Year: 1899

page_text: I, THOMAS WILBY, of Chester, Pennsylvania, United States of America,
Gentleman, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide an improvement in electric are lamps
whereby the adjustment of the carbons is rendered more even and the steadiness
of the light improved.
An electric arc lamp possessing my improvement comprises the usual magnet,
magnet core, etc.
I provide a dash-pot or cylinder which has a piston head adapted for recipro-
catory movement therein, a piston-rod attached to the piston, and a rigid con-
nection between the rod and the magnet core. An opening or channel extends
from above the piston head to below it, and is adapted to be automatically closed
when the piston ascends and opened when it descends.
The mechanism for effecting that object preferably consists of a sliding con-
nection between the piston head and the piston-rod, and a bore which extends
from the upper end of the piston-rod and opens through its side.
The piston head has preferably a recess in its lower face, and the piston-rod
may be movably connected to the piston head; the rod being provided with a boss
to limit its movement, and a channel extending longitudinally thereof.
Dated this 21st day of Sentember 1899
P. R. J. WILLIS,
Agent for Applicant.
I, THOMAS WILBY, of Chester, Pennsylvania, United States of America,
Gentleman, 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:-
-
My invention relates to new and useful improvements in electric-arc lamps
and has for its object to provide a lamp of this class of the usual size but in which
a long upper carbon may be fed forward and almost entirely consumed before
it is necessary to replace it, with the result that less frequent removals of old
carbons and substitutions of new ones will be required, an object heretofore only
accomplished by employing an elongated lamp frame adapted to receive long
upper carbons.
1

page_text: Figure 1 is a view in side elevation of an electric-arc lamp embodying my
improvements.
Fig. 2 is a central vertical sectional elevational view taken on the dotted
lines 2-2 (Figs. 3 and 4) the sight being taken in the direction of the arrows
applied to said lines.
Fig. 3 is a top plan view of the lamp structure.
Fig. 4 is a sectional plan view on the plane of the dotted lines 4-4 (Fig. 1).
Fig. 5 is a central sectional elevational view of the dash-pot removed from the
lamp.
In the several views the usual lamp casing is omitted.
a represents an upper plate, a² a lower plate, and a³ side bars connecting the
same. A depending hanger a connected to the plate a² supports a socket a³,
globe a and lower carbon a' of usual construction. c¹, c² are binding posts on
the plate a to which are connected the line conductors 61, 62. The post has a
contact plate with which the inner end of the movable switch bar is adapted
to make contact. The switch bar c is mounted upon a conducting pivot to the
lower end of which the magnet coil D is, through the conductor d, connected.
The magnet coil 1), of ordinary construction, is secured to the lower face of
the plate a¹, and disposed within it, free for vertical reciprocation, is a core E,
formed with a central axial aperture and equipped as to its lower end with
a lateral extension e. A dash-pot F is conveniently suspended from the plate a¹
in the vicinity of the magnet, and has a piston head f, adapted to move vertically
therein, and a piston rod fi of novel construction, connected to it, and the lower
end of which is rigidly connected to the lateral extension e of the core E.
The upper end of the piston rod f¹ extends through the piston head f and has a
slight independent longitudinal play with respect to the same, being limited in
such independent movement, in one direction by the contact of its flaring
upper end with the upper face of the piston head, and in the other direction
by the contact of a boss or enlargement f³, intermediate of its length, with a
slightly recessed seat in the lower face of said piston head, (Fig. 5). The
piston rod f¹ for an upper portion of its length is hollow, and the wall of the
rod has, at a point near the lower end of said bore, a lateral outlet adapted
to place the said bore in communication with the atmosphere below the piston
head, the bore and outlet together forming a channel f³ (Fig. 5). It will be
readily understood that whereas in the upward movement of the piston head an
effective air cushion is formed within the dash-pot its subsequent descending
movement will be quick and exempt from retardation by the air.
G is a hollow carbon sleeve, of brass or other suitable material, which fits ap-
proximately the upper carbon I, and fits snugly the interior of the hollow magnet
core E to which it is secured by the screw i. To prevent undue movement of the
upper carbon I with respect to the sleeve G, and keep the parts in contemplated
normal relationship, a holder is provided such as a collar or band g (Fig. 2)
adapted to encircle the carbon and having on its upper and lower edges a series
of projections or serrations some inward to clasp the carbon and others outward
to make contact with the inner face of the sleeve.
His an annulus having a bore very slightly exceeding in diameter that of the
upper carbon upon which, below the lower end of the sleeve G, it is seated,
and it has a projecting finger h to the outer end of which is connected the lower
end of a link h¹ the upper end of which is connected to the magnet core E. When
the annulus H is horizontal, the carbon I can pass freely vertically through
it but when tilted (Fig. 2) it binds upon the carbon and if drawn upwards raises
the carbon also. A guide J surrounds the carbon sleeve G and is adapted to retain
the same in vertical position, being supported upon a suitable standard j attached
to the plate a².
The current, which enters the lamp through the conductor 61 runs to the
binding post cl, and is conducted thence by the conductor 63 to the binding post 64
and thereby placed in circuit with the magnet core from which it passes through

