IMPROVEMENTS IN APPARATUS FOR ELECTRIC-LIGHTING
Year: 1882

page_text: LETTERS PATENT to George Hawkes, of Victoria Chambers, in the City of
Westminster, Gentleman, for an Invention of "IMPROVEMENTS IN APPARATUS
FOR ELECTRIC-LIGHTING."
PROVISIONAL SPECIFICATION left by the said George Hawkes at the Office
of the Commissioners of Patents on the 11th January 1882.
GEORGE HAWKES of Victoria Chambers in the City of Westminster Gentleman.
"IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING."
My improvements relate to the construction of electric lamps with a view to
simplify the mechanism, shunts, and regulating gear in connection therewith.
In constructing an electric lamp according to my Invention I employ mercury or
weights for the purpose of forcing the lower or negative carbon by means of tubes
into proper position with the upper or positive carbon, and I regulate the ascent of
the lower carbon by the varying action of a magnet or solenoid, which I place in a
branch circuit in the lamp. The duty of this magnet is to operate on a movable
armature or keeper combined with a clutch or jam ring, turning on two centres,
together with a spring descending from the outer one of two screws which operate.
from the upper one of two metal plates in the negative circuit. This spring in the
first instance by its operation prevents the ascent of the lower or negative
carbon, but gradually yields and allows it to approach towards the positive
carbon, staying the progress however of the lower carbon at a proper distance to
form the arc, and according to the strength of the branch magnet. This action
continues until both carbons are consumed or the current be shunted to the next
pair.
On a metal plate in the positive circuit I place a main magnet with armature.
The duty of this magnet is by attracting its armature to separate the carbons when
the electric current is flowing. The armature is fixed to the top or positive carbon
holder. This carbon holder passes through the back piece of the main magnet, or
through an independent metal guide, and also through the metal plate in the
positive circuit. Around this carbon holder I place a spiral spring calculated to

page_text: overpower when necessary the ascent of the lower carbon, and force it back to its
proper position; or I may use a bow spring. I do not allow this spring to operate
upon the armature beyond a prescribed distance, and to effect my object I have an
independent ring with two movable guides into and between which the spring fits.
These guides have free action, but I pre-determine the length of their descent.
Underneath the armature in the positive circuit I have two contact pieces of
platinum, attached thereto, and from the metal plate in the same circuit I have also
two similar contact pieces, one insulated from the positive main circuit before the
latter reaches the main magnet, and the other from the negative main current.
My object in adopting these contact pieces is to short circuit the main magnet,
and conduct the current on to the next pair of carbons, or other lamps in case the
main circuit becomes broken in the lamp, and the positive armature falls on to the
metal plate by its own weight; I thus render the circuit independent of any
particular lamp.
In constructing a lamp with two pairs of electrodes, I pre-arrange the point at
which one of the lower carbons stops ascending: I use a spring operating from
a metal plate in the negative circuit, and pressing against one of two armatures
of the branch magnet, thus acting upon the clutch, and preventing the ascent of
whichever carbon I wish kept stationary and out of the circuit for the time being.
At the right moment this spring is released by the other armature and allows
the regulating apparatus free action. Or I may apply two additional clutches, or
jamming rings with arms in connection with springs which will be freed at the
proper moment.
In addition to having the lower carbon ascend by the force of mercury, or
weights, I may by any suitable means such as lowering by the aid of thick fluid,
weights, or other device, cause the upper carbon to descend and adopt the same
regulation in every respect as hereinbefore described, only that it will be inverted
and I may place both the magnet in the main circuit and the magnet in the branch
circuit on the positive metal plate, in which case I prefer to turn the poles of the
main magnet upwards, with its armature or keeper supported by a spring.
When the electric current is flowing this magnet will by attracting its armature
cause the lower carbon to descend by the fall of the inner two of four metal tubes,
and thereby establish the arc subject to the same regulation as herein before
described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Hawkes in the Great Seal Patent Office on the 11th July
1882.
