without materially affecting the working of either one of the said combinations.
In Fig. 1 A is the socket piece forming a termination suitable for attachment to an
ordinary "bayonet " lamp holder, a, a, are the brass contact pieces connected with
the primary winding B of the transformer. C represents the iron core of the
transformer, and D the secondary winding of insulated iron or copper wire,
the ends of which are connected with the vacuum tube F by means of the
terminals E, E and a pair of wires.
a¹ is an axial brass tube made in one piece with the socket piece A. and provided
at the upper end with a screw nut H and washer I for holding the transformer at
the top.
K is a wooden bobbin or flanged tube, on which are wound the coils of the
transformer, and which in the present case is provided with intermediate flanges or
discs to separate the different sections of the transformer, and with curved ends to
facilitate the winding of the iron wire C which acts as an iron core and forms a
closed magnetic circuit. Each section of the transformer is surrounded with a
layer of insulating material, indicated in the drawing by thick black lines. Another
layer J of insulating material covers the outside of the transformer, as well as the
inner surface or bore of the hollow bobbin, so as to form an insulating base for the
iron C.
In Fig. 7, a² are a pair of pins, which form the terminals of an ordinary
Edison-Swan lamp holder A' and are pressed upward by a pair of helical springs,
so as to abut against and maintain contact with the primary terminals or contact
pieces a a of the socket piece A. The lower end of the transformer is indicated by
dotted lines.

page_text: In the example shown by Figs. 3 to 5, the ends of the secondary winding (B) are
connected with two short cylindrical metal foils L L situated between the two
open-ended glass cylinders M and M'. Each vacuum tube has its terminals
connected with a pair of foils (N, N, N¹, N', N2, N2, etc. one terminal to each foil),
mounted on the outer glass cylinder M at opposite ends thereof and in inductive
proximity to the annular foils L, L, which are connected with the secondary winding
by means of metallic pins m passing through the inner glass tube M. The socket
piece A, shown in Figs. 1 and 3, is suitable for an ordinary holder as used for
incandescent lamps.
In every case the core or iron mass should be laminated, or made of iron or
otherwise minutely divided; the primary winding should be an insulated conductor
of comparatively short section, and the secondary should be an insulated conductor
of greater length and smaller sectional area, the lengths, weights and proportions
being adapted to the effect which it may be desired to produce.
If it is necessary, to erect generating machinery specially for supplying this
apparatus with current, we may advantageously use a dynamo machine whose
frequency of alternation is greater than that usually employed (provided that the
distance to which the current must be transmitted is not considerable), which, as is
well understood, will have the effect of allowing a proportionate reduction in the
size of the transformer. Where it is not desired, that the lamp holder on which
our electric lighting combination is placed, shall also be capable of being used for
incandescent lamps of the ordinary voltage, we may wire several of these
combinations in series, and choose the proportions of the primary windings of the
transformers accordingly.
In many cases we find it advantageous, to do this, and sometimes to use an
incandescent lamp or other resistance in series with the said combinations, this being
specially desirable, when the secondary winding of the transformer is coupled
directly with the tube, as otherwise the vacuum discharge (being so far of a
disruptive character) causes an excessive current to pass, if the electromotive force
is sufficient to first produce the discharge therein. As this sudden accession of
secondary current needs a proportionate increase in that flowing through the
primary winding, without which it cannot occur, the before mentioned resistance in
the primary circuit, by reducing the energy which would otherwise be available,
minimises this deleterious flow of current in the tube and saves the electrodes
thereof from being melted or damaged.
It will be understood, that the forms, dimensions, and proportions of the different
parts shown in the drawings, by way of example, may be widely modified, without
departing from our invention. For instance, if the lamp holder has a shape different
from the "bayonet" holder now commonly used for attaching incandescent electric
lamps, the part which is here described as a socket piece must be altered to
correspond.
"
Although the special arrangement of a transformer and accessories in combination
with an incandescent lamp holder is primarily and chiefly intended for the purpose
of electric illumination by means of vacuum tubes, the high tension currents or
discharges obtained by means of such transformers may be employed also for other
purposes.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination of an electric induction coil or transformer, with a socket
piece adapted to be fixed to a lamp holder and to make electric contact with the
same, and a vacuum or Geissler tube, all being mechanically and electrically
connected together, substantially as described and for the purpose specified.
2. The combination of an electric induction coil or transformer, with a socket
piece adapted to be fixed to a lamp holder and to make electric contact with the

page_text: same, the said transformer being supported by the socket piece and electrically
connected with the same, substantially as described.
3. The combination of a socket piece adapted to be fixed to a lamp holder and
to make electric contact therewith, with an electric induction coil or transformer
supported by the said socket piece and having its primary winding connected there-
with, a pair of metal foils mounted on a sheet of insulating material and forming
terminals for the secondary windings of the transformer, a pair or pairs of metal
foils mounted on the opposite side of the said insulating sheet and in inductive
proximity to the corresponding terminals of the said secondary winding, and a
vacuum or Geissler tube or tubes, each having its terminals or electrodes connected
with a pair of metal foils on the induced side of the insulating sheet, the whole
being mechanically connected together, substantially as described and for the
purposes specified.
4. The combination of an electric transformer, with a cylinder of insulating
material surrounding the same, a pair of annular metal foils mounted on the inner
surface of the said cylinder and forming the secondary terminals of the transformer,
and two or more pairs of metal foils mounted on the outer surface of the said
cylinder in inductive proximity to the inner foils, the whole being mechanically
connected together substantially as described and for the purpose specified.
5. The combination of an electric transformer, with a cylinder of insulating
material surrounding the same, a pair of annular metal foils mounted on the inner
surface of the said cylinder and forming the secondary terminals of the transformer,
two or more pairs of metal foils mounted on the outer surface of the said cylinder in
inductive proximity to the inner foils, and two or more vacuum or Geissler tubes,
each having its electrodes connected with a pair of the said outer metal foils, the
whole being mechanically connected together and adapted to operate substantially
as described.
6. In an electric lighting combination of the type specified, a transformer
constructed and arranged substantially as described and shown by the drawings.
Dated this 29th day of July 1893.
'
FAIRFAX & WETTER,
433, Strand, London, Agents.