IMPROVEMENTS IN AND APPERTAINING TO INCANDESCENT ELECTRIC LAMPS AND THEIR HOLDERS ALSO IN THE SWITCHES EMPLOYED THEREIN "
Year: 1883

page_text: LETTERS PATENT to Louis Goldberg of Love Lane in the City of London and
Alexander Leslie Fyfe of Brixton in the County of Surrey for an Invention
of "IMPROVEMENTS IN AND APPERTAINING TO INCANDESCENT
ELECTRIC
LAMPS AND THEIR HOLDERS ALSO IN THE SWITCHES EMPLOYED THEREIN
"
PROVISIONAL SPECIFICATION left by the said Louis Goldberg and
Alexander Leslie Fyfe at the Office of the Commissioners of Patents on the
31st December 1883.
LOUIS GOLDBERG of Love Lane in the City of London, and ALEXANDER LESLIE
FYFE of Brixton in the County of Surrey, "IMPROVEMENTS IN AND APPERTAINING
TO INCANDESCENT ELECTRIC LAMPS AND THEIR HOLDERS, ALSO IN THE SWITCHES
EMPLOYED THEREIN,"
The usual method of making filaments for incandescent lamps is to stamp them,
out of paper or similar material, in suitable dies, and then carbonise them. And
whenever thread or vegetable fibre has been used, filaments of only simple curved
shapes could be produced.
We prefer to use thread to form the filaments, and to get over the difficulty of
producing the necessary shape to give a luminous light, and to prevent the eye
from following the simple shapes now in use, we prepare a carbon block with
projecting pins. We produce any shape of filament we may require by winding
the thread over the pins, which can be placed in different positions in the block, so
as to give the desired shape.
After the thread is wound round the pins-care being taken to prevent the
thread filaments from touching one another-the block is placed in the crucible and
carbonized in the usual way.
The carbonized thread is then fixed in specially made platinum conductors, and
cemented up in the usual way.
To make electrical connection, we use two flat metal half-rings attached to the
neck of the glass bulb, said rings having ridges raised on their centres, and
grooves on their sides. The usual socket is furnished with suitable grooves to
•

page_text: receive the half-rings, so that when the bulb is inserted in the socket and
turned partly round, complete electrical connection is made and the lamp safely
attached.
By making and arranging the electrical connection as described, the unsightliness
of the means by which connection is usually made, is not seen, and at the same
time any form of plain or ornamental design desired may be used.
Instead of using the usual tap as used in gas lighting, we make an ornamental
ring to form the tap, and to give the fingers a better hold, we mill the same round
the edges. The "make and break" is formed by making the milled ring work in
a slot attached to a cam.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Louis Goldberg and Alexander Leslie Fyfe in the Patent Office on
the 30th June 1884.
LOUIS GOLDBERG, of Love Lane in the City of London, and ALEXANDER LESLIE
FYFE, of Brixton in the County of Surrey "IMPROVEMENTS IN AND APPERTAINING
TO INCANDESCENT ELECTRIC LAMPS AND THEIR HOLDERS, ALSO IN SWITCHES
EMPLOYED THEREIN
"
The objects of our invention are improvements in incandescent electric lamps,
and consist of, firstly, an improved method of manufacturing the carbon filaments;
secondly, an improved incandescent lamp holder; and thirdly, an improved switch
for lighting or extinguishing the lamps.
In order that our invention may be fully understood, we refer to the accom-
panying drawings which are to be read with this specification as a part thereof.
Like parts are marked by the same reference letters.
Up to the present time the usual method of manufacturing carbon filaments has
been to stamp them out of paper or similar material in dies of suitable shape and
afterwards to carbonize them. Sometimes thread or vegetable fibre has been used
instead of paper, but always with the objection that filaments of only very simple
curves could be produced therefrom.
The first part of our invention consists in a method of manufacturing carbon
filaments in such a way, that any desired curve no matter how complex may be
produced. It is a well known fact that a filament of simple curve is always open
to the objection that its outline is so conspicuous that the eye of the observer is
continually following it. The advantage of a filament made according to our
invention is this, that its curves are so complex, that their outlines are rendered
indistinguishable and merged as it were in each other, while at the same time there
is no diminution in the luminous brilliancy of the light.
Our method is as follows. We prepare blocks of carbon with pins projecting
therefrom. These pins are arranged according to a definite design, the line
connecting them being the required shape of the carbon filament. The shaping
blocks are made in any convenient way either by casting or pressing them in
moulds or dies, or by inserting the pins in plain blocks, and with any convenient
strengthening ties and handles.
We use thread, by preference, for the manufacture of our filaments and wind it
round and about the lines of pins taking care that no two threads touch each other.
The blocks are then placed in the crucible and the threads carbonised in the
usual way.
Figure 1 is a plan and Figure 2 a side elevation illustrating this part of our
invention. A is the carbon block, and B. B. B; C. C. C; D. D. D; are pins
arranged in sets for having the thread E wound round them. It is obvious.
that a block can be made of any convenient size, and with its sets of pins arranged
to produce filaments of differing or similar outline. Fis an iron tie to prevent the
block being broken and has suitable lifting handles G. G.
The carbonised filaments are then attached to platinum conductors, preferably
made with tubulated or socket ends in which the filaments can be firmly fixed by
cement, pressure or electro deposition.
The second part of our invention relates to an improved holder for incandescent
electric lamps.
Figure 3 illustrates in front elevation and Figure 4 in section of our improved
holder.
HH are two short half circles of metal mounted upon a block I of non
conducting material. J is a clip for attaching the lamp holder to a bracket or

