Improvements in Electric Arc Lamps.
Year: 1897

page_text: Date of Application, 20th Sept., 1897
Complete Specification Left, 20th June, 1898-Accepted, 20th Aug.,
1898
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Bennard H. Pomeroy, a Citizen of the United
States, residing at Brooklyn, in the County of Queens, and State of New York,
in the United States of America, Electrician,) to be as follows: -
This invention relates to the carbon feeding mechanism for electric arc lamps,
and to the transparent or translucent globe employed for enclosing the arc to
increase the life of the carbons.
The object of this invention is:
First: To simplify and cheapen the feeding mechanism and to obtain a positive
and perfect feed as the carbons are consumed, and which mechanism will avoid the
slipping or sticking of the carbons.
Second: To provide an improved support for the arc enclosing globe which will
permit lateral movement of the globe while maintaining the support practically
air-tight, and whereby the globe will readily adjust itself to variations in the upper
carbon and thereby prevent the binding of the carbon at the entrance of the globe
and further to provide a cap for the globe which will prevent the entrance
of air.
In an arc lamp constructed in accordance with this invention, the negative
carbon may be held in any suitable manner within a stationary support, while the
positive carbon is carried by a rack bar. This rack bar meshes with a pinion
rigidly mounted upon an arbor which carries an escape wheel. The arbor of the
escape wheel is journalled in cross-bars forming part of a frame adapted to move
vertically on guide posts which are secured in a suitable manner to the frame of
the arc lamp mechanism. One or more of the guide posts are screw threaded at the
lower end to receive nuts which serve as adjustable stops for limiting the downward
movement of the frame. A magnet connected in series with the carbons, is
provided for striking the arc and for controlling the feeding mechanism. The core
of this magnet is connected with a lifting frame which is pivoted at a suitable
point to the frame of the lamp mechanism, and this lifting frame carries a pallet
which co-operates with the escape wheel to form an escapement for controlling the
gravitation of the rack bar.
The pallet is carried by an arbor pivoted in the lifting frame and which arbor
also carries a weight having two lugs which rest on the lower frame plate of the
lamp mechanism, when the lifting frame is in its lowermost position, i.c., the
position which it assumes when the magnet is not energized. In this position of
the weight, the pallet is held clear of the escape wheel and the rack is free to
descend so that the carbons will touch. The object of the weight carried by the
arbor of the pallet is to give a slow movement to the escapement. The frame which
carries the escape wheel is raised through two laterally projecting pins with which
the lifting frame engages when raised by the action of the magnet. The arbor
.

page_text: which carries the pallet is provided with a finger, which when the lifting frame is
raised by the action of the magnet, is brought into engagement with a pin or other
stop which will prevent the oscillation of the pallet and hence lock the escape
wheel against rotation and thereby raise the positive carbon to strike the arc. The
pin or stop which engages with the finger on the arbor of the pallet, is preferably
adjustable to adjust the point at which the escapement will be locked.
The operation of the feeding mechanism is as follows.
When the magnet is energized, the movement of its core raises the lifting frame,
and which frame engaging with the pins on the escape wheel frame, raises that
frame without affecting the rack-bar, since the escape wheel is free to rotate. The
continued upward movement of the lifting frame will bring the finger on the arbor
of the pallet into engagement with the stop, when the pallet will lock the escape
wheel. The escape wheel being now locked against rotation, the rack-bar, which
carries the positive carbon, will be carried upward through the upward movement
of the escape wheel frame and effect the separation of the carbons and strike the
arc. The striking of the arc increases the resistance, as will be well under-
stood, and the pull of the magnet will decrease, whereupon the lifting frame will.
descend a sufficient distance to disengage the finger on the arbor of the pallet from.
the stop and thus release the escapement and permit the rack-bar and positive
carbon to descend by gravity a slight distance. This action will decrease the
resistance at the arc and the magnet will again give a slight upward pull to the
lifting frame sufficient to again lock the escapement. This action adjusts the arc
and as the positive carbon is consumed and the resistance at the arc increases, the
pull of the magnet will decrease, whereupon the escapement will be released again
and permit a slight downward feed of the carbon until the resistance decreases to
the proper point, whereupon the escapement will be locked again by the action of
the magnet.
