provements in and connected with Arc Lamps
Year: 1895

page_text: Date of Application, 6th May, 1895
Complete Specification Left 6th Feb, 1896-Accepted, 7th Mar, 1896
PROVISIONAL SPECIFICATION
Improvements in and connected with Arc Lamps
I, WILLIAM JANDUS, 66, Victoria Street, Westminster, Electrical Engineer,
do hereby declare the nature of this invention to be as follow-
The annexed drawings and the following description set forth in detail, one
mechanical form embodying the invention, such detail construction being but one
of various mechanical forms in which the principle of the invention may be used
In said annexed drawings
-
Figure 1 represents an axial section of the upper portion of my improved electric
lamp,
Figure 2 an axial section of the lower portion of the lamp, sud section being taken
in a plane standing at an angle of 40° to the plane of the section, Figure 1,
Figure 3 a plan view of the under side of the lower ring of the lower carbon
frame, and the carbon holder in the same,
Figure 4 a perspective view of the lower carbon holder,
Figure 5 an axial section of the caroon sheath,
Figure
6 perspective view of
Figure 7 an axial section of the
clutch ring, and
pan and tube of the armature
°
A
A tube A, has a hanger A', or a rosette, secured to its upper end, and is closed
air tight Said tube is electrically insulated from the hanger or rosette in any
suitable or preferred manner The tube has an axial magnet tube B, secured to
its lower end, which magnet tube is axially secured in the upper end of a magnet
body, B of cylindrical outline The lower portion of the magnet tube has an
upwardly tapering bore or recess b The lower end of the magnet body is open,
and has an internal shoulder 1, into which the upper end of a short cylindrical
casing B2, fits, and said casing has a narrow neck B, which 13 continued in a round
cap B at the end of the neck A tube b² of brass or other non-magnetic metal,
fits with its upper end upon the lower end of the magnet tube, and has a flange ba
at its lower end, which fits under the internal shoulder 6 of the magnet body
lining of brass or other non-magnetic metal, fits in the cylindrical casing B2,
has a flange at its upper end, which flange and the flange & are clamped between
the internal shoulder of the magnet body and the end of the cylindrical casing
Said casing is secured to the magnet body by means of screws, The bottom
lining for the casing is formed with an upward annular bulge 67, and is continued by
a tube 8, which fits within an enlargement & in the bore of the neck A tube bio
has a flange at its lower end, with which it rests upon the shoulder at the lower
end of the enlargement in the neck, the lower end of the neck lining 68, bearing
against the flange and securing the tube An annular space is formed between the
upright tube 60 and the neck lining b The bore of the upright tube 610 is the
same as the bore of the axial tube A, and of the unenlarged bore of the neck
coil C is placed around the tube B2 and the magnet tube, and has one terminal c, in
electrical contact with the magnet body, while the other terminal is passed through
an insulation in the magnet body, and is continued in the positive conductor G,
which is called out through the upper portion of the lamp casing A tubular
armature E hts freely, and has vertical play within the tube b³, and is upwardly
tapering, so as to correspond to the outline of the upwardly tapering bore or
ccess in the magnet tube An iron pan e¹ is secured to the lower end of the
tubular armature, and has a free fit and vertical play within the lining of the
A

page_text: cylindrical casing B², and said pan has upwardly flaring inuei sides and cylindrical
outer side A tube e extends from the bottom of the pan, into the annulai space
between the upright tube 610 and the neck lining 68 The lower portion of the
armature body is formed with longitudinal, radiating slots e, in which slots the
clutchings have vertical and radial play The rings are partly confined in their
play by a ring e³, which is vertically movable upon the armature and which passes
through the clutch 11ngs The clutch rings have a V-shaped peripheral gioove,
which groove is knurled or otherwise roughened, and the inner flaring side of the
pan is also roughened, so that the rings will be prevented from slipping, when the
armature is drawn upward and the flaring side of the pan forces the rings against
the carbon or carbon holder The roughening of the peripheral grooves of the
clutch rings will also aid in the rings obtaining firm grip upon the carbon oi
carbon holder The round cap B*, has an annulu flange, the under .ide of which
