Multiple Change-over Mechanism for Electric Aro Lamps.
Year: 1893

page_text: Date of Application, 16th Mar., 1893
Complete Specification Left, 8th Dec., 1893-Accepted, 24th Feb., 1894
PROVISIONAL SPECIFICATION.
Multiple Change-over Mechanism for Electric Aro Lamps.
WILLIAM JAMES DAVY of 41. Wandsworth Bridge Road Fulham S. W. London
Mechanical and Electrical Engineer do hereby declare the nature of this invention
to be as follows:-
The object of this invention is to provide an improved change-over mechanism
for electric arc lamps whereby a series of pairs of carbons are successively and
automatically brought into use and consumption, the said mechanism being
applicable to arc lamps of the kind known as non-focussing lamps as well as to
those known as focussing lamps.
I employ in each lamp two holders for holding a reserve stock of carbons, and
two working holders in which the pair of active carbons are held, and by suitable
arrangements I provide for the successive transference of pairs of carbons from
the stock holders to the working holders as required by the consumption of carbon
in the lamp. In order to facilitate this operation I attach suitable ferrules to the
ends of the carbone, which are to be fixed firmly thereto, and I insert these
ferruled ends into sockets preferably arranged in a circle in the stock holders, and
Cause them to be held thereinto, by & against the action of springs, by keys or
other locking devices, so that when such locking devices are released the carbons
are forced out of the sockets in the stock carbon holder. Each working carbon
holder has a number of sockets corresponding to the number of sockets in the
stock holder from which it draws its supply of carbons, and the sockets in the
working holders have their axes coinciding with the axes of the sockets in
the stock holders so that when a working holder and a stock holder are brought
into contact by virtue of either of them eliding on the fixed side rods or central
guides of the lamp, any one of the carbons which is released from the stock
holder will be forced by the springs above mentioned into the corresponding
sockets in the working holder, and held thereto by a spring catch or key of suitable
form.
When the working holders have approached within a certain distance of each
other by reason of the consumption of the active carbons, I cause que or other
of them to operate directly or indirectly a relay contact to a solenoid working a
switch which diverts the electrical current away from the lamp and directs it
through the coils of a solenoid having a soft iron core attached by cords or other
suitable means to the sliding carbon holders. The soft iron core is drawn up into
the solenoid and the working carbon holders and stock carbon holders are thereby
brought into contact with each other so that fresh carbons can easily pass from the
stock holders to the working holders.
I provide for the release of the carbons from the stock holders by allowing the
mutual approach of the stock holders and the working holders to operate, directly
or indirectly, a toothed disc upon the stock holder, which revolves concentrically
therewith, & which successively engages and releases the locking devices for
holding the carbons into the stock holder against the action of the springs above
mentioned.
At the same instant, and also by reason of the close approach of the stock
holder to the working holder, or vice versa, the switch is again operated and ourrent
cut off from the change-over mechanism which remains inoperative, and the current
once more flows through the ordinary regulating mechanism of the lamp, and an
arc is struck and maintained between the fresh set of carbons.

page_text: .
;
It must be understood that I may cause the action of the solenoid either to
bring the working holders back into contact with the stock holders to receive fresh
carbons, or may cause either of the working holders to remain stationary and to
be approached by the stock holder for the purpose of receiving a fresh carbon
therefrom according to whether the lump is of the focussing or of the non-focussing
type.
It must also be understood that this change-over mechanism is entirely separate
from & independent of the mechanism for regulating the arc, and that it remains
entirely out of action during the ordinary working of the lamp.
For facilitating the attachment of the ferrules above mentioned to the carbons,
the fixed or non-active ends of the carbons are enlarged for a short distance
forming a shoulder between the enlarged portion and the rest of the carbon. The
enlarged portion is made to fit into the ferrule and a nut which slides over the
portion of the carbon having the smaller diameter but catches against the larger
diameter of the shoulder, is screwed on or into the ferrule, and the carbon and
ferrule are thereby firmly and accurately attached.
The key or locking device for holding a ferrule into a socket in a stock holder,
is preferably applied to a cylindrical tail on the ferrule which projects through the
bottom of the socket. The key will swing from one end on a pin or pivot on tho
back of the stock holder, and its other end will be forced by a spring to eugnge
into a groove turned upon the cylindrical tail of the ferrule, until it is swung-
aside and the ferrule released by the action of the toothed disc above mentioned.
The groove on the tail of the ferrule will be a complete circumferential groove so
that the ferrules with their carbons will become immediately locked into the
..sockets when they are pressed thereinto, without other manipulation and without
reference to the direction in which they may be turned.
The spring keys for retaining the ferrules in the working holders, sliould also
ongage into circumferential grooves on the ferrules, so that they will be properly
locked and retained, in whatever direction they may be turned at the moment they
are shot into the working holders..
Dated this 8th day of March 1893.
WILLIAM J. DAVY.
COMPLETE SPECIFICATION.
Multiple Change-over Mechanism for. Electric Aro Lamps..
I WILLIAM JAMES DAVY of 161 Huddleston Road Tufnell Park N. London
late of 41 Wandsworth Bridge Road Fulham S. W. Mechanical and Electrical
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:-
The object of this invention is to provide an improved change over mechanism
for electric aro lamps, whereby a series of pairs of carbons are successively and
automatically brought into use and consumption.
In describing my invention I make reference to the accompanying drawings in
which.
Fig. 1 is a sectional elevation of an electric arc lamp showing such parts as are.
necessary for the purpose of this description.
Fig. 2 is a drawing showing the stock carbon holder.
Fig. 3 & 3 is a drawing showing the working carbon, holder adapted to carry
one carbon in the centre and receive successive carbons from the stock-holder.
Fig. 4 is a drawing of the switch.
Fig. 5 is a drawing of one of the ferrules.
Fig. 6 is a view showing the lever pawl and rack.
In Fig. 1. A. A' are two stock holders fixed firmly to the top and bottom portions

