Improvements in Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 3rd Mar., 1896-Accepted, 30th May, 1896
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I, THOMAS EDGAR ADAMS of 938 Case Avenue, in the City of Cleveland,
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 arc lamps and more particularly to
such as are adapted to operate with an alternating current.
In the operation of alternating current arc lamps as heretofore constructed, there
has been an annoying chattering when the lamps were started, due to the sudden
and repeated making and breaking of the circuit during the period necessary for the
carbon points to become sufficiently heated to maintain the normal arc.
It is the object of my invention to provide an alternating current are lamp with
means whereby to prevent the chattering incident to the starting of such lamps as
they have heretofore been constructed.
A further object is to provide simple and efficient means whereby to cause
the carbon points to be sufficiently heated to maintain a normal arc before such are
shall have been formed.
A further object is to so construct an alternating current are lamp that when
current enters the lamp a small are will be first formed between the carbon points
and the separation of the carbons retarded sufficiently to cause their points to be
properly heated to maintain the subsequently formed normal arc.
A further object is to so construct an arc lamp as to prevent an abnormal rise of
current.
A further object is to produce an arc lamp which shall be simple in construction,
and effectual, in all respects, in the performance of its functions.
With these objects in view, the invention consists in the combination with
a magnet and the carbons, of a pivoted lever, connected with the armature of said
magnet and with the carbons, and a dash pot connected with said lever said dash
pot being so constructed as to first permit a free movement of the lever; then retard
the movement of the lever and then permit its free movement whereby to retard
the separation of the carbons and then permit them to separate sufficiently to form
a normal arc.
The invention also consists in the combination with the separating magnet and
the carbons of an arc lamp, of a pivoted lever, a spring connection between said
lever and the armature of the magnet, a connection between the lever and the
carbons and a dash pot connected with said lever.
The invention also consists in the combination with a separating magnet and the
carbons of an arc lamp, of a pivoted lever connected with the carbons and a spring
lever secured to the pivoted end of the pivoted lever, and connected with the
armature of the magnet.
And the invention also consists in certain novel features of construction
and combinations and arrangements of parts as hereinafter set forth and pointed out
n the claims.
In the accompanying drawings:
Figure 1 is an elevation of my improved lamp with the casing open and the cap
of the casing partly broken away.
Figures 224 9 are views of the clutch

page_text: Figure 4 is an enlarged sectional view of the lamp.
Figure 4A is a view of the spring 10.
Figure 5 is a view showing the lower portion of the lamp.
Figure 6 is a detail view of the spark arrester.
A represents the lamp casing made preferably of cast metal and comprises a
base or floor a, sides b made in sections hinged together and having flanges b
secured to the base or floor and a cap e secured to the upper ends of the side
sections b.
A magnet or solenoid B is disposed within the casing and depends from the car c
to which it is secured, said cap having a seat against which the upper head of the
spool rests.
The heads magnet spool or frame are constructed, preferably of wood or similar
material which is not liable to become unduly heated. The upper head, d, of the
spool is made with a central conical hole d, the smaller end of which is coincident
with the upper face of said head d. A screw d is passed through the hole d² (from
inside the coil) so that its head will rest in the said conical hole and its body
project beyond the head d of the spool. The screw d' is passed through a hole in
the cap of the lamp and provided on its free end with a suitable nut d'. The
heads d, e, of the spool are made with perforated ears d, e, for the accommodation
of bolts 1, 1, which serve to secure a plate 2 to the under face of the lower head e
of the spool. One end of the plate 2 is enlarged and made to form an inverted
U-shaped yoke between the depending arms 3, of which a short shaft 4 is pivotally
mounted. A lever 5 is secured to the short shaft 4 and projects horizontally
therefrom, said lever terminating at a point near the opposite wall of the casing,
where it is pivotally connected with the rod 6 of a piston 7. The piston 7 enters a
dash pot 8 and the latter is pivotally connected with an arm 9 secured to the upper
head of the magnet spool. The upper portion of the dash pot is made slightly
larger than the lower end and at a point somewhat above said lower end a series of
small holes 9 is made in the wall of the dash pot. Thus when the piston moves
upwardly within the dash pot, it will at first meet with little, if any resistance
owing to the escape of air through the holes, but when the piston reaches and
passes these holes (which are in the smaller portion of the dash-pot) considerable
resistance will be offered to the movement of the piston.
