Year: 1897

page_text: Date of Application, 8th Feb., 1897
Complete Specification Left, 4th Nov., 1897-Accepted, 11th Dec., 1897
аго патра.
I, WILLIAM JAMES DAVY, Engineer, of 27 Drayton Park, Holloway, 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 positive and negative carbon holders are connected together by
a flexible connection passing over a pulley and in which the upper carbon holder
tends to descend by gravity and thus at the same time to draw up the lower carbon
holder so as to bring the two carbons into contact and has for its object to provide
an improved grip device acting on the flexible connection and operating to strike the
arc and control the feed of the carbons, to facilitate the cleaning of the guides of
carbon holders of arc lamps, to facilitate the fixing and removal of the covers and
shades and to insulate the framework of the arc lamp.
The improved grip device acts by gravity and consists of a support link and a free
link pivoted together at one end, two jaws between which the flexible connection
passes and which are attached to the links near the pivot and so that they approach
or recede from one another as the end of a link is raised or lowered to grip or release
the flexible connection, a pillar mounted on a fixed support and to which the outer
end of the support link is pivoted, an arm attached to the support link and extending
over the outer end of the free link, an L-lever pivoted at its angle to the arm and at
its end to the outer end of the free link and a stop on which the ends of the links
rest and a means for operating the free end of the L-lever according to the resistance
of the arc.
In order to facilitate the cleaning of the guide rods of the cross head carrying the
upper carbon holder, the rods pass through holes in the lower frame bracket and
through bell mouthed holes in one of the upper discs of the frame and are secured in
place by set screws in the lower bracket.
The main supporting disc and the holder of the shade are provided with studs on
the ends of springs and adapted when the covers and holders are in place to take
into holes in the cover and to secure the parts in place.
In order to insulate the framework of the lamp, the terminals are insulated from
the supporting disc, the upper carbon holder is insulated from its cross head and is
connected up by a flexible and insulated conductor the guide tube for the tail rod
of the lower carbon holder is insulated from the frame and the flexible cord is
insulated from the tail rod, and the tail rod or lower carbon holder is connected up
by a flexible and insulated conductor.
Dated this 8th. day of February 1897.
WHEATLEY & MACKENZIE
40 Chancery Lane, London, W.C. Agents.

page_text: Improvements in Electric Arc Lamps.
I, WILLIAM JAMES DAVY, Engineer, of Horsell Road Works, Ronald's Road,
Highbury, in the County of London, late of 27 Drayton Park, Holloway, 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 for improvements in electric are lamps relates more especially to
lamps in which the positive and negative carbon holders are connected together by a
flexible connection passing over a pulley and in which the upper caroon holder tends
to descend by gravity and thus at the same time to draw up the lower carbon holder
so as to bring the two carbons into contact and has for its object to provide an
improved grip device acting on the flexible connection and operating to strike the
arc and control the feed of the carbons, to facilitate the cleaning of the guides of
carbon holders of arc lamps, to facilitate the fixing and removal of the covers and
globes and to insulate the framework of the arc lamp.
The improved grip device acts by gravity and consists of a support link and a free
link pivoted together at one end, two jaws between which the flexible connection
passes and which are attached to the links near the pivot and so that they approach
or recede from one another as the end of a link is raised or lowered to grip or release
the flexible connection, a pillar mounted on a fixed support and to which the outer
end of the support link is pivoted, an arm attached to the support link and extending
over the outer end of the free link, an L lever pivoted at its angle to the arm and at
its end to the outer end of the free link and a stop on which the ends of the links
rest, and a means for operating the free end of the L-lever according to the resistance
of the arc.
In order to facilitate the cleaning of the guide rods of the cross head carrying the
upper carbon holder, the rods pass through holes in the lower frame bracket and
through bell mouthed holes in one of the upper discs of the frame and are secured in
place by set screws in the lower bracket.
The main supporting disc and the holder of the globe are provided with studs on
the ends of springs and adapted when the covers and holders are in place to take into
holes in the cover and to secure the parts in place.
In order to insulate the framework of the lanp, the terminals are insulated from
the supporting disc, the upper carbon holder is insulated from its cross head and is
connected up by a flexible and insulated conductor, the guide tube for the tail rod
of the lower carbon holder is insulated from the frame and the flexible cord is
insulated from the tail rod, and the tail rod or lower carbon holder is connected up
by a flexible and insulated conductor fixed to the tail rod guide tube.
In the accompanying sheet of illustrative drawings:
;
Fig. 1 is a sectional elevation of an electric are lamp constructed according to this
invention and
Fig. 2 is a similar section of the upper part of the lamp taken at right angles to
fig. 1.
Fig. 3 is a sectional plan.
Fig. 4 is a plan of the cross head of the upper carbon holder.
Fig. 5 is a sectional elevation showing the gravity friction grip device for the
flexible connection, and
Fig. 6 is a plan of the same.
Fig. 7 is a longitudinal section showing the method of fixing the main guide rod
of the cross head of the upper carbon holder, and
Figs. 8 and 9 are longitudinal and cross sections showing the arrangement of guides
for the lower carbon holder.

