IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1879

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents, 66,
Chancery Lane, in the County of Middlesex, Mechanical Draughtsman, for
the Invention of "IMPROVEMENTS IN ELECTRIC LAMPS." A communication
from abroad by Ferdinando Tommasi, of Paris, in the Republic of France.
Sealed the 13th April 1880, and dated the 29th October 1879.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton at
the Office of the Commissioners of Patents on the 29th October 1879.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN ELECTRIC
LAMPS." [A communication from abroad by Ferdinando Tommasi, of Paris, in the
Republic of France.]
The chief object of this Invention is so to arrange electric lamps (whether
pedestal or suspended) that no lateral shadow shall be cast therefrom.
In constructing a pedestal lamp a carbon block carried by a central rod is used
for a series of carbon electrodes, arranged around the rod, to butt against. These
carbon electrodes float in mercury tubes, which incline inwards towards a common
centre. The tubes are carried by brackets, which are secured to the top of the
pedestal of the lamp, and they are insulated therefrom.
The block of carbon is made adjustable on its support, and the tendency of the
mercury in the tubes is to hold the electrodes in contact therewith. The electrodes
(of which there may be six, more or less) are arranged to act by preference in pairs,
and in the space enclosed within the ring of tubes is situate an arrangement of
clockwork for bringing the pair of electrodes in succession within the electric
circuit.
In front of a barrel containing the coiled spring or motor of the clock mechanism
is a disc furnished with metallic segments, corresponding in number to the
electrodes and arranged as a divided ring, each segment being insulated from the
others. Upon the face of this disc and concentric with the ring of segments is a
larger and a smaller metallic ring. Through the centre of this disc the arbor of
the spring barrel passes, and to it rotary motion is communicated through the
clock work. Mounted on but insulated from this arbor are two arms, which stand

page_text: out in opposite directions and overlie each a segment at opposite sides of the disc.
One of these arms, the sides being in metallic contact with its segment, is in
contact with the larger ring, and the other arm is in like contact with the smaller
ring. The segments are each connected by a wire with a mercury tube. The two
concentric rings are connected with opposite poles of the electric generator.
When the mechanism is set in action the arms will pass in succession over the
pairs of segments, and thereby bring their corresponding carbons within the
circuit.
Thus a succession of carbons will be brought into use, a second pair so soon
as the first pair has been consumed, and so on, thereby keeping up a continuous
light.
If desired, single carbons may be used with the central block, in which case this
block will be connected with one pole of the generator.
When constructing a suspended lamp, suitable for throwing down the light upon
a table, the carbon tubes are carried by brackets from the reflecting shade, and the
mechanism for rotating the above described commutator is placed above the
reflector, or it may be at any suitable distance from the lamp.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed by
the said Alfred Vincent Newton in the Great Seal Patent Office on the 29th
April 1880.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN ELECTRIC
LAMPS." A communication from abroad by Ferdinando Tommasi, of Paris, in the
Republic of France.
The chief object of this Invention is so to arrange electric lamps (whether
pedestal or suspended) that no lateral shadow shall be cast therefrom. In con-
structing a pedestal lamp a carbon block carrried by a central rod is used for a
series of carbon electrodes (arranged around the rod) to butt against. These
carbon electrodes float in mercury tubes, which incline inwards towards a common
centre. The tubes are carried by brackets, which are secured to the top of the
pedestal of the lamp, and they are insulated therefrom. The block of carbon is
made adjustable on its support, and the tendency of the mercury in the tubes is to
hold the electrodes in contact therewith. The electrodes (of which there may be
six, more or less) are arranged to act by preference in pairs, and in the space
enclosed within the ring of tubes is situate an arrangement of clockwork for
bringing the pairs of electrodes in succession within the electric circuit. In front
of a barrel containing the coiled spring or motor of the clock mechanism is a disc
furnished with metallic segments, corresponding in number to the electrodes and
arranged as a divided ring, each segment being insulated from the others. Upon
the face of this disc and concentric with the ring of segments is a larger and a
smaller metallic ring. Through the centre of this disc the arbor of the spring barrel
passes, and to it rotary motion is communicated through the clock work. Mounted
on but insulated from this arbor are two arms, which stand out in opposite
directions and overlie each a segment at opposite sides of the disc. One of these
arms besides being in metallic contact with its segment is in contact with the
larger ring, and the other arm is in like contact with the smaller ring. The
segments are each connected by a wire with a mercury tube. The two concentric
rings are connected with opposite poles of the electric generator. When the
mechanism is set in action the arms will pass in succession over the pairs of
segments, and thereby bring their corresponding carbons within the circuit.
Thus a succession of carbons will be brought into use, a second pair so soon as the
first pair has been consumed, and so on, thereby keeping up a continuous light.
I will first describe in detail this arrangement of electric lamp, with reference to
Figures 1 and 2 of the accompanying Drawing, and I will then explain certain
modifications of the Invention to render the same better adapted to certain uses.
Fig. 1 is a vertical section taken through the centre of the improved lamp, and
Fig. 2 is a sectional plan view taken in the line 1, 2, of Fig. 1.
a to a (Fig. 2) are the carbons contained in tubular carbon holders b' to bº,
which are charged with mercury and are mounted on a common platform c, which
is carried by supports d secured to the lamp stand. This platform is covered with
a sheet of vulcanite or any other insulating material, which will have the effect
of insulating the tubes and their carbons from the body of the lamp. Standing up
from the platform is a metal rod f, which receives at its upper end the carbon
block g. This block is constantly pushed upwards against an adjustable nut h on
the rod f by means of a helical spring surrounding the rod f.
At the lower part of the lamp and in front of the supports d is the commutator.
for changing the course of the current, and thereby bringing fresh carbons within
the circuit. The mechanism for actuating the commutator consists of a spring.
barrel mounted on a shaft i and furnished with a ring of teeth in gear with a
pinion j. On the axle of this pinion is mounted a wheel k which gears into a.

