IMPROVE- MENTS IN ELECTRIC LAMPS
Year: 1881

page_text: LETTERS PATENT to Henri Adrien Bonneville, of the British and Foreign
Patent Offices, 8, Rue de la Chaussée d'Antin, Paris, France, and 90, Cannon
Street, in the City of London, Patent Agent, for an Invention of "IMPROVE-
MENTS IN ELECTRIC LAMPS." A communication from Leo Daft, of Brooklyn,
County and State of New York, United States of America.
COMPLETE SPECIFICATION filed by the said Henri Adrien Bonneville at
the Office of the Commissioners of Patents on the 1st November 1881.
HENRI ADRIEN BONNEVILLE, of the British and Foreign Patent Offices, 8, Rue
de la Chaussée d'Antin, Paris, France, and 90, Cannon Street, in the City of
London, Patent Agent. "IMPROVEMENTS IN ELECTRIC LAMPS." A communi-
cation from Leo Daft, of Brooklyn, County and State of New York, United States
of America.
The first part of the Invention relates to electric light mechanism, and it consists
in the following specific devices or their equivalents, whereby the carbon sticks
usually employed are automatically adjusted and kept in such a position and
relation to each other that a continuous and effective light shall be had without
the necessity of manual interference, as well on a single lamp as when a series of
lamps are used in the same circuit; also to the arrangement and construction
of the frame supporting the electric lamp as will hereafter appear, whereby a perfect
insulation between the two carbons is effected and the light is improved.
The second part of the Invention relates to means for hanging or suspending
electric lamps, especially from the ceilings or other parts of a building.
One of the disadvantages attending the use of the electric light in factories and
other places where machinery is used bas been that by the action of the
vibrations of the ceilings due to the machinery in operation the light is rendered
unsteady.
The second part of the Invention consists in the employment of metallic elastic
suspension devices for the purpose of hanging an electric lamp to the ceiling or
other part of a building for the purpose of absorbing vibrations, and arranging such
suspension devices to form part of the circuit through the lamp, so that the same
also act as conductors for the electrical current.
The Invention is illustrated in the accompanying Drawings, in which
Fig. 1 represents a part section and a part side view.
Fio 2 in plan or ton view of the Invention

page_text: Fig. 3 shows a piece or wire composing the suspension spring in cross SECTION
an enlarged scale.
Fig. 4 is a sectional side view of one of the lamps provided with a regulator.
Fig. 5 is a transverse vertical section of the same.
Fig. 6 is a perspective view of the clamp detached on a larger scale than the
previous Figure.
Similar letters indicate corresponding parts.
The letter A designates a helix of insulated wire in the form of a tube or hollow
cylinder which rests upon the upper traverse or bridge A¹ connected by glass
tubes E, E, with the lower traverse G. Within the axial cavity of the helix A is
contained an iron core C and the rod B, which latter is fixed or firmly secured to
the core and moves together therewith freely within the cavity of the belix, the rod
being guided in the top plate of the helix, and in a bridge Ñ¹ which is secured to
the under side of the traverse A¹.
The rod B is by preference made in two sections which are united by a screw
coupling a, and in the lower tubular section B¹ is placed loosely the upper or
positive carbon F so that the carbon moves freely therein and can descend by its
inherent gravity. To the lower end of the tubular section B' of the rod B are
secured carbon detaining fingers b, which extend from an annular head c screwed
or otherwise secured to the end of the section B¹. These fingers b are by preference
made of platinum, porcelain, or other refractory material to avoid injury thereto
by the heat to which they are exposed when the lamp is in operation, and their
points bear against the tapering sides of the lower end of the carbon F in such a
manner that as the carbon is consumed the fingers allow it to sink down auto-
matically and without requiring any manual interference until nearly all the
carbon is consumed, whilst at the same time any upward motion of the rod B and
core C is shared by the carbon.
On the rod B is secured by a set screw d a ring 7, which acts as a stop to the
upward motion of the parts, hereinafter more fully explained.
