IMPROVE- MENTS IN ELECTRICAL ARC-LAMPS
Year: 1885

page_text: I ALBERT FERDINAND LINK of 8 Union Court Old Broad Street in the City of
London, Merchant do hereby declare the nature of my Invention for IMPROVE-
MENTS IN ELECTRICAL ARC-LAMPS a communication from Ludwig Scharn weber
Manufacturer of Kiel, in the German Empire, to be as follows:-
The object of my invention is to effect improvements in the regulation of the
approach of the carbons in electrical arc-lamps.
In carrying out my invention I fit the ordinary copper-wire solenoid with a
frame above, and a bracket below the same. In the centre of the solenoid I place
an iron tube, which enters the solenoid about two thirds of its length from the
bottom end.
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Inside the iron tube I place a brass tube of longer dimensions, in which brass
tube I place the positive carbon, and above this carbon (in the tube) I place a
weight which presses the carbon downwards.
The lower (negative) carbon is held by means of a bracket, which is suitably
isolated. A spiral spring is inserted in the bracket to impart a slight upward
pressure to the lower carbon..
The upper carbon holder is sustained by a spiral spring in the upper frame and
a string or chain is attached to the weight in order to sustain the same when the
carbon is consumed.
A switch is provided in the upper frame whereby the electric current is inter-
rupted when the string or chain is rendered taut by the falling of the weight.
In order to regulate more perfectly the approach of the carbons towards each
other I fit to each carbon holder a metal bar. These bars are bent at their ends
towards the points of the carbons, against which they press and thereby retain the
carbons. As the heat, to which these bars are exposed, is very great, I sometimes
fit points thereto formed of such metals as platinum, iridium, phosphoridium,
osmium, osmium-iridium, or other suitable metals or a mixture of two or more
of them. The points are enclosed in platinum or platiniridium; the latter metal
being fastened to the holder.

page_text: To prevent the entry of the electric current into the points last mentioned such
points may be attached to the bars by means of fire proof cement, magnesia
cement being a suitable material for the purpose.
Another method consists in the adaptation of a hard mineral instead of a metal
for forming the points to the bars which mineral must not be fusible or a conductor
of electricity, such as chromo-oxyde, aluminium-oxyde and their compounds.
I sometimes vary the arrangement of the springs and switches herein before
described, and place the same below the solenoid so as to regulate the descent of
the upper carbon in accordance with the intensity of the current and the position
and condition of the carbons.
GEO. DOWNING,
Agent for Applicant.
improvements in Electrical Arc-lamps.
I, ALBERT FERDINAND LINK, of 8 Union Court, Old Broad Street, in the City
of London, Merchant, do hereby declare the nature of my said invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
The object of my invention is to effect improvements in the regulation of the
approach of the carbons in electrical arc-lamps.
In carrying out my invention I fit the ordinary copper-wire solenoid with a
frame above, and a bracket below the same. In the centre of the solenoid I place
an iron tube, which enters the solenoid about two thirds of its length from the
bottom end.
Inside the iron tube I fix a brass tube of longer dimensions, in which brass tube
I place the positive carbon, and above this carbon (in the tube) I place a weight
which presses the carbon downwards.
The lower (negative) carbon is held by means of a bracket, which is suitably
insulated. A spiral spring is inserted in the bracket to impart a slight upward
pressure to the lower carbon.
The upper carbon holder is sustained by a spiral spring in the upper frame, and
a string or chain is attached to the weight in order to sustain the same when the
carbon is consumed.
A switch is provided in the upper frame whereby the electric current is inter-
rupted when the string or chain is rendered taut by the falling of the weight.
In order to regulate more perfectly the approach of the carbons towards each
other I fit to each carbon holder a metal bar.-These bars are bent at their ends

page_text: '
towards the points of the caroons, against which they press and thereby retain the
carbons. As the heat, to which these bars are exposed, is very great, I sometimes
fit points thereto formed of such metals as platinum, iridium, phosphoridium,
osmium osmium-iridium, or other suitable metals or a mixture of two or more of
them. The points are enclosed in platinum or platin-iridium; the latter metal
being fastened to the holder.
To prevent the entry of the electric current into the points last mentioned, such
points may be attached to the bars by means of fire proof cement, magnesia cetuent
being a suitable material for the purpose.
Another method consists in the adaptation of a hard mineral instead of a metal
for forming the points to the bars, which mineral must not be fusible or a conductor
of electricity, such as chromo-oxyde, aluminium-oxide and their compounds.
I sometimes vary the arrangement of the springs and switches herein before
described, and place the same below the solenoid, so as to regulate the descent of
the upper carbon in accordance with the intensity of the current and the position
and condition of the carbons.
And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings.
One method of carrying out my invention is shewn in Fig. 1, in which S is the
solenoid, consisting of a bobbin, fitted with a copper wire coil. This solenoid is
for the purpose of drawing up the core and attached carbon holder and so separating
the carbons. R is a frame soldered or otherwise attached to the solenoid, as shewn ;
and the bracket T is in like manner fitted to the underside of the same. A brass
tube o¹ is fixed inside an iron tube E, the latter reaching to about two thirds of its
length into the solenoid. The tube o¹ extends above the solenoid and incloses a
weight g. An insulated arm t, formed of brass, is attached to the bracket T. This
arm carries a short brass tube o². The carbon holders h¹ and h are attached to the
tubes of and o³, and the carbons a¹ and a² are placed vertically within the carbon
holders as shewn.
The upper carbon a¹ is pressed downwards by the weight g, and the lower
carbon a¹ is pressed upwards by a spiral spring, (not shown in the drawing).
In order to keep the points of the carbons slightly apart two bars c¹ and c³ are
fitted. The points of these bars press against the conical ends of the carbons, and
retain them in position; and, as the points of the carbons are consumed, they are
pressed forward against the points of the rods.
As the points of the rods c¹ c' are subjected to a very high temperature, I attach
thereto, at ss, additional points, made of such metals as platinum or iridium, or a
mixture of both of such metals. For the same purpose phosphoridium or osmium
and osmium iridium may be used. As the latter metal can only be obtained in
small grains, and cannot easily be kept in the copper holder, I adopt the arrange-
ment shewn in Fig. 4; in which the point o 8, consisting of osmium-iridium, is
enclosed in platinum or platin-iridium, pl; and this latter metal is fitted to the
holder c. In order to more perfectly insulate the points I sometimes adopt the
method shewn in Fig. 2.-In this arrangement the point 8, (formed of any of
the metals aforesaid) is fixed in the holder c² by means of any suitable fireproof
cement at i, such cement being necessarily a nonconductor of electricity, such as
magnesia-cement, or the mineral called Muscovite.
Other materials may also be used for the same purpose, such minerals as silicium
and its combinations, quartz, lardite, &c.; also the oxides of certain metals as
chromo-oxide, aluminium-oxide, and their combinations.
The automatic switch in Fig. 1 consists of two metallic springs f¹ƒ³. f¹ com-
municates with the frame R by metallic contact, and f' is insulated from the
frame R but connected with the conductor e; i is a block of ebonite attached to f³.
While the carbons are in their proper position for illumination (as shewn) the
current which enters at d, into the bobbin, passes through e, f, f¹, and the lamp
itself to a' a, and discharges through t and t¹.

