Improvements in Arc Electric Lamps.
Year: 1896

page_text: Date of Application, 12th May, 1895-Accepted, 4th July, 1896
COMPLETE SPECIFICATION.
Improvements in Arc Electric Lamps.
I, ALVIE OSCAR MACKIN, Electrical Engineer, of Anderson, County of
Madison, State of Indiana, United States of America, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention has relation to arc electric lamps, and is designed to provide
a self-trimming magazine lamp wherein a large number of carbons may be
successively fed into operation automatically, the lower or negative carbon being
released and dropped out when the positive carbon has been fed and burned
to a certain point, said positive carbon being at the same time released and
dropped into the negative holder where it is caught and held, while a new
carbon is fed from the magazine into the positive holder, this action being
repeated while the lamp is in operation, until all the carbons are exhausted from
the magazine.
This invention is also designed to obviate the use of the feed rod commonly
employed, the carbons being held and fed directly by means of automatic clutches
of simple character operating by gravity and controlled by the current, the feeding
devices being of such character as to insure a steady light. Other objects of this
invention will hereinafter appear.
Figure 1 is a side elevation of lamp with casings, globe, and sleeve 38, in
section, and electric connections shown diagrammatically, in part.
Figure 2 is an enlarged view of lower portion of Figure 1 with posts 33, and
extensions 82, in section, the magnet 29, its armature, lever 34, etc. being shown
outside casing for better illustration.
Figure 3 is a section through upper part of Figure 1 on line w―w.
Figure 4 is a section on line -, Figure 3.
Figure 5 is a section on line y-y, Figure 3.
Figure 6 is a detail sectional view showing lower carbon holder, carbon in
position.
Figure 7 is a similar view with parts in position to receive new carbon.
Figure 8 is a section on line 2-z, Figure 6.
Figure 9 is a detail sectional view showing modification of lower carbon
holder.
Figure 10 is a section on line a-a, Figure 9.
Figure 11 is a detail view of upper carbon holder, lever 64, etc., tube 37 being in
section.
Figure 12 is a section on line b-b, Figure 11.
Figure 13 is a detail plan view of magnets 21, armature to same, etc.
Figure 14 is a detail plan view of plate 27, and means for short circuiting.
Figure 15 is a detail view of armature to magnet 29, and attachments, contact
plate 36, and electric connections.
Figure 16 is a cross section through one of the bows of the globe holder.
Figure 17 is a section through lower part of shaft 8, showing middle disk 11, and
attached hook.
Figure 18 is a diagrammatic view illustrating the circuits.
The numeral 1 designates the frame of the lamp at the upper portion of which
the carbon magazine is supported. Said magazine is shown as consisting of an

page_text: upper, hollow, inverted cone 2, and a second and similarly placed lower cone 3.
The cone 2, is formed with a central opening 4, in its bottom, from which radiate a
series of slots 5, which extend to the rim portion 6, and are of the proper width t
receive the carbons in vertical position. The lower cone 3, is formed with a series
of radial troughs or channels 7, which correspond in number and position to the
slots 5, being designed to receive therein the lower ends of the carbons. 8, is a
central rotary shaft whose lower end has a bearing on the central bottom portion
of the cone 3, and its upper portion in an arm 9, of the frame. The lower portion
of said shaft is hollow with a vertical opening or slot 10, in one side of the proper
character to receive a carbon. Formed on or secured to the said hollow portion,
are two disks 11, each of which has a slot 12, opposite to and corresponding with
the slot 10. Secured to each disk and extending across in front of the slot 12, but
at some distance therefrom is a hook 13. 14, is a third disk which is suspended
from the arm 9, and forms a bearing for the upper ends of the carbons. Placed in
each of the slots 5, is a gravity roller 15, which is designed to travel behind the
last carbon in said slot as it feeds towards the center, to assist the feed and to
prevent the carbon falling outwardly. The edges of the slots 5, are formed with
notched ribs or flanges 16, upon which the axis of the said rollers travel, each of
the notches having a vertical shoulder 17, which prevents the roller from moving
backwardly under the action of the wind swaying the lamp, or from other causes.
Where each of the troughs or channels 7, runs into the central cavity of the
cone 3, there is placed a small lug 17, which is hinged at 17%, and is normally held
by a spring in such position that its upper end forms a stop for the carbon.