•
The lower carbon is preferably seated in a socket which is clamped to the bottom
of the lamp frame. This socket has a tapering inner surface to form a seat for the
tapering neck of the enclosing globe. The tapering neck preferably has a ground
surface so as to form a close joint at the bottom. The diameter at the top of the
socket is such as to allow a slight lateral movement of the globe
while maintaining a practically airtight joint at the bottom of the
socket. The upper carbon passes through a cap having several chambers, through
which the carbon passes. These chambers are preferably formed by several circular
inverted cup shaped parts screwed together, each part having a central opening
through which the carbon passes. The diameters of these openings are such that
the carbon will fit as tightly as possible without interfering with the proper feeding
of the carbon. In practice it is difficult to prevent the entrance of air where the
upper carbon enters the enclosing globe, and it is for this reason that the several
chambers are provided, whereby the air entering the chambers becomes diluted
with the gases which escape from the globe, and it has been found in practice,
that this arrangement is very effective in excluding the air from the enclosing
globe. To make this more clear, let it be supposed that the gases formed within.
the enclosing globe escape around the carbon into the first chamber of the cap, the
gases will become diluted with the air in that chamber, and the diluted gases
escaping from that chamber into the second chamber of the cap, will become diluted
with the air in the latter chamber, resulting in a mixture of air and gases less
dense than that in the first chamber. The diluted gases escaping into the third
chamber will become mixed with the air of that chamber, resulting in a mixture
less dense than the second, and thus it will be seen that the air entering the
chambers becomes so diluted with the gases therein that practically no air will
enter the enclosing globe. It has been found in practice that three chambers give
highly satisfactory results, but still better results might be obtained by adding.
additional chambers, but this is deemed unnecessary. In addition to the openings
in the walls of the chambers through which the carbon passes, each chamber is
provided with an opening normally held closed by a valve which will permit the

page_text: escape of the gases to successive chambers and from within the last chamber should
the pressure become too high.
Dated this 20th day of September 1897.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.
Improvements in Electric Are Lamps.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Bennard H. Pomeroy, a Citizen of the United
States, residing at Brooklyn, in the City of New York, State of New York, in the
United States of America, Electrician) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
-
This invention relates to the carbon feeding mechanism for electric arc lamps;
and to improvements in the construction and arrangement of transparent or
translucent globes employed for enclosing the arc to increase the life of the
carbons.
The objects of the invention are:
First, to simplify and cheapen the feeding mechanism and to obtain a positive
and perfect feed as the carbons are consumed, which mechanism will avoid the
slipping or sticking of the carbons:
Second, to provide an improved support for the arc enclosing globe which will
permit lateral movement of the globe while maintaining the support practically
airtight, and whereby the globe will readily adjust itself to variations in the upper
carbon and thereby prevent the binding of the carbon at the entrance of the
globe;
Third, as an equivalent construction to that just referred to, to provide for
rigidly supporting the enclosing globe, the cover or cap thereof being arranged in
such a way as to permit lateral movement of said cap or cover arising by reason
of the variations in the movement of the upper carbon; and
Fourth, to provide an improved cap or cover for the enclosing globe which will
prevent the entrance of air within the globe, and thereby will materially reduce the
rate of consumption at the arc.
In order that the invention may be better understood, attention is directed to the
accompanying drawings forming a part of this specification, and in which Fig. 1
is a vertical sectional view with the enclosing globe removed and illustrating
particularly the improved feeding mechanism; Fig. 2 a section through the
feeding mechanism at right angles to Fig. 1; Fig. 3 a section of the enclosing
globe, showing the cap or cover and also the socket for receiving the lower end of
the globe and negative carbon; and Fig. 4 a section of a modified form of cap or
cover.
Referring to Figures 1 and 2, A indicates the positive carbon and B the magnet
or solenoid which is in series with and is used for striking the arc, a solenoid
being illustrated.