is shouldered and bears against sheet metal washer, which bears against an
insulating washer F of asbestos, or similar non-conducting heat resisting and
yielding material A spring washer of sheet metal, and shaped so as to have a
downward spring, bears agunst the under side of the asbestos washer, and has
downward bulge, into which fits another asbestos washer f¹, against the inner portion
of which the lower edge of the cap B bears The lower cubon fime consists of
two aims G which extend downward from a cucular neck G¹, which be us against
the sping washer F, and is drawn upward to climp all of the washers against the
cap B and its flange, by means of screws f which tre insulated from the flange of
the cap and the upper metallic washer, but ac in metallic contact with the neck of
the cai bon frame The bottom g' of the neck, which together with the cap forms the
brush box, is composed of a refractory and non conducting substance, and has a
central opening g', tounded from above and bevelled from below An annular brush
support, is clamped between the edge of the cap and the asbestos washer f',
and a number of bi ush rings f have support and play in radial planes upon this
support An annular theostat II his perforated eas projecting from its innci
edge, and screws 1, pass through and are insulated from said eais, into the flange
of the cap B
The negative conductor J, of the lamp, enters the upper portion
of the lamp casing and passes down to the rheostat, to one terminal of which it
is connected The other terminal of the heostat is connected to one of the
screws and through said screw to the lower carbon fiame The lower carbon
frame has a ring G², formed at its inner side with two diametrically opposite
notches g³ The lower carbon holder consists of a socl et K in which the cubon
inay be secured by a suitable clamp sciew or by other means, and a spider K¹,
having long lugs k, projecting from the lower portions of its arms, so as to bear
against the under side of the ring of the carbon frame, when inserted into the same
The upper portions of the ends of two arms have short lugs k' which may ship
through the notches of the ring, and may rest upon the upper edge of the littei
when the spider has been partly rotated A stud 9 projects fi on the lower edge
of the carbon frame ring, at a point where it may stop one of the lower lugs & of
the spider, when the latter has been inserted and paitly rotated, and a screw g₁
passes through the ring at such distance from the stud, that it may be screwed
inward and bear against the side of one arm of the spider, opposed to the stud,
so that the spider may be held against rotation in either direction, when adjusted
as above stated The lower portion of the carbon socket, below the spider, is sciew-
threaded, and the lower end of the socket is bevelled so as to be easily engaged by
the upper internally bevelled end of a screw-threaded socket L having an insulating
handle l Two dished, or bulged sheet metal plates, and 1³ are secured upon the
handle socket, and clamp the edge of the lower bottom opening of the globe M
between them The dished or bulged plates have openings 13 which establish
communication between the interior and exterior of the globe, and a pan
18 yieldingly supported upon the insulating handle, to cover the openings
and to serve as
a large sized valve for the openings, to admit of limited
anlet and free outlet of air into and out of the globe The spider has
14

page_text: an annular flange upon its upper side, which forms a seat for the
lower neck n of the inner arc-inclosing globe N The upper end of said
globe is covered by a downwardly dished cover n' having a large central
opening, and by a cap n² which is downwardly dished and has a smaller central
opening A washer n having a central opering, the edges of which are curved
downward, and a flat washer n having a plain central opening are placed, the
latter above the former upon the cover, and in the space between the cover and
the cap
The openings in the washers are of the same diameter and are of a
diameter slightly greater than the diameter of the largest carbon to be used in the
lamp A carbon sheath O is preferably employed in the lamp, to increase the
extent to which the upper carbou may be burned, and to serve as a cut out for
the lamp when the carbons are consumed to such extent that the upper end of the
carbon drops below the clutch ungs Said sheath consists of an upper portion o of
some non-conducting material capable of resisting heat, such as clay, glass or
porcelain, or mica, asbestos or similar material, and a lower socket o' into which
the carbon may be inserted and held The sheath is of a diameter slightly greater
