Improvements in Electrical Glow Lamps.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electrical Glow Lamps.
I, PAUL SCHARF, of VII Doblergasse No. 10, Vienna, Austria, Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention has for its object so to construct electrical glow lamps that when
they have been used for the full term of the duration of the filament, they can by
a simple operation and in employing nearly all their original component parts be
converted into lamps that will operate efficiently for another period, and, in con-
sequence of the arrangement of their carbon filaments will enable their
illuminating power to be fully utilized.'
This is effected by employing in lieu of the single long carbon filament such as
has been heretofore generally used, a number of shorter filaments preferably con-
nected in series and so arranged that as they become used up, they can be separately
changed, while .occupying such a position in the glass globe as will prevent the
obscuring of parts of the incandescent filament by external parts of the casing and
thus avoid loss of light. The changing of the carbon threads can be effected
several times.
These carbon filaments are attached in the known manner to their wire supports,
which are connected in a new manner to intermediate wires, while the glass globe
is made in two separate parts and is in addition secured to a readily disconnected
mounting so that a repeated use of all parts of the lamp with the exception of the
useless carbon filaments, and a ready interchange of these, is rendered possible.
A glow lamp constructed according to my invention is shewn on the accompany-
ing drawing, in which Figure 1 shews an elevation, Figure 2 a vertical section,
while Figures 3 to 5 shew to an enlarged scale the support of the carbon filaments
respectively in top plan, vertical section, and bottom plan. Figures 6 to 8 shew
respectively the strap for securing the lamp to the holder with its parts separated,
and in the partly closed and the fully closed positions.
The lamp globe consists, as shewn, of two separate glass bodies, namely the
globe proper, A, with its neck, and the closing cap B. Both parts have ground
edges with which they are fitted together, and which are preferably formed with
heads, for facilitating the grinding and preventing cracking during the various
manipulations to which they are subject.
The two platinum wires 2 p2 are melted into the glass in the usual manner,
and for economising platinum they, may have short nickle wires n' n² soldered to
them...
In the globe part of the glass, A, there are provided in place of the usual long
thin carbon looped filament, a number of short looped filaments a which can be
repared of better quality than the long filaments, and which can be separately
changed so that only that one of the short filaments (which are connected in series)
need be changed which is burnt out, and not the entire carbon filaments.
For this purpose the carbon loops, a are fixed to a common support T of insulat-
ing material (glass or porcelain) by means of short lengths of wire b, which are so
passed in a looped form through holes in the ring or disc shaped support, that their

page_text: ends project above the upper side thereof. Two of these wire loops project, each
with one of its ends and 2 downwards beyond the lower support surface, and
serve for leading the current to and from the filaments; the other ends of the
wire loops are so connected to the carbon filaments that the latter constitute a
system of incandescence bodies connected in series as shewn in the diagram plan
at Figure 5.
With very powerful lamps (from 500 candle power upwards) it is of advantage
to connect the several carbon filaments in parallel because by that means the use
to thick carbon filaments, that can only with difficulty be produced of good quality,
is obviated, and because in the event of one filament becoming inoperative, the
lamp still continues in action, whereas with the series connection the entire lamp
is put out of action in the event of- one filament becoming defective, also whereas
the changing of the small lamps with ordinary mounting devices is easily effected,
with large lamps which, as is known, require special mounting devices, and very
reliable contacts this can only be effected with considerable difficulty during the
working; for this reason therefore it is preferable to employ a connection in
parallel of the filaments for the large lamps.
The connection of the carbon filaments, a witn the wire loops b is effected by
means of the wire electrodes e¹ e, which are connected by their one end in the
known manner (by electro-deposition of carbon or by a conducting cement) to
the respective ends of the carbon filaments, while the free ends of these electrodes
are formed into a socket-shape by making them as helical coils oo. These latter
are fitted on the ends of the wire loops projecting from the support T, and are
fixed thereto by pressing the coils together, whereby the wire loops are at the
same time prevented from dropping down through the support.
b
This connection is quite sufficient and reliable both mechanically and as regards
the electrical contact, and it will not become loosened by the heating when the
lamp is in action; in addition, it affords the possibility of opening out the coil
by a pull exerted on the electrodes, and thus enables a carbon filament that has
become useless to be readily detached together with its wires el e³ from the wire
loops b in order to be replaced by a new one.
