A NEW OR IMPROVED ELECTRIC LAMP OF THE ARC TYPE."
Year: 1882

page_text: LETTERS PATENT to Rankin Kennedy of Glasgow in the County of Lanark
North Britain Electrician-for an invention of "A NEW OR IMPROVED
ELECTRIC LAMP OF THE ARC TYPE."
PROVISIONAL SPECIFICATION left by the said Rankin Kennedy at the
Office of the Commissioners of Patents on the 13th March 1882.
RANKIN KENNEDY of Glasgow, in the County of Lanark, North Britain,
Electrician, A NEW OR IMPROVED ELECTRIC LAMP OF THE ARC TYPE,"
This invention which relates to a new or improved Electric lamp of the arc type
consists in making the regulating apparatus of two coils of wire, one fixed and
forming a solenoid of thick wire, the other coil being wound on a soft iron tube
and of very fine wire.-This tube carrying the fine wire coil slides easily inside the
solenoid. To the lower end of the iron tube is fixed the upper carbon, a cross bar
carrying two pulleys acting against two guide rods steadies this carbon and the
lower end of the iron tube.
The lower carbon is also fixed in a cross bar running on pulleys on the guide
bars; the upper and lower cross-bars are attached to each other by cords passing
over pulleys so that when the upper carbon rises the lower one falls and vice
versa. One of these pulleys has a ratchet and pawl on it so that it can only rotate
in one direction.
When current Electricity is passed into the lamp, the whole current passes
through the thick wire coil and thence through the carbons, this current passing
through the thick wire coil acts on the iron tube and draws it up causing the two
carbons to recede from each other.-Immediately the carbons begin to recede a
part of the current begins to pass through the fine wire coil in such a direction as
to cause the iron tube to be repelled downwards, the rising of the tube (and with
it the carbon) is thus checked at a certain distance, proportional to the difference
between the drawing up power and the repelling power, by this means the space
between the two carbon points is always maintained the same; should the two.
[Price 6d1

page_text: carbon points come too close, the thick coil becomes most powerful and the tube
is drawn up; should the points become too far apart the coil on the tube becomes
most powerful and it is repelled so that a balance is set up whereby the two carbon
points are maintained at a uniform distance apart.
The ratchet on the pulley checks its turning to allow the carbons meeting so
that the friction of the cord slipping over it lessens the suddenness of the repelling
power. By these means a steady uniform light is kept up between the two carbon
points.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Rankin Kennedy in the Great Seal Patent Office on the
12th September 1882.
RANKIN KENNEDY, of Glasgow, in the County of Lanark, North Britain,
Electrician, "A NEW OR IMPROVED ELECTRIC-LAMP OF THE ARC TYPE,"
My Invention which relates to a new or improved Electric lamp of the arc type
consists in making the regulating apparatus of two coils of wire, one fixed and
forming a solenoid of thick wire, the other coil being wound on a soft iron tube
and of very fine wire. This tube carrying the fine wire coil slides easily inside the
solenoid. To the lower end of the iron tube is fixed the upper carbon, a cross-bar
carrying two pulleys acting against two guide rods may be used to steady this
carbon and the lower end of the iron tube.
The lower carbon is also fixed in a cross-bar running on pulleys on the guide
bars; the upper and lower cross-bars are attached to each other by cords passing
over pulleys so that when the upper carbon rises the lower one falls and vice versa.
One of these pulleys may have a ratchet and pawl on it, so that it can only rotate
in one direction.
When a current of Electricity enters the lamp, it passes through the thick wire
coil, and thence through the carbons. This current passing through the thick wire
coil acts on the iron tube, and draws it up causing the two carbons to recede from
each other. Immediately the carbons begin to recede, a part of the current begins
to pass through the fine wire coil in such a direction as to cause the iron tube,
and the fine wire coil, which is wound upon it, to be repelled downwards. The
rising of the tube (and with it the carbon) is thus checked at a certain distance
which depends on the difference between the attracting and repelling powers of the
coils; and by this means the space between the two carbon points is maintained
constant. Should the two carbon points come too close, the thick coil becomes
the more powerful and the tube is drawn up; should the points become too much
separated the fine-wire coil on the tube becomes the more powerful, and this tube is
repelled downwards so that a balance is set up whereby the two carbon points are
maintained at a uniform distance apart

page_text: When a ratchet is provided on the pulley, it checks the turning of the pulley
and allows the carbons to meet and the friction of the cord slipping over the pulley
thus stopped by the ratchet, lessens the suddenness of the motion of the carbons
towards each other under the repelling power; but the ratchet may be dispensed
with. By these means a steady uniform light is kept up between the two carbon
points.