page_text: the
u, for
upper carbon traveller b,
passes
The main guide rod
through the lower bracket c of the lamp and through the tube d fixed
between the upper and lower discs
eel and into a bell-mouthed
hole
in a boss on the underside of the upper disc e and on which the upper end
of the tube d fits. The rod a is fixed in the bracket c, by a set screw c¹ taking
into a recess in the rod a. A tube d', fixed to the traveller b, slides on the rod a
and can pass up the tube d. The other guide rod a¹ for the traveller 6 also passes
through a hole in the bracket c and enters a bell mouthed hole in the lower disc e¹
and is also tixed by a set screw c¹. On loosening the set screws c¹ the guide rods can
easily be removed for cleaning.
The upper carbon traveller b is insulated from the carbon holder 61 by the
insulation 63 and is connected to the end of the flexible connection passing over the
pulley The arm 62 is connected by the flexible conductor m to the terminals *.
The lower carbon holder is fixed to a tail rod g sliding in a tube passing through
the lower bracket c and through an insulating bush e in the lower disc e¹. The tube
is also insulated from the bracket c and is fixed in the bracket c by means of a split
ring c² fitted in the hole in the bracket and fitted with a mica or insulating ring c
just fitting the tube h. By tightening up the screw c¹ the tube his gripped in the
compound ring c² c3 and thus fixed in the bracket but insulated therefrom. The cross
head y projects through a slot g² and carries a clip g³ insulated from it and adapted
to be connected to the flexible connection l. The tail rod g slides easily in a bush g*
in the end of the tube h and has a fluted head 95 fitting but sliding freely internally
in the tube h.
The two terminals m² m³ are both insulated from the lower disce¹and the terminal m*
The ter-
is connected to the top carbon holder b¹ by the flexible conductor m.
minal m³ is connected by a conductor m³ to the series coil m itself connected by
the conductor m" to the tube h of the lower carbon holder, and to the holder f by a
flexible cord m7.
On the disc e¹ are fixed two spring plugs n adapted to take into holes n² in the
cover n³. The globe holder o is provided with finger plates o' and with spring plugs o²
adapted when the holder and cover are in place to take into holes o³ in the cover n³.
The parts are thus easily removed to facilitate cleaning or repairs.
The gravity friction grip device consists of two pairs of links p p r r pivoted
together at one end and carrying projections or jaws 8 s¹ between which passes the
flexible connection l. The support links p p¹ are pivoted to the support p² mounted
on the lower disc e¹ and have armis p³ pt fixed thereto. The lever t is pivoted at
its angle between the free ends of the arms p³ pt and one end is pivoted between
the free ends of the links 71 and its other end is connected by an adjustable link t
to a lever t' pivoted on a lug t³ on the upper disc e and connected at its ends to the
cores vb of the main and shunt solenoids m and m'. Normally the lower ends of
the links pprr¹ rest on the lower disc e¹.
The operation is as follows:-The carbons are normally in contact and the grip
device rests on the lower disc e¹. On passing the current to the lamp, the core v¹ of
the main solenoid m* is lifted up, and through the link t¹ raises the end of the lever t
causing the jaws 8 8¹ to first grip the flexible connection and then to raise the
grip device bodily off the disc e¹ and thus by means of the flexible connection / raise
the top carbon holder and lower the bottom carbon holder to strike the arc. As the
resistance of the are increases due to the burning away of the carbons the power of
the main solenoid m¹ decreases and then gradually the grip device is lowered on to
the disc e and the jaws 8 8¹ relax their hold on the flexible connection
and a continuous and steady feed is obtained by the connection feeding
slowly through the jaws 8 s¹. If the lamp is worked in series the shunt solenoid m²,
which is connected across the terminals m² m³ by the conductors m³ m, helps to
feed the carbons together and maintain a steady arc. In order to assist the striking
of the are a dash pot x is introduced, the piston of this is connected to the
lower plate e and the dash pot x is attached by a link to the lever g².
It will readily be understood that the grip device may be applied to any lamp

page_text: in which one of the carbon holders always tends to move by gravity or otherwise
in a direction to approach the other carbon and that the grip device can act on the
carbon, its guide rod, or other traversing part attached to the moving carbon.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is
1. In electric arc lamps in which one carbon holder tends to approach the
other the gravity friction grip device consisting of a support link and a free link
pivoted together at one end, two jaws between which a traversing part attached to the
approaching carbon passes and which are attached to the links near the pivot and so
that they approach or recede from one another as the end of a link is raised or lowered
to grip or release the said traversing part, a pillar mounted on a fixed support and to
which the outer end of the support link is pivoted, an arm attached to the support.
link and extending over to near the outer end of the free link, an L-lever pivoted at
its angle to the arm and at its end to the free end of the free link, a stop on which
the ends of the link rest and a means for operating the free end of the L-lever
according to the resistance of the arc.
2. The method of fixing the guide rods of are lamps so that they can readily be
removed for cleaning, substai tially as described.
3. The method of connecting the globe holder to the lamp, substantially as
described.
4. The method of connecting the cover to the lamp, substantially as described.
5. Insulating the different parts of the lamp through which the current is
necessarily passed from the framework of the lamp so that the lamp can readily be
handled even when the current is on.
6. The improved gravity friction grip device substantially as described.
Dated this 3rd day of November 1897.
WHEATLEY & MACKENZIE,
40 Chancery Lane London W.C. Agents.