Improvements in Arc Lamps.
Year: 1889

page_text: Date of Application, 13th May, 1889
**Complete Spécification Left, 10th Feb., 1890-Accepted, 15th Mar., 1890.
Improvements in Arc Lamps.
I, SEBASTIAN ZIANI DE FERRANTI of 120 Fellows Road Hampstead in the
County of Middlesex Electrician do hereby declare the nature of this Invention to
be as follows:-
This Invention has for its object improvements in arc lamps.
I construct the lamp in such a manner that when the carbons are too far apart
they are free to be brought towards one another by the action of a weight.but
if brought too close are locked and restrained from approaching nearer by a pawl
or clutch which when the distance between the carbons again becomes too great is
put out of action by the movement of the moveable core of a solenoid coil through
which either the current feeding the lamp or a current passing in a shunt around the
lamp passes. I also control the speed at which the carbons when set free can move
towards one another by a brake block or friction surface pressed against some moving.
part of the lamp by the action of an electro magnet or solenoid through the coils
of which an alternating or intermittent current with which the lamp is fed is
passed.
-
At each alternation the magnet or solenoid ceases to hold the part and for an
instant the part is free to move but the distance it can move at each pulsation of the
current is extremely small.
1000
CARPMAEL & Co.,
A ventsi
•
COMPLETE SPECIFICATION.
Improvements in Arc Lamps.
1, SEBASTIAN ZIANI DE FERRANTI, of 120 Fellows Road, Hampstead, in' the
County of Middlesex, Electrician, 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 for its object improvements in arc lamps.
In my specification No. 7275 in the year 1889 I have described the use in lamps
which are fed with an alternating or intermittent current of a multiple pole magnet
acting upon an iron disc to control the speed at which the carbons come together.
According to my present invention I control the approach of the carbons by
mechanical retardation an electro-magnet or solenoid being caused to hold a brake
block in contact with a disc or part moving with the carbons. At each alternation
of the current the pressure of the brake block is relieved but the distance which the
part can move in the interval is extremely small. In conjunction with such con-
trolling apparatus I employ mechanism such as is described in my former specifica-
tion by which when the carbons are brought close enough they are locked and
restrained from approaching nearer by a pawl or clutch which when the distance
between the carbons again becomes too great is put out of action by the movement
of the moveable core of a solenoid coil through which either the current supplied.to
the carbons of the lamp.or the current in a shunt around the cat bons, passes:
In order that my said invention may be fully understood and readily carried into,
effect I will proceed to describe the drawings hereunto annexed.

page_text: The general arrangement of the lamp is similar to that of the lamp shown by the
Figures 1, 2 and 3 of my former specification.
The two carbons J J are connected with an endless chain F and tend to come
together in consequence of the superior weight of the upper carbon holder. The
chain passes around a chain pinion D on the axis of which is the disc E; con-
sequently the carbons can only come together at such a speed as the rotation of the
disc E admits. V1 is a brake block on the periphery of the disc; it is carried by a
lever V on which is an armature attracted by the electro-magnet M. This magnet
which may as already stated be in circuit with the carbons, produces an intermittent
pressure of the brake block upon the disc which permits of a slow rotary-movement.
This movement is however regulated by the pawl N on the lever O The lever O
is connected by a rod with the solenoid core P which is influenced by the solenoid C
in which it may be the same current passes as influences the magnet M. As
explained in my former specification when the core P is sufficiently raised by the
attraction of the coil C the pawl N engages with the teeth of the disc E and locks
it so that it can only move with the lever O. But when the core P descends the
stop pin R trips the pawl and the carbons approach each other.
In Figure 2 the upper carbon holder is attached to a rod S which sustains it; the
descent of the rod is retarded by the lever V and brake block V₁ which latter is
intermittently pressed against the rod by the magnet M. Thus the speed of descent of
the upper carbon is regulated. Further the distance between the carbons is con-
trolled by the solenoid C and core P as described in my former specification. O is
a lever moving with the core P it carries a pawl N engaging with rack teeth on the
rod S..
When the core P is
passing in the solenoid
:
raised a certain distance in conséquence of the current
being of the full strength, the pawl N engages and the
descent of the rod S and upper carbon is arrested except as the pawl N together. with
the core itself descends. But when the core P reaches a certain point the stop
pin R trips the pawl so that it no longer prevents the approach of the carbons; as
soon however as the current in the solenoid C again becomes sufficient, the core P
is lifted and the pawl N again engages.
So long as the pawl is engaged the distance between the carbons is controlled by
the position of the solenoid core; and when the pawl ceases to be engaged the carbons
approach until the pawl again comes into action...
The movement of the core P may be also controlled by a magnet W and lever ✗.
By the intermittent attraction of the magnet the brake block X is caused to press
upon the rod Y attached to the core P.
Having, now particularly described and ascertained the nature of my said inven-
tion and in what, manner the same is to be performed 1 declare that what I
claim is
:.
1. An electric are lamp in which the speed at which the carbons are allowed to
approach each other is regulated by the intermittent pressure, upon a disc or part
moving with the carbons (or one of them) of a brake block brought into action by
an. electro magnet or solenoid energised by an alternating or intermittent current
passing in its.coils.
2. The combination in an electric are lamp of a disc or part moving with
the carbons (or one of them); a brake block brought into action by an electro-magnet
or solenoid energised by an alternating or intermittent current; a clutch or pawl
acting to stop the carbons approaching one another if sufficient current is passing ;
and a solenoid acting to release the clutch or pawl when two little current is
passing...
3. The construction of electric arc lamps substantially as described.
CARPMAEL & Co.,
Agents for the Applicant.