Year: 1897

page_text: We, WILLIAM JAMES DAVY, Engineer, and GEORGE THOMAS-DAVIES, Engineer,
both of Horsell Road Works, Ronald's Road, Highbury, in the County of London, do
hereby declare the nature of this invention to be as follows:-
This invention for improvements in electric arc lamps relates more especially to
lamps in which the arc burns in an enclosed chamber to increase the length of life of
the carbons and one of the objects of this invention is to provide an efficient enclosed
alternate or direct current arc lamp.
The frame, of the lamp consists of a central tube and of an upper disc near its
lower end rigidly secured to the central tube. The top of the central tube is closed
and the ornamental casing and suspending piece are fixed to the top of the central
tube by a pin passing through the casing and piece and a plug in the upper end of
the tube. A lower disc is secured to the upper disc by bolts and a casing is clamped
between the discs. The bottom yoke is carried from the lower disc by yoke
rods.
The regulating bobbin is wound on a former and between two flanges on an outer
tube forced against the upper dise by a spring cap sliding on the central tube. Thin
longitudinal strips of iron are bound round the controlling coil so that it also forms
an impedence coil. The tubular core slides within the outer tube and is connected
to a double dash pot arrangement formed by the central tube, a cylinder working as
a piston in the tube and a piston fixed to the tube.
The core is connected by flexible cords to the outer ends of the links of a link
grip device similar to that described in prior Patent No. 5474 of 1894, and the inner
ends of the links are guided in fixed brackets.
The lower carbon holder screws or fits into the lower end of the enclosing bell and
the whole rests on a spring in a recess in a stud screwing into a cross har fitting in
notches or trunnions in the bottom yoke. The outer globe is passed over the stud
and secured by a nut.
27th due of Angust 1897
We, WILLIAM JAMES DAVY, and GEORGE THOMAS-DAVIES, of Horsell Road Works,
Ronald's Road, Highbury, in the County of London, Engineers, do hereby declare the
Laine 077

page_text: 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 for improvements in electric arc lamps relates more especially to.
lamps in which the are burns in an enclosed chamber to increase the length of life of
the carbons and one of the objects of this invention is to provide an efficient enclosed
alternate or direct current arc lamp.
In this lamp a perfect enclosure is obtained without the aid of the outer globe so
that the capacity of the chamber is small, and without the use of a sliding or
similar joint through which air and gas can diffuse or pass.
In the accompanying sheets of illustrative drawings:
Fig. 1 is a sectional elevation of an enclosed are lamp constructed according to this
invention.
Fig. 2 is a section at right angles to Fig. 1.
Fig. 3 is a cross section of the controlling bobbin or solenoid.
Figs. 4, 5 and 6 are detail views showing the arrangement of securing the enclosing
globe to the lower carbon holder which is fixed.
Fig. 7 shows the method of suspending the solenoid core from the dash pot.
Figs. 8, 9 and 10 are details of the brake or controlling gear, and Figs. Il and 12
details of the dash pot for steadying the mechanism.
The frame of the lamp consists of the central tube a and of the upper disc b
rigidly secured to the tube a. The top of the tube a is closed by a disc a' fitting
tightly therein and secured to an ebonite plug a² fixed in the upper end of the tube .
The ornamental casing c of the lamp and the suspending piece c¹ are secured to
the tube a by the bolt c2 passing through c c¹ and a². Below the upper disc b
is a lower disc d secured to the disc b by the bolts d. A casing e is clamped
between the discs b and d and thus forms with the discs and d an enclosed
chamber of the regulating mechanism. The bottom yoke is carried from the lower
disc d by the yoke rods 1.
The regulating bobbin g is wound on a former and between two flanges g¹ fixed
on a tube g² that is forced against the upper disc b by the spring cap g3 sliding
on the frame tube a. Thin longitudinal strips g of iron are placed round this
bobbin and forced into shape and secured in position by the binding wires g³.
The regulating coil thus also forms an impedence coil.
The tubular core h, made of iron strips for alternate current lamps and iron tube
for direct current lamps, slides free within the tube g² and is suspended from the
dash poti by the side links h¹ and bolt h² working in slots a' in the frame
tube . The core his connected to the brake or regulating mechanisms by the
flexible cords h³ h.
The upper carbon holder slides in the frame tube a and is connected by the
flexible conducting wire to the binding screw 12 in one of the side links h¹.
The upper carbon m passes between two jaws nn¹ fixed respectively between
pair links n n³ and n¹ n³ connected together at their free ends. The links n² 12t
are pivoted together at their meeting ends and at their outer ends are connected
together by the cords h³ passing through a loose sleeve 5 to one side of the end of the
tubular core h and the links n³ n5 by similar cords h4 passing through a similar
sleeve to the other side of the end of the core h.
The
The cords h³ h can be adjusted by sliding the sleeves h' h on the cords and fixing
them by means of set screws h³. The jaws norinally rest on the stop plate hs.
sleeves can be dispensed with, the cords being simply sewn or otherwise secured.
The pivots are extended outwards and guided in slots in the fixed brackets hº.
object of the slotted brackets is to prevent the brake from moving out of its position
when inserting carbons.
The
The lower carbon holder o screws or fits into the lower end of the enclosing trans-
parent bell p and the whole rests on a spring o¹ fitting in a recess or hole in the stud o²
screwing into a cross bar f2 fitting in notches or trunnions in the bottom yoke f.
The cross piece f² can be lifted out of the yoke f. The stud o2 also carries the nut o³
for securing the usual globe q in position.