On the lower disk 11, is a projection 11, designed to engage with the said lugs
successively to depress them to permit the carbon to slide into the feed tube,
as hereinafter described. The purpose of these devices is to relieve the
lower disk 11, from the friction of the carbons, which would otherwise press
against it.
The upper end portion of the shaft 8, is formed with a spiral thread 18, engaged
by a nut 19, which turns loosely in armature 20, of electro-magnet 21, supported
on the arm 9. Armature 20 is prevented from rotation by means of notches 22, in
its ends, which engage posts 23, on the magnets. Seated around said posts and
bearing against the under side of the armature, are springs 24, which act to recover
the armature. The nut 19 has a ratchet and pawl device 25, which permits the
nut to turn freely on the shaft as the armature is recovered, but which holds said
nut to the armature during the attraction of the armature towards the maguet,
whereby the said shaft will be rotated.
26 designates a feed tube which is secured in the bottom of the cone 3, and there
is a plate 27, through which the tube extends; 28, 28, designate the resistance
maguets, shown as supported underneath the plate 27. 29 is a magnet whose coil
is in a shunt of the main or lamp circuit. 30, is the armature of the said magnet,
which is suspended by a spring resistance coil 31, attached at its upper end to an
adjusting screw 32, which is seated in and insulated from the plate 27; 32, is a
lower plate which is connected with the plate 27, by the two oppositely placed,
hollow posts 33. Attached to the armature 30 is a lever 34, which is also pivoted
to a lug 35, secured to and insulated from one of the posts 33. The upper arm
of said lever normally rests against a contact plate 36, which is also secured to
and insulated from the post 33.
37 designates the holder and clamp for the upper or positive carbon, which
consists of a vertically movable tube whose upper end is a short distance below the
lower end of the feed tube 26; the lower end of said tube, when in its lowest
position, is designed to rest upon perforated cap plate 38, which is secured to a
sleeve 38", which depends from the under side of the lower plate. The lower end
of the said tube is formed with a squared portion 38, to opposite lateral faces of
which are pivoted lever dogs or clutches 39, whose inner arms extend into the
tubo through slots 40, and are shaped to partially embrace or grip the carbon.

page_text: Attached to the outer arms of the respective lever dogs or clutches are rods 41,
whose upper ends are secured to the armature 42, of the magnet 28, said armature
being free to slide vertically on the said tube. When the said maguet is in action,
and the armature is attracted thereto, the tube is raised and the dogs or clutches
are thrown into position to grip the carbon. When, however, the armature is
released as hereinafter described, the tube drops onto the cap, and the dogs are
thrown out of gripping relation to the carbon by reason of the down thrust of the
rods 41, due to the dropping of the armature.
The lower carbon holder consists of an upper short tube portion 43, which is
carried by a box 44, a lower tube portion 46, and the clamps 47 and 48. The
clamp 47, consists of two lever dogs, whose outer arms are pivoted to the lateral
walls of the box 44, at the points 49, and whose inner arms extend into the
portion 46, through the slots 50, and are shaped to grip a carbon. The part 46, it
will be observed, is suspended within the box 44, by means of these lever dogs.
See Figures 6, 7 and 8. In Figures 9 and 10, I have shown a slightly different
form of these dogs, wherein they are each pivoted to the box 44, near their outer
ends, and upon the opposite side of the part 46, to that in which is the slot 50,
through which their gripping ends enter. Attached to the part 46, is a yoke 52,
whose lower transverse arm constitutes an armature 52, for electro-magnets 53,
which are supported within the yoke but independently thereof.