When however, the piston reaches the enlarged upper portion of the dash pot, no
further resistance will be offered to its progress and it will quickly complete its
upward movement. The mechanical operations are of great importance in the
electrical operation of the lamp, (especially when starting), as will be hereinafter
fully explained.
A long range spring arm 10 preferably larger at one end than at the other, is
secured at its larger end to the shaft 4 of lever 5 and at its smaller end to the
core B' of the solenoid, the movements of the core B' being thus transmitted to the
lever, through the medium of the said long range spring arm or lever 10.
The upward movement of the lever 5 will be limited by the core B¹ and the dash
pot and the downward movement of said lever will be limited by a screw 11 at the
lower end of an arm 12, the latter being supported from the plate 2.
A bracket 12 is secured to the cap c at one side thereof and made with a binding
post 13 for the reception of one of the leading in wires of the lamp. A hood or
frame 14 is made integral with the bracket 12 and at one end has a perforated
enlargement 15 for the reception of the upper end of a guide tube 16, the lower end
of said guide tube being fastened to a plate 17 secured to but insulated from
the lamp floor. A guide rod 18 is secured at its upper end to the bracket 12,
passes through the plate 17 and at its lower end is electrically connected with the
lamp arm C. Between said guide tube and rod a cross head 19 is disposed, said
cross head having rollers 20 mounted thereon to run on said guide tube and rod.
An arm 21 is secured to the cross head and is effectually insulated therefrom,
preferably by means of non-combustible material 22, such as mica. The arm 21

page_text: projects laterally from the cross head and is provided at its free end with ears 23,
between which the upper carbon holder 24 is pivotally connected. In order
to permit the cross head 19 to move freely between its guides without binding, said
cross head is provided with a weight 25 at the opposite side thereof from the arm 22,
adapted to counterbalance said arm and parts carried thereby.
The upper carbon holder is connected, by means of a flexible cable 26, with
one end of the coil of the solenoid and the other end of said coil is connected
with a binder 27, which latter is also adapted for the reception of the plus
leading-in wire.
The arm C of the lamp is secured to and insulated from the base of the lamp
frame and is made, throughout the major portion of its length, in the form of a flat,
hollow shield 29 which communicates at its upper end with an elougated slot 30 in
the plate 17. Through this slot and into the hollow shield, a clutch blade 31
projects, the upper end of said clutch blade being secured to the cross head. The
fower end of the clutch blade is provided with a roller 31 adapted to roll within
the shield 29.
A rod 32 is located in the guide tube 16 and projects downwardly through a
portion of the lamp arm. To the upper end of this rod a chain 33 (or other
flexible device), is connected and passes up over a pulley 34 mounted in the
hood 14. From the pulley 34 the chain is extended downwardly and counected to
the cross head 19.
The lamp arm C is made with parallel flanges 35 having inwardly projecting
guide ribs 36, which enter grooves made in the opposite faces of a sliding
bracket 37, the latter being secured to the lower end of the rud 32. The
bracket 37 is made with an outwardly projecting flattened arm 38, to which the
lower carbon holder 39 is connected. Above the lower carbon holder, a carbon
guide 40 is secured to the arm of the lamp, or more strictly speaking, to a lug
projecting from the shield 29.
The globe holder 41 (with attached ash receiver 42) is removably connected
with the lower end of the lamp arm. For this purpose the globe holder is made
with inwardly projecting ears 43, to which a socket piece 44 is secured and adapted
to receive the lower end of the lamp arm and lie flat against the rear face thereof.