When connecting the conducting wires of the support T with the platinum
wires 2 melted into the glass cap B, or to the extensions n' n² thereof, it is
necessary to consider the suitable position of the carbon filaments a, in order, as
first above stated, to avoid losses of light, which occur in ordinary glow lamps
through the fact that the part of the carbon filament which reaches into the neck
of the globe, and which is also heated to incandescence, is more or less covered by
the coloured or otherwise ornamented bell or tulip shaped glasses which generally
cover the neck of the lamp. In order, while retaining the said ornamental glasses,
not to lose any of the light of the filament, the support T together with the carbon
filaments a are shifted forward into the middle of the globe, this being only
possible when the ordinary long carbon loop is divided up into several short loops
according to my invention.
The connection is consequently effected by mears of intermediate wires d'
which are formed at both ends with coiled sockets, into which are inserted respect-
ively the wires k¹ and n¹ n² these being secured by pinching the coiled sockets
together.
By this means the support T is secured firmly to the cap B of the globe, while
on the other hand it can be readily detached therefrom by drawing off the said
coils, which is of importance for facilitating the renewal of a carbon filament when
the lamp is opened.
The perfect air tight and secure connection of the parts A and B of the globe at
their ground edges is effected by means of a glass cement composed of a finely
ground melt of minium (or other lead salt) boracic acid, and silicic acid (in the
form of finely ground pure sand) which cement before use, is made into a liquid
paste by means of turpentine, or other suitable liquid resin.
The proportions of the said ingredients is preferably: 7 parts of minium,

page_text: 2 parts of crystallised boracic acid, and one part of sand; only the lead salt, how-
ever, is the absolutely necessary ingredient, as the boracic acid or the silicic acid
can be dispensed with.
Other suitable compounds may be prepared with 10 parts of minium and 3 parts
of boracic acid, or with 8 parts of mínium and 2 parts of sand.
After applying the cement to the edges of the parts A and B and allowing the
same to dry the two parts are fitted together and the connected edges are heated
to slight redness, whereby the cement is melted so that the two ground edges are
closely secured together in an airtight manner thereby.
By varying the proportions of the ingredients the cement can be made to suit
the particular kind of glass of which the globe is made this being determined
by experiment.
As the Glass globe forms an essential part of the glow lamp, and is to be used
repeatedly, it follows that a new description of metal socket for the same, and a
special mode of connecting the same with the globe becomes essentially necessary
because the present description of metal sockets fixed by cementing or by gypsum
does not readily allow of a repeated use of the glass globe.
Such a socket which can not only be readily removed and refixed, but also
establishes a secure fastening between the metal and the perfectly smooth cylin-
drical part of the glass globe; without requiring projections or recesses in the
latter, which facilitate cracking consists of a ring t of the vulcanised caoutchouc
r gutta percha, fitted on the neck of the globe, and of a socket u, the upper
annular part of which is divided by longitudinal slots into spring tongues ' round
these is fitted a clamping ring Z, which is drawn together by screws or other means,
whereby the tongues are pressed into the ring and the latter is pressed with
sufficient force against the glass to prevent any shifting of the ring and con-
sequently of the socket.
The clamping ring may advantageously be formed as shewn at Figures 6 to 8,
consisting of an open sheet metal ring the two ends 2% of which are bent into a
hook-shape; a spring yoke piece y, also having inward bent hook-shaped ends, is
hooked into the one end Z' of the ring, while its other end engages with a slightly
bent middle piece a, which abuts with its one end against the other hooked end Za
of the ring, and is formed with a finger . Thus when the piece a is forced down
against the ring Z it exercises a kind of excentric action by which a strong draw-
ing together of the ring Z, is effected. The finger al is in this motion brought
between two projecting loops Z3 formed on the ring by slitting and stamping and
it can be secured in that position by a seal, so that any nonpermitted opening of
the fastening is prevented.
Instead of the above described clamping ring there may be used for pressing the
tongues u against the ring t, a wire coiled several times round the tongues u and
having its ends twisted together which device is very strong and would be cheaper
than the clamping ring Z.
Doted this 7th day of December 1896.
ABEL & IMRAY,
Agents for the Applicant.
I, PAUL SCHARF, of VII Doblergasse No. 10, Vienna, Austria, Engineer, do
hereby declare the nature of this invention and in what manner the same is to be

page_text: performed to be particularly described and ascertained in and by the following
statement:
This invention has for its object so to construct electrical glow lamps that when
they have been used for the full term of the duration of the filament, they can by
a simple operation and in employing nearly all their original component parts be
converted into lamps that, will operate efficiently for another period, and, in con-
sequence of the arrangement of their carbon filaments will enable their
illuminating power to be fully utilized.
