Improvements in Electric Arc Lamps.
Year: 1899

page_text: Improvements in Electric Arc Lamps.
We, THE JANDUS ARC LAMP AND ELECTRIC COMPANY LIMITED, and ADRIAN
DENMAN JONES, both of Victoria Works, Old Charlton, Kent, Manufacturers, do
hereby declare the nature of this invention to be as follows:-
Our invention relates to improvements in enclosed arc lamps.
We find that with the methods of holding the inner globe and centering the
upper carbon hitherto used there has been considerable trouble, owing to the
breakage of this inner globe.
Our invention has for its object to lessen the risk of breakage of the inner
globe, and to enable the lamp to be more readily trimmed.
Our invention consists in an improved form of globe support and arrangement
for allowing the upper carbon to be accurately centred and yet readily fed as
required, while retaining a very nearly gas tight joint between the upper carbon
and the top of the inner globe.
In carrying our invention into effect according to one modification, we provide
an upper frame, connected to the positive carbon, in which a usual feeding device
is placed. The lower end of this frame we provide with an end having a circular
hole in the centre of it, and an inwardly projecting ring or tubular support. This
holder or tubular support is bored out an easy fit for the upper part of a removable
iron cap. This iron cap has a hole through it, which hole almost exactly fits
the carbon at its upper end, and is a slack fit for the carbon at its lower part,
that is, this hole through which the carbon passes is tapered, having its wide
end toward the arc. A circular shoulder is turned on the lower part of this
removable cap, and one side of this shoulder forms a flanged face or circular
abutment, against which the ground top of the inner globe of the lamp fits. The
upwardly projecting tubular part of the iron cap passes into the hole in the
positive carbon frame, and provides accurate centering for the positive carbon.
The inner globe we secure at its bottom to the negative carbon support by
means of a necked portion formed on the lower part of the globe near its bottom
edge. The bottom edge is carefully ground, and rests on a suitable packing
washer laid in a groove supported on the negative carbon holder. The metal
ring forming this groove portion has its inner wall projecting up above the height
of its outer wall. This inner wall is internally screwed, and a flanged cap is
provided having an external screw of such a diameter that it will engage with the
internally screwed portion of the globe support. The flanged portion of the ring
is larger in diameter than the necked portion of the globe, and the upper mouth
of the globe is large enough for this flanged ring to pass through freely.
The flanged ring is then passed through the upper mouth of the globe, and
screwed into engagement with the internally screwed ring holding the packing
washer against which the globe is to be pressed. The flanged ring is then screwed
0 down, and its flanged portion engages with the necked portion of the globe,
forcing it against the packing held in the grooved ring. This grooved ring hold-
ing the packing is itself screwed on to the lower carbon holder by the same
internally screwed part with which the inner flanged ring engages,

page_text: The upper iron removable cap being an easy fit for the tubular support formed
in the positive upper carbon holder, and having its tapered hole through which
the carbon passes, is capable of seating itself to form a gas-tight or approximately
gas-tight joint against the top of the inner globe, and yet will not jamb the carbon
should the top of the globe be slightly eccentric.
This improved construction also greatly facilitates the trimming of the lamp.
Total (41
1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.
Are Lamps.
We, THE JANDUS ARC LAMP AND ELECTRIC COMPANY LIMITED Manufacturers..
and ADRIAN DENMAN JONES, Work's Manager, formerly of Victoria Works, Old
Charlton, Kent, but now of Hartham Works, Hartham Road, Holloway, London,
N., 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:-
Our invention relates to improvements in enclosed arc lamps.
We find that with the methods of holding the inner globe and centering the
upper carbon hitherto used there has been considerable trouble, owing to the
breakage of this inner globe.
Our invention has for its object to lessen the risk of breakage of the inner
globe, and to enable the lamp to be more readily trimmed.
Our invention consists in an improved form of globe support and arrangement
for allowing the upper carbon to be accurately centred and yet readily fed as
required without jamming, while retaining a very nearly gas-tight joint between
the upper carbon and the top of the inner globe.
Our invention further consists in an improved method of supporting the bottom
of the inner globe.
Referring now to the accompanying drawings which illustrate our invention:--
Figure is a sectional elevation of part of an arc-lamp, illustrating one modi-
fication of the first part of our invention.
Figure 2 is a sectional elevation of part of an are lamp illustrating another
modification of our invention.
Figure is a sectional elevation of part of an arc lamp illustrating the second
part of our invention.
Figures 4, 5, 6, 7, and 8, illustrate some details of the second part of our in-
vention, drawn to a larger scale.
Referring to Figure 1, a is an upper frame supporting the positive carbon b.
in which frame a usual feeding device is placed. The lower end of this frame has
a circular hole e, and an inwardly projecting annulus . This annular holder or
tubular support is hored out such a fit for the boss of a removable cap e as
to prevent the cap tilting sufficiently to jam the carbon: this iron cap has a
tapered hole s through it, which hole at its upper end almost exactly fits the
carbon, and at its lower part is a slack fit for the carbon.
Figure 2 illustrates a modified form of the first part of our invention, a different
form of globe being shown. This modification is the same as the first, with the
exception that, instead of the hole in the cap being tapered, it is recessed as

