Improvements in Enclosed Electric Arc Lamps.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Enclosed Electric Arc Lamps.
I, WILLIAM JAMES DAVY, of 27, Drayton Park, Highbury, in the County of
London, Engineer, do hereby declare the nature of this invention to be as
follows:-
-
This invention for improvements in enclosed electric are lamps has for its
object to provide a simple, efficient and cheap lamp having a good sealing and
a small enclosed space, and a bell and lower carbon holder that can be easily
cleaned and got at, and relates to the regulating and feed device, to the means
for fixing the enclosing bell in position, to the contact between the sliding carbon
holder and the fixed part of the lamp, to the attachment of the lower carbon
holder to the enclosing glass bell of the lamp, to the holding of the usual globe
in position, and to the cut out.
In a lamp constructed according to this invention in order to regulate the feed
of the upper carbon the upper carbon passes through a central hole in a disc
working in a cylinder and loosely connected near its periphery to the regulating
mechanism. The regulating mechanism comprises a sector lever over which
passes a flexible cord connected at one end to the core of the regulating solenoid
and at the other end to the upper end of the piston rod of a dash pot, the lower
end of the dash pot piston rod being connected to the feed disc. The lever being
sector-shaped always has the same leverage. The piston rod of the dash pot
passes through bushes or glands and the upper gland is covered with a silk bag
to keep out dust and dirt, whilst the lower bush or gland leads into the feed disc
cylinder. The piston of the dash pot is made loose in its cylinder. If the lanıp
is a differential lamp the two cores of the solenoids may be arranged to counter-
balance one another.
The upper carbon holder slides in a tube fitted into the top of the feed disc
cylinder and is closed at its upper end. In order to make contact between the
sliding carbon holder and the tube, its top is made cone shaped, metal balls are
placed within the tube and are forced against the cone and tube by a heavy ball,
cone, spring disc or the like. In a modified arrangement a helical spring or
coil is wound helically on a recessed or smaller diameter of the carbon holder
and thus makes contact with both the carbon holder and the tube.
The enclosing bell is drawn up against a flange on the lower face of the feed
disc cylinder by means of links whose lower ends are turned upwards into a
recess in the metal fitting at the bottom of the bell and whose upper ends are
attached to helical springs hung on insulated lugs on the frame and passing
through insulating pieces on the flange against which the bell is drawn. The
metal fitting also carries the lower carbon holder.
The usual globe is attached by clips to a ring that when the globe is inserted
in place is pressed over spring catches on the lamp casing.
The guide tube is sealed at its top by a cap that is connected to but insulated
from a plate that is secured to the cover or crown plate of the lamp.

page_text: Leakage of air into the lamp can only take place through the dash pot at its
bushes or glands and this leakage helps to control or dash the action.
The cut out of the lamp is directly operated by the controlling lever.
The cut out of the lamp is operated directly by the sector-shaped lever to break
completely the shunt circuit to save damage to the shunt coil when the arc fails
and so that if the carbons come together again the series coil thus acts to re-
make the circuit.
Dated this 14th day of January 1899.
Improvements in Enclosed Electric Arc Lamps.
I, WILLIAM JAMES DAVY, Engineer, late of 27, Drayton Park, Highbury, in
the County of London, but now of 52, Durham Road, East Finchley, in the
County of Middlesex, 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: —
This invention for improvements in enclosed electric arc lamps has for its
object to provide a simple, efficient and cheap lamp having a good sealing and
a small enclosed space, and a bell and lower carbon holder that can be easily
cleaned and got at, and relates to the regulating and feed device, to the means
for fixing the enclosing bell in position, to the attachment of the lower carbon
holder to the enclosing bell of the lamp, to the holding of the usual globe in
position and to the cut out.
In a lamp constructed according to this invention, the enclosed chamber com
prises the usual glass bell, the regulating mechanism chamber against which the
bell is firmly pressed and a tube fixed centrally to the chamber opposite to the
bell. The feed of the upper carbon is controlled by means of a rod passing into
the mechanism chamber. In order to regulate the feed of the upper carbon the
upper carbon passes through a central hole in a disc working in the mechanism
chamber and loosely connected near its periphery to the controlling rod. The
regulating mechanism situated outside the enclosure comprises a sector lever
over which passes a flexible cord or band connected at one end to the core of the
regulating solenoid and at the other end to the upper end of the regulating rod.