The traverse G is fully insulated from the traverse A' by being connected thereto
through the glass tubes E, E, as before stated. From the traverse G rises a
tube H which communicates with the interior of the glass tubes E, E, by
channels in the traverse G, and into which is placed the lower or negative
carbon F¹. On the top of the tube H is firmly secured a cap I which forms the
guide for the lower carbon F', and from the upper end of which branch detaining
fingers g, by preference made of refractory material. These fingers are so shaped
that they bear against the sides of the tapering end of the lower carbon F¹, and by
this means the carbon is prevented from being forced up beyond the desired point
by its impelling device next described. Through the glass tubes E, E, the holder H
is supplied with a liquid, such as mercury, in such a manner that it has a tendency
to force the carbon F¹ upward, and hence the carbon moves upward automatically
as it is consumed and its point maintains the required position without manual
interference. When the carbons F, F', have have been properly adjusted, and before
a current of electricity is passed through the lamp, the rod B sinks down until the
point of the carbon F meets that of the carbon F¹.
In the cavity of the helix A is enclosed a spring K which surrounds the rod B
and is connected at one end to the upper end of the core C, and at its opposite end
to the cap closing the cavity in the helix, thus constituting a support for both the
core and the rod. The tension of this spring K is so adjusted that it counter-
balances the weight of the core C and rod B when the two carbons are in contact,
and by its means the core is rendered susceptible to slight variations in the electric
current. It is obvious that a weight can be substituted for the spring K.
Now, one pole of a battery or other suitable source of electricity being attached
to the traverse or bridge G, while the other pole is connected through the helix to
the traverse or bridge A¹, the electric current passes from the helix through the
traverse A¹, rod B, and carbons F, F', down to the traverse G, thus completing the
circuit. By the force of the axial magnetism thus created the core C is drawn up

page_text: within the cavity of the helix A, carrying up with it the rod B and carbon F, and
as the carbons are thus separated the electric light is produced. By a proper
adjustment of the tension of the spring K or its substitute, the carbon F is raised
by the core C exactly to the desired distance from the carbon F¹, provided the
strength of the electric current remains uniform, but in order to prevent the rod B
from rising up too far the stop e is applied to it, and so adjusted that the carbon F
can be raised only a little beyond the desired distance.
As the carbons burn away the carbon F sinks down by its inherent gravity, and
the carbon F is raised by the action of the liquid in the holder H, and hence a
constant voltaic arc is maintained at one and the same point or focus. But if
from any cause, such, for instance, as the formation of a crater on the negative
carbon, which is liable to break off, the voltaic arc should be increased, thereby
diminishing the strength of the electric current owing to the increased resistance,
then the magnetism of the helix is weakened, and accordingly the core, the rod B,
and the carbon F move downward by the force of gravity until the consequent
shortening of the voltaic are increases the strength of the current and stops the
downward movement; or if from any cause the voltaic arc should be increased,
and consequently the force of the electric current weakened to such an extent that
the core C, rod B, and carbon F are permitted to sink down until the point of the
carbon F comes in contact with the point of the carbon F¹, then the strength of
the current increases instantly to such an extent that the core C and rod B are
raised until caught up by the stop e, and the correct voltaic arc is immediately
restored.
If the carbon F has been consumed the lower tubular section B' of the rod B is
unscrewed, and after a fresh carbon has been introduced said section is replaced.
When the carbon F¹ is consumed the cap I is taken off, so that a fresh carbon can
be introduced into the holder H.
An additional advantage of the glass tubes E, E, connecting the traverses A¹, G,
is that they produce much less shade than the metallic rods or standards usually
employed in electric lamps.