page_text: pinion, which drives a train of wheels k', k, ke³, and pinions ², j³, j, whereby the
fly m is rotated at a sufficient speed to regulate the movement of the shaft i. This
shaft passes through the commutator n, formed of a disc of vulcanite or other
suitable insulating material fitted with as many distinct metallic segments o¹ to 06
as there are carbons in the lamp (in this instance six).
Two elastic fingers p and q diametrically opposite each other and electrically
insulated the one from the other are mounted on the shaft i, and while turning
with the shaft bear upon the two metallic segments that are diametrically opposite
each other.
Attached to each of these segments is a terminal p' to po, to which is connected
a wire s¹ to s6, corresponding to one of the tubes 6' to 66, and consequently to one
of the carbons a¹ to aº.
The disc also carries two concentric metal rings t, u, which project slightly.
from the insulating material like the segments o¹ to 0%, and are connected
respectively with the two terminals v, w, which connect in the usual manner with.
the terminals x, y, by which the current enters and leaves the lamp.
The elastic fingers p, q, are arranged so that the finger p touches also the metallic
ring u, while the finger q touches also the ring t. This arrangement will be better
understood by reference to the plan Fig. 2, which shews the fingers placed hori-
zontally and respectively touching the segments o³ and o².
On the contrary, Fig. 1 shews the two fingers as placed vertically, and it may
be observed that their width is sufficient to bridge the space between two segments
and touch them both at the same time, consequently no interruption to the light
will occur. The terminal x is electrically connected to the exterior ring t of the
commutator, from thence the current passes through the finger p, Fig. 2, to the
segment o³, from thence by the wire so it passes through the carbon as to the block g.
It then descends by the carbon a² to the wire & to the segment o³, thence through
the second finger 9 to the interior ring u, and thence to the other terminal y.
It will now be seen that the light is established between the two opposite
carbons a² and aº, all exterior shadows being avoided.
The fingers being driven by the clock train in turning pass successively over all
the segments, the opposite two of which will always be in contact with the fingers
at the same time, thus causing the current to pass through the two carbons in
connection therewith and producing the light.
It will be understood that it is easy to arrange the commutator so that only one
carbon shall be in the circuit at a time. In this case it will only be necessary to
dismount one of the fingers, leaving the communications established as before
between the segments and the carbons, and to place the carbon block g in com-
munication with one of the terminals x, y, by which the current enters or leaves
the lamp. The light will then be produced successively from each of the carbons
and the block g.
When constructing a suspended lamp suitable for throwing down the light upon
a table the carbon tubes are carried by brackets from the inside of the reflecting
shade, the mechanism for rotating the above described commutator being placed
above the reflector in a box which surrounds the central carbon block, or it may
be placed at any convenient spot at a distance from the lamp.
It may sometimes be desirable to effect the distribution of the current by hand
instead of automatically as described, the carbons being put respectively into the
circuit by wires with a commutator or with a current distributing mechanism
similar to that above described, but more or less removed from the lamp.
Fig. 3 shews a special arrangement of the improved lamp adapted for submarine
use, for instance, for fishing, diving, &c.
To simplify the lamp as much as possible it is preferable to remove the
automatic or hand distributing arrangement from the lamp, and to place it on
board the boat in connection with which the lamp is working or upon the adjacent.
shore.