On the regulating rod is the piston of a dash pot mounted on the top but at one
side of the mechanism chamber. The lever being sector shaped always has the
same leverage. The regulating rod passes through bushes or glands at the ends
of the dash pot and the upper gland is covered with a silk bag to keep out dust
and dirt, whilst the lower bush or gland leads direct into the mechanism chamber.
The piston of the dash pot is made loose in its cylinder. Leakage of air into
the lamp can only take place through the dash pot at its bushes or glands and
this leakage helps to control or dash the action. If the lamp is a differential
lamp the two cores of the solenoids may be arranged to counterbalance one
another.
The upper carbon holder slides in a tube fitted into the top of the mechanism
chamber, and closed at its upper end.
The enclosing bell is drawn up against a flange on the lower face of the feed
dise cylinder by means of a yoke whose lower end is turned upwards into a recess
in the metal fitting at the bottom of the bell and whose upper ends are attached

page_text: to helical springs hung on insulated lugs on the frame and passing through
insulating pieces on the flange against which the bell is drawn. The metal fitting
also carries the lower carbon holder.
The usual globe is attached by clips to a ring provided with projections that
pass through slots cut in an internal flange in the case when the globe can be
secured by giving it a partial rotation.
The guide tube is sealed at its top by a cap that is connected to but insulated
from a plate that is secured to the cover or crown plate of the lamp.
The cut out of the lamp is operated directly by the sector shaped lever to break
completely the shunt circuit to save damage to the shunt coil when the arc fails
and so that if the carbons come together again the series coil thus acts to re-
make the circuit.
In the accompanying illustrative drawings:
Fig. 1 is a vertical section of an enclosed arc lamp constructed according to
this invention and Fig. 2 is a sectional elevation of the same. Figs. 3 and 4 are
sectional plans on the lines - and y-y of Fig. 1. Figs. 5 and are elevation
and plan showing the shunt circuit cut out as applied to a differentially controlled
lamp; and Fig. 7 is a diagram of the cut out."
The frame or main structure of the lamp comprises the grip chamber a con-
taining the device that regulates the upper carbon and the tube b, fixed in and
opening into the upper end of the grip chamber a and closed at its upper end.
The lower carbon holder c is fixed to the bottom of the enclosing bell d and the
bell d is forced upwards against a packing washer d' on the bottom of the grip
chamber by means of the loop or yoke e that is formed at its centre with a pro-
jection taking into a circular recess c¹ in the bottom of the lower carbon
holder c and that has loops e at its upper ends by which it is drawn upwards by
the spring bolts 3 that pass through insulating bushes e on the plate and
hung on the insulating projections e fixed on the frame plate 3. As shown the
packing washer is inserted in a groove in a plate secured to the flanges a¹
of the grip chamber by the screws ³. The yoke e also serves to convey the
current to the lower carbon holder.
It will readily be seen that in order to remove the enclosing bell and lower
carbon holder it is only necessary to pull down the yoke and draw it to one side,
it swiveling on the loops e² when the bell and lower carbon holder will fall.
The upper carbon holder f slides in the tube b and the upper carbon is
controlled by a disc g having a central hole gl through which the carbon passes.
The disc g works in the grip chamber a and is loosely connected near its periphery
to the controlling rod h and rests opposite to the rod on the stop a. If the
rod is moved upwards it cants the disc g and causes it to grip the carbon and
then to raise it to strike the arc; at the same time raising the disc g off the
stop a².
On the descent of the rod the disc g comes in contact with the stop a²
and partially releases the carbon which feeds steadily through the disc.
The regulating mechanism situated outside the enclosure comprises a lever i
fulcrummed at on a bush fixed on the tube b. The lever is connected on
opposite sides of its fulcrum by the flexible connections to the solenoid
cores and and to the controlling rod h, the cords passing over the curved
surfaces so that the leverage is constant. The flexible connections in
alternate current lamps are connected to the cores with intermediate springs
On the top of the grip chamber a at one side is the dash pot cylinder m and
the controlling rod h passes centrally through the cylinder m and has fixed on it
the dash pot piston m¹. The rod is guided in the bushes m2 m³ and the upper
bush m is surrounded by a silk bag that is also tied to the rod so as to keep
out all dust. Leakage of air into the enclosed chamber can only take place
through the upper bush m³ and as the leakage only occurs when the lamp is
subjected to sudden or excessive variation it helps to control or dash the action.
