IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Login Lineff at the Office
of the Commissioners of Patents on the 5th July 1883.
33
ALEXANDER LOGIN LINEFF of 36 Wilmington Square Clerkenwell in the County.
of Middlesex Engineer and Electrician " IMPROVEMENTS IN ELECTRIC ARC LAMPS
The objects of this Invention are-
a j
1st To effect a perfect and easily adjustable separation of the carbon electrodes
of electric arc lamps.
2nd To attain a very sensitive automatic feed, thus ensuring a uniform length of
voltaic arc, especially when many such lamps are worked in series.
3rd To entirely dispense with springs which in other lamps of the same type act
against electro-magnets, thus giving variable pressure according to the temperature
of the spring.
T
To effect these objects I form electric arc lamps of a train of wheel-work actuated
by the weight of a rack which serves at the same time as upper carbon holder.-
The rack is made to gear into a pinion on the first arbor of the train of wheels.
The same arbor has fast upon it a ratchet wheel and loose upon it a toothed
wheel which carries a pawl to engage with the teeth of the ratchet wheel. If the
rack is raised the ratchet wheel is turned without turning the toothed wheel as
the pawl then slips over the teeth of the ratchet wheel but when the rack descends
the pawl locking into the teeth of the ratchet wheel causes the toothed wheel to,
revolve with the ratchet wheel.
On the same arbor is also fixed another ratchet wheel-A hook carried by a
lever which can be made to oscillate on the arbor can be made to engage with the
teeth of this wheel.
One arm of the lever carries the armature of an electro magnet through the
coils of which the electric current is passed.
When the current is turned on, the electro magnet attracts the armature and as
it begins to rise the hook above mentioned is first caused to engage with the teeth
of the ratchet wheel on the first arbor and then as it further rises to turn this
arbor and so raise the rack a distance and draw the upper carbon a distance from
the lower carbon so separating the carbons the distance requisite for obtaining the
arc. Afterwards when the armature has risen to a certain height and the required
length of arc has been obtained the hook disengages itself from the ratchet wheel
.

page_text: the arbor is then free to be turned in the opposite direction by the action of the
weight of the rack whenever the last arbor of the train of wheels is allowed to
revolve.
The last arbor of the train of wheels has a fly wheel fast upon it and a friction
brake is caused to act against this wheel.
When the lamp is burning and the arc is of the length required the fly wheel is
by the action of the friction brake prevented from turning.
When the arc gets too long the action of the friction brake upon the fly wheel is
relaxed and the wheel is free to turn the upper carbon can then descend. This is
effected in the following manner.
The friction break is composed of a strip of metal which can be held against the
periphery of the fly wheel.
One end of it is fixed the other end carries the armature of an electro-magnet.
The bobbins of this magnet are first wound with a few layers of comparatively
stout insulated wire in shunt with the larger bobbins of the electro-magnet
previously mentioned and over the above stout wire there is wound a sufficient
length of very thin wire in opposite direction to the former thus making a bobbin
of suitable resistance and in shunt with the whole lamp.
When the arc is of normal length; a very small portion of the main current
passes through the shunt of fine wire and a much larger quantity passes through
the first layers of thick wire which act in opposition to the feeble current in the
fine wire. Consequently the armature is attracted and the strip of metal then
acts as a break on the fly, wheel and stops the descent of the upper carbon.
Directly the arc increases in length, less current passes through the first layers of
thick wire and much more through the thin wire; thus the magnet 'core is
demagnetised and the armature.drops on to a support. The fly-wheel being now
free the whole train of wheels starts under the weight of the rack till the arc takes
its normal length, when the electro-magnet attracts the armature again and thus
stops the sinking of the upper electrode.
The armature is not allowed to touch the electro-magnet but comes to one side
of it and nearly touches this, which arrangement makes the regulation considerably
more sensitive.
The length of the arc can be regulated by simply moving the core of the
electro-magnet either up or down.
The arc cannot possibly increase much in length the feeding is frequent, but
little at the time, thus a very steady and uniform light is obtained, as well as a
maximum power, and any number of lamps can be put in one single circuit.