Improvements in or connected with Electric Aro Lamps.
Year: 1895

page_text: Date of Application, 23rd Oct., 1895
Complete Specification Left, 23rd July, 1896-Accepted, 3rd Oct., 1896
PROVISIONAL SPECIFICATION
Improvements in or connected with Electric Aro Lamps.
I WILLIAM JAMES DAVY, of 4 Parolles Road, Holloway, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows
1
This invention has for its object to provide an automatic cut out which will cut
in again if the lamp should right itself; and also a spring carbon holder that can
adjust itself to bear over a length of the carbon and consists of a contact piece
adapted to make contact to short circuit the lamp and its own operating mechanism
when the are hecomes abnormally long, and a latch lever carrying a contact piece
adapted when the lamp has been short circuited as above to fall under and make
contact with the first contact piece to continue the short circuiting until a curient
is again established through the lamp; and of a split socket the two portions of
the socket being connected together at their ends by a spring or springs so that
one can pivot relatively to the other and thus tend to press on the carbons over
their whole length.
In one form of cut out and cut in a weighted contact piece is attached to the
lever operated by the core of the shunt solenoid of the lamp so that when the arc
becomes abnormally long it is raised against a second contact piece and short
circuits the lamp through a resistance
A latch lever connected to the armature
of a series magnet then falls under and makes contact with the moving contact
piece when in its raised position and before it falls owing to the shunt solenoid
being short circuited and continues the short circuiting. It will be seen that in
this position the regulating mechanism of the lamp is in such position as to leave
the carbons free to come together and the moment the carbons come together the
series magnet attracts the latch lever and opens the short circuit.
Dated this 23rd day of October 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents
Improvements in or connected with Electrio Aro Lamps.
1, WILLIAM JAMES DAVY, of Rostrevor, Boundaries Road, Balham, in the
County of Surrey, late of 4 Parolles Road, Holloway, in the County of Middlesex,
Engineer, 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 to provide an automatic cut out which will cut
in again if the lamp should right itself; and also a spring carbon holder that can
adjust itself to bear over a length of the carbon; and consists of a contact piece
adapted to make contact to short circuit the lamp and its own operating mechanism
when the arc becomes abnormally long, and a latch lever carrying a contact piece
adapted when the lamp has been short cucuited as above to fall under and make
Price Bl

page_text: contact with the first contact piece to continue the short circuiting until a current
1s again established through the lamp; and of a split socket, the two portions of
the socket being connected together at their ends by a spring or springs so that one
can pivot relatively to the other and thus tend to press on the carbons over their
whole length.
In one form of cut out and cut in a weighted contact piece is attached to the
lever operated by the core of the shunt solenoid of the lamp so that when the arc
becomes abnormally long it is raised against a second contact piece and short
circuits the lamp through a resistance. A latch lever connected to the armature
of a series magnet then falls under and makes contact with the moving contact
piece when in its raised position and before it falls owing to the shunt solenoid
beng short circunted and continues the short circuiting. It will be seen that in
this position the regulating mechanism of the lamp is in such position as to leave
the carbons free to come together and the moment the carbons come together the
series magnet attracts the latch lever and opens the short circuit.
In the accompanying sheet of illustrative diawings
Fig. 1 is a sectional elevation of the upper part of an arc lamp provided with a
cut out constructed according to this invention.
Figs. 23 and 4 are a side elevation, an end elevation and plan respectively of
the cut out.
Fig. 5 is an elevation of a carbon holder constructed according to this invention,
and Fig 6 is a plan of the same
Figs 7 and 8 are an elevation and section of a modified construction of carbon
holder.
Referring to Figs 1, 2, 3 and 4, the lever p operated by the shunt solenoid s
Fig. 1 cares a contnet piece and fixed above this contact piece is a contact
piece p. A latch lever a carrying a contact piece is pivoted to the frame of
the magnet so that it tends to fall under the contact piece p when the contact
piece p is in its raised position. The lever a 18 attached to the aimature of the
magnet which is connected in series with the carbou. The contact piece al 18
connected through the frame of the magnet to one terminal of the lamp and the
contact piece p is connected to the same terminal. The contact piece is
connected through a resistance to the other terminal of the lamp.
The action is as follows: The shunt solenoid & when the arc becomes abnormally
long draws in its core thus raising the weighted contact piece p³ against the fixed
contact piece p and short circuiting the lamp through the resistance. The
series magnet then allows the latch lever to drop under the weighted contact
piece and make contact thorewith before the said contact piece falls owing to
the shunt solenoid being short circuited. The lever p, if such lever is used to
control the feed gear of a gravity led lamp is then in such a position that the feed
mechanism is freed from its restraint so that the carbons are free to come together.
If the current through the carbons be again established by forcing the carbons into
contact, the car bons feeding together, shaking the lamp, or otherwise, the series
magnet² attracts the latch lever opening the short circuit and the lever p is
free again.
The spring carbon holder shown in Figs. 5 and 6 consists of a split socket 1, 2,
the two portions of the socket being connected together at then ends by the
springs The two parts thus tend to press on the carbons over their whole
length.
In the modification shown in Figs. 7 and 8, a flat spring 4 is rigidly attached to
the part socket 1 and loosely to the part socket 2 so that one side of the socket is
free to pivot to a slight extent in the direction of its length.
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. A cut out for an are lamp consisting of a contact piece adapted to make

page_text: contact to short circuit the lamp and its own operating mechanism when the arc
becomes abnormally long, and a latch lever carrying a contact piece adapted when
the lamp has been short cncuited as above to fall under and make contact with the
first contact pieco to continue the short circuiting until a current is again established
through the lamp.
2 A cut out for an are lamp consisting of a weighted contact piece, a shunt
solenoid and core adapted to raise the contact piece, a second contact piece fixed
in the path of the moving contact piece, a series magnet and armature a latch level
connected to the armature and forming a third contact piece tending to fall under
and make contact with the moving contact piece and hold it in its raised position
the first contact piece being connected through a resistance to one terminal of the
lamp and the other two to the other terminal.
3 A carbon holder consisting of a split socket and of a spring or springs
connecting the two sockets in such manner that one is free to rock relatively to the
other to press on the whole length of carbon within the socket
4. The improvements in cut outs substantially as described with reference to
Figs. 1, 2, 3 and 4 of the drawings.
5. The improvements in carbon holders substantially as described with reference
to Figs. 5, 6, 7 and 8 of the drawings.
Dated this 23rd day of July 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, Loudou, W.C., Agents.