Improvements in Aro Electric Lamps.
Year: 1892

page_text: Date of Application, 3rd Mar., 1892
Complete Specification Left, 2nd Dec., 1892-Accepted, 14th Jan., 1893
PROVISIONAL SPECIFICATION.
'Improvements in Aro Electric Lamps.
I, JAMES BROCKIE, of 65 Lowth Road, Camberwell, in the County of London,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
1+
.
IT
My invention relates to a construction of arc electric lamp and regulating
mechanism for the proper control of the carbons, in such manner that the lamp is
less liable to derangement, requires less attention as to cleaning, is more compact,
that the regulation is more certain, and the voltage at the carbon points is kept
more uniform than in lamps usually employed.
The mechanical construction of the lamp in respect to its framework and
arrangement of carbon holders is substantially as follows when arranged for two
distinct pairs of carbons.
'
There is a cylindrical top crown or plate, having a diaphragm a few inches
below it fixed to it by two side plates or pillars; in this space, the focussing wheels
and brake levers are placed. Below this diaphragm is fixed centrally a vertical
metal tube or rod, the length of which slightly exceeds the travel of the positive.
carbon. At the lower end of this central tube or rod is fixed another diaphragm
constituting the base plate of the lamp, through holes in which the carbon-holder-
rods slide up and down. To the base-plate near its edge are fixed two vertical
tubes and another tube (preferably square) is fixed in the centre of the base plate,
another disc or diaphragm is attached to the lower ends of these three tubes, this
last disc having two large holes cut in the two. spaces between the three tubes,
through which holes pass the two positive carbons and their holders. The two
negative carbon-holder-rods pass up through the two side tubes; and the two
positive carbon-holder-rods are provided with cross-heads which are guided by the
two outside tubes and the central square tube; the top of each of the two positive
carbon-holder-rods is furnished with a disc slightly larger than the diameter, of.
the rod, which slides freely up and down in the interior of a tube, erected between
the base plate and top diaphragm. A tape or cord attached to the top of each of the
two positive carbon-holder-rods, passes over a large pulley at the top of the lamp, the
other end of this tape being attached to the top of the corresponding negative
(carbon-holder-rod, so that as the positive carbon-holder-rod descends it raises the.
negative carbon-holder-rod or if metallic tapes or cords are used to conduct the.
current as will be afterwards explained two separate cords or tapes are used each.
fixed to its own pulley.
1.
"In order to keep the cranked negative carbon-holders in true position, two
vertical guide rods for each are erected between the base plate and top diaphragm,
of the lamp, and a suitable cross head fixed to but insulated from each carbon-..
holder-rod, slides up and down between these rods.
T'enclose the interior of the lamp between the top crown and base plate in a
cylindrical case having at its lower end a flange somewhat larger in diameter than
the cylinder which is held up to the base plate by screws or otherwise.
10
The top of the cylindrical case fits within a lip projecting down from the top..
crown, so that rain cannot enter it. I usually place the terminals on the top of the
crown, and protect the insulation of both or of the negative only. from rain &c.,
by a suitable hood on the terminal itself. I fix and manipulate the globe in the,
following manner. I provide a metallic ring the internal diameter of which, is
slightly greater than the external diameter of the third or lowest diaphragm, to
which it may be fixed; the external diameter of this ring being greater than the
upper opening of the globe, a lip is preferably formed to. project down from this

page_text: $
ring nearly fitting the mouth of the globe. To the under side of this ring two
vertical rods are fixed, having fixed to their lower ends a double cross bar having
fixed to its centre a short tube or pin upon which the globe carrier plate slides,
and is fixed by a catch or screw.
.
The rods are made of such length that when the globe is resting upon the carrier
on the bottom pin or tube, the large ring fits close down upon the top of the globe,
which being thus held between it and the carrier below, can be raised by lifting
the top ring without being attached to it by the outside netting usually employed.
This top ring has a cross bar carrying centrally a vertical rod which can slide
up and down within the central square guide tube previously mentioned; a set
screw or other suitable catch being provided to fix the globe in its. uppermost or
normal position, or when it is lowered sufficiently to allow for the proper trimming
of the lamp.