page_text: By preference the carbons are made to burn in pairs; they may be four, six, or
more in number according to the time the light is required..
The Drawing shews as an example a lamp with only one pair of carbons, in order
that the construction may be the more clearly understood.
The carbons a¹, a², are placed in mercury tubes b', 62, in electrical communication
with the body of the lamp, and they are held up by their buoyancy in the mercury
against the insulated carbon blocks g¹, g².
The whole is enclosed in a cylindrical glass case A, closed at its ends by discs
which are held in place by a central rod f, terminating at its upper end in a ring,
to which is attached a cord E for the purpose of sustaining the apparatus in the
water.
.
Insulated wires C³, 0%, are twisted round this cord, and are connected to
terminals x, y, screwed to the upper end of the lamp. An india rubber dome B
is attached to and surrounds the upper end of the apparatus, which renders it
perfectly watertight.
It is as well to remark that a lamp, constructed as above described, may be
made without a commutator should it be desirable to render it very simple and
cheap.
Figures 4, 5, and 6 shew arrangements intended to maintain the level of the
mercury in the tubes containing the carbon electrodes as these latter are
consumed.
In the arrangement shewn at Fig. 4 the bottoms of the tubes are connected to
reservoirs F filled with mercury, upon the surface of which are placed weights
calculated to counter balance the columns of mercury contained in the tubes at the
moment of lighting the lamp.
This weight consists of a cup G in which may be placed sand, shot, mercury, &c.
This weight is carried by a piston H, which enters the cylindrical reservoir F
and rests on an elastic membrane fixed above the surface of the mercury.
This arrangement may be simplified as shewn in Fig. 5 by making use of
compressed air as a regulator of the level of the mercury, and in this case the tubes
6, 62, that contain the carbons a², a², communicate at their lower ends with special
receivers F, in which the air is compressed when the tube is filled.
As the level of the mercury becomes lowered by the rise of the carbons as they
are consumed this air will expand and cause the mercury to rise in the tube to its
original level.
Fig. 6 shews a modification in which the adjustable weight g is replaced by a
screw I, which will raise or lower the piston and cause the mercury to rise or fall
in the carbon tube.
If desired, the two tubes containing a pair of carbons may be mounted on the
same reservoir, and in certain cases all the tubes may be mounted on the same
reservoir; then by placing on this reservoir but one tubular receiver with its piston
and weight or screw a certain level may be maintained in all the tubes.
In order to carry out this modification it will be necessary to divide (by
insulating partition) the carbon block g into as many distinct divisions as there are
carbon rods.
Having now set forth the nature of the Invention of "Improvements in Electric
Lamps" as communicated to me from abroad, and explained the manner of carrying
the same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim,-
First. The arrangement above described for supporting the carbon holders,
whereby the use of external framing or supports that would throw shadows becomes
unnecessary.
Second. In connection with a multiple carbon lamp, arranged as above described,
the commutator or current controlling mechanism either contained in or situate at
a distance from the lamp for bringing into the circuit successive carbons or pairs of
carbons, for the purpose above set forth.

page_text: Third. The modified form of lamp, as described with reference to Fig. 3, adapted
for submarine purposes..
Fourth. The means, above described, for maintaining the carbon electrodes in
contact with the fixed carbon block at an uniform pressure thoughout their
incandescence.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto set my
hand and seal, the Twenty ninth day of April, in the year of our Lord One
thousand eight hundred and eighty.
A. V. NEWTON. (L.S.)