GEORGE HAWKES of Victoria Chambers in the City of Westminster Gentleman.
"IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING."
This Invention relates to improvements in arc lamps the object being to simplify
the construction and improve the working of the same.
I will first describe my Invention in relation to a lamp provided with a single
pair of electrodes I will then shew its application to lamps in which a pair of
electrodes is used, the second or additional pair coming into use automatically
after the consumption or destruction of the first pair of electrodes.
In the accompanying Drawings Figures 1 and 2 Sheet I. shew in vertical section
taken in planes at right angles the one to the other, an arc lamp with my improve-
ments applied thereto the parts being shewn in the position they will assume when
the lamp is alight.
Fig 3 Sheet II. is a sectional plan view of the lamp taken in the line 1. 2 of
Figures 1 and 2 and Fig: 4 is a sectional plan taken in the line 3. 4 of the same
Figures.
:
1
Fig 5 is a partial sectional elevation of the lamp shewing the change in the
position of the armature of the main electro magnet and the parts in immediate
connection therewith when the lamp is out of circuit.
The frame of the lamp is constructed as is usual of three metal plates A A¹ A³
secured together by vertical columns A³ A4 and A5 and furnished with a main
electro-magnet and a branch or a derived current magnet for regulating the positive
and negative electrodes or carbons. The column A³ which is in connection say
with the positive wire, is insulated from all the metal plates, and the column A'
which is connected with the negative wire is insulated from the uppermost plate A²
only. B is a closed tubular case pendent from the lowermost plate A and
containing the lower carbon holder with the means for raising it. C is the upper
carbon and D is the lower carbon. D' is the lower carbon holder, which passes up
through an opening in the plates A and A¹ and between the cores of the electro
magnet E which is in the branch or derived circuit.
Attached to the armature of this magnet and overlying the centre of the plate A
is the gripping piece F carried by pivot pins f and having an opening through it
to allow of the free passage upwards of the carbon holder when the armature E¹
is attracted by its magnet and the gripping piece is thereby raised as shewn at
Fig: 1.
This gripping piece is caused to bind upon the carbon holder and arrest its
upward motion by means of a coiled spring F¹ which presses down upon the
armature and thereby serves to overcome the attractive force of the electro magnet
when its current becomes weak owing to the too rapid rise of the carbon D. The
carbon C is fitted to a carbon holder C¹ which passes through the plate A² and
above this plate it is squared to enter a square hole in a guide frame C bolted to
the plate A. Keyed to the carbon holder C' is the armature G¹ of the electro
magnet G which is in the main circuit, its coils being connected by a coupling
screw g with the column A³ and by the coupling screw g¹ with the plate A² which
is in metallic contact with the carbon holder C. This electro magnet G serves as is
well known to part the carbons, and thereby to establish and maintain the electric
arc. In order however to provide a delicate adjustment for the carbon C I employ
the following arrangement: H is a coiled spring surrounding the upper part of the

page_text: carbon holder C¹ and retained between two collars h h' which also surround the
carbon holder. The lower collar h is suspended from the guide frame C³ by means
of pendent rods which pass freely through the head of the guide frame and are
each provided with a head to take a bearing on the guide frame. The upper
collar his attached to a pair of guide rods which after passing up through the guide
frame C² are connected together by a cross head-Upon this cross head bears a
regulating screw I, which projects through the back piece of the electro magnet G
and serves to determine the amount of compression that shall be put upon the
coiled spring H. This spring, it will be understood, is intended to press upon the
armature G when it is attracted by its electro magnet and thereby to counteract,
to any desired extent, the action of that magnet, determine the position at which
the armature shall rest, and consequently fix the position for the upper carbon C.