than the central openings in the washers at the top of the inner globe, so that the
sheath may be held by said washers when the lower edge of the socket strikes
them, and the upper carbon may be consumed with an increasing length of arc,
which at last will break the arc 1 ne socket which is preferably of metal, is of
such length that its upper end will be below the contact point of the brush rings,
when the lower end rests upon the washers, so that the brush rings will then be in
contact with the insulating portion of the sheath, which will also break the lamp
circuit
The outer
For the purpose of illustrating the manner in which the lamp is used and operates,
the lamp will be presumed to be in the condition illustrated in Figures 1 and 2,
without carbons When now the lamp is to be trimmed, the insulating handle at
the bottom of the globe is grasped and rotated to unscrew the handle socket from
the threaded end of the lower carbon socket The globe will rotate with the
handle, and may be removed when the parts are un-crewed The set screw in the
lower ring of the carbon supporting frame may now be unsciewed so as to permit
of the spider and lower carbon holler being rotated to bring the short lugs ki upon
the spider aims to register with the notches in the ring when the spider may be
withdrawn from the ring, and the inner are inclosing globe with it The lower
carbon may now be inserted and secured in its sochet, and the upper carbon and its
sheath may be inserted through the washer openings in the upper end of the inner
globe, whereupon the carbon sheath my be guided between the brushes in the
brush box, and the inner globe and the lower carbon holder and spider again
secured in place in the ring of the lower carbon supporting frame
globe may now be slipped over said frame, and the handle socket screwed upon the
threaded portion of the carbon socket-the bevelled ends of said parts facilitating
the engagement of said parts When the outer globe is screwed home, its upper
edge, which is ground perfectly level, will force the spring washer F' against the
asbestos washer F, and will make a snug and air-tight fit, air-tightly closing the top
of the globe
When the current is turned on in the lamp, it passes through the
positive conductor, around the coil, and into the magnet body, from which it will
be fed to the upper cat bon through the upper part of the brush box, which forms a
part of the magnet body, to the brushes, which feed the current to the upper
carbon I he curent passes through the carbons, through the lower carbon frame,
through the screw f, to the rheostat, and from the sime to the negative lamp
conducto When the current is closed, the coil will be energized, and the armature
will be drawn upward, raising the upper carbon from the lower, and striking the arc
As the cylindrical armature pan and its neck move from the bottom of their respective
chambers, the first pull of the armature will be against a partial vacuum, whereby
the first upward movement of the carbon, in stiiking the arc, will be even and
without jerk
When the armature pan has been raised, sufficient air has entered
below to form a cushion for the same, so that the armature and carbon will now be

page_text: perfectly cushioned in its movement in either direction This cushion will dispense
with the necessity of the armature having air cushion in the magnet bore, so that
the fit of the armature in sud bore will not require to be very snug, whereby
binding of the armature in the bore is prevented The pan, being of a proportion-
ately large diameter will not require a very snug fit in the casing at the bottom of
the magnet, for which reason another source of binding of the armature is
prevented The knurling or other roughening of the clutch rings and the flaring
interior of the armature pan will cause said rings to clutch the carbon or carbon
sheath with a grip which is positive and will not admit of the carbon slipping down
while the armature is raised As the armature pan is of the same material as the
cylindrical casing within which it has an cushioned play said pan will not bind in
the casing on account of expanding by the heat ascending from the arc, as the
expansion of the cylindrical casing equals the expansion of the pan, and the brass
hining of the casing will on account of the greater co-efficient of expansion of brass
than of iron-expind with the casing and offer no resistance to the expansion of
the same
The upper part of the outer arc-inclosing chamber, the brush box, the
neck and cylindrical casing, the bore of the magnet and the axial tube A, all
communicate and are closed air-tight, so that there is no upward escape for the