Thus the globe can either be taken off bodily from below, or lowered on an
extension piece on the bottom cross bar, or the whole frame, rings, and globe, can
be lowered together for trimming or other purposes.
I prefer to enclose the space between the Hange of the cylindrical casing and
the lowest diaphragm in an outer casing which may be of an ornamental character
and which does not closely fit around the flange but as it extends over and around
the outside diameter of the top globe ring; any rain which may find its way past
the flange of the cylindrical case upon the slanting globe will find its way out
over the globe ring and the outside surface of the globe. This protecting casing
can readily be pushed upwards to any extent so that the guide rods and carbons
from end to end can be thoroughly inspected and cleaned, and the trimming
facilitated whilst at the same time when the casing is lowered on the globe ring, the
protection from weather is complete. A reflector may be fixed or the upper side
of the globe ring, and if this reflector is to be guided in raising and lowering the
lamp the globe ring to which it is attached is preferably fixed to the body of
the lamp. If a lantern is used instead of a globe, it may be attached to the
reflector by a hinge and catch, or it may be carried by a central rod in the same
manner as the globe.
L.prefer to make the focussing wheels act as regulators in the following manner
I make. them of large diameter so that they make less than one revolution during
the total travel of the positive carbon-holder-rods, and I make each wheel consist
of two discs, electrically insulated from each other, the metallic band or cord
attached to the positive carbon-holder-rod running on the one disc and the negative
carbon-holder-rod band or cord running on the other, a flexible spiral conducting,
band is electrically connected to the negative terminal of the lamp and a few turns
of this are coiled round the spindle which carries the focussing wheels its free
end being electrically connected to the metallic band or cord attached to the
negative carbon-holder-rod.
The other metallic band or cord is attached to that one of the two wheels which
is, in electrical connection with the body of the lamp which is positive, so that no
spiral flexible band is necessary to conduct the current to it, unless the current is
unusually great; the weight of both the positive and negative carbon-holder rods
being sufficient to ensure good electrical contact of the strong metallic spindle which
carries the wheels. What I have called the focussing wheels, are shaped as cams
or snails so that the weight attached to a band fixed to their peripherics tends to
turn them with a gradually increasing or decreasing leverage according to the
direction of pull.
I form and set each pair of cams (forming one focussing wheel) in such a relation
to each other that, when all the positive tape is wound on the one cam and the
negative tape unwound from the other the positive carbon holder rod will as the
carbons become consumed pull up the weight of the ascending negative carbon
holder rod by an increasing leverage the positive cam gaining while the negative
loses leverage. In this manner I compensate for the loss of weight of the
carbon. as it is consumed and for the loss of carbon resistance due to the shortening
t.i.

page_text: of the carbon as it is consumed; and I thus avoid the abnormal lengthening" of "arc
usually produced towards the end of the life of the carbons.
By gearing a brake wheel or a train of wheels into a spur wheel on the spindle
of these cams (driven by the descending weight of the positive carbon-holder-rod)
the descent of the carbon-holder-rod can obviously be controlled by any known
brake or clutch gear suitable for an arc lamp to regulate the feed of the carbons.
In some cases I use for the purpose a retarding brake acting on the periphery of
a drum which is directly fixed to the spindle carrying the cams, thus avoiding all
gearing, and below this drum I place a horizontal lever rocking on a pivot vertically
below the axis of the 'drum. Between this lever and the drum I fix, a yielding
brake block so that as the lever begins to rock in the one direction, the block
comes in contact with the drum and turns it partly round, yet if the lever is further
rocked the spring yields avoiding jamming of the brake between the drum and
lever. I operate this rocking lever by any well known and effective electrical
controlling solenoids or magnets but especially by that combination of electrical
coils described fully in the Specification No. 12681 of 1885.
By fixing on the cam a pin or stud which comes against the regulating lever, or
a suitable projection from it, when the carbons are consumed. I provide that the
weight of the holder-rod of the carbon first burnt out, is still supported by the
regulating lever, and I thus keep the voltage of the current for the second carbon
the same as the first.
