Improvements in Electric Arc Lamps.
Year: 1895

page_text: Date of Application, 22nd Oct, 1895-4ccepted, 8th Feb., 1896
CUMI DELE DI PUITIVATION.
Improvements in Electric Arc Lamps.
I, THOMAS EDGAR ADAMS, of 938 Case Avenue, Cleveland, in the County of
Cuyahoga, and State of Ohio, United States of America Electrical Engineer,
do hereby declare the nature of my 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 an improvement in electic arc lamps, the object of the
invention being to provide a simple and efficient construction of electro-motor
regulating mechanism for actuating the cat bons and moving them into contact and
then separating them to establish the arc; for regulating the length of the arc
and maintaining it uniform in its length and bulliancy, by adjusting and feeding
both the upper and lower carbons; a further object is to provide an improved cut-
out for short cu citing the lamp when cient ceases to flow in the lamp cu cunt ;
a further object is to provide improved means for automatically switching a faulty
lamp out of cu cuit, a further object is to provide an improved cut-out by means
of which a lamp after having been automatically switched out of cucuit, owing to
the sticking on derangement of some of its parts will be automatically switched
into encuit again in the event its carbons are fed on brought into contact with each
other; a further object is to provide a supplemental low resistance cut-out for
automatically switching a lamp out of cucuit and out of operation when its carbons
shall have been consumed or sufficiently consumed; a further object is to furnish
the lamp with an improved clutch and clutch blade, also with a globe support of
such construction that it will serve as a guide and protecting sheath for the clutch-
blade, a futher object is to provide improved means for supporting the globe also
for an improved construction of casing so as to render readily accessible every part
of the regulating mechamsm for the purpose of inspection and adjustment;
also to provide certain other features of improvement which will be hereinafter
explained.
With these objects in view my invention consists in an electie arc lamp
comprising certain features of construction and combinations of parts as will be
hereinafter described and pointed out in the claims.
In the accompanying drawings,
Fig. 1 18 a view paitly vertical section and partly in side elevation of one
construction of lamp embodying my invention The parts are represented in the
position they occupy when the lamp is not in operation.
Fig. 2 1s a view similar to Fig 1, excepting it shows the lamp just after current
has been switched through it and the cai bons have been brought together
preparatory to their separation and the establishment of the arc.
Fig. 3 is an enlarged detached view of the electro-motor part of the regulating
mechanism.
Fig. 4 is an enlarged detached view of the carbous and clutch mechanism.
Fig. 5 is a transverse section taken through the cross head.
Fig 6 is a transverse section taken through the lower portion of the sheath and
lower carbon holder
Fig. 718 a view partly in side elevation and partly in vertical section of the
globe-holder and cup hinged thereto.
Fig 8 is a view in side elevation of the lamp showing the construction of the
casing.

page_text: one citam
Figs. 11 and 12 are views of the clutch.
Fig. 13 is a diagrammatical view of the circuits.
A represents the casing which is preferably made of cast iron and comprises
top-section A', fixed side sections A2, A3, detachable side section A, hinged
doo A and bottom section or flooi A. Top section A' is cast in a single piece,
its downwardly projecting flange a heing provided with an inner shoulder a¹ against
which fit the upper ends of the side sections A2 A which are seemed thereto by
screws a² passing through lugs a³, or the parts may be fastened together in any
other desired manner. Detachable section A is fastened in place by screws a, so
that it may be readily removed to allow of access to the regulating mechanism on
the rear side of the lamp, while that portion of the mechanism located on the front
er opposite side of the lamp may be inspected, and the feeding carbon renewed, by
opening the hinged doo A. The bottom section or floor A of the lamp is secured
to the inwardly projecting flanges a³ on the lower ends of the side sections To
the top of the casing is fastened a loop having formed therein a series of notches
an either one of which the hook by which the lamp is suspended may engage,
In
view of the fact that the weight of the regulating mechanism may not be centrally
disposed within the casing, the latter if hung from a central bail, might not hang
vertically, but by providing a series of hooks as described the suspending hook
may be inserted in the proper notch to cause the lamp to assume a vertical position
when suspended for use This construction of casing is strong and economical in
118 manufacture; affords a reliable and diable support for the regulating mechanism
and is susceptible of artistic ornamentation and finish
B is an electro-magnet, the core B of which is constructed with a screw threaded
extension at its upper end which passes upwardly through the yoke-piece B³, flat
bearing on scat B³ cast on the underside of the casing and through the latter, and
is secured in place by a cap-nut B. By tightening the cap-nut the electro-magnet
and yoke are firmly secured in place and in proper alignment with one another and
with the other parts of the lamp. To the depending pole of the magnet is fa-tened
a plate or bracket B5 which is provided with downwardly depending cars between
which the amature-lever C is pivoted
To minimize fiction and wear, 1 provide armature lever with steel bearing
points which are supported m countersunk holes c¹ formed in the enis b.