The negative carbon holder consists of piece c having the recess c¹ at its bottom
for the projection e¹ of the yoke e and the flange c² that bears against the inside

page_text: of the bell d. The nut 3 secures the piece c to the bell. The upper end of the
piece c is bored out to fit the negative carbon and is split to form spring jaws 6.
Figs. 5, 6 and 7 show the shunt cut out as applied to a differential lamp for
a series circuit. The cut out lever is fulcrummed at k¹ on a neck ring
clamped upon the main tube b. This neck ring carries the spring contact of
the cut out insulated from the neck ring by the strip k. The projections 12 13 on
the lever allow the main lever i to engage it, and one of these projections 12
forms part of the switch making contact with the spring . In Fig. 5 the shunt
circuit is shown broken, and the lever i is drawn down to its full position by the
shunt coil previously to breaking circuit.
One end of the shunt coil is connected to the negative terminal of the lamp,
the other end of the shunt being connected to the spring j. The lever ¹ is
connected to the tube 6 and when the lever is operated by the engagement of
the lever and projection 3 the shunt circuit is broken at the switch. When
the lamp rights itself say by the carbons falling together and completing the
series circuit, the lever i is oscillated and re-forms the shunt circuit by oscillating
the lever . This is done quickly as the shunt circuit being open does not act
against the series coil.
The usual globe o is attached to the ring o2 provided with projections of and
when the globe o is inserted in place the projections are forced through slots
in the inturned flange o¹ of the casing and the globe is given a partial rotation
to hold it in position.
The tube is sealed at its top
from the plate 2 by the bolt
having the insulating washers
plate 2 by the screws p.
The current enters the lamp at
.
by a cap 62 and is connected to but insulated
passing through the insulating bush and
The plate p is secured to the canopy or cover
+ and passes round the series coil and thence
to the framework at r, through the carbons, yoke e, insulated terminals,
insulated terminal 2 and out at The shunt coils are connected across the +
and
the
-
-
poles of the lamp one wire to the terminal or frame and the other to
terminal. n is a roller and n¹ is a link.
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 an enclosed are lamp in which the carbon tends to feed forward, the
feed mechanism chamber closed at its ends, a transparent enclosing bell bearing
against one end of the chamber, a carbon passing through this end of the chamber
into the enclosing bell, a dise fitting loosely in the mechanism chamber and
having a hole through which the carbon passes freely, a regulating rod loosely
attached to the dise near its periphery, a stop adapted to limit the motion of the
disc at an opposite point of the periphery, and a means for determining the
position of the rod according to the resistance of the arc.
2. An enclosed arc lamp consisting of the carbon guide tube closed at one
end, the feed mechanism chamber attached at one end to the other end of the
guide tube, a transparent enclosing bell bearing against the other end of the
chamber, a dash pot fixed on the end at one side of the chamber, a piston working
in the dash pot and a rod fixed to the piston passing into the mechanism chamber
to operate the feed device therein and passing outwards to the regulating
mechanism the whole forming an enclosed chamber in which any transference
of gases has to take place through the dash pot.
3. The means for fixing the enclosing bell in position consisting of a fitting
fixed on the end of the bell opposite to its mouth and provided at its outer end
with a recess, a loop or double yoke having a projection bearing in the recess
and side aims, and spring bolts hung on the lamp frame and a swivel joint
connecting the side arms of the yoke to the spring bolts.
4. The shunt cut out device comprising a cut out lever fulcrummed to a ring

page_text: on the main tube and capable of being engaged by the main lever, an insulated
spring contact plate forming with the cut out lever the cut out switch, and a
shunt coil one end of which is connected to the negative terminal of the lamp
whilst the other end is connected to the spring contact.
5. The improved enclosed electric arc lamp, substantially as described and
illustrated in the accompanying drawings.
Dated this 11th day of Octobon 1900
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.