Improvements in Electric - Arc Lamps.
Year: 1897

page_text: Improvements in Electric - Arc Lamps.
I, JAMES BROCKIE of 12 Tyson Road, Forest Hill, in the County of Kent, Engineer,
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 a strong, light and cheap construction of the framing of
an electric arc lamp as I shall describe referring to the accompanying drawings.
Figs 1 and 2 are sections on planes at right angles to each other and
Fig 3 is a sectional plan of a lamp framing according to my invention for a single
set of carbons :-
Figs 4, 5, & 6 are similar views of a framing adapted for two sets of carbons.
Like letters of reference are employed in all the figures to denote corresponding
parts.
Referring first to Figs 1, 2 and 3, the base plate A and the top plate B are connected
by a central tube C which is about the same length as the positive or upper carbon
and has within it a sliding weight W to which this carbon is attached. As the
weight W fits the interior of the tube which may be closed at the top, the tube and
weight would in that case act as a dash pot, preventing sudden movements of the
carbon. Two smaller tubes D and E, each about twice the length of the tube C, are
also fixed to the plates A and B, and their lower ends, extending below A, are
connected by a ring F. Within the tube D slides a rod G which is connected by
a chain or cord passing over a pulley H to the weight W, and from the lower end
of the rod G an arm K projects through a long slot in the side of the tube D,
and carries the negative or lower carbon. Also from the upper end of G an arm L
projects through a slot in the side of D this arm being made with a fork which
embraces the tube C, the rod G being thus prevented from turning. Instead of
employing an arm such as L, the arm K may be extended and terminate with a fork
embracing the tube E as a guide. The space between the plates A and B is enclosed
within a casing M and covered by a dome N having two insulated terminals P, Q,
which are connected preferably by screw unions with two corresponding terminals P¹ Qi
fixed insulated on the plate B, one of the terminals P, Q, is connected to the
positive and the other to the negative conductor. On the top of the dome N is an
insulating piece R, which may be, as shewn, in the form of a roller by which the
lamp is suspended. The casing M has at its upper edge a pair of bayonet catch
slots S which engage on studs projecting from the lower edge of the dome N.
The lower edge of the casing M has an inwardly projecting lip which fits under the
edge of the plate A.
As shewn in Figs 4, 5 and 6, there are two tubes C¹ C² for the two positive carbon
holders, and the tube E has within it a rod G¹ with arm K₁ for carrying the
second negative carbon.
When it is desired to insulate the casing M and dome N from the parts which carry
the current, the lower ends of the tubes C, C1 and C2 are fixed insulated on the
plate A, the two tubes D and E are fixed insulated to both plates A and B, and the
rim of the plate B is provided with a ring V or a number of buttons of insulating
material interposed between the casing M and the plate B. Instead of tubes D

page_text: and E, rods may be employed in which case the arms carrying the negative carbons
would be made with eyes to slide along these rods.
The ring F shewn in Figs 1 and 2 serves to hold the globe X which rests upon a
shoulder of the ring and can be lifted when the lamp has to be trimmed, instead of
being lowered as is usual for many lamps. The opening of the ring is closed under-
neath by an ash tray Y which may be of glass.
As shewn in Figs 4 and 5, the tubes or rods D, E are connected by a transverse
bar E¹ from which the ash tray Y is suspended, the globe X in this case resting on
the tray, which can be unfastened from F" when the lamp is to be trimmed.
and ascertained the nature of this
Having now particularly described
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A frame for an electric arc lamp consisting of two plates connected by a central
tube and two side tubes or rods, the central tube containing the holder of the positive
carbon and one of the side tubes or rods serving as guide for the holder of the
negative carbon, substantially as described with reference to Figs 1, 2 and 3.
2. The modified arrangement for two sets of carbons, having two tubes for the
holders of the positive carbons, and both side tubes or rods arranged to guide
the holders of the negative carbons, substantially as described with reference to
Figs 4, 5 and 6.
3. For guiding the negative carbon, an arm attached to the rod of its holder and
having a fork embracing the central tube, as described.
4. For enclosing and covering the upper part of the lamp, the casing and dome
detachably connected as described.
5. In combination with the two side tubes or rods a ring connecting their lower
ends and supporting the globe substantially as described.
Dated this 28th day of September 1897.