A screw serves to draw together the ears and regulate the end play or thrust of
the bearing points c of the armature level This construction insures a strong and
efficient pivotal connection of the parts.
Arinature leve C is provided near its fiee cud with transversely elongated
slots through which are inserted screws for adjustably securing in place the
amature C, which latter is made of aunealed non and is so shaped as to move
freely between the face of the pole-piece and the adjacent face or side of the
lower end of the yoke-piece. Thus it will be observed, a complete magnetic circuit
is formed which includes the magnet core-joke-piece, pole and amature. The
an-gap between the amature and pole may be iegulated as desned by adjusting
the amature on the amature lever, while the air gap between the amature and
yoke may be adjusted and regulated by the adjusting screw which passes through
the yoke and heats against the plate 15.
An inverted dash-pot cylinder Dis pivoted at its upper and closed end to a lug d
fastened to the yoke-piece, while the pistou-rod d' is pivoted to the outer end of
the armature level. The piston of the dash-pot may be made of any desired
weight, by regulating which I am enabled to adjust the lamp for arcs of different
length 1 vary the weight of the piston by removing metal therefrom by dulling
holes in it or otherwise removing a portion of its metal, and add to its weight by
inserting lead into holes dulled in it o vary its weight in any other suitable
manner. There are so many ways for varying the weight of the piston that I do
not restrict myself to any particular method, or construction of parts for
accomplishing this end. The bore of the cylinder of the dash-pot is gradually

page_text: enlarged 110m the point aº LO
explained.
tor a purpose which win ос дегенатье
E 18 a clutch-rod, which is pivoted at its upper end to the short arm 1 of the
amature level, while to its lower end is secured the clutch E', detached views of
which are represented in Figs. 11 and 12. Clutch-iod is made in two parts e and e¹,
one part screwing into the other so that the rod may be readily adjusted in length.
Clutch E consists of the U-shaped bail E' through the ends of which is inserted
a sciew Es which serves to hold them in position. E and E are clamping plates
each of which is constructed with notches e²e formed in its side edges, and with
hooks When the plates are assembled as shown, the inwardly bent ends e
of the bail, will operate to diaw the plates toward one another when the bail
is lifted to a horizontal position, and cause the plate to engage and clutch the
opposite sides of the clutch blade o bar F, and to lift it and regulate its
position When the clutch is lowered so that it rests upon the lamp floor A³, or
horizontal arms of the clutch trip the bail will fall and operate to wedge apait the
clutch plates and clease them from the clutch-blade, thereby allowing the latter
to feed though them.
Clutch blade is a flat blade which may be made of steel, or brass or any other
desired material. It is secured at its upper end to a cross-head F' to which 18
attached a block or socket F in which is detachably secured the upper carbon X.
A thumb screw, being provided for secuing the carbon within the socket
Cross-head F1s constructed as follows --
Two
Sis a transverse plate or bar which slides on the conducting guide bar or
blade and has secured thereto a bracket S' which extends in real of the guide
bar. Between plate S and bracket S' is fastened one end of a contact brush S³ the
outer end of which bears against the conducting bar or guide. Depending lugs & &
are cast or formed integral with the plate S, between which is hinged the lug s¹ on
the carbon-holder F. "This hinged connection is so loose and free that the lower
end of the upper carbon may freely move in any duection. To the plate S 19
firmly seemed a plate T by means of the rivets t. These plates S and T are
insulated from one another by means of the mica plates and washer t
porcelam tollers U U' are secured by rivets to the rear side of the plate S.