48 are two clamps or clutches (before referred to) which are pivoted to opposite
sides of the part 46, and whose lower arms 54, are arranged to swing below the
lower end of 46, and are shaped to the carbon; 55, are dogs pivoted to the upper
arm of the yoke 52, one behind each of the clutches, their purpose being to limit
the outward swing of the clutches 48, at the proper times and to hold the arms 54,
underneath the orifice of the tube portion 46. These dogs 55, normally hang in
such position that the clutches 48, are free to swing outward and away from
underneath 46, and they are forced into locking position by means of pins 56, with
which they engage as the yoke is drawn upwardly, as more fully hereinafter
described. In order to hold the said clutches 47, in this outward position, each is
provided at the upper end of one or both of its vertical arms above the pivot with
a book portion 57, which normally engages a pin 58, of the box 44. The weight
of the yoke and armature causes the engagement of this hook and pin to throw the
said clutches outwardly as will be readily understood. See Figure 6. 59 is the
positive terminal of the feed or supply wire which is connected to a binding
post 60, on the plate 27. From this binding post the current passes by the con-
nection 61, to a lever 62, of an automatic switch or cut out device; said lever is
pivoted at 63, to the sleeve 38", before described. The lower arm of said lever
is held in contact with the upper arm of a second lever 64, by means of a
spring 60°, of slight tension. The lever 64, is pivoted to sleeve 38, at the point 66
and its lower arm has an inward stud or projection 67, which enters the tube 37,
through a slot in said tube and contacts with the upper carbon A. 68, is a
stationary contact with which the upper arm of the lever 62, is designed to engage,
but with which it is normally out of engagement, being held in this position as
will be readily seen by the contact of the stud 67, with the carbon A. When,
however, the upper end of said carbon is fed below the said stud, the latter moves
further into the tube by the gravity of the lever 64, which throws the upper arm
of the lever 62, into contact with 68. This cut out device usually exists in
duplicate upon both sides of the sleeve 38, the two devices being electrically
connected.
The current normally passes by the connection 61, to the lever 62, thence to
lever 64, and to the carbon A, thence to the lower carbon B, and from thence by
wire 69, to the coils of the magnets 28. From the magnets 28, it passes by
connection 70, to the contact plate 36, thence through lever 34, and connection
to the main binding post 72, to which is attached the negative terminal of the feed
wire, thus completing the main or lamp circuit. 73, is the shunt in which is

page_text: located the magnet 29. 74, is a connection from the wire 69 to the resistance
coil 31. 75, is the connection from the stationary contact 68, to the coils of
magnets 53. 76, is a connection from the said magnets to the magnets 21. 77, is
the return wire from the magnets 21, to the main negative binding post 72. 78 is a
hand switch for cutting the lamp out of circuit. 79 is an automatic cut out for
shunting the lamp should it become inoperative; this cut out will be more fully
described after the general operation of the lamp has been explained.
Starting with the first pair of carbons properly trimmed and the lamp burning,
the operation is described as follows :-As the enrbons burn away, the resistance
through the main circuit including the magnets 28, becomes greater, causing a
stronger current to flow through the coil of the shunted magnet 29, until said.
magnet becomes strong enough to attract its armature 30. This armature being
attracted against the tension of the spring 31, the lever 34, is rocked on its pivot
out of contact with the plate 36, thereby cutting the magnets 28, completely out
of circuit. The return circuit from the lower carbon is now made through the
connection 74, resistance coil 31, lever 34, and connection 71, to binding post 72.
When the magnets 28 are cut out, the armature 42, drops slightly, carrying with
it the tube 37, until the latter is stopped by the cap plate 38; this movement
through the rod 41, rocks the dogs or clutches 39, away from the carbon, which
feeds down by gravity, restoring the main circuit to norinal condition, and
restoring thereto the current which was momentarily diverted into the coil of the
shunt magnet 29. The armature 30, is now released from the magnet 29, which
restores the contact between the lever 34, and plate 36, and throws the magnets 28,
back into circuit. The armature 42, is now attracted raising the tube 37, slightly,
and setting the clutches 39, upon the carbon. The actions just described are in
practice momentary in character and the actual movement of the armature 42, is
very slight, being simply a vibration, which results in a regular feed and a steady
light. This action is continued until the upper carbon has been fed down to a
point where its upper end passes the stud 67, when the lever 64, swings as above
described to operate lever 62, to make contact with the plate 68. This done the
current passes to the magnets 53, which are energized, and the armature 52ª, is
attracted. This raises the yoke 52, which rocks the clamp dogs 47, to release
their grip on the lower carbon, which drops out and onto the ground. As the
yoke rises, the hook portions 57, of the clamps 48, are released from the pins 58,
and as soon as the lower carbon has fallen out, said clamps swing into position
underneath the part 46, to catch the upper carbon when it descends. At the same
time the dogs 55 are, by engagement with the pins 56, forced behind the clamps 48,
to lock them in such position.
