IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1881

page_text: PROVISIONAL -SPECIFICATION-left-by-William Morgan-Brown at the
Office of the Commissioners of Patents on the 19th September 1881. A com-
munication from abroad by Edwin Marshall Fox, of New York, United States
of America.
WILLIAM MORGAN-BROWN, Patent Agent, of 38, Southampton Buildings, London.
"IMPROVEMENTS IN ELECTRIC LAMPS." [A communication from abroad by Edwin
Marshall Fox, of New York, United States of America.]
These improvements relate to electric lamps, for which vacuum chambers or
globes of glass are employed, and have for their object to facilitate the operation of
drawing the vacuum, and to dispense with the usual operation of sealing off the
chamber after the vacuum is drawn.
The nature of the said Invention consists,-
First. In an apertured stop plug, through or by means of which the air. can be
drawn, and the globe closed air tight by simply turning the plug.
Second. In certain features of construction by which the plug is utilized as the
support for the conducting wires and carbon.
Third. In the use of a tube sealed in the side of the chamber, and around the
conducting wires, whereby the necessity of sealing the glass directly to the
conductors is avoided, and
Fourth. In carbon holders of metal, soldered or otherwise permanently attached
to the carbons, and held on the conductors by clamping devices.
The globe which may be of any usual or desired form, and is formed with
the tubular neck. The end of the neck is closed either by a tapering pin or
plug, or by a socket piece into which the tube enters to form an air tight but
separable joint. In one form, the end of the tube is closed by a tapering glass
plug, and the contact surfaces of the plug and tube are ground to form a perfect
joint. Wires pass through the plug lengthwise of the same, the glass being sealed
tightly around the wires. The plug is formed with a passage, which opens at the
inner end of the tube, and also at one side in the ground surface of the joint.
The tube is formed with a stem or nipple at one side in such position that it
can be made to coincide with the end of the passage.

page_text: By these means an opening from the outside to the interior of the chamber can
be had by turning the plug or the lamp, and such opening cut off in the same
manner.
To exhaust the chamber or globe, the plug having the wires and carbon attached,
is first put in place with the aperture coinciding with the nipple. The pump is
then attached to the nipple and the air drawn, after which, by a partial turn of
the plug, or the globe, the passage is closed, and the exhausted globe thus
hermetically closed. The same operation is repeated in case the plug is removed
for renewal of the carbon.
In another form the plug is cup shaped, and in that case the side is simply
apertured to coincide with the nipple of the neck. In either form the wires,
instead of passing through the plug, may enter at the side of the tubular neck.
In another form the plug is shown hollow, or as a socket that receives the end
of neck, and in that case the drawing nipple is formed on the socket, and the neck
is apertured.
In any of these forms the plug may be fitted in a suitable stand, and thus
support the lamp, or the lamp may be supported or suspended in any suitable
manner.
In another form the plug is fitted crosswise of the neck, which is formed with a
socket or seat to receive it.
The improvements in the manner of sustaining and sealing the conductors at
the point where they enter the globe, and also the means for sustaining the carbon
on the conductors are as follows:-
A short tube of metal, or other suitable material, is secured in the side of the
Conductors
globe, the glass being sealed tightly around the outside of the tube.
enter the globe through the tube, and the outer end of the tube is sealed around
the wires to prevent inlet of air.
The conductors are covered with insulating material to prevent short circuiting.
This tube prevents contact of the conductors with the glass, and the risk of injury
to the joint, by expansion and contraction. The tube forms no part of the
conductors, and for that reason will be less subject to heating.
The ends of the conductors are formed to receive metal holders that are attached
to the ends of the carbon. The holders are short pieces of, wires, to which the
-carbons-are-securely-attached-by-soldering-or-by-other-means-that-makes-n-
permanent and rigid attachment.
The conductors are provided with sockets for receiving the ends of the holders
and screws for clamping them, or any suitable clamps may be used for the
purpose.
A convenient means of attachment, in larger size, which may be used for
connecting the holders to the conductors, or the carbons to the holders, consists in
simply coiling or twisting the one wire around the other or around the carbon.
In the latter case, the attachment is made secure by fusing metal in the coil.
When the carbon requires renewal the plug will be removed, and the holders
detached by inserting the fingers or a suitable tool through the opening, after
which a new carbon, having holders attached, can be inserted and secured. The
plug is then to be replaced and the globe exhausted as before.