Chain G is connected with the roller U by means of a bail or ing 95 encn cling
the rolle U while the other roller U₁ serves as a slide on the tube G. To the
outer end of the plate T is riveted the upper end of the clutch blade F. The
cross-head and carbon socket or holder nie connected by a flexible conductor U³.
From the foregoing it will be observed that the cross head is composed of two
parts which are insulated from one another, whereby one poition serves as a
conductor for carrying current to the positive carbon.
-
The upper carbon X pusses freely though an insulating thimble fo fitted into
the lamp floor. In view of the fact that the socket or holder F is free to adjust
itself laterally the upper carbon though crooked, or out of alignment, will readily
feed through the insulating thimble.
G is a tube extending through the lamp floor and insulated therefiom by an
insulating washer or slecve g. The upper end of the tube is fastened to a sleeve
formed on an arm g² of the terminal sleeve g³. A set-screw 9° serves to secure the
end of the conductor within the terminal sleeve. To the lower end of the tube G
is fastened a forked or ing guide G1 through which the lower carbon X' moves
freely and is guided A metal rod G extends through tube G and has secured to
its upper end, one end of a chain G³ which passes over a sheave 9 and is fastened
at its other end to the bail g of the cross-head To the lower end of the rud G
Is fastened a bracket G in the outer end of which is secured the lower carbon-
holder G, which is insulated from the bracket by an insulating washer
Bracket G is insulated from the iod G' by means of an insulating sleeve 97. The
lower carbon holder and the 1od g' are electrically connected by the conductor g
His a sheath which is preferably made of two sections which are secured
together by screws ². The upper end of the sheath is provided with an outwardly

page_text: projecting flange which seats against the underside of the lamp floor and is secured
thereto by the screws. Clutch blade F fits loosely within the sheath which is
placed edgewise to the arc so as to offer the minimum obstruction to the lays of
light The lower portion of the sheath on its inner edge is provided with parallel
ways with which engage a slide or cross head formed on the bracket G. By
this construction the lower carbon is guided throughout the range of its vertal
adjustment and securely retained against rotary displacement
I is the positive terminal of the lamp to which is secured by screws or rivets, the
conducting guide bar or blade I¹ the lower end of which is fastened to a lug or
flange connected to or formed integral with the casing, and is insulated therefrom
by means of the insulating sleeve and washer. A sheet metal strip 12 of good
electrical conductivity, is fastened at one end to the conducting guide I while its
opposite end is perforated and so formed as to encucle and fit into the insulating
sleeve through which the upper carbon passes. The upper carbon as it is fed will
rub against the conducting strip 12 and keep it bright and maintain therewith a
good electrical contact whereby a larger proportion of the current flowing to the
are will be conducted by means of this strip duectly to the upper carbon and at a
point near its lower end which of course materially reduces the resistance to the
flow of current.
Electro-magnet B as wound with a coarse wire helix J, one end of which is
connected with the positive terminal of the lamp while its opposite end 13 connected
with a contact post J which is provided with a stationary contact J which may
Le made of platinum, silver, carbon or other desired material. A fine we helix K,
also encircles the core of electio-magnet B and is wound in the same direction as
the coarse we helix. The opposite ends of the fine wue helix are secured
respectively to the positive and negative terminals of the lamp and thus form a
shunt to the arc.
K is a switch lever, its hinged end being of large curient carrying capacity and
constructed with a rule joint, and preferably finished with a spring washer
whereby its free end will remain in any position to which it may be moved The
lower and free end of the switch lever is inruished with a contact ), which engages
the stationary contact Ja A contact post K2 arranged to be engaged by the lower
end of the switch lever K when moved outwardly to the limit of its travel, has one
end of a resistance coil or stack A connected therewith, the opposite end being
connected in series by a conductor with some portion of the coarse we helix.
The proportion of the comse wire helix which will be included in series with the
resistance A can readily be determined by proper tests.
The short aim 7 of armature lever C is constructed with an upwardly projecting
arm to which is riveted a contact block 2 but insulated from and having a
shoulder and a finger l' When no current is passing through the lamp and the
amate level is in its depressed position finger will engage the lower end of
the switch lever and thereby maintain the contacts J2 and 7, closed for the passage
of curient through them. When the armatime lever is raised to its normal position
the shoulder 13 will strike the lower end of the switch lever and open the
contacts J, and open the count of the coarse wire helix.