This is effected by employing in lieu of the single long carbon filament such as
has been heretofore generally used, a number of shorter filaments preferably con-
nected in series and so arranged that as they become used up, they can be separately
changed, while occupying such a position in the glass globe as will prevent the
obscuring of parts of the incandescent filament by external parts of the casing and
thus avoid loss of light. The changing of the carbon threads can be effected
several times.
These carbon filaments are attached in the known manner to their wire supports,
which are connected in a new manner to intermediate wires, while the glass globe
is. made in two separate parts and is in addition secured to a readily disconnected
mcunting so that a repeated use of all parts of the lamp with the exception of the
useless carbon filaments, and a ready interchange of these, is rendered possible.
A glow lamp constructed according to my invention is shewn in the drawings
accompanying my Provisional Specification, in which Figure 1 is an elevation,
Figure 2 a vertical section, while Figures 3 to 5 shew to an enlarged scale the
support of the carbon filaments respectively in top plan, vertical section, and
bottom plan. Figures 6 to 8 shew respectively the strap for securing the lamp to
the holder with its parts separated, and in the partly closed and the fully closed
positions.
The lamp globe consists, as shewn, of two separate glass bodies, namely the
globe proper, A, with its neck, and the closing cap B. Both parts have ground
edges with which they are fitted together, and which are preferably formed with
beads, for facilitating the grinding, and preventing cracking during the various
manipulations to which they are subject.
The two platinum wires p p are sealed into the glass in the, usual manner,
and for economising platinum they may have short nickle wires n' n soldered to
them.
In the globe part of the glass A, there are provided instead of the usual long
thin carbon looped filament, a number of short looped filaments a which can be
prepared of better quality than the long filaments, and which can be separately
changed so that only that one of the short filaments, (which are connected in series)
need be changed which is burnt out, and not the entire carbon filaments.
For this purpose the carbon loops a are fixed to a common support T of insulat-
ing material (glass or porcelain) by means of short lengths of wire b, which are so
passed in a looped form through holes in the ring or disc shaped support, that their
ends project above the upper side thereof. Two of these wire loops project, each
with one of its ends and downwards beyond the lower surface of the support,
and serve for leading the current to and from the filaments; the other ends of the
wire loops are so connected to the carbon filaments that the latter constitute a
system of incandescence bodies connected in series as shewn in the diagram plan
at Figure 5.
With very powerful lamps (from 500 candle power upwards) it is of advantage
to connect the several carbon filaments in parallel because by that means the use
to thick carbon filaments, that can only with difficulty be produced of good quality,
is obviated, and because in the event of one filament becoming inoperative, the
lamp still continues in action, whereas with the series connection the entire lamp
is put out of action in the event of one filament becoming defective, also whereas
the changing of the small lamps with ordinary mounting devices is easily effected,

page_text: with large lamps which, as is known, require special mounting devices, and very
reliable contacts this can only be effected with considerable difficulty during the
working; for this reason therefore it, is preferable to employ a connection in
parallel of the. filaments for., the large lamps.
The connection of the carbon filaments a with the wire loops 6 is effected by
means of the wire electrodes el e, which are connected by their one end in the
known manner (by electro-deposition of carbon or by a conducting cement) to
the respective ends of the carbon filaments, while the free ends' of these electrodes
are formed into socket-shape by making them as helical coils oo. These coils
are fitted on the ends of the wire loops b projecting from the support T, and are
fixed thereto by squeezing the coils, whereby the wire loops are at the same time
prevented from dropping down through the support T.
This connection is quite sufficient and reliable both mechanically and as regards
the electrical contact, and it does not become loosened by the heating when the
lamp is in action; in addition, it-affords the possibility of opening out the coil
by a pull exerted 'on the electrodes, and thus enables a carbon filament that has
become useless to be readily detached together with its wires e e from the wire
loops in order to have a new one substituted for it.
When connecting the conducting wires of the support T with the platinum
wires sealed in the glass cap B, or to the extensions n' n³, it is necessary
to consider the suitable position of the carbon filaments a, in order, as first
above stated, to avoid losses of light, which occur in ordinary glow lamps
through the fact that the part of the carbon filament which reaches. into the neck
of the globe, and which is also heated to incandescence, is more or less covered by
the coloured or otherwise ornamented bell or tulip shaped glasses which generally
cover the neck of the lamp. In order, while retaining the said ornamental glasses,
not to lose any of the light of the filament, the support T together with the carbon
filaments a are shifted forward into the middle of the globe, this being only
possible when the ordinary long carbon loop is divided up into several short loops
according to my invention..