This position will however be maintained only so long as the main current serves
to maintain the energy of the electro magnet G unabated, for so soon as its energy
drops the effective power of the spring will proportionately increase, and the
armature and its carbon holder will be depressed. It will now be understood that
should the arc become too long, consequent upon the failure of the lower carbon to
rise, the spring H will press down the armature until checked by the pendent
collar h, and after this the armature will fall by its own weight, thereby bringing
the upper carbon into contact with the advancing lower carbon and closing the
main circuit. The light will then be immediately re-established by the electro-
magnet G drawing up the armature-and with it the upper carbon-to its regulated
position. A tendency is given to the lower carbon to rise continuously and at a
rate conforming as close as may be to its rate of consumption. This I effect
preferably by weighting the carbon holder D¹ as shewn best in Fig: 2, the weights,
pullies, and carbon holder used, being enclosed in the tube B, screwed into a socket
on the underside of the plate A. The centre of this tube is fitted with an open
tube B' in which works loosely a piston D2 pendent from the carbon holder D¹.
In this tube B' I place oil or other suitable liquid which the piston is intended
to displace, and thereby to retard or regulate the speed of advance of the lower
carbon.
I have said that the advance of this carbon is checked by the action of the
coiled spring F¹ upon the gripping piece F, which is held out of action by the
electro inagnet E to allow the carbon to rise freely.-It is however necessary to
regulate with great nicety the action of this spring, and also so to limit the upward
movement of the armature E¹ to which the gripping piece is attached as to prevent
the armature from being drawn into contact with its electro-magnet. For this double
purpose I provide a hollow reguating screw F', which, passing through the plate A¹
bears upon the coiled sdring f¹ that is made fast to the armature E¹, and the
hollow screw I tap to receive an elongated screw f³ which projects down through
the coiled spring so as to form a stop to the rising armature. By the adjustment
therefore of the screw F2 the force of the spring is regulated so as to counteract to
the required extent the energy of the electro-magnet Ĕ, and the rise of the armature
under the attraction of the electro-magnet is limited by the screw F³ so as to
retain it in a position that will ensure its remaining sensitive to the counteracting
influences of the spring and magnet.
It will now be understood that the spring F1 being adjusted to the normal
energy of the electro magnet E, the carbon D will be free to rise. Should however
the required amount of feed be exceeded, the length of arc will be unduly decreased,
thereby decreasing the amount of resistance in the main current; the result of this
will be an increased energy in the electro magnet G and a diminished energy in
the electro magnet E owing to the weakness of the derived current. The spring Fl
will now force back the armature E' and in doing so will cause the gripping piece F¹
to arrest the carbon and retain it quiescent until the normal resistance to the main
current is restored by the separation of the carbons and the derived current has
recovered its normal strength. The lower carbon will then be unlocked, and its
advance will proceed as before.

page_text: In order to cut out a lamp from a circuit when some accident has happened to
the carbons of that lamp, I adopt the following contrivance..
Insulated from the top plate A2, but resting upon it, is a strip of metal K, which
is in metallic connection with the column A³, and underlies one end of the arinature
G-K' is a similar strip of insulated metal, but connected with the column A¹.
The armature G¹ at the parts which overlie the strips K K' is fitted with platinum
points. While the lamp is in action the armature being held up by the attraction
of its electro magnet, will be clear of these insulated metal strips, but so soon an
undue resistance is offered to the main current, the power of the electro magnet
will be overcome by the spring H, and the armature will be thrown down into
contact with the strips K K¹ as shewn at Fig: 5. A short circuit will thus be made,
the armature forming a bridge for the current and the lamp will thus be thrown
out of circuit.
In constructing a lamp with two pairs of electrodes, I provide for the locking of
one of the lower carbon holders out of action and the unlocking by the acting
lower carbon, holder (for the time being) of the locked holder when a change of
carbons is required to be effected.-The armature of the electro magnet in the main
circuit I make cruciform, so that it may carry a pair of carbon holders. Standing
up from the centre of the cruciform armature is a rod G2 which passes through the
guide frame and acts as a central guide to the armature. Surrounding this rod.
are the collars h h¹ which embrace the spring H by which the movements of the
armature are regulated.-The armature of the electro magnet in the derived current
I form in two parts, attaching to each a gripping piece for regulating the ascent of
the lower_carbons. This arrangement is illustrated in the vertical section Fig. 6
Sheet III and in partial vertical section Fig: 7 the latter being taken at right
angles to Fig: 6. Fig: 8 is a sectional plan view of the double lamp taken at the
line 5. 6 of Fig: 6 and Fig: 9 is a sectional plan view taken at the line 7. 8 of
Fig: 6.