When the amatue
lever is raised to an abnormal height due to the passage of an abnormally strong
curient through the shunt we helix, shoulder will move the switch lever into
contact with the contact post K2, and thereby close the encuit through a portion of
the coaise wie helix and the resistance in series therewith
The upper end of the switch lever is constructed with a projection L³ which
presses against a sping when the lower end is moved nearly into contact with
the post K* This spring operates to open the contact between the switch lever
and post K2 before the carbon-points have been separated so as to prevent the
formation of a spark between such contacts when separated
The plate or bracket B to which the armature level is hinged, 13 constructed
with a bracket on which are mounted the stationary and the cut-out contacts
The negative terminal tube socket y' and bracket aims in which the sheave

page_text: is Jounalled are all cast in a single piece, while the spring stop L' may be cast
integral with the other parts o may be made in a separate piece and riveted
thereto
To insure a good contact between the tube G and guide rod G³, a wire contact
binsh M is attached to the guide rod and moves with it and thereby maintains good
contact between the tube and 1od therein.
N is a globe pan in which is seated the lower end of the globe N¹ and 18-
constructed with depending flanges m and secured and properly insulated theref! >m
depending arms which are provided with one or more notches n' in which engage
the elongated lugs 22 (one or more) formed in the side of the sheath. By simply
lifting the globe pan and globe and disengaging the notch and lug, the globe my
be lowered and readily removed.
To the lower portion of the globe pan is hinged at a³ a semi-circular cup NS-
which is prouded on its free end with a sping catch N by which it is detachably
fastened to the globe pan
Telescopic wire gauze sections 0 0' are fastened to the casing and globe for
excluding insects &c. from the aic
The inwardly beveled portion of the lamp casing is cast with a circular series of
openings W which are covered by wire gauze W. The walls of the casing in
rear of these openings are beveled as shown at W2 whereby any rain that may beat
through the wie gauze coverings will un downwardly and be prevented from
entering the casing. These openings afford a free chculation of the onter air
throughout the interior of the casing and consequently prevent the magnets or
other parts from becoming unduly heated The lower end of the casing is
constructed with a downwardly projecting flange having a fluted edge Y which,
while serving to protect the wnc gauze telescopic sections, allows of the fee
esrape of heated an.
Having described the construction of parts of my improved lamp I will now
describe its operation
When no crent is passing though the lamp, the armature lever will be mits
lower position as illustrated in the detached view of Fig. 1 and the clutch will
engage the clutch blade and sense to uphold it and thereby maintain the carbons
in a separated relation and thus prevent the passage of any current through them.
In this condition there are two ciremits through the lamp to wit, one through the
constantly closed high resistance shunt helix, and another though the coarse wire
hehx, contacts Ja and switch lever to the negative terminal of the lamp. On.
the passage of emirent through the lamp practically the entire current will flow
through the low resistance encet including the coarse we helix with the result
that the latter will be energized, and will impart suficient strength to the magnet
to lift the aimatate, thereby lowering the clutch and cause it to ielense the clutch
blade, and thus allow the upper cbon to feed downwardly and the lower carbon
to feed upwardly until the two are brought into contact with one another. The
aimate as it is raised by the action of the coarse we magnet, attains sufficient
momentum, to cause the shoulder 13 on the armature level to engage the lower end
of the switch lever and open the contacts J and thus break the cncunt through
the coarse wire magnet. In order that the aimature may operate with a certainty
to open the contacts JJ, and thus open the cucuit of the course wie helix, the
upper portion of the boie of the dash-pot is enlarged, as I have already explained,
and thereby insures perfect freedom of action to the amature level when at the
highest limit of its travel Immediately on the opening of the encuit of the coarse
wire helix all the cunent which has hitherto passed through it, is instantly
diverted through the conducting blade or bar from which, part of the current
flows to and through the carbons by way of the contact bush conductor S carbon
holder or socket 1, while the remainder flows through the contact strip I² to the
upper carbon.