And in order that my said Invention may be properly understood, I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to
the accompanying Drawings, and to the letters and figures marked thereon that is
to say
Figure 1, represents in front elevation a lamp constructed according to my
Invention.
Figure 2, represents a transverse section of the same.
Figure 3, represents a lamp constructed according to a modification of my present
Invention shewn in part elevation and part in vertical section.
Figure 4, represents a corresponding view of a lamp constructed according to a
further modification of my present Invention.
Referring to Figures 1, and 2, the current of electricity passes from the line wire
into the lamp through the terminal a, which is insulated from the body of the lamp
by the block b, of vulcanite or any other suitable non-conducting material and
then enters the solenoid or coil B, through the connection c The inner end of the
coil B, is in metallic connection with the bobbin d, on which it is coiled, and from
this bobbin d, the current passes to the plate e, thence through the connection f
and carbons g, and h, to the lower carbon carrier i.-From this carrier i, the
current passes out of the lamp through the rollers j, and p, and the rods k, and u,
and the tie-bar w', and through the terminal l, (which is insulated from the plate e,
by the block m, and with which the rod k, is in metallic connection) to the
return wire.
The two rods k, and u, constitute the guides of the carrier i, and they are
insulated from the plate e, at their upper ends by the washers x¹ of vulcanite, or
other suitable non-conducting material. To ensure a more perfect connection
between the rollers j, and p, and rods k, and u, and to ensure the proper guidance
of the pulleys without the necessity for using inflexible guide rods and for perfect
fitting of the rollers to the rods, the pin o, which carries the roller p, is made free
to slide horizontally in a slot formed in the carrier i, and there are provided two
springs n, n, which bear against the pin o. The two rollers j, and p, are thus
pressed in opposite directions, and are caused to bear against the guide rods k,
and u, with pressure, whose amount depends on the strength of the springs.
The upper carbon g, is attached to the lower extremity of the iron tube u¹, and
this iron tube u', along with the solenoid C, of fine wire hereinafter more par-
ticularly described, along with the upper carbon g, and its attachments is carried
by two chains w, and y, which respectively pass over the two pulleys v, and g'.-
At the other ends of these chains the carbon-carrier i, which carries the lower
carbon h, is suspended, and the carbon carrier i, is weighted with a counterpoise l'.
The weights of the iron tube u¹, the fine wire solenoid C, the carbon g, and attach-
ments at the extremities y', y¹, of the chains w, and y, and of the carbon-carrier i-
the lower carbon h, and the counterpoise 1, at the extremities 21, 21, of the chains w,
and y, and the connecting wires a¹, b', c¹, and d', are so adjusted that there is a
tendency for the carbons to approach each other when there is no electric current
passing through the lamp; and the carbons g, and h, do approach and come into
contact before the lamp becomes lighted. As soon however as a current of sufficient
strength commences to pass through the solenoid B, and the carbons g and h, the
current passing through the solenoid acts on the iron tube u², and draws it upward
partially into the interior of the solenoid B.-The carbon-carrier i, and the carbon h,
which as herein before described is carried by the chains w, and y, passing over the

page_text: pulleys v, and g¹, moves downwards. The two carbons g, and h, are thus separated
and the electric arc is formed between their points.