In these Figures the same letters of reference are employed as those used in
describing the single lamp and special reference will therefore be made only to the
parts which are modified in, or added to this lamp. The carbon holders D. are
made independent of each other, but between them is mounted a gripping lever L
(shewn in partial section at Fig: 6) which is free to rock vertically on a pin
carried by a bracket bolted to the underside of the plate A. One end of this
gripping lever is formed with a loop or ring to embrace one of the carbon holders D'
and the tail of this lever is made elastic and projects into the path of an adjustable
stud standing out from the other carbon holder D'. The lever L is held in its
gripping position by means of a rod 2 which bears upon the tail of the gripping
lever it being supported in a vertical position by passing through guiding holes in
the plates A A'. When however the stud rises up into contact with the tail of
the lever L, which it will do, so soon as it is necessary to bring a second pair of
electrodes into use the lever L will be tipped, and the locked carbon holder being
thereby released, it will be free to rise under the action of its weighted cords.
I have said that the armature of the magnet E is divided, this is shewn best at
Fig: 9, where each part of the armature is represented as provided with a gripping
piece F and controlled as before described by a spring and regulating screws.
The object of thus dividing the armature E' is to ensure a proper action of both
gripping pieces, even though the size of the carbon holders should somewhat
differ.
The form of the other armature G₁ and the mode of attaching the upper carbon
holders thereto, is clearly shewn at Figs: 6 and 8 and as its action is precisely
similar to the armature of the single lamp, no further reference to it will be
required.
As a modification of this lamp I may use in place of the gripping lever L the
arrangement shewn at Fig: 10 where a light spring made fast to the plate, A is
shewn as holding down the gripping piece of the lower carbon (which is out of use)
by pressing against the edge of the armature attached to the gripping piece. The

page_text: release of this armature from the spring will be caused by the attraction of the
electro magnet which will occur so soon as the derived current is strengthened by the
depletion of the main current caused by the burning out or destruction of the first
pair of carbons.
Having now set forth the nature of my Invention of "Improvements in
Apparatus for Electric Lighting" and having explained the manner of carrying the
same into effect I wish it to be understood that under the above in part recited
Letters Patent I claim-
First: In combination with an electro magnet in the main circuit of the lamp the
armature of which carries one of the carbon holders, an adjustable spring for acting
antagonistically thereto upon the armature of that magnet and thereby determining
the position of the carbon according to the variations of the current produced by
variations in the length of the arc, for the purpose above set forth.
Second: In combination with an electro magnet in the derived circuit a regu-
lated spring for acting antagonistically thereto upon the armature of such magnet
to which a gripping piece is attached such spring serving to depress the armature
and by means of the gripping piece arrest the progress of the advancing carbon
when the derived current is depleted by reason of the too near approach of the
carbon.
Third: In combination with the electro magnet in the derived circuit and the
spring which presses upon its armature, an adjustable screw stop for holding the
armature out of contact with the poles of its magnet and thereby rendering it the
more sensitive to the action of the pressure spring.
Fourth In combination with the armature of the electro magnet in the main
circuit, two contact pieces connected respectively with the positive and negative
conducting wires for the purpose of short circuiting the current when a defect in
the electrodes has occurred and thereby throwing the lamp out of circuit..
Fifth The adaptation, to electric lamps constructed to receive two pairs of
electrodes as shewn on Sheet III, of the means above described for locking out
and releasing one of the advancing electrodes for the purpose above set forth.
In witness whereof I the said George Hawkes have hereunto set my hand
and seal the Tenth day of July in the year of our Lord One thousand
eight hundred and eighty two.
ARADAR IT THE TA
GEORGE HAW
HAWKES. (L.S.)