page_text: its equivalent. KK are the leads to connecting screws L L soldered to the metal
half circles H H. The latter as shewn do not touch, and their lower edges are
swayed outwards to admit of the easy insertion of the lamp. M, M are two
metal prongs connected to the platinum conductors N N respectively and to the
neck of the lamp in any convenient and effective way. These prongs have their
extremities m, m, pointed, and bent outwards. Two holes O, O, are cut in the
half circles H H to receive the ends of the prongs which thus put the filament P in
circuit with the leads K. K. The filament is kept in position by having the
conductors N N passed through a glass bar Q.
Figures 5 and 6 illustrate in plan and Figure 7 in elevation another variety of
our improved lamp holder. The former is a. plan of the neck of the bulb and the
latter of the holder.
The neck R of the bulb carries two metal half rings S S, each one carrying a
ridge T and a groove U. The conductors N N are connected to these two rings
respectively. V is the holder grooved vertically to receive the ridges T. T. which
are then turned round into an annular groove W W of a section corresponding to
that of the half rings S S contact being made through the ridges T T meeting the
terminals of the leads K K.
The third part of our invention relates to improvements in lighting and
extinguishing incandescent lamps and is illustrated in plan in Figures 8 and in
sectional elevation in Figure 9.
At a convenient point in the holder, for instance on the block I and below the
connecting screws L L we mount an ornamental or milled ring of non-conducting
material containing two metal quadrants X X. This ring Z' works in an annular
groove in the block I. When the quadrants X X contact with the leads and the
metal half rings H H as shewn the lamp is lighted while a turn sufficient to effect
a break extinguishes the lamp.
Another of our improved methods of lighting and extinguishing incandescent
lamps is illustrated in plan in Figure 10 and in elevation in Figure 11.
The ring Z actuates the cams Y Y by means of pins working in the slots, in said
cams, and making electrical contact between the leads and the metal half rings HН
as shown and so lighting the lamp while a reverse movement of the ring breaks
contact and extinguishes the lamp.
Having now particularly described and ascertained the nature of our invention
and in what manner the same may be advantageously carried into effect, we
declare that what we consider new therein and therefore covered by the hereinbefore
in part recited Letters Patent to be,-
First. The improved carbon block and method of manufacturing carbon
filaments thereon as hereinbefore described with reference to Figures 1 and 2.
Second. The improved holder for an incandescent electric lamp substantially as
described and illustrated with reference to Figures 3 and 4.
Third. The improved holder for an incandescent electric lamp substantially as
described and illustrated with reference to Figures 5, 6 and 7.
Fourth. The improved make and break devices for lighting and extinguishing
incandescent electric lamps substantially as described and illustrated with reference
to Figures 8, 9, 10 and 11.
In witness whereof I the said Louis Goldberg have hereunto set my hand
and seal this Twenty seventh day of June in the year of our Lord One thousand
eight hundred and eighty four.
AATRA