:
The connection is consequently effected by means of intermediate wires d'a
which are coiled at both ends to form sockets, into which are inserted respectively
the wires and n¹ n2, these being secured by squeezing the coils.
By this means the support T is secured firmly to the cap B of the globe, while
on the other hand it can be readily, detached therefrom by drawing off the coils;
this is of importance for facilitating the renewal of a carbon filament; when
the lamp is opened.
The perfect air tight and secure connection of the parts A. and B of the globe at
their ground edges is effected by means. of a glass cement composed of a finely
ground melt of minium (or other lead salt) boracic acid; and silicic acid-(in the
form of finely ground pure sand) which cement before use, is made into a liquid
paste by means of turpentine, or other suitable liquid resin.
The proportions of the said ingredients are preferably: 7 parts of minium,
2 parts of crystallised boracic acid, and one part of sand; only, the lead salt, how-
ever, is the absolutely necessary ingredient, as the boracic acid, or the silicic acid
can be dispensed with.
Other suitable compounds may be prepared with '10 parts of 'minium and 3 parts
of boracic acid, or with 8 parts of minium and 2 parts of sand.
After applying the cement to the edges of the parts A and B and allowing the
same to dry the two parts are fitted together and the connected edges are heated
to slight redness, whereby the cement is melted so that the two ground edges are
closely secured together in an air-tight manner.
By varying the proportions of the ingredients the cement can be made to suit
the particular kind of glass of which the globe is made this being determined
by experiment.
As the Glass globe forms an essential part of the glow lamp, and is to be used
repeatedly, it follows that a new description of metal socket for it, and a

page_text: special mode of connecting the socket with the globe becomes essentially necessary
because the present description of metal sockets fixed by cementing or by gypsum
does not readily allow of a repeated use of the glass globe.
Such a socket which can not only be readily removed and refixed, but also
establishes a secure fastening between the metal and the perfectly smooth cylin- 5
drical part of the glass globe; without requiring projections or recesses in the
latter which facilitate cracking, consists of a ring of vulcanised caoutchouc
or gutta percha, fitted on the neck of the globe, and of a socket u, the upper
annular part of which is divided by longitudinal slits into spring tongues u¹; round
these is fitted a clamping ring 7, which is drawn together by screws or other means, 1
whereby the tongues are pressed into the ring t and the ring is pressed with
sufficient force against the glass to prevent any shifting of the ring and con-
sequently of the socket.
The clamping ring may advantageously be formed as shewn at Figures 6 to 8,
consisting of an open sheet metal ring the two ends Z Z3 of which are bent into
hook-shape; a spring yoke piece y, also having inwardly bent hook-shaped ends, is
hooked into the one end 7 of the ring, while its other end engages with a slightly
bent middle piece, which abuts with its one end against the other hooked end Z³
of the ring, and is formed with a finger a¹. Thus when the piece is forced down
against the ring Z it exercises a kind of excentric action by which a strong draw-
ing together of the ring Z, is effected. The finger is in this motion brought
between two projecting loops 73 formed on the ring by slitting and stamping and
it can be secured in that position by a seal, so that any unauthorized opening of
the fastening is prevented.
Instead of the above described clamping ring there may be used for pressing the
tongues against the ring t, a wire coiled several times round the tongues and
having its ends twisted together which device is very strong and would be cheaper
than the clamping ring Z.
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. The globe for an electrical glow lamp consisting of two parts having their
edges secured together by a glass cement.
2. Constructing the light giving part as a number of separate filaments attached
to wires coiled so as to form sockets which by squeezing are fixed to wires con-
nected with the leading in wires, the filaments being connected in series or in
parallel.
3. The insulating support for the filament wires connected to the leading in
wires by two wires having their ends coiled into socket form engaging the leading
in wires and a pair of wires projecting down from the support.
4. The removable socket attached to the globe by clamping its slitted upper
margin on a packing ring encircling the neck of the globe.
5. For securing together the two parts of the lamp a cement prepared and
applied as described.
Dated this 6th day of September 1897.
ABEL & IMRAY,
Agents for the Applicant.