The socket piece or casing 44 is made with books 45 adapted to engage lugs 46 on
the lamp arm and thus support the globe holder on said arm. The socket piece 44
is preferably insulated from the globe holder, and the latter is prevented from
accidental displacement from the lugs 46 by means of a bar 47, which is connected
to the lamp arm at one end and at the other end bears on the socket piece 44.
A globe 49 is supported in the globe holder and the space between the top of the
globe and at the bottom of the lamp easing is closed by wire netting which serves
as a spark arrester 49°. The frame of the spark arrester is composed of two sheet
metal strips 49, 49, secured to the edges of the wire netting; the strip 49° being
made wider than the strip 494 and adapted to rest on the globe, said strip 49
having a scalloped or otherwise decorated lower edge which gives a finish to the
top of the globe. One end of the spark arrester is made with a lip 49 to overlap
the other end. The strip 49° is made at one end with an elongated slot 491,
through which a screw 498 on the other end of said strip passes. A thumb nut 49
is placed on the end of this screw and made to bear on the end of the strip 49°.
Thus the spark arrester can be readily adjusted to properly fit the globe and can
be secured at any desired adjustment.
From the construction and arrangement of parts above described it will be
seen that the upper carbon holder is electrically connected with the coil of the
solenoid, which latter is connected with the plus leading-in wire, and that the lower
carbon holder is electrically connected with the minus terminal of the lamp through
the lower carbon holder, rod 32, chain 33 to hood 14, also through lamp arm, guide
rod and tube, plate 17, cross head, flexible mechanical connection between cross
head and rod 32. The lower carbon holder is connected with the lamp arm by
means of a flexible conductor e³.

page_text: .
An adjustable rod 48 is connected at one end to the lever 5 at a point in
proximity to its fulcrum and at the lower end said rod is connected with a
clutch 49 adapted to grasp the clutch blade 31, so that when the lever 5 is raised
the clutch blade will also be raised, resulting in the separation of the carbons, the
upper carbon moving upwardly and the lower carbon moving downwardly.
The clutch 49 comprises two jaws 50, 51 having flat faces adapted to engage
the respective faces of the clutch blade and an operating lever 52. The jaw 50
is made with parallel arms 53, between which the jaw 51 is disposed and these
arms terminate in curved downward extensions 54. Each arm 53 is made with a
downwardly projecting tooth 55 which are engaged by similar teeth 56 on the
lever 52, whereby to form a fulcrum for said lever. The lever 52 is made with a
yoke 57 which projects forwardly and loosely embraces the jaws 50, 51, the free
end of said yoke being curved upwardly and made with a hole 58 for the attach-
ment of the rod 48. The curved extensions 54 of the jaw embrace the rear end
of the yoke and prevent the displacement of the lever 52. The lever 52 is made
with a long arm 59 adapted to engage an insulated stop 60 on the lamp floor or
base and at the inner end of this arm a recess 61 is made in the upper face thereof
for the accommodation of a lug 62 projecting from the back of the jaw 51. A
screw 63 is inserted in the rear face of the jaw 51 and so as to be disposed under
the inner end of the arm 59, said lug and screw serving to prevent vertical
displacement of said jaw 51.
The extreme inner end of the arm 59 of the lever 52, bears against the rear
face of the jaw 51 between the lug 62 and screw 63 and below the fulcrum of said
lever on the arms 53 of jaw 50. From this construction and arrangement of parts
it will be seen that when the lever 5 moves up, the rod 48 will pull on the yoke
end of lever 52 and cause the latter to turn on its fulcrum and force the jaws
tightly against the blade 31 so as to clutch the same, a continued upwardly move-
ment of said lever 5 causing the clutch blade to be raised and the carbons
separated in an obvious manner. When the lever 5 moves downwardly the
clutch blade and clutch will move downwardly also and when they have moved
downwardly sufficiently to permit the arm 59 of lever 52 to engage the stop 60 on
the lamp floor, the arm 59 of lever 52 will be raised and the clutch blade released
from the clutch to permit the carbons to feed.