expanding gases in the arc inclosure excepting through the yieldingly closed bottom
opening in the outer arc inclosure The lower portion of the magnet structure-
the cylindrical casing B2, air-tightly surrounds the tubular amature and clutch
mechanism, so that the ornamental and protective casing, which surrounds the
upper portion of the lamp structure, will not be required to be air-tight at any
point, but may be ventilated at any suitable or desired point, wherever ventilation
may be required to keep the operative portions of the lamp cool The arrangement
of the annular rheostat at a point above the arc inclosure and below the feed
mechanism, and surrounding the lamp structure, with an an space between it and
said structure, will keep the theostat from being heated from the arc and plices it
at a point where it will not occupy room required for the regulating mechanism
and where it will adapt itself to the ornamental outline of the lamp The upwardly
projecting tube 610, upon which the tubee of the armature plays, projects sufficiently
above the bottom of the cylindrical casing, which forms the lower portion of the
magnet structure, to project above the bottom of the armature pan, when the latter
18 in its lowermost position and to thereby raise the clutchings and throw them
back, to admit of the free up and down passage of the upper electrode
insulating bottom of the brush box prevents short-circuiting which might occur in
the lamp if the brush ings or the electrode should come in contact with the bottom
of the box, and said bottom was made from a conducting material
The
Other modes of applying the principle of my invention may be employed
for the mode herein explained Change may therefore be made as regards the
mechanism thus disclosed, provided the principles of construction set forth are
employed
בד
Improvements in and connected with Arc Lamps
I, WILLIAM JANDUS, 66, Victoria Street, Westminster, Electrical 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 n and by the following 5
statement
The drawings filed with the Provisional Specification and the following

page_text: description set forth in detail, one mechanical form embodying the invention such
detail construction being but one of various mechanical forms in which the
principle of the invention may be used
In the drawings
Figure 1 represents an axial section of the upper portion of my improved electric
lamp
Figure 2 an axial section of the lower portion of the lamp, said section being
taken in a plane standing at an angle of 40° to the plane of the section Figure 1
Figure 3 a plan view of the under side of the lower ng of the lower carbon
frame, and the carbon holder in the same
Figure 4 a perspective view of the lower carbon holder,
Figure 5 an axial section of the carbon sheath
Figure 6 a perspective view of a clutch ring, and
1igure 7 an axial section of the pan and tube of the armature
A tube A, has a hanger A', or a rosette, secured to its upper end, and is closed
an-tight Said tube is electically insulated from the hanger o rosette in any
suitable or preferred manner The tube has an axial magnet tube B secured to
its lower end, which magnet tube is axially secured in the upper end of a magnet
body, B', of cylindrical outline The lower portion of the magnet tube has an
upwardly tapering bore or recess b The lower end of the magnet body is open,
and has an internal should b', into which the upper end of a short cylindrical
casing B2, fit, and said casing has a narrow neck B³, which is continued in a round
cap B at the end of the neck A tube 2 of brass or other non-magnetic metal,
fits with its upper end upon the lower end of the magnet tube and has a flange 63
at its lower end, which fits under the internal shoulder of the magnet body
A lining of briss or other non-magnetic met il, fits in the cylindrical casing B³,
has a flange at its upper end, which flange and the flange 63 are clamped between
the internal shoulder of the magnet body and the end of the cylindrical casing
Said casing is secured to the magnet body by means of sciews, be
The bottom
lining for the casing is formed with an upward annulat bulge b', and is continued
by a tube 8, which fits within an enlargement in the bore of the nech
A tube bo has a flange at its lower end, with which it rests upon the shoulder
at the lower end of the enlargement in the neck, the lower end of the neck lining 8,
bearing against the flange and securing the tube An annular space is formed
between the upright tube 10 and the neck lining 8 The bore of the upright
tube is the same as the bore of the axial tube A, and of the unenlarged bore of
the neck A coil is placed around the tube B2 and the magnet tube, and has