page_text: As the upper carbon is consumed the weight g descends into the tube, drawing
the string after it; and when the carbon is entirely consumed the string k is
drawn taut by the weight, the switch f¹ thereby becomes disconnected; the
spring then presses forward, and the end of f¹ then rests against the ebonite i ;
whereby the current is broken. The spring p sustains the tube o¹.
An equivalent arrangement may, if preferred, be fitted in connection with the
lower carbon a².
As the tension of the dynamo or battery from which the lamps are worked is
very low, the disconnecting apparatus shewn in Fig. 3 may also be used. When
the upper carbon is nearly consumed the string k is drawn taut and the weight g
is thereby suspended and the upper carbon holder ceases to bear such weight g,
and the spring p then sustains the weight of the upper carbon holder; the upper
carbon holder will therefore cease to fall any further, and the arc light will
consequently be extinguished. As the upper positive carbon receives more heat
than the under negative, the application of the carbon holder-points for the upper
carbon may, when using stronger currents sometimes be omitted, while the same
may still be used and applied to the lower carbon.
Figs. 5 and 6 shew two methods of imparting pressure to the carbons, which
allow the carbons to approach, and retard their motion by means of the application
of very moderate pressure.
In Fig. 5 the two springs ff are attached to the iron block E. When the lamp
is not burning and the upper carbon rests upon the lower carbon, the springs press
but lightly on the carbon, as seen by the position of the two rollers r r.
As soon as the current is again established E is drawn upwards into the solenoid,
whereby the springs are pressed together by the rollers, the springs then clip the
carbon.and slightly raise it, and the arc is formed. If the arc becomes longer and
the current diminishes E falls again out of the bobbin, the springs slightly relax
their hold and allow the carbon to descend as required.
Fig. 6 shews arrangement for effecting the same object. The points is im-
movably fixed to E while the opposite point is adapted to the bent lever w, turning
on a centre at c.
On the arm m, fixed to E, the spiral spring f is fitted which presses the lever w
against the upper carbon. If there is no current in the lamp the fall of the iron
block E brings the end of the bent lever w down to and in contact with the
provision g. This loosens the pressure of the lever wagainst the carbon and allows
the carbon to fall; the same operation takes place when the arc has become too
long through the burning away of the carbon points.
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 application and use of carbon holder points, for governing the position of
the carbons in electric arc lamps, such points being manufactured from platinum
metal or its alloys or from phosphoridium, substantially as herein before described,
and shewn on the drawings.
2. The method of insulating the carbon holder points, for the purposes aforesaid,
by means of fire proof cement or a socket filled with a fire proof mineral,
substantially as herein before described and shewn in Figs. 2 and 4 of the
drawings.
3. The application and use of carbon holder points for the purposes aforesaid,
manufactured from fire proof non-conducting minerals, such as silicates, chromo-
oxide, aluminium-oxyde, or their combinations, substantially as herein before
described.
4. The application and use of carbon holder points, for the purposes aforesaid,
consisting of a grain of osmium-iridium, enclosed or mounted in a piece of
platinum, or platin-iridium, the latter being mounted in copper or brass, sub-
stantially as herein before described.

page_text: 5. The application and use, in electric arc lamps, of the automatic disconnecting
apparatus, whereby the disconnection takes place when the carbon is consumed;
actuated by a weight or spring, substantially as herein before described and shewn
in Fig. 1 of the drawings.
. 6. The application and use, in electric arc lamps, of the automatic disconnecting
apparatus, substantially as herein before described and shewn in Fig. 3 of the
drawings.
7. The application and use, in electric arc lamps, of the method of regulating
the relative positions of the carbons by means of the springs ff and rollers rr,
substantially as herein before described and shewn in Fig. 5 of the drawings.
8. The application and use, in electric arc lamps, of the method of regulating
the relative positions of the carbons, by means of the arrangement substantially
as herein before described and shewn in Fig. 6 of the drawings.
9. The general construction, combination and arrangement of the several and
respective parts, together forming my improvements in electric arc lamps, sub-
stantially as herein before described and shewn on the drawings.
GEO. DOWNING,
Agent for Applicant.