'The above description refers to double carbon lamps which however by a few
obvious 'modifications can be used for single carbons.
Dated this ad dev of March 1899
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
•
Improvements in Arc Electric Lamps.
I, JAMES BROCKIE, of 65 Lowth Road, Camberwell, in the County of London,
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 :-
My invention relates to a construction of arc electric lamp and regulating
mechanism for the proper control of the carbons, in such manner that the lamp is
less liable to derangement, requires less attention as to cleaning, is more compact,
that the regulation is more certain, and the voltage at the carbon points is kept
more uniform than in lamps usually employed.
In the accompanying drawings of a lamp according to my invention arranged
for two pairs of carbons
Figs. 1 and 2 are elevations partly in section on planes at right angles to each
other,
Fig. 2 shewing only the upper part of the lamp.
Fig 3 is a side view of the cam discs for the ribbons which suspend the carbons.
Figs. 4, 5, 6 and 7 are plans on the lines 4-4, 5-5, 6-6, and 7-7 respectively.
A circular top crown or plate A has a diaphragm B a few inches below it fixed
to it by an upward extension of a central tube F or by brackets F¹. In this space
the brake wheels D and cam discs fg with the brake mechanism are placed.
Below the diaphragm B is fixed centrally the vertical metal tube or rod F the
length of which slightly exceeds the travel of the upper or positive carbon. At
the lower end of this central tube or rod is fixed another diaphragm or base plate G
through holes in which the carbon holder rods slide up and down. To the base
plate: G near its' edge are fixed two vertical tubes H and in its centre a tube K
(preferably square) another disc or diaphragm L is'attached to the lower ends of
the three tubes HHK, this last disc having two large holes M through which

page_text: pass the two positive carbons and their holders OO. The two negative carbon
holder rods N N pass up through the two side tubes H H and the two positive
carbon holder rods P P are provided with cross heads R R which are guided by
the tubes H H and the central tube K. A button on the top of each of the two
positive carbon holder rods slides freely up and down in the interior of a tube T
extending from the base plate G to the top diaphragm B.
A non conducting tape or cord attached to the top of each of the two positive
carbon holder rods may pass over a pulley at the top of the lamp, the other end of
this tape being attached to the top of the corresponding negative carbon-holder-
rod so that as the positive carbon descends it raises the negative carbon. When
metallic tapes or cords are used to conduct the current, as will be hereafter
explained, two such conducting cords or tapes are used separately, each fixed to its
own pulley which is in the form of a snail or cam disc.
In order to keep the cranked negative carbon holders in true position, two
vertical guide rods VV for each are erected between the base plate G and the top
diaphragm B and a cross head W, fixed to but insulated from each carbon holder
rod, slides up and down along the rods V V. These rods themselves may be
insulated, in which case the crossheads W need not be insulated from N N.
I enclose the interior of the lamp between the top crown A and the base plate G
in a cylindrical case X.
The top of the cylindrical case fits within a lip A' projecting down from the top
crown A so that rain cannot enter it. I usually place the terminals on the top
of the crown, and I protect the insulation of both or of the negative only from
rain or moisture by a suitable hood on the terminal itself. 1 fix and manipulate
the globe in the following manner. I provide a metallic ring Z encircling the
third or lowest diaphragm L, its external diameter being greater than the upper
opening of the globe and preferably made with a lip z projecting down and
nearly fitting the mouth of the globe. To the underside of this ring are fixed
two vertical rods a a carrying at their lower ends a double cross bar having
in its centre a short tube or pin d upon which the globe carrier plate e slides, being
held by a bayonet catch or it might be by a screw.
The cross bar bis preferably made double as shewn in Fig. 7 to permit the
negative carbon holders to pass between its arms.
The rods a a are made of such length that, when the globe is resting upon the
carrier e on the pin or tube d, the ring Z fits closely down upon the top of the
globe which being thus held between it and the carrier e below, can be raised by
lifting the ring Z without being attached to it by outside netting such as is usually
employed.
This top ring may have a cross bar carrying centrally a vertical rod which can
slide up and down within the central guide tube K.