page_text: .
of the lamp. BB' are rings fitted around the outside of the holders A A¹ and free
to turn concentrically therewith. These rings are made with a groove on their
inner side, within which slides the bead of the spring keys a Fig. 2. Slots 6 are
pitched at certain distances around this groove which give room for spring keys a
to work. Attached to the stock holder is a lever, pall, and rack, c, d, e Fig. 2 & 6
operated by the working holder and operating with the revolving rings B. B'.
The said stock carbon holders, hold firmly in place and ready to be delivered into
the working carbon holder C C¹ four, or more sets of carbons as shown Fig. 1.
CC are the working carbon holders fixed to rods or cords and suitably guided
and controlled by the striking and regulating mechanism of the lamp in the usual
way. Such striking and regulating mechanism may be of any approved form and
is therefore not shown in the drawings.
In order to facilitate the recharging of the lamp I attach the ends of the carbons
to ferruleaf, Figs. No. 1 & 5, and insert these into sockets O. Figs. No. 1 & 2
preferably arranged in a circle in the stock holders, these ferrules are securely held
in place, and compress the springs g, Figs. No. 1 & 2, and are prevented from
springing out by the spring keys a Fig. 2. which fit into the recess of the ferrule i.
Euch working carbon holder C C' is formed with a number of tapered sockets,
corresponding with the the number of sockets in the stock carbon holder from
which it derives its supply of carbons, and the sockets of each holder have their
axes coinciding with each other. Into these scckets are arranged to fit nicely,
the ferrules, Figs. 1 & 5, as shown. These ferrules are constructed with a
circumferential groove i, to receive and be held in place by the aforementioned
spring keys a & h Fig³; 2 & 3 by this arrangement the ferrule may be inserted in
any position. The carbons are held firmly within the ferrules by means of the
key Fig. 5. It will be seen that the mechanism for holding and releasing the
carbons in the top and bottom stock-holders is similar in construction, and is
operated in a similar manner.
2
A switch shown in off position Fig. 4 is placed and fixed in a suitable position
in the lamp and is operated indirectly by a lever ze by the working carbon holder
or rod, thus allowing the current to pass to the solenoid D, which is preferably
fixed below the lower stock holder A' Fig. 1.
It will be seen that if a current is passed through the coils of the solenoid D the
soft iron core k, which is attached to the lower working carbon holder will be
drawn into the solenoid, and at the same time separate the two carbon holders
which are connected together by a suitable cord or chain passing over a pulley
suitably fixed on the lamp.
The action of the mechanism is as follows:-The top and bottom stock-carbon
holders being charged, the central carbons are first brought into action in the
carbon holders C C¹, and the change over mechanism is entirely out of action until
the central carbons are nearly consumed; when this stage is reached it is the duty
of the mechanism hereinbefore described, to introduce a fresh set of carbons into
the working bolders CC. This is effected by the downward travel of the top
carbon holder which has a projection so placed as to trip the lever & operating
the switch Fig. 4 cutting the current off the carbons and allowing the current to
pass to the solenoid D which as already stated, causes the core with the bottom
carbon holder attached to be drawn down, and the top carbon holder to be drawn
up, until they come in contact with the lever, pawl, and rack arrangement Fig. 6,
secured to the stock holders and operating the revolving rings B. B'. By the
movement of the rings B. B' the spring keys a are released into the recesses in the
rings B B¹, successively in pairs, thus releasing a fresh pair of carbons with their
respective ferrules, which are quickly shot into the carbon holders by the springs
behind them, and are prevented from falling out by the spring keys h. At the
same moment that this operation is performed the switch is again operated and the
current cut off from the solenoid, which allows the carbon holders to fall together
with the fresh pair of carbons, and the arc is again struck and maintained by the
ordinary mechanism of the lamp until these carbons are again consumed, when the

page_text: above operation again takes place. When all the carbons have been released
the lower ring B in revolving operates a small lever switch or contact, & thus
automatically cuts out the solenoid by breaking the circuit which is operated &
opened or slut by the switch Fig. 4 and thus prevents the mechanism from again
operating mutil the magazine is replenished.
It must be understood that I may cause the action of the solenoid either to bring
the working holders back into contact with the stock holders to receive fresh
carbons, or I may cause either of the working carbon holders to remain stationary,
and to be approached by the stock holders for the purpose of receiving fresh
carbons therefrom, according to whether the lamp is of the focussing or non-
focussing type. I may modify the form and dimensions of my improved electric
arc lamp according to requirements, without departing from the nature of my
invention.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In change over mechanism for electric arc lamps the combination of the stock
carbon holders A. A' with the circular ring B B' together with the springs, keys,
pawl, lever and toothed rack, for the purpose of releasing successive carbons
substantially as herein described and illustrated.
2. In change over mechanism for electric are lamps, the combination of ferrules,
carbons, and keys, substantially as herein described and illustrated.
3. In change over mechanism for electric arc lamps, the combination of the
Bolenoid D with the core k. attached to the lower carbon holder C, and controlling
by suitable means the upper working carbon holder C, substantially as hereinbefore
described and illustrated.
4. In change over mechanism for electric arc lamps, the combination of the
switch Fig. 4 with the solenoid D for switching the main current through the coils
of the said solenoid for the purpose of drawing back the working carbon holders to
receive fresh carbons from their respective stuck-holders substantially as described
and illustrated.
5. The improved construction with reference to Figs. 1 to 6 of the accompanying
drawings and operating for the purpose as above specified, substantially as described
and illustrated.
Dated this 7th day of December 1893.