Upon the breaking of the circuit including the coarse wie helix, the magnet is
endered so weak as to be incapable of upholding the armature which will

page_text: •
-
instantly drop with the result that the clutch will instantly grip aud raise the
clutch bar and upper carbon and at the same time depress the lower carbon, thus
interrupting the circuit and establishing an are between the carbons. The
armature level in dropping and establishing the atc, does not fall to the limit of its
downward movement because immediately upon the establishment of the are, the
resistance of the latter to the passage of current through it will operate to divert
such an amount of current through the fine we shunt helix as to so strengthen it
that it will serve to uphold the armature in such a position as will result in the
maintainance of an arc of uniform length and brilliancy. As the carbons are
gradually consumed the are elongates with the result that its resistance is increased
and hence an increased amount of current is diverted through the shunt magnet
rendering it sufficiently strong to depress the clutch until it strikes the lamp floor
o1 clutch trip lever P when it releases its ginsp on the clutch blade and allows
the latter to feed though it and cause the carbons to feed toward one another.
As the carbons approach one another the arc is shortened, its resistance decreased
and the shunt magnet is correspondingly weakened whereby the amature descends
slightly and separates the carbons
In this manner the mechanism of the lamp automatically regulates the length of
the arc and feeds the carbons to compensate for their wearing away in burning.
Throughout the adjustment of the aimature in the normal operation of the lamp,
its movement is made gradual and is rendered perfectly steady and uniform by
means of the dash-pot, the piston of which is at such times within the comparatively
tight fitting portion of the bore of the cylinder. The weight of the parts connected
with the upper carbon is made slightly less than the weight of the armature aud
lever, and also of the parts connected with the lower carbon, so that as the armatie
and lower carbon descend, the upper carbon will be raised and the carbons will be
separated. From the foregoing it will be observed that the establishment of the
aic is effected by the action of the coarse we magnet which is in a circuit around
the arc, while the regulation of the length of the arc and the feed of the caibona is
effected by the varying strength of the fine wire nagnet acting in opposition to the
weight of the armature and its lever.
The carbons are adjusted and fed until they have been consumed or sufficiently
consumed, when a lug P on the clutch blade engages the long arm p of a bell crank
lever P which is pivoted at pl and thereby inises the short arm p² on which rests
the clutch, and consequently disengages the latter from the clutch blade and allows
the upper carbon holder to drop into contact with the conducting strip and with
a lug or collar P2 secured to the tube G. In this way the current is short
circuited through the carbon-holder and the tube G through which it flows to the
uegative terminal of the lamp.
The trip lever P¹ is provided with an arm at its upper end which extends
over the top of the clutch and limits its upward movement.
In the event the lamp should refuse to feed by reason of the sticking o
derangement of some of the parts of its regulating inechanism, the carbons will
continue to buin away and the arc will grow longer and longer with the result that
the magnet will be rendered abnormally strong by reason of the abnormally strong
current diverted through the fine wire helix. As a result of this action the
magnet will lift the amature to such a height that the shoulder on the armature
level will strike the switch lever and move it over and into contact with the
post K2 thereby establishing a cut out circuit around the arc composing a part
of the coarse wire helix and the resistance coil in series therewith. This cut
out circuit will maintain the integrity of the main circuit and prevent the
extinguishment of other lamps burning therein, and so long as the carbons remain
In a separated relation the cut-out circuit will be maintained by the action of
that poition of the coarse wire helix which forms a part of it But in the event
the cai bons should feed together, which might result from jairing the lamp or
from some other cause, then the carbons would form a closed cucut through
the lamp of such low resistance that a greater portion of the current which had

page_text: hitherto passed through the coaise wie helix will now be shunted around it, with
the result that it will be so weakened as to be incapable of upholding the armature
which will drop and again establish the arc.
I employ a weight to act in opposition to the pull of the coarse and fine wie
magnets because it is far superior in its operation to that of a spring. The weight
exerts pinetically a constant force throughout the entire range of movement of the
amatue, though it acts most effectively when it is opposing the action of the fine
wne magnet in eflecting the adjustment and regulation of the carbons, because,
when so acting, the amature is in a position to afford the weight its maximum
leverage, while a spring could not act with any degree of uniformity throughout so
wide a range of adjustment
By feeding the upper and lower car bous I provide a lamp in which the arc is
maintaimed at practically a fixed point and hence I am enabled to use a smaller
globe than would be possible with a lamp in which the lower carbon is stationary
which results in the giadunk lower mg of the are as the carbons buin away
By employing a pan of carbons in which the upper or feeding carbon is of an
inch in diameter and 14 mches in length and the lower or negative cat bon is an
mch in diameter and 12 inches in length, I am enabled to maintain an arc of
normal and uniform builliancy for om 11 to 18 hours-a sufficient length of time
to last all might.