As above stated, the most objectionable features in the operation of an are lamp
with an alternating current, is the annoying chattering caused when the lamp is
started, and this chattering is due to the repeated breaking and making of the
circuit between the carbons during the time the points of the carbons are becoming
sufficiently heated to insure the maintenance of the normal arc. It is known that
before the normal arc can be maintained, when an alternating current is employed,
the carbon points must be sufficiently heated to throw a certain amount of
volatilized carbon. In alternating current arc lamps the separating solenoid or
magnet is included in series in a normally closed circuit with the carbons, so that
when the current first enters the lamp the resistance is so low that a heavy current
passes through the solenoid or magnet and causes it to become so strong as to
violently separate the carbons to the full extent for a normal arc and before the
points of the carbons can have possibly become sufficiently heated to insure the
maintenance of the normal arc. The arc is therefore ruptured and the circuit
instantly broken thus depriving the solenoid of its energy and permitting the
carbons to again come together aud close the circuit through the solenoid, the
result of which is to again violently separate the carbons. These operations, with
the accompanying chatter, will continue until the temperature of the points of the
carbons shall have reached such a degree as will cause them to throw off sufficient
volatilized carbon to insure the maintenance of the normal arc.
By my improvements I avoid these continuous violent separations of the
consequent breaking of the circuit with accompanying chatter, and this result I
accomplish by causing a small preliminary are to be formed and maintained for

page_text: a sufficient length of time to properly heat the carbon points to insure the
maintenance of the consequently formed normal arc. The action of the parts in
the performance of these functions is as follows:
When no current is passing through the lamp the parts assume the positions
shown in Figure 1, with the carbons in contact with each other. When the
current enters the lamp, the solenoid will be energized to raise its core, which
movement of the core will be transmitted to the lever 5 through the medium of the
long range spring 10. The free upward movement of the lever 5 will be permitted
until the piston of the dash pot reaches the perforations in the latter, during which
movement of said lever the carbons will be slightly separated so as to form a small
preliminary are between them.
As soon as the piston 7 reaches the perforations in the dash pot, the upward
movement of the lever 5 (and the separation of the carbons) will be retarded, and
this retarded movement of the lever and carbons will continue until the piston 7
passes above the smaller portion of the dash pot 8 during which time the preliminary
arc is being maintained and the carbon points heating to & sufficient degree
to maintain a normal arc. As soon as the piston 7 reaches the enlarged end of the
dash pot 8, the resistance against its further upward movement will be removed
and it will move freely upwardly, permitting the lever 5 to be freely raised by the
action of the solenoid (acting through the long range spring 10) and the carbons to
be separated sufficiently to form a normal are which will be maintained. The
enlarged portion of the dash pot is of sufficient extent to permit a free movement
of the piston, up and down, to allow the proper movements of the lever 5 for
feeding the carbons.
An advantage gained by having the core or armature attached to the mechanism
through a proper range of proper strength, is the prevention of an abnormal rise
of current, as the core having drawn up into the spool, forms an effectual choking
coil and the current cannot rise much above normal. The action continues while
the arc is slowly forming its proper resistance.
By a proper proportioning of the strength and range of the lever spring 10 in
connection with the dash pot that will first allow a short free movement of the
carbons, then retard their movement for a short period and again permit perfect
freedom a complete and perfect starting of an alternating lamp, without the usual
chattering, is secured.
.
My improvements are comparatively simple in construction and effectual in all
respects, in the performance of their functions.