If these lamps are used in series, that is to say, if a number of lamps are included
in one and the same circuit, it becomes desirable to furnish such lamp with a
regulator for the purpose of preventing one lamp from using more than its proper
share of the electric current. This regulator is shown in Figures 5 and 6. It
consists of two hollow coils M, M, and an armature N, which is provided with
legs n, n, extending into the axial cavities of the coils. Said coils are in the main
circuit, one end of their helix being connected by wire 20 with a binding post K,
while the other end of said helix connects by wire 21 with the bridge A'. The
ends of the main helix A are also attached, one to the binding post K and the
other to the upper bridge A¹. The binding post K¹ is connected to the lower
bridge G, while both binding posts are insulated from the bridge A¹. The
armature N of the regulator coils connects by rods o, o, (Fig. 5) with the core C
of the main helix. In the example shown in Fig. 4 the core rests upon springs K°,
which take the place of the spring K, shown in Fig. 1.
The regulator helix is made of very fine wire, so that its resistance is very much
greater than that of the main helix, the proportion being about 75 to 1, so that by
far the largest portion of the electric current passes through the main helix. If
from some cause one lamp should take more than its share of the electric current
the tendency would be to increase the electric are of this lamp, but the strength of
the current through the regulator coils increases at the same time, and the
increased downward pressure of the armature N will counteract the increased
upward pressure of the core C, so that the electric are will not be perceptibly
changed.
In Figures 5 and 6 is also shown a new clamp P for regulating the position of
the upper carbon, and if this clamp used the rod B slides freely in the core C.
A detached perspective view of this clamp is shown in Fig. 6. It consists of a
ring p through which the rod B passes loosely and from which rises an arm q.

page_text: To the upper end of this arm is firmly connected the segmental shoe r. The
arm q swings on a pivot 8, which has its bearing in a bracket t extending from the
core C. The shoe r is made of soft iron, and as the core C becomes magnetic by
the electric current passing through the helix A it attracts the shoe, and the ring p
is caused to hug the rod B, so that said rod, together with the carbon F, will rise
when the core rises, but if the force of the electric current through the helix A
decreases the shoe is not attracted with sufficient force to retain the rod B, and
this rod together with the carbon F descend.
By a proper adjustment of the parts which constitute the clamp the action of
said clamp becomes such that the carbons are retained in the proper relation to
each other and that a steady light is produced.
The letters J, J¹, designate spiral springs constituting the elastic suspension
devices whereby the lamp is hung as to a ceiling. The wire which is used in the
manufacture of these springs consists of a core h of steel and a coating or shell i
of copper (see Fig. 3), so that the wire forms a good conductor of electricity, and
the springs are connected at their upper ends to posta el, which are connected to
the terminals of line wires 10, 11, and at their lower ends to the binding
posts K, K¹, of the lamp, so that the springs form a part of the circuit through it.
The binding posts K, K¹, may be attached to the insulated spool of the helix A,
and the post K may be connected with the traverse G by a wire or wires 12
dipping into the mercury in the tubes E, whilst the post K may be connected with
one end of the helix wire, as at 13, and the other end of the helix wire connected
with the bridge A', as at 14.
It will be readily understood that the springs J, J, absorb or take up any
vibrations of the ceiling or other part to which the lamp is hung, thus preventing
the transmission of such vibrations to the body of the lamp to affect the light,
whilst the peculiar arrangement of the springs increases their utility by causing
them to act as conductors for the electric current.
Both the construction and arrangement of the elastic suspension devices may be
modified without departure from the Invention.
Having thus described the nature of the said Invention, I claim as new, and
desire to secure by Letters Patent,--
1. In an electric lamp the combination with the helix A and its axial magnetic
core C of a rod B which is fixed to the core, and slides freely in the helix together
therewith, a carbon placed loosely into the lower hollow end B¹ of the rod B and
detaining fingers arranged on the lower end of said rod to act upon the conical
end of the gravitating carbon, all constructed to operate substantially as described
for the purpose set forth.
2. In an electric lamp the combination with the helix and its loose axial
magnetic core C of a rod B which is fixed to the core, and slides freely in the
helix together therewith, a carbon placed loosely into the lower hollow end B' of
the rod B, detaining fingers arranged on the lower end of said rod to act upon
the conical end of the gravitating carbon, and a stop e secured to the rod B, all
constructed to operate substantially as described for the purpose set forth.