one terminal c, in electrical contact with the magnet body, while the other terminal
is passed through an insulation in the magnet body, and is continued in the
positive conductor G, which is carried out through the upper portion of the lamp
casing A tubular armature fits freely, and has vertical play within the tube b³,
and is upwardly tapering, so as to correspond to the outline of the upwardly
tapering bore or recess b in the magnet tube An iron pan E' is secured to the
lower end of the tubular armature, and has a free fit and vertical play within the
lining of the cylindrical casing B2, and said pan has upwardly flaring inner sides
and cylindrical outer sides A tube e extends from the bottom of the pan, into the
annular space between the upright tube 10 and the neck lining 18 The lower
portion of the armature body is formed with longitudinal, radiating slots e, in
which slots the clutch rings e have vertical and radial play The rings are partly
confined in their play by a 1ng e³, which is vertically movable upon the mature
and which passes through the clutch ings The clutchings have a V-shaped
peripheral groove, which groove is knurled or otherwise roughened, and the inner
flaring side of the pan is also roughened, so that the rings will be prevented from
slipping, when the armature is diawn upward and the flaring side of the pan forces
the rings against the carbon or carbon holder The roughening of the peripheral
grooves of the clutch rings will also aid in the rings obtaining a firm grip upon the
carbon or carbon holder The round cap B, has an annular flange &¹³, the under

page_text: side of which is shouldered and bears against a sheet metal washer, which bears
against an insulating washer, 1, of asbestos, or similar non conducting heat
resisting and yielding material A. spring washer F¹ of sheet metal, and shaped
so as to have a downward spring, bears against the under side of the asbestos
washer, and has a downwaid bulge, into which fits another asbestos washer f¹,
against the inner portion of which the lower edge of the cap B* bears The lower
carbon frame consists of two arms G which extend downward from a circular
neck G¹, which bears against the spring washer F¹, and is drawn upward t clamp
all of the washers against the cap B4 and its flange, by means of screws f" which
are insulated from the flange of the cap and the upper metallic washer, but are in
metallic contact with the neck of the carbon frame The bottom g' of the neck
which together with the cap forms the brush box, 18 composed of a refractory and
non conducting substance, and has a central opening g', rounded from above and
bevelled from below An annular brush support f³, 18 clamped between the edge
of the cap and the isbestos washer f', and a number of brush rings have support
and play in radi il planes upon this support An annular rheostat H has p foiated
ears projecting from its inner edge, and screws h', pass through and are insulated
from said ears, into the flange of the cap B The negative conductor J, of the
lamp, enters the upper portion of the lamp casing and passes down to the rheostat,
to one terminal of which it is connected The other terminal of the rheostat is
connected to one of the sciews f" and through said screw to the lower cu bon frame
The lower carbon fiame has ring G formed at its inner side with two
diametrically opposite notches g² The lower carbon holder consists of a socket K
in which the carbon may be secured by a suitable clamp screw or by other means,
and a spider K, having long lugs h, projecting from the lower portions of its arms,
so as to bear against the under side of the ring of the carbon frame, when inserted
into the same The upper portions of the ends of two arms have short lugs kl
which may slip through the notches of the ring, and may rest upon the upper edge
of the latter when the spider has been partly rotated A stud g³ projects from
the lower edge of the caibon fiame ring, at a point where it may stop one of the
lower lugs of the spider, when the latter has been inserted and partly rotated,
and a sciew passes through the 1ng at such distance from the stud, that it may
be screwed inward and bear against the side of one arm of the spider, opposed to
the tud, so that the spider may be held against 1otation in either duection, when
adjusted as above stated The lower portion of the carbon socket below the
spider, is screw-tl readed, and the lower end of the socket is bevelled so as to be
casily engaged by the upper internally bevelled end of a screw-threaded socket L
having an insulating handle / Iwo dished, or bulged sheet metal plates, l'and /
are secured upon the handle socket, and clamp the edge of the lower bottom
