IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1880

page_text: LETTERS PATENT to George Guillaume André, of Dorking, in the County of
Surrey, for an Invention of "IMPROVEMENTS IN ELECTRIC LAMPS."
PROVISIONAL SPECIFICATION left by the said George Guillaume André at
the Office of the Commissioners of Patents on the 13th April 1880.
GEORGE GUILLAUME ANDRÉ, of Dorking, in the County of Surrey. "IMPROVE-
MENTS IN ELECTRIC LAMPS."
In electric lamps in which a stick of carbon is made to "burn" in a closed vessel
or globe, the atmosphere contained therein when the light is turned out by the
current being cut off consists of carbonic oxide and nitrogen; owing to practical
difficulties in the way of making joints it is generally found that the atmospheric
air while the lamp cools down slowly enters the globe, and the atmosphere therein
then consists of carbonic oxide mixed with oxygen and nitrogen, forming an
inflammable mixture, which when the lamp is relit causes an explosion, and a
destruction of the globe, and sometimes also the interior parts of the lamp.
The objects of this Invention are to prevent the above evil, to regulate the
consumption of the carbon as desired, and as regards carbon lamps working by
incandescence to preserve the point of the carbon.
According to this Invention I displace the contents of the closed vessel during
the cooling of the lamp, and I feed it while in action with atmospheric air
at a definite rate. I accomplish this by providing the globe or parts connected
therewith with two small apertures suitably placed and proportioned; the
atmosphere within the lamp escapes by one, and atmospheric air from without
enters by the other, the former aperture is by preference made larger than the
latter. When the lamp is alight I feed the incandescent carbon point slowly with
air by the aperture aforesaid, and I thus cause it to retain its form by the definite
or regulated air feed, so that the loss of light which now takes place in closed
lamps is prevented, the carbon dust thrown off by the current being also burnt,
and thus forming no deposit; I thus save current force, while gaining the advantages
pertaining to the burning in the open.
One of the apertures may be closed during the action of the lamp in order to
"

page_text: lessen the consumption of carbon. I prefer to do this automatically; for this
purpose a closing valve may be connected to a solenoid or electro magnet, which is
put into action when the current is turned on for lighting, or it may be done by
the expansion of a body by hoat.
Or both apertures may be so closed, in which case the aforesaid feed during the 5
action of the lamp does not take place.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Guillaume André in the Great Seal Patent Office on the
13th October 1880.
GEORGE GUILLAUME ANDRÉ, of Dorking, in the County of Surrey. "IMPROVE-
MENTS IN ELECTRIC LAMPS."
In electric lamps in which a stick of carbon is made to "burn" in a closed vessel
or.globo, the atmosphere contained therein when the light is turned out by the
current being cut off consists of carbonic oxide and nitrogen; owing to practical
difficulties in the way of making joints it is generally found that the atmospheric
air while the lamp cools down slowly enters the globe, and the atmosphere therein
then consists of carbonic oxide mixed with oxygen and nitrogen, forming an
inflammable mixture, which when the lamp is relit causes an explosion and a
'destruction of the globe, and sometimes also the interior parts of the lamp.
The objects of this Invention are to prevent the above evil, to regulate the
consumption of the carbon as desired, and as regards carbon lamps working by
incandescence to preserve the point of the carbon.
According to this Invention I displace the contents of the closed vessel or lantern
during the cooling of the lamp, and I feed it while in action with atmospheric air
at a definite rate. I accomplish this by providing the globe or lantern or parts
connected therewith with two small apertures suitably placed and proportioned, the
atmosphere within the lamp or lantern escapes by one, and atmospheric air from
without enters by the other, the former aperture is by preference made larger than
the latter. When the lamp is alight I feed the incandescent carbon point slowly
with air by the aperture aforesaid, and I thus cause it to retain its pointed form
by the definite or regulated air feed, so that the loss of light which now takes place
in closed lamps is prevented to a certain extent, the carbon dust thrown off
by the current being also burnt, and thus forming little or no deposit. I thus
save current force, while gaining the advantages pertaining to the burning in
the open.
One of the apertures may be closed during the action of the lamp in order to
lessen the consumption of carbon. I prefer to do this automatically; for this
purpose a closing valve may be connected to a solenoid or electro magnet, which is
put into action when the current is turned on for lighting, or it might be done by