Various slight changes might be made in the details of construction of my
invention without departing from the spirit thereof or limiting its scope and hence
I do not wish to limit myself to the precise details of construction herein set
forth, but,
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 is :-
1st. In an arc lamp, the combination with a separating magnet and the carbons,
of a pivoted lever connected with the carbons and with the armature of the
magnet, and a dash pot, the piston of which is connected with the armature of said
lever said dash pot being so constructed and arranged as to first permit a free
movement of the lever to cause the formation of a small arc between the carbons;
then retard the movement of the lever whereby to maintain said small arc for a
short period, and then permit the free movement of the lever whereby to allow
the carbons to be separated sufficiently to form a normal arc, substantially as
set forth.
2nd. In an arc lamp, the combination with a separating magnet and the
carbons, of a pivoted lever connected with the armature of the magnet and with
the carbons and a dash pot having its piston connected with the lever, the bore

page_text: or said dash pot being larger at one end than at the other, substantially as and for
the purpose set forth.
3rd. In an arc lamp, the combination with the separating magnet and the
carbons, of a pivoted lever connected with the armature of the magnet and with
the carbons, and a dash pot having its piston connected with said lever, said dash-
pot having a bore larger at one end than at the other and having perforations in
its smaller part, substantially as and for the purpose set forth.
4th. In an arc lamp, the combination with a separating magnet and the carbons,
of a lever pivoted at one end and connected with the carbons, and a long range
spring secured at one end to the pivoted end of the lever and connected at the
other end to the armature of the magnet, substantially as set forth.
5th. In an arc lamp, the combination with a separating magnet and the
carbons, of a pivoted lever connected with the carbons, and a flat spring
secured at one end to the pivoted end of the lever and connected at the other end
to the armature of the magnet, substantially as set forth.
6th. In an arc lamp, the combination with the separating magnet and the
carbons, of a plate secured to the spool of the magnet and having arms, a shaft
mounted between said arms, a lever secured to said shaft and connected with
the carbons, and a spring also secured to said shaft and connected with the
armature of the magnet, substantially as set forth.
7th. In an
arc lamp, the combination with a separating magnet and the
carbons, of an oscillatory shaft, a lever secured to said shaft, a dash pot having its
piston connected with the free end of said lever, and a spring secured at one end
to said shaft and connected at its other end with the armature of the magnet,
substantially as set forth.
8th. In an arc lamp, the combination with a casing, of a magnet having a
wooden headed spool secured to said casing, a plate secured to said wooden spool,
a lever pivotally supported by said plate, having a yielding connection between the
pivoted end of said lever and the armature of the magnet, and a connection between
said lever and the carbons of the lamp, substantially as set forth.
9th. In an arc lamp, the combination with a frame or casing having a hole in its
top, of a separating magnet, the upper bead of the spool of said magnet having a
conical hole, and a screw having head disposed in said conical hole and its body
portion projecting through said hole in the top of the casing, and a nut on said
screw, substantially as set forth.
10th. In an arc lamp, the combination with a guide tube and a guide rod,
connected at one end with the negative terminal of the lamp and a plate connected
with their other ends, of a sliding cross head disposed between said tube and rod,
an arm secured to and insulated from the cross head, an upper carbon holder
connected to said arm and with the positive terminal of the lamp and a lower
carbon holder connected with the cross head, substantially as set forth.
11th. In an arc lamp, the combination with a hood connected with the negative
terminal of the lamp, of a guide tube and a guide rod secured to said hood, a sliding
cross head between said tube and rod, an upper carhon holder carried by but
insulated from the cross head, a rod in the tube, a lower carbon holder attached to
said rod, a pulley mounted in said hood and a chain connected to the rod in the
guide tube and to the cross head and passing over said pulley, substantially as set
forth.
12th. In an arc lamp, the combination with a casing and vertical guides therein,
of a sliding cross head between said guides, a laterally projecting arm secured to
but insulated therefrom, a lower carbon holder, a flexible connection between the
lower carbon holder and the cross head, and a weight on said cross head adapted
to counter-balance said laterally projecting arm and parts carried thereby,
substantially as set forth.