3. In an electric lamp the combination with the helix A and its loose axial
magnetic core C of a rod B which is fixed to the core, and slides freely in the
helix together therewith, a carbon placed loosely into the lower hollow end B¹ of
the rod B, detaining fingers arranged on the lower end of the rod to act upon the
conical end of the gravitating carbon, and a balance spring or weight supporting
the core and rod, all constructed to operate substantially as described for the purpose
set forth.
4. In an electric lamp the combination with the helix A and its loose axial
magnetic core C of a rod B which is fixed to the core, and slides freely in the
helix together therewith, a carbon placed loosely in the lower hollow end B¹ of the
rod B, detaining fingers arranged on the lower end of the rod to act upon the
conical end of the gravitating carbon, a stop e fastened to the rod B, and a balance

page_text: spring or weight supporting the core and rod, all constructed to operate substantially
as described for the purpose set forth.
5. The combination in an electric lamp of a holder H for the lower carbon con-
structed to receive a liquid, such as mercury, whereby the carbon is automatically
forced upward, and detaining fingers arranged on the upper end of the holder to
act on the conical end of the carbon, substantially as described for the purpose set
forth.
6. The combination in an electric lamp of two carbons F, F¹, a holder B, B¹, in
which the upper gravitating carbon F is free to move, detaining fingers which are
attached to the holder B, B¹, and allow the carbon F to sink down by its inherent
gravity as its point is consumed, a holder H for the second or lower carbon F¹
constructed to receive a liquid, such as mercury, whereby the lower carbon is
automatically forced upward, and detaining fingers arranged on the upper end of
the holder H to bear against the conical end of the lower carbon, all constructed
to operate substantially as described for the purpose set forth.
7. In an electric lamp the combination with the helix A and its loose axial
magnetic core C of a holder B, B', fixed to the core, and sliding together therewith
in the helix A, a carbon placed loosely into said holder, detaining fingers b arranged
on the lower end of the holder B, B¹, to act on the conical end of the gravitating
carbon, a holder H for the second or lower carbon F¹, constructed to receive a
liquid, such as mercury, whereby the lower carbon is automatically forced upward
and detaining fingers arranged on the upper end of the holder H to act on the
conical end of the lower carbon, all constructed to operate substantially as described
for the purpose set forth.
8. In an electric lamp the combination with a helix A and its loose axial
magnetic C of a holder B, B¹, fixed to the core C, and sliding together there-
with in the helix A, a stop e secured to said holder, a carbon F placed loosely
in the holder, detaining fingers b arranged on the lower end of the holder to act on
the conical end of the gravitating carbon, a holder H for the second or lower
carbon F constructed to receive a liquid, such as mercury, whereby the lower
carbon is automatically forced upward and detaining fingers arranged on the upper
end of the holder H to bear against the conical end of the lower carbon, all
constructed to operate substantially as described for the purpose set forth.
9. In an electric lamp the combination with the transverse A' and the holder
B, B¹, for the upper carbon F of glass tubes E, E, a traverse G, the holder H, and
suitable channels leading from the glass tubes into the holder H, substantially as
described for the purpose set forth.
10. The combination, substantially as herein before described, of the regulator
composed of hollow coils M, M, the armature N provided with legs which extend
into the axial cavities of the coils M, M, the helix A, and its loose axial magnetic
core, said core being connected to the armature N.
11. The combination with the belix A, its loose axial core, and the rod B, which
contains the carbon F of a clamp, the action of which depends upon the attractive
force of the core.
12. The combination with an electric lamp constructed to be hung to the ceiling
of a building or other place, of elastic metallic suspension devices which are
adapted to conduct the electrical current thus forming part of the circuit through
the lamp, substantially as described.
In witness whereof, I, the said Henri Adrien Bonneville, have hereto set my
hand and seal, this Twenty ninth day of October, in the year of our
Lord One thousand eight hundred and eighty-one.