Having now particularly described and ascertained the nature of my said juven
on and
claum is
what manner the same is to be performed, I declare that what 1
1st. In an electie are lamp, the combination with the electrodes, of a couse
we helix, a switch for switching the coarse we helix into and out of a low
esistance cncunt around the electrodes and a weighted amature and atmature
level, and devices connected with the amature level for adjusting and feeding the
electrodes, said parts being constructed and nanged substantially as described
hereby the weighted aimate selves to retain the electrodes in a separated
relation when no cui rent is passing through the lamp and on the passage of current
through the lamp to be raised by its acquined momentuin above its normal position
jon feeding the carbons and thereby bung the can bons into contact and then open
the switch contacts and switch the coarse we helix out of encuit and then fall
into its normal position for feeding and separate the electrodes and establish an 'arð
between them, substantially as set forth
2nd. In an electric are lamp, the combination with the electrodes, and a magnet
for causing the electiode to move into contact, of a pivoted lever, a weighted
aunature for said magnet, carried by the lever, for separating the electrodes and
establishing the are, and a switch in the path of movement of said lever and
adapted to be operated by the momentum of the weighted animature to open-cucuit,
aid magnet, substantially as set forth.
31d In an electie aic lamp, the combination with the carbous, a coarse wile
magnet and an atinature lo said magnet, of a switch and a resistance connected in
series with a part only of the helix of the coarse wie magnet, substantially as set
forth.
4th. In an arc lamp, the combination with a guide rod and the lower carbon
holder connected thereto, of a sheath disposed at one side thereof, parallel flanges
o guide ways projecting from said sheath toward said carbon-holder, a bracket
connecting said guide rod and carbon holder and a cross head on said biacket and
disposed between said parallel flanges or guide ways, substantially as set forth
5th. In an arc lamp, the combination with the carbon holdeis, of a guide rod
secured to the lower carbon holder a flexible connection between said guide rod
and the upper carbon holder, a sheath, a clutch blade in said sheath, a clutch,
guide ways on the sheath, and a bracket projecting from the lower carbon holder
and having one end disposed between said guide ways, substantially as set forth.

page_text: 6th The combination with the clutch blade, of a flattened sheath airanged
edgenise to the arc, substantially as set forth.
7th The combination with a sheath secured to the underside of the lamp floor,
a clutch blade arranged to pass through the lamp floor and into the sheath and a
clutch situated above the lamp Hoor, substantially as set forth.
8th The combination with a tube and iod moving therein, of the lower carbon-
holder connected to said tod below the tube, and guide ways below and independent
of the tube for retaining the lower carbon-holder in proper position, substantially
-as set forth.
9th In an are lamp, the combination with a vertically movable cross head, of
an upper carbon holder pivotally connerted thereto, a sleeve-in the floor of the
lamp though which the upper carbon is guided and guides for the respective
ends of the cross head, substantially as set forth
10th. In an arc lamp, the combination with the casing, a magnet secured thereto
and a yoke piece disposed alongside the mag set, a bracket secured to the depending
pole of the magnet, au amature lever pivoted in sand bracket, au amature carried
by said lever and entering between the pole of the magnet and the yoke piece, and
an adjusting screw passing through the yoke piece and engaging sal bracket,
-substantially as set forth
11th The combination with the magnet, its armature and a cut-out switch, of a
dash-pot having the bore of its cylinder enlauged at one end, substantially as sel
-forth.
12th The combination with a magnet and a plate secured to its lower end, said
plate having depending ears, of an armature provided with steel pointed bearings,
which fit in countersunk openings in said depending ears, and a screw passing
through the ens for securing the aimatme beatings in place, substantially as set
forth
13th The combination with the upper sections of the lamp casing constructed
with a flat seat on its under side, of a magnet baving a core constructed with a
sciew threaded extension which extends though the seat and casing, a yoke
interposed between the magnet and seat, and a nut foi secumg the parts in place
14th A casing for an electic arc lamp consisting of a top section cast in
single-piece, side sections, fastened to the top section, one detachable side section,
a hinged doo, and a bottom section fastened to the side sections substantially as
-set forth.