opening of the globe M between them I he dished or bulged plates have
openings which establish communication between the interior and exterior of the
globe, and a pan is yieldingly supported upon the insulating handle, to cover the
openings and to serve as a large sized valve for the openings, to admit of limited
inlet and free outlet of an into and out of the globe The spider has an annulai
flange upon its upper side, which forms a seat for the lower neck n of the inner
arc-inclosing globe N The upper end of said globe is covered by a downwardly
dished covei ¹ having a large central opening, and by a cap n² which is downwardly
dished and has a smaller cential opening A washer n having a central opening,
the edges of which are cuived downward, and a flat washer n having a plain
central opening, are placed, the latter above the former, upon the cover, and in the
space between the cover and the cap The openings in the washers are of the
same diameter, and are of a diameter slightly greater than the diameter of
the largest carbon to be used in the lamp A carbon sheath is preferably
employed in the lamp, to increase the extent to which the upper carbon may be
burned, and to serve as a cut-out for the lamp when the carbons are consumed to
such extent that the upper end of the carbon drops below the clutch ring> Said
sheath consists of an upper portion o of some non-conducting material capable of

page_text: resisting heat, such as clay, glass or porcelain, on
mica, asbestos, or similar
material, and a lower socket o into which the carbon may be inserted and held
The sheath is of a diameter slightly greater than the central openings in the
washers at the top of the inue: globe so that the sheath may be held by said
washers when the lower edge of the so het stikes them, and the upper cubon may
be consumed with an increasing length of rc, which at last will break the arc
The socket which is preferably of metal, is of such length that its upper end will
be below the contact point of the brush rings, when the lower end rests upon the
washers, so that the brush rings will then be in contact with the insulating portion
of the sheath, which will also break the lamp cucunt
upon
For the purpose of illustrating the manner in which the lamp is used and operates,
the lamp will be presumed to be in the condition illustrated in Figures 1 and 2,
without carbons When now the lamp is to be trimmed, the insulating handle at
the bottom of the globe is grasped and rotated to unscrew the handle socket from
the threaded end of the lower carbon socl et The globe will rotate with the
handle, and may be removed when the parts are unscrewed
The set screw in the
lower ring of the carbon supporting frame may now be unscrewed so as to permit
of the spider and lower carbon holder being 1otated to bing the short lugs
the spider arms to register with the notches in the ing, when the spider may be
withdrawn from the ring, and the inner arc-inclosing globe with it
The lower
carbon may now be inserted and secured in its socket, and the upper carbon and
its sheath may be inserted through the washer openings in the upper end of the
inner globe, whereupon the carbon sheath may be guided between the brushes in
the brush box, and the inner globe and the lower carbon holder and spider again
secmed in place in the ring of the lower carbon supporting frame
The outer
globe may now be slipped over said frame, and the handle socket sciewed
upon the
threaded portion of the carbon socket-the bevelled ends of said parts facilitating
the engagement of said parts When the outer globe is screwed home, its uppei
edge which is ground perfectly level, will force the spring washer F¹ against
the asbestos wisher F, and will make a snug and an-tight fit, an-tightly closing
the top of the globe When the current is tuined on in the lamp, it passes
through the positive conductor, around the coil, and into the magnet body, from
which it will be fed to the upper carbon through the upper put of the brush
box, which forins a part of the magnet body, to the brushes which feed the current
to the upper carbon I he cunent pas es through the carbons, through the lower
carbon frame, through the screw 2, to the rheostat, and from the same to the
negative lamp conductor When the cuiren is closed, the coil will be energized,
and the amature will be drawn upward raising the upper carbon from the lower,
and stuking the aic As the cylindrical amature pan and its neck move from the
bottom of the respective chambers, the first pull of the amature will be against
a putial vacuum, whereby the first upward movement of the carbon, in striking
the arc, will be even and without Jork When the armature pan has been used,