I prefer to enclose the space between the base plate G and the diaphragm L
in an outer casing gl which may be of an ornamental character and which does not
closely, fit around the flanges, but, as it extends over and around the outside diameter
of the ring Z, such rain as may find its way past the flange of the cylindrical case X
will pass out over the ring Z. and the outside of the globe. This protecting
casing g can readily be pushed upwards to any extent so that the guide rods and
carbons from end to end can be thoroughly inspected and cleaned, the trimming
being thus facilitated.
When the casing is lowered on the globe ring there is complete protection from
weather..
I prefer to make the brake and focussing wheels Dfg act as regulators in the
following manner. I make them of large diameter so that they make less than
one revolution during the total travel of the positive carbon holder rods; and I fix
to each brake wheel D two cam discs f and g electrically insulated from each other.
The metallic band or cord U attached to the positive carbon holder rod is attached
to and passes over the one disc fand the negative carbon holder, rod band or
cord U³ to and over the other cam disc g which is electrically connected to the
"

page_text: negative terminal of the lamp by a flexible conducting band wound several times
spirally round but without touching the axis of the focussing wheels, its spiral
convolutions allowing free movement of the cam dise to which it is attached.
The metallic band or cord U is attached to the wheel in electrical connection
with the body of the lamp which is positive.
The cam discs fg are so spirally shaped and so set in relation to each other
that when all the positive tape U is wound on the one cam f and the negative
tape U is unwound from the other, the weight of the positive carbon and its
holder P will, as the carbons become consumed, pull up the negative carbon and its
holder rod N with an increasing leverage, the positive cam f gaining, while the
negative g loses leverage. In this manner I compensate for the greater loss of
weight of the positive carbon as it is consumed, and also for the lessening of the
carbon resistance due to the shortening of the carbons as they are both consumed,
and I thus avoid the abnormal lengthening of arc which usually occurs towards the
end of the life of the carbons.
By gearing a brake wheel or a train of wheels into a spur wheel on the spindle
of the cams fg the feed of the carbons can obviously be controlled by any known
regulating brake or clutch.
For this purpose a retarding brake may be arranged, as shewn, to act on the
periphery of the brake wheel D which is directly fixed to the cam discs fg, thus
avoiding all gearing. Below this drum is a horizontal lever M¹ rocking on a pivot
vertically below the axis of the drum.
On this lever, between it and the drum, is fixed a yielding brake block preferably
a small roller m of caoutchouc or other elastic material.
This roller, being pressed against the periphery of D, acts as a brake pre-
venting D from turning, not only so, but when the lever M' is moved so as to raise m
the wheel D is turned a little backwards. When again the lever M' is moved so
as to lower m, the wheel D is left free to turn allowing the carbons to approach
each other.
I operate the lever by any well known and effective controlling solenoids or
electro magnets, as for instance that shewn in the drawings where S and S¹ are two
solenoids having their cores (which are attracted upwards) linked to the ends of
the lever M. The coil of the one solenoid S is of low resistance in the lamp
circuit and that of the other S¹ is of high resistance in a shunt to the lamp circuit.
By fixing on a suitable part of the brake wheel Da pin or stud & which comes
against a projection m' from the regulating lever, when the carbons are consumed,
I provide that the weight of the holder of the carbons first burnt out, remains
supported by the regulating lever, and I thus keep the voltage of the current for
the succeeding carbons the same as for the first.
The above description refers to double carbon lamps which, however, by a few
obvious modifications can be used for single carbons.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. An arc electric lamp having its framing consisting of a top crown, three plates
or diaphragms and a bottom crosshead connected together by tubes and rods some of
which serve as guides for the carbon holders, the upper part cantaining regulating
mechanism enclosed within a cylindrical casing and the lower part supporting a
globe and moulding, substantially as described.
2. In an arc electric lamp, regulating and focussing mechanism consisting of a
brake wheel having attached to it two insulated cam discs with conducting ribbons
connected respectively to the positive and negative carbons, and a brake and lever
operated by regulating solenoids or electromagnets, substantially as described.
1
2000
ABEL & IMRAY,
Agents for the Applicant.