Improvements in Electric Are Lamps.
Year: 1899

page_text: Date of Application, 13th Jan., 1899-Accepted, 24th June, 1899
COMPLETE SPECIFICATION.
Improvements in Electric Are Lamps.
We, WALLACE JAMES LAMBERT SANDY, of 27, Catherine Street, Strand, and
THOMAS GEER, of Ventnor Villa, Goldsmith Road, New Southgate, both in the
County of Middlesex, Electrical Engineers, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
According to this invention the upper carbon of the lamp is free to slide in a
tube its motion being controlled by a clutch.
Parallel with the carbon is a rod which is free to slide vertically. At the upper
end of the rod is a dash pot and to the lower end is pivotted the clutch which
controls the motion of the carbon. The rod passes through a solenoid and has
attached to it an iron core. As the current passing through the solenoid varies
the rod is raised or lowered.
The clutch consists of a plate having a hole in it through which the carbon
passes, when this plate is not horizontal or approaching thereto the carbon is
prevented from moving downwards.
As the rod moves downwards the clutch whose free end rests on a plate
approaches the horizontal and the carbon is allowed to slide down until the rod
is moved up again.
In some cases two solenoids are employed their cores being connected together
by a bar to which the rod is pivotted.
The drawings illustrate lamps made in accordance with this invention.
Figure 1 is an elevation of a lamp with one solenoid.
Figure 2 is a similar view of a lamp with two solenoids, and
Figure 3 is a plan of the clutch.
a is the carbon free to slide in a tube its motion being controlled by the
clutch c.
is a plate on which the free end of the clutch rests.
d is the rod to which the clutch e is pivotted having at its other end a dash
pot e.
In the lamp shown in Figure 1 the rod d passes through a solenoid f and has
attached to it a core g.
In the lamp shown in Figure 2 there are two solenoids hh having cores i i
connected together by a link k which is pivotted to the rod at 7.
When no current is passing through the lamp the upper carbon rests on the
lower; directly current passes, the solenoid attracts its core, raising the rod, the
clutch then grips the carbon and lifts it. The dash pot moderates the movements
of the rod and may also limit its upward movement
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A clutch embracing the upper carbon pivotted to a rod descending from a
solenoid core which is parallel with the carbon, a dash pot for moderating the

page_text: movement of the solenoid core and a stop to limit the descent of the clutch and
so set the carbon free as the current passing diminishes substantially as described.
2. A clutch embracing the upper carbon pivotted to the lower end of a rod,
which passes through a solenoid and has at its upper end a dash pot, and a stop
to limit the descent of the clutch and so set the carbon free as the current passing
diminishes substantially as described.
3. A clutch embracing the upper carbon, a rod parallel with the carbon, to the
lower end of which the clutch is pivotted, a dash pot for moderating the move-
ment of the rod, a solenoid or solenoids for lifting the rods and a stop to limit
the descent of the clutch and so set the carbon free as the current passing
diminishes substantially as described.
4. Electric arc lamps substantially as described and illustrated in the drawings.
Dated this 13th day of January 1899.
WALLACE J. L. SANDY,
THOMAS GEER.