IMPROVE- MENTS IN ELECTRIC LAMPS
Year: 1878

page_text: LETTERS PATENT to John Scudamore Sellon, Metallurgist, of Hatton Garden,
in the County of Middlesex, and William Ladd and Henry Edmunds, both of
Beak Street, in the same County, Engineers, for the Invention of "IMPROVE-
MENTS IN ELECTRIC LAMPS."
Sealed the 13th May 1879, and dated the 15th November 1878.
PROVISIONAL SPECIFICATION left by the said John Scudamore Sellon,
William Ladd, and Henry Edmunds at the Office of the Commissioners of
Patents on the 15th November 1878.
JOHN SCUDAMORE SELLON, Metallurgist, of Hatton Garden, in the County of
Middlesex, and WILLIAM LADD and HENRY EDMUNDS, both of Beak Street, in the
same County, Engineers. "IMPROVEMENTS IN ELECTRIC LAMPS."
The object of this Invention is to provide a simple and efficient means for
establishing and maintaining the light of electric lamps, whether used singly or in
groups. In order to render unnecessary the mechanism heretofore employed for
retaining or sustaining the carbon points in the desired position, we propose to
insert the carbons in guides in which they will move freely and bring their extre-
mities into contact with fixed rests carried by bracket or other supports connected
rigidly with their respective guides, and forming portions of the circuit. These
supports will convey the currents to or from the carbon points, and will sustain the
weight or pressure of the carbous. By making these supports of iridium or similar
heat resisting metal, they will not suffer from the heat of the electric arc.
These carbon points may be set at an incline or parallel to each other, and in
each case provision is made for establishing the light. When the carbon points are
set at an incline, the guide for one of these points is pivotted to a fixed support,
and is capable of rocking thereon to put its carbon in or out of contact with the
carbon of the fixed guide. When the lamp is out of use, the carbon points will be
in contact, and the circuit will be unbroken at that point. In order to open the
circuit and produce the electric arc, an electro magnet is placed within the circuit
D