The carbon A is carried by a rack bar C or by a plurality of rack bars arranged
in any suitable way. This rack bar meshes with a pinion D rigidly mounted
upon an arbor d which also carries an escape-wheel D¹. The arbor d is journaled
in cross-bars e of a frame E made of light sheet metal. This frame is adapted to
move vertically on two guide-bars F and F¹ which are secured between the upper

page_text: and lower plates of the main frame G of the regulating mechanism. The bar F is
preferably screw-threaded at its lower end, and two nuts fare provided on the
screw-threaded portion to serve as an adjustable stop for limiting the downward
movement of the frame E. The top plate of the frame E may be provided with a
pad e² of cloth or other elastic material to cushion the upward stroke of the frame
on striking the arc. If desired, a suitable dash-pot of any desired arrangement
may be employed to retard this initial movement.
The core 6 of the striking and regulating solenoid B is connected with a lifting
frame H, which is pivoted at h to the frame G. Said lifting frame comprises
essentially two parallel arms connected at their forward ends by a suitable link.
to the core b. This lifting frame carries a pallet I, which co-operates with the
escape-wheel D¹ to form an escapement for controlling the downward movement
of the rack-bar C. The said pallet is carried by an arbor i, to which is rigidly
secured a weight I having two lugs which rest on the lower plate of the frame G
when the lifting frame H is in its lowermost position, i.c., the position it assumes
when the solenoid B is not energized. When the lugs thus rest on the frame G,
the pallet will be held in the central. position clear of the escape wheel, and the
rack C will be free to descend, so that the carbons will be brought together.
The object of the weight I' is to give to the pallet sufficient inertia to provide for
a slow movement of the escapement.
The frame E is provided with two laterally projecting pins e¹, with which the
lifting frame H engages when raised by the action of the solenoid B, or instead
the said lifting frame may engage directly beneath the frame E upon the energiza-
tion of said solenoid. The stop nuts f are adjusted so that the lifting frame H will
have a free movement for a short distance before engaging the pins e¹ of the
frame E. The object of this free movement is to first bring the pallet into engage-
ment with the escape-wheel before the lifting frame begins to raise the frame E.
The arbor i is provided with a finger K, which, when the lifting frame is raised
a sufficient distance, will engage with the pink and prevent the oscillation of the
pallet and hence lock the escape-wheel against rotation, which action will prevent
the rack bar C from descending relatively to the pinion D.
The pink is preferably carried by a head adjustable upon a post projecting
from the lower plate of the frame G, but it is obvious that said pin may be
sustained in any other suitable way.
'
The operation of the improved feeding mechanism will be as follows: When the
solenoid B is energized, its core b will be drawn upward elevating the lifting
frame H and engaging the pallet with the escape-wheel D¹. As the lifting frame
continues to move upward, its engagement with the pins e¹ elevates the frame E,
but since the pallet is free to oscillate, the escape wheel D¹ and pinion D will rotate
without affecting the rack bar C, which therefore will retain its original position
with the two carbons in contact. When, however, the lifting frame H has
travelled almost to its full upward movement, the finger K will engage with the
pin and the pallet will therefore be prevented from oscillating. This therefore
locks the rotation of the pinion D), and the further movement of the lifting frame H
will elevate the rack bar C, thus separating the carbons and striking the arc.
As the arc widens, the resistance thereof will increase and the flow of current
therethrough will correspondingly drop. This will decrease the current energizing
the solenoid B, which will permit the lifting frame H to descend slightly, where-
upon the finger K becomes disengaged from the pin k, thus releasing the escape-
ment and permitting the rack-bar C and carbon A to descend by gravity a slight
distance until the resistance of the arc has been lowered to its normal condition.
