IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1881

page_text: LETTERS PATENT to Robert Renton Gibbs, of Liverpool, in the County of
Lancaster, Hot Water Engineer, for an Invention of "IMPROVEMENTS IN
ELECTRIC LAMPS,”
PROVISIONAL SPECIFICATION left by the said Robert Renton Gibbs at the
Office of the Commissioners of Patents on the 18th October 1881.
ROBERT RENTON GIBBS, of Liverpool, in the County of Lancaster, Hot Water
Engineer. "IMPROVEMENTS IN ELECTRIC LAMPS."
The Invention relates to electric lamps, such as the Jablochkoff, in which there
are two or more candles consisting of carbons placed side by side and parallel or
nearly parallel to each other, and in which as soon as one candle is consumed
another is automatically kindled.
The objects are to cheapen the construction of such lamps, to render the action
certain, to simplify the mechanism, and to enable them to be kept in order and
used by any ordinary attendant.
In carrying my Invention into practice each candle is held between a socket
secured to a table of ebonite or otherwise insulated, and a socket attached to or
fixed at one end of a lever free to move on a fulcrum at or near its centre. The
other end of the said lever consists of or has attached thereto a spring or springs.
The said lever is of metal, or a conducting wire or wires is or are led from one end
of the lever to the other. The carbons forming a candle are held in proper position
by means of a spring or springs tending to bring them into contact. One of the
two conducting wires is from the source of electricity, and is secured to one of the
fixed sockets, and the other conducting wire is connected so as to be in communi-
cation with a movable socket of one of the adjacent candles. The lever carrying
the movable socket of the candle to which the conducting wire is attached is not
prolonged beyond the fulcrum pin.
The action is as follows:-A current of electricity passes by the wire to the
fixed socket, thence through the carbons to the movable socket of a candle, after
which the current passes through the levers to the second conducting wire, or
vice versa.
When a candle has been nearly consumed, the ends are shorter than a
stop, preferable the usual insulating strips placed between the carbons of Jablochkoff
and like candles, and the movable socket acted upon by its spring moves into
contact with the fixed socket, and the current passes on through the next candle.
The candle, to which one of the terminal or conducting wires is connected, is
sometimes made with two fixed sockets.

page_text: When the last candle of the series has been consumed the spring ³ moves the
lever and socket c³ into contact with the socket 6, so that the continuity of the
circuit is not broken, and there is no interference with the current passing to other
lamps on the same circuit.
When there is a separate circuit for each lamp the terminal sockets bs, cs, may
be fixed.
The lamp above described and illustrated is shown fitted with Jablochkoff
candles of the usual pattern. I prefer that the carbons should be of larger cross
section to present less resistance to the passage of the electric current.
When it is desirable to use continuous instead of the alternating currents usually
employed with Jablochkoff and like candles, I insulate the carbon pencils on three
sides leaving the adjacent sides bare; or I cause the carbon pencils to revolve in
opposite directions. The above arrangements of carbons are also applicable where
alternating currents are used.
Having now described and illustrated my said improvements in such manner
that others will be enabled to carry my improvements into effect, I claim,―
The improvements in electric lamps, substantially as herein set forth.
In witness whereof, I, the said Robert Renton Gibbs, have hereunto set
my hand and seal, this Fifteenth day of April, in the year of our Lord
One thousand eight hundred and eighty two.
J. JOHNSON,
Patent Office,
Witness.
4, Clayton Sqr.,
L'pool.
ROBERT RENTON GIBBS. (LS.)