13th. In an arc lamp, the combination with the upper carbon holder, of guides,
a lamp arm, lower carbon holder, and a cross head between said guides all

page_text: connected with the negative terminal of the lamp, a flexible mechanical connection
between the cross head and lower carbon holder, and an arm secured to but.
insulated from the cross head for carrying the upper carbon holder, substantially
as set forth.
14th. In an arc lamp the combination with a casing and a lamp arm secured
thereto and having lugs near its lower end, of a globe holder having inwardly
projecting ears, a socket or casting secured to and insulated from said ears and
adapted to receive the lamp arm, and hooks on said socket or casting adapted to
engage the lugs on the lamp arm, substantially as set forth.
15th. In an are lamp the combination with a casing and a lamp arm secured
thereto, and having lugs near its lower end, of a globe holder having inwardly
projecting ears, a socket or casting secured to and insulated from said ears and
adapted to receive the lamp arm, hooks on said socket or casting adapted to engage
the lugs on the lamp arm and a bar attached to the lamp arm and adapted to
prevent accidental displacement of the globe holder, substantially as set forth.
16th. In an arc lamp, the combination with a casing, and guides therein, a
sliding cross head between said guides, and an upper and a lower carbon holder
connected with said cross head, of a hollow, flat lamp arm, a clutch blade secured
to the cross head and entering said arm, a roller mounted in the end of said clutch
blade, and a clutch, substantially as set forth.
17th. In a clutch, the combination with the jaws, of arms projecting from one
jaw, and a lever having its fulcrum on said arms and having bearing below its.
fulcrum against the other jaw, substantially as set forth.
18th. In a clutch, the combination with two jaws, of arms on one of said jaws.
adapted to receive the other jaw between them, a lever adapted to bear against the
last-mentioned jaw, said lever having a yoke to embrace both of said jaws and
having its fulcrum on said arms above the bearing of said lever against the jaw,
substantially as set forth.
19th. In a clutch the combination with two jaws, of arms projecting from one
jaw and adapted to receive the other jaw between them, teeth projecting from said
arms, a lever adapted to embrace said jaws and bear against one of them, and teeth
or projections on the lever adapted to bear against the teeth on said arms,
substantially as set forth.
20th. In a clutch the combination with two jaws, of arms projecting from one of
said jaws and embracing the other jaw; said arms having curved extensions and a
lever adapted to embrace both of said jaws and bear against one of them, said
lever having.its fulcrum on said arms and said curved extensions serving to prevent
displacement of said lever, substantially as set forth.
21st. In a clutch the combination with two jaws, of arms projecting from one of
said jaws and embracing the other, said arms having curved extensions, and a lever
having one end made to form a yoke to embrace said jaws and bear against one of
them, said curved extensions being disposed behind said yoke to prevent the
displacement of the lever, substantially as set forth.
22nd. In a clutch, the combination with two jaws, of arms projecting from one of
said jaws, a lever fulcrumed on said arms, one end of said lever being made to form
a yoke to embrace the jaws and the other end being made in the form of a long
arm, the inner end of which engages one of said jaws, substantially as set forth.
23rd. In a clutch, the combination with two jaws, one of said jaws having arms,
of a lug on the back of the other jaw and a lever fulcrumed on said arms and
bearing against said last-mentioned jaw at the base of the lug thereon, substantially
as set forth.
24th. In a clutch, the combination with two jaws, and having arms, of a lug and
3 screw on the back of the other jaw, and a lever having a yoke to embrace said
jaws and having a fulcrum on said arms, said lever also having a bearings against
the last-mentioned jaw between said lug and screw, substantially as set forth.
25th. In an arc lump, the combination with the lamp casing and globe, of a spark

page_text: arrester between said casing and globe, the frame of said spark arrester being
slotted, a screw passing through said slot and a thumb nut on said screw, sub-
stantially as set forth.
Dated this 3rd day of March 1896.
HERBERT HADDAN & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents for Applicant.