page_text: holder, through the carbons to the lower carbon holder and by the conductor 13 to
the insulated binding screw thence through the regulating solenoid to the negative
terminal.
The carbons being in contact the upper carbon resting on the lower by its own
weight, on the passage of the current through the solenoid, the core h and conse-
quently the cords h³ h are drawn up and first raise the links n¹ n² n³ n¹ off the stop
plate and then cause the jaws to grip the carbon and raise it and strike the arc.
the are lengthens due to the burning away, gradually the grip device is lowered
onto the stop plate and the jaws relax their hold on the carbon and a continuous and
steady feed is obtained by the upper carbon slowly descending through the jaws.
As
The spaces open to the are are thus the chamber enclosed by the bell P, the
chamber enclosed by the casing e, the frame tube a, and the solenoid g². Any
excessive pressure of gases accumulating escapes through the spring cap g³ or the
mouth of the bell, the spring o' acting as relief.
To renew the carbons the screw o³ is slackened to remove the globe, the stud o²
is then unscrewed out of the cross piece f2 until the cross piece can be raised out of
its recesses or trunnion bearings in the yoke f and then removed with the bell and
lower carbon holder through the yoke f, the top carbon and holder following by its
weight. The top carbon is then removed and inserted in the lower carbon holder and
a fresh carbon placed in the upper holder when the bell and lower carbon are placed
in position forcing upwards the upper carbon holder to its upper position. The upper
edge of the bell rests against an asbestos washers and by gently screwing up the
stud o² the bell is forced against the asbestos, the spring allowing for expansion
and contraction and the like. The globe q is then replaced.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. The improved means for enclosing are lamps consisting of the fixed solenoid
tube separating the core and the coils and enabling the lamps to be enclosed sub-
stantially as described.
2. The construction and arrangement of the frame of the enclosed arc lamp
consisting of the central frame tube, the solenoid tube, the upper disc secured
thereto, the lower disc bolted to the upper disc, the enclosing ring enclosing the
space between the two dises and the lower yoke secured by yoke rods to the lower
disc and the glass bell, the whole forming a perfectly closed chamber substantially
as described.
3. The construction and arrangement of the frame and supporting parts of the
lamp substantially as described with reference to the drawings so as to form a small
perfectly closed chamber.
.
4. The gravity friction grip.device consisting of the jaws, the jointed links and
the cords or chains connecting the links to the core of the solenoid.
5. The means for securing the enclosing bell in position consisting of the bottom
yoke supported from the frame of the lamp, the cross bar fitting in notches in the
yoke, the stud screwing into the cross bar, the lower carbon holder secured to the
transparent bell, and a spring within the stud and on which the carbon holder
rests.

page_text: 6. The means for securing the enclosing bell in position substantially as described
with reference to the drawings.
7. The improved construction of electric arc lamps, substantially as described with
reference to the drawings.
Dated this 27th day of May 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.