The main or lamp circuit being now broken the current is thrown into the
magnet 29 and the same action follows as was described in connection with the
feeding of the upper carbon, the clamps 39, remaining open to permit said carbon
to fall out of the upper holder and drop into the lower one, when it is caught
and held by the clamps 48. At the same time the magnets 53, are energized, the
upper magnets 21, are also energized, and attract the armature 20, which rotates
the shaft 8, causing the hook 13, to engage a carbon and draw it into the hollow
portion of the said shaft. This is done in the following mauner:-The lug 17,
being depressed by the projection 11", the lower end of the carbon readily slides
into the upper end of the feed tube 26, down which it commences to slide until
the upper end of said carbon falls through the slot of the upper disk 13, into the
hollow portion of said shaft; the carbon now slides down the tube 26, into the
tube 37, until its lower end strikes the stud 67, and forces it outward, actuating
levers 62, and 64, to cut off the current from the magnets 53 and 21. As soon as
the magnets 53, are cut out, the armature 52, and yoke 52, drops, which causes
the clutches 47, to grip the lower carbon, the dogs 55, to be released, and the
clutches 48, to swing back. At the same time the armature 20, is recovered by
its springs, the nut 19, turning freely on the shaft 8. The inner end of the stud 67,

page_text: is beveled off in order that it will be readily forced outward by the contact of the
descending carbon therewith. The upper carbon continues to descend until the
circuit is again established through the carbons, and the magnets 28, put into
circuit in the manner above described. The armature 42, is now attracted and
the clutches 39, caused to grip said upper carbon. This operation is repeated, one
carbon being taken successively from each of the holders in the magazine during
each revolution of the shaft 8.1
The automatic cut out 79, consists of a contact arm secured to an insulated
from the post 33, in such position that when the armature 30, is attracted, the
upper arm of the lever 34, will contact therewith, and by means of a connection 80,
to the post 60, short circuit the lamp, the current from the positive binding post
passing to contact 79, thence to lever 34, and thence to post 72. When, therefore,
the lamp becomes inoperative by reason of the failure of the feeding mechanism to
operate, or from other causes, the increased resistance in the main circuit
causes the magnet 29, to be energized, its armature 30, is attracted and the lamp
is shunted.
The adjustable screw which is attached to coil spring 31, forms a means for
regulating the candle power of the lamp, since by adjusting this screw to increase
the tension of the spring, or diminish it, a corresponding increase or decrease of
current in the coil of magnet 29, will be necessary to attract said armature. The
feed will therefore take place at longer or shorter intervals and the length of the
arc varied.
81, designates the globe holder, the bows of which are formed at their upper
ends with vertical extensions 82, which extend into the hollow posts 33, and are
formed each with a groove or key way 83. 84, are set screws which engage the
said grooves and by means of which the holder is secured; by loosening these
screws the holder can be lowered for the insertion or removal of the globe. Said
bows are grooved, as indicated at 84", to form seats for the circuit wires to the
magnets 53, and for the return wire from the lower carbon holder to the magnets 28.
85, is a casing which protects the magnet 28, and the adjacent mechanism. A
suitable hood (not shown) will also be placed over the magazine and the upper
portion of the lamp.
It will be observed that inasmuch as the magnets 28, are entirely cut out of
the circuit at the time the feed is made, the feeding devices are sure to operate
properly.
It will be observed further that in a lamp of this character there is a great
saving of carbon, since when the positive carbon has been burned to the full extent
possible, it takes the place of the lower carbon where it is again burned until but
a short piece remains and it is dropped out.
The lamp as above described is designed for use with a direct current.
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 :-
1. An arc electric lamp having a magazine containing a plurality of carbons,
a path or passage from the magazine to the first carbon holder, and from the first
carbon holder to the second carbon holder and electro-:nagnets for automatically
operating the carbon holders to release one carbon and substitute another,
substantially as described and shown.
2. An arc electric lamp having a supply of duplicate carbons, carbon holders
having clutches, electro-magnets for automatically operating the clutches to permit
a carbon to pass from the positive holder to the negative holder and from the
supply to the positive holder, substantially as described and shown.
3. An arc electric lamp having a chamber or magazine containing a supply of
duplicate carbons, clutches for the positive and negative carbon holders, electro-
magnets to strike the arc and feed the carbons in one circuit, electro-magnets to

page_text: automatically release the carbons located in a branch circuit and a switch in said
branch circuit operated by a carbon holder at a predetermined point in its
movement, substantially as described and shown.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.