When the arc is adjusted and the resistance is decreased, the increase in current
energizing the solenoid B will attract the core 6 sufficiently to elevate the lifting
frame and engage the finger K with the stop k, so that the upper carbon will be
locked in its adjusted position. As the carbons are consumed and the resistance at
the arc increases, the attraction of the solenoid B will decrease, wherepon the
escapement will be released again and the positive carbon will descend a slight
'

page_text: distance as before, after which the escapement will be locked again by the upward
movement of the lifting frame due to the increased magnetization of the solenoid
under the effect of the increase in current. It will therefore be seen that the
adjusting mechanism for the carbon is positive in its operation and of the highest
simplicity, only a single solenoid or magnet being used both for striking the arc
and for regulating it after it has been initially formed.
Referring to Fig. 3, which illustrates the preferred arrangement of enclosing
globe for the arc, whereby its life may be prolonged, A and B represent the positive
and negative carbons respectively, and C the transparent or translucent enclosing
globe. At the top of this globe is placed a cap D containing a number of chambers,
three being shown and marked d¹, d2 and d³. These chambers are preferably
formed by constructing the cap in several circular cup-shaped parts having
flanges d, to which the successive parts forming the cap are screwed, as illustrated.
Instead of screwing these parts together, they may be secured solely by frictional
engagement, as shown in Fig. 4. Preferably the top of each section of the cap is
provided with a vent-hole x, which is normally closed by any suitable form of
valve, a ball being shown and contained within a perforated shell ³. While in
practice it is desirable to make use of vent-holes through the chambers referred
to, it will be evident that they may be dispensed with, as shown in Fig. 4. Each
section of the cap is provided with a central opening y, through which the carbon
passes, and
these openings are of such diameter that the carbon A
will fit as tightly as is consistent with the proper feeding of the
carbon, the object of the close fit being to
make the cap as air-
tight as practicable to prevent the entrance of air into the enclosing
globe C. The lower end of the globe is formed with a contracted neck c, which
tapers slightly towards its lower end, and through which the lower carbon passes.
The said contracted.neck is normally received in a socket E, which may constitute
a part of the lower carbon-holder. This form of base for the globe C permits of a
very close fitting cap D, through which the carbon A passes, and if for any reason
the carbon A should move out of its vertical line of travel, or should there be any
tendency of the carbon to bind from any cause, the globe C may move with it, the
contracted neck c working slightly in the socket E and thus preventing or greatly
reducing any binding action between that carbon and the cap D. Instead, however,
of providing a close fitting cap for the globe C, and of mounting the said globe at
its lower end in a loose joint, good results will be obtained if the neck c fits tightly
within the socket E so as to support the globe rigidly, and if the cap is made
slightly larger at the upper part of the globe so as to move with respect to the same
under any variations in the feed of the carbon, as shown in Fig. 4.
.
The object of providing the cap with the several chambers d, etc., is to dilute the
air which may enter with the gases that escape from the globe C; and thus prevent
the entrance of air into the enclosing globe. To make this more clear, let it be
supposed that the gases formed within the globe C escape around the carbon A
through the opening y and through openings of section d of the cap into the
first chamber d. The gases will become diluted with the air in that chamber and
will pass successively into chambers d³, where they will mix with the air in such
chambers. Thus it will be seen that the air entering the chambers becomes
gradually more and more diluted with the gases therein, so that practically no air
will enter the globe C.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In arc lamp mechanism, the combination of a gravity feeding carbon rod,
an escape-wheel geared thereto and having a vertically movable bearing, a
pallet for said escape-wheel carried by a pivoted lever, a solenoid or magnet having
a core or armature connected with said lever, and a stop for arresting the oscillation
of the pallet, substantially as and for the purpose set forth.

page_text: 2. In arc lamp mechanism, the combination of a gravity feeding carbon rod,
an escape-wheel geared thereto and having a vertically movable bearing, a pallet
for said escape-wheel carried by a pivoted lever, a solenoid or magnet connected
in series with the arc and having a core or arimature connected with said lever, and
a stop for arresting the oscillation of the pallet, substantially as and for the pur-
pose set forth.