page_text: own at f, and a shoulder is left, through which the carbon is
his shoulder may be slightly rounded at its edges to prevent it scraping the
rbon.
It will be seen in both these modifications, that the play of the boss on the cap e
the hole e, is such, in proportion to the length of the boss engaging in the hole,
at the tilting of the cap to fit the top of the globe, will be so limited as to
revent jamming of the carbon. Also the play of the boss will permit of some
ccentricity of the globe when there is no tilting.
This improved construction also greatly facilitates the trimming of the lamp,
nd centering of the upper carbon.
Figures 3, 4, 5, 6, 7, and 8, illustrate the second part of our invention which
onsists in securing an inner globe h at its bottom part, to the negative carbon
upport k The bottom edge of the globe is carefully ground, and rests on a
vasher made of asbestos or other suitable material, which lies in a recess of a
Hanged supporting collar m made of brass, iron or other suitable metal
Figures 4, 5 and 6, drawn to an enlarged scale illustrate the flanged supporting
collar m in plan, elevation and vertical section respectively. This metal support-
ing collar m has its inner flange projecting above the height of its outer
flange and the inner flange is screwed internally to receive a flanged ring n
which is screwed externally. Figures 7 and 8 drawn to the same enlarged scale
are respectively plan and elevation of the flanged ring » Figure 6 is a section
showing the ring n in position.
The flange on the ring is larger than a neck o formed on the globe, while the
upper mouth of the globe is large enough for the ring n to pass freely.
When the globe has been placed on the flanged supporting collar m, (the
washer having been inserted) the flanged ring is passed through the upper
mouth of the globe, and screwed into engagement with the internal screw of the
supporting collar m until the flange of the ring presses against the neck of the
globe thus forcing the globe against the washer and forming a gas-tight or
approximately gas-tight joint.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what we
claim is
1. In an enclosed are lamp, a cap for the top of the are enclosing globe adapted
to adjust itself to form a nearly gas-tight joint with the top of the said globe.
and to fit the carbon closely while permitting the feed, and preventing jamming
of the carbon, substantially as described.
2. In an arc lamp, the combination with an annulus, such as d. on the frame
supporting the upper carbon, of a cap, such as e having a boss such as the said
boss fitting the interior of the annulus, and having an internally tapered hole
such as, substantially as and for the purposes hereinbefore described with
reference to Figure 1.
3. In an arc lamp, the combination with an annulus such as 7, on the frame
supporting the upper carbon, of a cap such as e having a boss such as r the said
45 boss fitting the interior of the annulus, and having a hole with a recess such as f
and a shoulder such as g. substantially as and for the purposes hereinbefore
described with reference to Figure 2.
4. In an enclosed arc lamp, securing the lower end of the are enclosing globe
by pressing the lower edge of the globe by means of an inner flanged ring
50 against a suitable washer, carried by a supporting collar, fixed on the lower carbo
support the flanged upper portion of the said inner ring, engaging with a neel
formed on the inner globe, and said inner flanged ring screwing into the interio
of an inner flange on the said supporting collar substantially as hereinbefor
described.
55
5. In an enclosed arc lamp. securing the lower end of the inner globe. agains
a washer such as 7 situated in a supporting collar such as m by means of a flange

page_text: ring such as n which screws into the said collar, the flanged portion of the ring
pressing against a necked portion of the globe such as o substantially as and for
the purposes hereinbefore described with reference to Figures 3, 4, 5, 6, 7, and 8.
Dated this 23rd day of March 1900
MARKS & CLERK,
18. Southampton Buildings. London, W.C.