sufficient an has entered below to form a cushion for the sɩme so that the
amature and carbon will now be perfectly cushioned in its movement in either
dnection This cushion will di pense with the necessity of the armature having
an cushion in the magnet bore so that the fit of the at mature in said bore will not
require to be very snug, whereby binding of the armature in the bore is prevented
The pan, being of a proportionately laige diameter, will not require a vety snug
fit in the cising at the bottom of the magnet, for which reason another source of
binding of the armature is prevented The knurling or other roughening of the
clutch rings and the flaring interior of the armature pan will cause said ings to
clutch the carbon or cubon sheath with a gup which is positive and will not admit
of the carbon slipping down while the armature is raised As the armature pan is
of the same material as the cylindrical casing within which it has a cushioned
play, said pan will not bind in the casing on account of expanding by the heat
ascending from the ac, as the expansion of the cylindrical casing equals the
expansion of the pan, and the brass lining of the casing will, on account of the

page_text: greater co-efficient of expansion of brass than of iron-expand with the casing and
offer no resistance to the expansion of the same The upper part of the outer arc-
inclosing chamber, the bruch box the neck and cylindrical casing, the bore of the
magnet, and the axial tube A, 'l communicate and are closed air-tight, so that
there is no upward escape for the expanding gases in the arc inclosure excepting
through the yieldingly closed bottom opening in the outer arc inclosure The
lower portion of the magnet structure-the cylindrical casing B2, air-tightly
surrounds the tubular armature and clutch mechanism, so that the ornamental and
protective casing, which surrounds the upper portion of the lamp structure will
not be required to be an-tight at any point, but may be ventilated at any suitable
or desired point, wherever ventilation may be required to keep the operative
portions of the lamp col The rangement of the annular rheostat at a point
above the arc inclosure and below the feed mechanism, and surrounding the lamp
structure with an air space between it and said structure, will keep the theostat
from being heated from the aic, and places it it a point where it will not occupy
100m required for the regulating mechanism and where it will adapt itself to the
ornamental outline of the lamp The upwardly projecting tube 610, upon which
the tube e of the mature pliss, projects sufficiently above the bottom of the
cylindrical casing, which forms the lower portion of the magnet structure, to
project above the bottom of the armature pan, when the latter is in its lowermost
position and to thereby raise the clutchings and throw them back, to admit of
the fice up and down passage of the upper electrode The insulating bottom of
the brush box prevents short-circuiting which might occur in the lamp if the brush
1ings or the electrode should come in contact with the bottom of the box, and said
bottom was made from a conducting material
Other modes of applying the principle of my invention may be employed for the
mode herein explained Change may therefore be made as regards the mechanism
thus di closed, provided the principles of construction set forth we employed
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim 15
―
1 In an arc lamp, operating mechanism comprising an annulai aimature
surrounding a carbon and an annular electro-magnet and coil or solenoid surrounding
the said armature, the armature being arranged to move easily in a cylinder formed
within the electro magnet and coil or solenoid and having at one end a large
piston operating in cylinder and acting to produce a checking or dash pot
effect substantially as hereinbefore described with reference to Figure 1 of the
drawings
2 In an arc lamp with clutch rings and conical carrier, roughening or seriating
the engaging surfaces of the rings and carrier to prevent slipping either on the
carrie surface on the carbon surface substantially as described with reference to
Figures 1, 6 and 7 of the accompanying drawings
3 In an arc lamp, an extended annular theostat as H Figure 1 in series with
the negative carbon the said heostat being placed outside the globe and arranged
to expose a considerable surface for the purpose of cooling as herein before et
forth
4 An ai lamp constructed and operating as her ein before described with reference
to the accompanying drawings
Dated the 5th 1...
1000
MARKS & CLERK,
18, Southampton Buildings, London, WC, and
13, Temple Street, Birmingham, Agents