page_text: .the expansion of a body by heat, but such an arrangement would not be simple
and quick in its action. Or both apertures may be so closed, in which case the
aforesaid feed during the action of the lamp does not take place.
In the accompanying Drawings I have shewn a few applications of this Invention
to electrical lamps now in use.
In Figure 11 have shewn it applied to one of my patent lamps, such parts of
same being shewn in section as refer to this present Invention. I provide a small
hole a through the sole or cover plate A of the lamp, and the size of this hole is
such as to supply the incandescent carbon with a small quantity of air sufficient to
preserve its form, and to burn the carbon dust thrown off, or nearly so; this
aperture may if desired be made adjustable by being increased in size, and fitted
with a somewhat conical screw, or one having one or more taper flats, which aro
broadest at the end filed on it (like a tap for forming screw thread in nuts), or in
any other suitable and well known manner. The tube B for the carbon and the
weight resting thereon is narrowed at the top at b. C is an iron cap or tube valve,
which is free to slide on the tube b; it has a leather washer c inside the top, and
has one or more holes at d; the cap tube C forms a solenoid core inside the coil D,
which rests on the flange B on the tube B; E is an insulating washer; as long as
the current is on and the lamp burning the core tube C is drawn down, and the
leather washer c then rests on the top of the tube part b, preventing air escape or
entry.at this place, but as soon as the lamp goes out, the current ceasing, the least
pressure inside the lamp globe or cylinder will raise the cap tube or valve C, and
such pressure will then be relieved, and a current established by the hole a and the
holes d. I thus prevent the possibility of an explosion; e is a helical spring for
raising the cap, tube, or valve C when the electric current ceases.
In Figure 2 I have shewn a similar lamp, but turned the other way up, and such
as I use for street lamps where the carbon is fed up from below. I form a fine
hole a in the sole plate A as before, and another larger hole at b, which latter is.
kept closed automatically by the valve c when the current is on by the electro-
magnet D attracting the armature C, which is on one arm of a bell crank lever, on
the other arm of which the valve c is arranged. A helical spring or other spring
may be arranged to assist the opening of the tube valve or other valve c.
practice I find that in the caso of this construction of lamp a small quantity of air
enters the globe or cylinder through the carbon holder F, where the carbon point G
passes out of same, so that here the special aperture a may be omitted.
In
Figure 3 is a side view, and Figure 4 an end view of an electro magnet D with
its armature C to which the valve stem c is connected.
Figure 5 shows the outlines of a lantern, such as is commonly used with a
Siemens or Serrin or Crompton or Brush lamp, to the top plate A of which my
automatic safety or ventilating valve is applied, similarly to that shown in Figure 2.
In these cases the lantern is an entirely closed one, whereas heretofore such lamps
have been used with a lantern more or less open.
Figure 6 shows the same automatic valve applied to a Jablochkoff lamp. The
base plate A in this case must be solid or closed.
In Figure 7 I have shown a lantern similar to Figure 5, but without a valve.
Instead of that it is simply provided with an aperture a, and another aperture b,
which may be larger, so as to produce a constant but small current of air; the
openings may be regulated by screws, as described with reference to Figure 1. The
same mode may be applied to other lamps. In Figure 8 I have shown it applied
to the André lamp, shown in Figure 1; the upper part is in this case made with an
aperture 6 without a valve, and with a smaller aperture a through the plate A, as
shown in Figure 1.
A practical engineer will readily understand that the construction and
combination of parts may be varied in a great many ways, and still carry out
the same objects. Circumstances and forms of lamps will in many cases determine
the arrangement of parts.

page_text: And having thus described and ascertained the nature of this Invention, and
some modes of carrying the same into effect, I declare that I claim,―
First. The mode herein described of supplying the carbon or other electric lamp
electrode in the interior of a closed vessel or lantern with a definite or regulated
quantity of air for the purposes specified.
Second. The mode herein described of supplying the carbon or other electric
lamp electrode in the interior of a closed vessel or lantern with a definite or
regulated quantity of air, the atmosphere or pressure in the interior of such vessel
being allowed to escape automatically, or a through air current produced when the
electric current ceases or the pressure within the lantern becomes too great for the
purposes specified.
Third. The combination of a valve and a solenoid or electro magnet for the
purpose specified.
Fourth. The application of a closed vessel or lantern to electric lamps, such
lantern having a definite or regulated air supply while the electric current is on, or
an automatically produced ventilation when the electric current ceases.
In witness whereof, I, the said George Guillaume André, have hereunto set
my hand and seal, this Thirteenth day of October, in the year of our Lord
One thousand eight hundred and eighty.
ATO Π
ANDDИ
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