The solenoid C, of fine wire wound upon the iron tube u¹, and which acts as a
shunt upon the arc neutralizes to a greater or less extent the attractive effect on
the iron tube u', of the solenoid B, when the length of the electric arc, and there-
fore. the resistance of the same becomes too great, and the two coils with the
current passing through them are mutually repulsive. In entering this solenoid C,
the current passes from the tube d, through the connection q, and bearing r, to the
pulley v. -From this pulley v, the current passes into the chain w, and from this
into the coil or inner solenoid C, through a connection, similar to that shewn at x,
as applied to the chain y.-The current is prevented from passing down the chain w,
and wires a¹, and 61, (whose ends are united by the nut m¹, which is provided to
regulate the length thereof) to the carbon carrier i, by the connecting piece z, being
formed of non-conducting material-After passing through the solenoid C, the
current passes through the herein before mentioned connection x, and chain y, and
through the wires c', and d³, (whose ends are united by the nut n', corresponding
to the nut m¹,) into the carrier i, through the connecting piece e¹, this connecting
piece e¹, being formed of metal in contradistinction to the connecting piece z, which
is formed of non-conducting material. From the carrier i, the current passes
through the roller j, and rod k, to the terminal 7, which is as hereinbefore men-
tioned connected with the return line wire.-The currents passing through the
inner and outer solenoids act on each other, and on the moveable iron tube u², in
such a way as to tend to push the moveable tube and inner solenoid outwards, and
so by means of the chains w, and y, and wires.a¹, b¹³, c¹, and d³, which support the
lower carbon carrier i, to cause the carbons g, and h, to approach each other until
the proper length of arc is arrived at.
The wires a¹, and c¹, are insulated from the plate e, through which they pass by
the collars f', f¹, formed of non-conducting material which are fitted into the
same.
On one edge of the pulley g', there are ratchet teeth, which are engaged with by
the pawl h', in such a direction as to prevent the carbons g, and h, receding one
from the other, while the lamp is in use, but when in starting the lamp, it is necessary
to push up the upper carbon holder and solenoid C, this may be effected by pulling
the cord, which is connected with the pawl h', and which disengages the same
from the ratchet teeth on the pulley g'.-The chains w, and y, are of the pattern
known as snake chains, and to prevent the chain y, from slipping upon the surface
of the pulley g', when the same is checked by the brake h¹, there is fitted around
the same an india-rubber band as represented at j¹, Figure 2. This pulley g¹, and
bearings k¹, are insulated from the plate s, by a strip t, of vulcanite or other suitable
non-conducting material.
For guiding the upper carbon g, there is provided the collar o', which is carried
by and may be adjusted upon the rod p¹, by the thumb-screw q¹.-This rod p¹, is
attached to the under-side of the plate e. The rod p¹, and collar o¹, also serve the
purpose of taking a portion of the current from the plate e, to the carbon g.
For convenience in suspending the lamp, there is fitted the bow r¹, secured to the
plate e, by the nuts &¹, and insulated therefrom by the washers and collars t¹.
The tube u', of the inner solenoid C, is guided at its upper end by three rollers v',
which bear against the inner surface of the bobbin d, of the large solenoid B.
Under a modification of my Invention, I construct an arc lamp as shewn on a
reduced scale partly in front elevation and partly in section at Figure 3, in which
the two solenoids A', B', are movable and which lamp I provide with a base or
stand so that it may be placed on a table or on any other support affording a level
foundation.
The action of this form of lamp is as follows:-The current passes into the
terminal a³, and into the frame of the lamp through the connections 6³, to the
guides c², from which the current passes through the metallic connections formed
by the collars d³, which slide upon the guides c³, and the metallic connection of the

page_text: brass bobbin e, with these collars d², into the solenoid A2, which has one of its ends
secured to the brass bobbin e³, and the other to the lower cross-piece at f', whose
collars g, g, are insulated from the guides c², c².
The current then passes from this cross-piece f*, (which is insulated from the
bobbin e, by the washer y²) through the lower carbon h2, to the upper carbon i³,
and its holder, which is in metallic connection with the tube of the smaller
solenoid B, through which the current then passes. The upper carbon holder, is
insulated from the upper part of the frame of the lamp by the collar k³, through
which it passes. The current then passes from the tube of the smaller solenoid B³,
through the rod w³, to the lower part of the frame 2, which is insulated from the
guides c³, c³, by the washers 12, 13.-The current is then taken off from the lamp
through the connection m³, with the negative terminal n², this terminal n², being
insulated from the body of the lamp by the washer o³.