3. In arc lamp mechanism, the combination of a gravity feeding carbon rod, an
escape-wheel geared thereto and having a vertically movable bearing, a pallet for
said escape-wheel carried by a pivoted lever, a centrally pivoted weighted arm on
the arbor of said pallet, a solenoid having a core connected with said lever, and a
stop for arresting the oscillation of the pallet substantially as and for the purpose
set forth.
.4. In arc lamp mechanism, the combination of a gravity feeding carbon rod, an
escape-wheel geared thereto and having a vertically movable hearing, a pallet for
said escape-wheel carried by a pivoted lever, means for holding the pallet out of
engagement with the escape-wheel when no current is flowing through the lamp, a
solenoid having a core connected with said lever, and a stop for arresting the
oscillation of the pallet, substantially as and for the purpose set forth.
5. In arc lamp mechanism, the combination of a gravity feeding carbon rod, an
escape-wheel geared thereto and having a vertically movable bearing, a pallet for
said escape-wheel carried by a pivoted lever, a centrally pivoted, weighted arm on
the arbor of said pallet, projections on said arm for holding the pallet out of
engagement with the escape-wheel when no current is flowing through the lamp, a
solenoid having a core connected with said lever, and a stop for arresting the
oscillation of the pallet substantially as and for the purpose set forth.
6. In arc lamp mechanism, the combination of a gravity feeding carbon rod, a
pinion meshing therewith, an escape-wheel rotating with said pinion, a vertically
movable frame in which the arbor of said pinion and escape-wheel is journalled, a
lifting frame, a pallet pivoted on said lifting frame, a solenoid having a core
connected with said lifting frame, and a stop for arresting the oscillation of the
pallet substantially as and for the purpose set forth.
7. In an arc lamp, the combination with the carbons, of an enclosing globe for
the are having an aperture through which a carbon passes with a practically air
tight fit, and an adjustable and practically air tight joint for seid globe where the
other carbon enters and whereby the globe is free to adjust itself relative to the
carbons while maintaining said last named joint air tight substantially as set
forth.
8. In an arc lamp, the combination with the carbons, of an enclosing globe for
the arc, having an aperture through which a carbon passes, and a practically air
tight universal joint for said globe where the other carbon enters and whereby the
globe is free to adjust itself relative to the carbons while maintaining said last
named joint air tight substantially as set forth.
9. In an arc lamp, the combination with the carbons of an enclosing globe for the
arc having one or more chambers at one end thereof, the walls of which are
provided with apertures through which a carbon passes, and a valve for permitting
the escape of gas from the enclosing globe into the adjacent chamber when the
pressure becomes too high, substantially as set forth.
10. In an arc lamp, the combination with the carbons, of an enclosing globe
for the arc having two or more chambers at one end thereof, and provided with
apertures through which a carbon passes, a valve for permitting the escape of gas
from the enclosing globe into the adjacent chamber when the pressure becomes too
high, and valves for each chamber permitting the escane of gas to successive
chambers and to the exterior of the last chamber, substantially as set forth.
11. In an arc lamp, the combination with the carbons, of an enclosing globe for
the arc, a cap for said globe provided with one or more chambers and apertures
in the walls of such chamber or chambers through which a carbon passes, sub-
stantially as and for the purpose set forth.

page_text: 12. In an arc lamp, the combination with the carbons, of an enclosing globe for
the arc, a cap for said globe provided with two or more chambers having apertures
through which a carbon passes, and valves for each chamber permitting the escape
of gases to successive chambers and to the exterior of the cap, substantially as set
forth.
13. In an arc lamp, the combination with the carbons, of an enclosing globe, and
a cap therefor through which one of the carbons passes, said cap consisting of
several circular cup-shaped parts screwed together to form separate chambers
having central openings in the walls thereof for the carbon, and valves for each
chamber, substantially as set forth.
14. In an arc lamp, the combination with the carbons, of an enclosing globe,
and a cap therefor movable with respect to said globe, and comprising a plurality
of chambers, substantially as set forth.
1 T 20+1, 1908
HARRIS & MILLS,
23, Southamptou Buildings, London, W.C., Agents.