15th. The combination with the depending sheath having an elongated bearing
formed on its lower end, of a globe piece constructed with a depending flange
provided with a notch within which engages the bearing on the sheath, substantially
-as set forth.
16th. In an electric arc lamp, a casing for the regulating mechanism provided
with a bottom or floor to exclude the gases from contact with the regulating
-mechanism, of a clutch sheath located beneath the floor, a clutch located above
the floor, an upper carbon-holder constructed to allow the upper carbon to move
laterally and thereby freely pass through an opening in the lamp floor, and a tube
extending though the floor for the passage of the guide rod and support for the
lower carbon, substantially as set forth.
17th. In an electric arc lanp the combination with the lamp casing and globe,
of telescopic wire gauze sections between the globe and casing, substantially as set
fortb.
18th. In an electic arc lamp, the combination with fine and conise wire helices,
an armature, and a switch level, of a contact, a resistance included in scries with
the contact and some portion of the coarse we helix, and a spring to moving the
switch level out of engagement with said contact, substantially as set forth.
19th. In an electric arc lamp, the combination with a flat clutch blade, of a
clutch consisting of two interlocking plates adapted to receive said clutch blade
between them, and a tilting bail for opening and closing said plate, substantially as
-Bet foith.

page_text: 20th A clutch consisting of two plates having interlocking hooks on then side-
edges, and a bail having hooked ends which engage between the hooks on the
adjacent edges of the plates, substantially as set forth.
21st In an arc lamp, the combination with an upper carbon holder, a clutch
blade caned thereby and a clutch to grasp said clutch blade, of a device con-
structed and adapted to be actuated by the clutch blade to automatically trip the
clutch when the car bons have been consumed or sufhciently consumed, substantially-
as set forth
22nd. In an clectic are lamp the combination with the upper carbon-holder, of
the tube dispo-ed alongside said carbon holder and electrically connected with the
negative terminal of the lamp, and a contact secured to the tube in the path of
said carbon holder and serving to short circuit the carbons when the latter have
been consumed or sufficiently consumed, substantially as set forth
231d. The combination with the cut out snitch lever, of an armature lover
provided with a finger for holding the lever in a position to close the contacts of
the coarse wire magnet circuit, and provided with a shoulder for shifting the switch
and opening the contacts, substantially as set forth
24th. In an ac lamp, the combination with an upper carbon holder and means
for moving and guiding the same, of a tube, a od in said tube, a lower carbou.
holder cared by said rod, and a guide carried by the tube, through which the
lower carbon passes, substantially as set forth
25th. In an are lamp, the combination with a magnet and a shunt circuit
including a portion of the coil of said magnet, of a plate having ears, an aimature
lever mounted in said eais, a stationary contact on said plate included in said shunt
circuit, a cnt out contact also on said plate, and a switch lever disposed between
said contacts, substantially as set forth
26th. The combination with the bracket of the negative terminal, a switch lever
lunged to the bracket, a spung attached to the bracket and arranged to engage a
projection on the switch lever, a spring stop for limiting the action of the spring
and means for actuating said levei, substantially as set forth.
27th. In an electric air-lamp the combination with the guide blade bar, of a
cross-head provided with an aim disposed at one side of said blade or bai and
contact-brushes which engage said blade at the opposite side the cof, substantially
as set forth.
28th. The combination with the clutch blade and clutch, of a tipping lever on
which the clutch iests, and a lug on the clutch blade for actuating it and disengaging
the clutch from the clutch blade, substantially as set forth.
29th. The combination with the clutch blade and clutch, of a tripping lever on
which the clutch rests, said lever being provided with an aim which limits the
upward movement of the clutch, substantially as set forth.
30th. In an electric are lamp the easing provided with a series of openings.
around the wardly inclined portion of its top, wie gauze coveting said openings
and beveled walls in tear of said we gauze coverings, substantially as set forth.
31st. The combination with the globe and telescopic we ganze sections, of the-
casing having an outwardly flaring fluted lower edge, substantially as set forth
Dated this 22nd day of October 1895.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents for Applicant.