The solenoid B, of fine wire wound upon the iron tube, u³, and which acts (as
herein before described with reference to Figures 1, and 2,) as a shunt upon the arc,
and neutralizes to a greater or less extent the attractive effect on the iron tube u³,
of the solenoid B2, when the length of the electric arc and therefore the resistance
of the same becomes too great, and the two coils with the current passing through
them are mutually repulsive: In entering the solenoid B2, the current passes from
the terminal a², to the pulley 82, and down the chain 2, with which the outer end
of the fine wire solenoid B, is in metallic connection.-After passing through the
solenoid B², the current passes to the tube u³, upon which it is wound and to which
the inner end of the solenoid B2, is connected, and thence through the spring sliding
piece v³, and rod w³, to the lower part of the frame ³, which is, as hereinbefore
described connected with the negative terminal n³, and return line wire.
Under another modification of my Invention I construct an arc lamp as shewn,
on a reduced scale partly in front elevation and partly in section at Figure 4, in
which the current of electricity is passed from the line wire into the lamp through
the terminal a, which is insulated from the body of the lamp by the washers b
formed of vulcanite or any other suitable non-conducting material and is then
passed by the metallic connection c³, to the block d³, and pulley e³, which are
insulated from the body of the lamp and from the rod, by the washers f³-
From the pulley e³, the current passes down the chain g³, which is insulated at one
extremity from the lower carbon carrier g³, by the connecting piece d*, which is
made of vulcanite, or any other suitable non-conducting material to the part h³, of
the upper carbon holder is, which is insulated on both sides as represented by the
dotted lines j and also from the rod, by the roller ³, being formed of vulcanite
or any other suitable non-conducting material. From the part h³, of the upper
carbon carrier 3, the current passes through the strip m³, into the inner solenoid A³,
of thick copper wire and through this solenoid As, to the iron tube 12³, upon which
it is wound and with which its inner end is connected. The current then passes
from the tube n³, through the carbons o³, and p³, into the lower carbon carrier q³,
and through the pulleys, 73, to the rods 8, and ³, and lower part of frame t
From the rod 8, the current then passes to the block u³, and pulley v³, which are
insulated from the body of the lamp by the washers w³, and thence through the
metallic connection, to the negative terminal y³, which is insulated from the
body of the lamp by the washers, and which is connected with the return line
wire. The solenoid A³, moves within an iron tube c', on which the solenoid B³, is
wound.
The solenoid B³, of fine wire acts as a shunt upon the arc, as hereinbefore
described with reference to Figures 1, 2, and 3, and in entering the solenoid B³,
the current passes from the terminal a³, into the same through the metallic
connection a', and passes out through the metallic connections 6, and ³, to the
terminal y, which is, as hereinbefore described connected with the return line wire.
The effect of the current passing through the solenoid A³, within the iron tube c*,
and of the currents passing through the two solenoids A³, and B³, is similar to that
herein before described, with reference to Figures 1, 2, and 3.

page_text: For the purpose of lightening the fine wire solenoid, a portion of the fine wire
may be wound upon the bobbin d, underneath. the thick wire solenoid, in which
case the wire connection between the two portions of the thin wire solenoid, passes
through an insulating collar in the plate s as shewn at Figure 1, of the Drawings.
Having now described and particularly ascertained the nature of my said
Invention and the system, mode or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that what I
consider to be novel and original and therefore claim as the Invention secured to
me by the hereinbefore in part recited Letters Patent is :-
First. The general arrangement and construction of Electric Lamps of the arc
type wherein two solenoids are used one working within the other for regulating
the length of arc or distance between the carbon points as herein before described
and shewn on the accompanying sheets of Drawings.
Second. The use in an Electric Lamp of a fine wire solenoid on an iron core
moving inside a thick wire solenoid as hereinbefore described.
Third. The use in an Electric lamp of a solenoid on an iron core moving within
an iron tube on which is wound another solenoid of fine or thick wire as
herein before described.
Fourth. The use in an Electric lamp of two solenoids one working within the
other and both movable as hereinbefore described, it being understood that these
two solenoids may be arranged on either of the methods claimed under the
preceding Second and Third claims as hereinbefore described.
In witness whereof I the said Rankin Kennedy have hereunto set my hand
and seal this Seventh day of September in the year of our Lord One
thousand eight hundred and eighty two.