page_text: the upper and lower carbons, thence through one of the hangers a to the resis-
tance K (Fig. 4) to a binding post k (Fig. 1) thence through a conductor L
(Fig. 1) to the magnet coil, and from the magnet coil by the conductor d to the
switch. The carbons being normally in contact as soon as the switch is
thrown, and the lamp thus placed in circuit, the magnet coils will become
energized and elevate the magnet core by virtue of the annulus and its connections
also elevating the upper carbon and the carbon sleeve so that an arc interval will
be formed between the opposing extremities of the carbons with the result that
the light will be generated. As the carbon burns away the interspace will
become greater and the current passing through the lamp will consequently
diminish with the result that the magnet core will slightly descend and lower
the upper carbon, the annulus and the sleeve. If the descent is sufficiently
great the annulus will as to its lower end make contact with the upper face of
the plate a or its associated parts and permit the carbon to descend a distance
somewhat greater than the descent of the magnet core. The interspace between
the carbons will thus be diminished and the strength of the current increased
with the result that the magnet coil will become stronger and slightly elevate the
magnet core and connected parts. If in the descent of the parts the annulus
has become horizontal so that the carbon has descended through it, the annulus
will, in taking hold of said carbon, make contact with it at a point slightly
above the point at which it was formerly engaged. By reason of the connection
between the magnet core and the dash-pot, the ascent of the said magnet-core
will be retarded and cushioned by the air 'behind the piston-head so that the
upward movement of the carbon will be gradual and easy, while, upon the other
hand, the descending movement of the upper carbon will, owing to the air-passage
in the piston rod, be very quick and sensitive to the changes in the force of the
current. Manifestly a carbon of the length shewn (Fig. 2) will burn many days
or until its upper end is in close proximity to the lower end of the tube.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
(1) In combination, a magnet, a magnet core, a dash-pot provided with a
piston head adapted for movement therein, a piston rod, a rigid or unyielding
connection between said rod and the magnet core, and an opening or channel
extending from above the piston head to below it and adapted to be automatically
closed in the ascending movement and automatically opened in the descending
movement of the piston rod, substantially as set forth.
(2) In combination, a magnet, a magnet core, a dash-pot provided with a
piston head the piston rod of which is connected to the magnet core, a sliding
connection between said piston head and said piston rod and a bore extending
from the upper end of said piston rod and opening through its side, substantially
as set forth.
(3) In combination with the magnet, a magnet core, a dash-pot, a piston head
mounted in said dash-pot and having a recess in its lower face, and a piston
rod movably connected to said piston head and provided with a boss 2 and a
channel f, substantially as set forth.
(4) In an electric-arc lamp a magnet, a magnet core, a dash-pot provided with
a piston head adapted for movement therein and having an opening therein
extending from its upper to its lower face and having recesses in its said upper
and lower faces, a piston rod movably connected to said piston head
having a flared upper end, a bore extending downwards, and a
lateral opening near the bottom of the said bore, and a boss
below the piston head, the opening in the piston head adapted to be auto-
matically closed in the ascending movement and automatically opened in the
descending movement of the piston rod, the piston-rod rigidly connected to the
magnet core, a sleeve fixed within the magnet core, a serrated collar within

page_text: the sleeve and around the upper carbon, an annulus or ring surrounding the upper
carbon and connected to the magnet core all substantially as described and
set forth.
P. R. J. WILLIS,
Agent for Applicant.