page_text: and in such position to act upon the pivotted carbon guide, and rock it on its
fulcrum so soon as the current is established. By this arrangement the lamp will be
lighted immediately the circuit is completed; the electro magnet then acting to
part the carbons and produce the arc. If from any accidental cause the light is
extinguished, the circuit will be broken, and the electro magnet becoming inope-
rative, will allow the rocking carbon to complete the circuit, by which means the
current will be re-established, and the lamp relighted.
When using parallel carbons their guides will be fixed, and the carbons resting
upon or pressing against the retaining or sustaining points will always preserve the
same relative position with respect to each other, their distance apart being de-
termined by the are desired to be produced. To provide for the lighting of this
modified form of lamp, we fit the lamp with a contact piece, which, when in position,
will close the circuit through the carbon points. This contact piece is by preference
carried by a hinged keeper which is operated on by an electro magnet placed
within the circuit: When the current is established, the electro magnet acting on
the hinged keeper will draw back the contact piece, and the arc will then be
formed. Should however the light be accidentally extinguished, the circuit will be
broken, and the electro magnet as in the first example ceasing to act, the contact
piece will, under a spring or other pressure, fall into position between the carbons,
and thus restore the circuit. The arm of this contact piece may carry a crossbar
which on one or both of the carbons failing, will come into metallic contact with
parts of the lamps connected with opposite poles of the electric generator, and thus
close the circuit, leaving the other lamps in the circuit unaffected.
This arrangement of automatic contact maker is applicable to other arrangements
of electric lamps than that above described.
-
By withdrawing one of the parallel carbons, and advancing one of the rests so
that both may be in contact with the remaining carbon, a closed circuit lamp is
produced in which all undue resistance to the passage of the current will be re-
moved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Scudamore Sellon, William Ladd, and Henry Edmunds in the
Great Seal Patent Office on the 15th May 1879.
JOHN SCUDAMORE SELLON, Metallurgist, of Hatton Garden, in the County of
Middlesex, and WILLIAM LADD and HENRY EDMUNDS, both of Beak Street, in the
same County, Engineers. "IMPROVEMENTS IN ELECTRIC LAMPS,"
The object of this Invention is to provide a simple and efficient means for
establishing and maintaining the light of clectric lamps, whether used singly or in
groups.
In order to render unnecessary the mechanism heretofore employed for retaining
or sustaining the carbon points in the desired position, we propose to insert the
carbons in guides in which they will move freely and bring their extremities into
contact with fixed rests or supports within the circuit. These supports will convey
the current to or from the carbon points, and will sustain the weight or pressure of
the carbons. By making these supports of iridium or similar heat resisting metal,
their permanence will be ensured.
The carbon points may be set at an incline or parallel to each other, and in each
case provision is made for establishing the light. When the carbon points are set
at an incline, the guide for one of these points is pivotted to a fixed support, and is
capable of working thereon to put its carbon in or out of contact with the carbon of
the fixed guide. When the lamp is out of use, the carbon points will be in contact,
and the circuit will be unbroken at that point.
In order to open the circuit and produce the electric arc, an electro magnet is
placed within the circuit and in such position as to act upon the pivotted carbon
guide and rock it on its fulcrum as soon as the current is established. By this
arrangement, the lamp will be lighted immediately the circuit is completed, the
electro magnet then acting to part the carbons and produce the arc.
If from any
accidental cause the light is extinguished the circuit will be broken, and the electro
magnet becoming inoperative will allow the rocking carbon to complete the circuit,
by which means the current will be re-established and the lamp relighted.
In the accompanying Drawing, Fig. 1 shews in front elevation an elastic lamp
constructed according to this part of our Invention.
To a base block A, two carbon guides B, B1, are secured; the guide B¹ is pivotted
at b to allow of its receiving a rocking motion. These guides are inclined to each
other to enable the carbons C, C', which they carry approaching each other, and
coming into contact at their points. Projecting from the outer sides of the fixed
and movable guides B, B₁, are bracket-pieces which serve to carry iridium tipped
rests or supports D, D. These supports, which are adjustable, are intended to
underlie the carbon points and retain them in position with respect to their guides.
Behind the carbons and enclosed within the guides are propelling springs c, c, which
serve to press their respective carbons forward and hold them in contact with their
rests or supports D. Fitted to the pivotted guide B₁ is an armature E opposite to
an electro magnet E¹ fixed to the base block A, and brought within the circuit of
the electric generator by means of a wire leading directly thereto, the other ex-
tremity of the coil of the electro magnet being connected with the pivot of the
guide ; a wire from the fixed guide B connects that guide with the opposite pole
of the electric generator.
may
A tendency is given to the pivotted guide by its overchanging weight, or it
be by a light spring to throw its carbon point into contact with the carbon point of
the fixed guide in the absence of a passing current. So soon however as the circuit
is complete the electro magnet will come into action, and by attracting the armature
E, the carbons will be drawn apart and the arc thereby established. As the carbons
are consumed they will be advanced by the propelling springs c, and held in contact
with the rests, which being practically metallic, continuations of the carbon guides

page_text: will act as conductors of the current to and from the points of the carbons, and
thereby diminish the resistance hitherto offered by the carbons to the passing
current.
It will now be seen that we ensure by means of the rests or supports the main-
tainance of the carbon points in their desired positions, and that without the risks
attendant on the use of mechanism for that purpose.
When using parallel carbons their guides will be fixed, and the carbons resting
upon or pressing against the retaining or sustaining points will always preserve the
same relative position with respect to each other, their distance apart being deter-
mined by the arc desired to be produced.
To provide for the lighting of this modified form of lamp, we fit the lamp with
a contact piece which, when in position, will close the circuit through the carbon
points. This contact piece is by preference carried by a hinged keeper which is
operated on by an electro magnet placed within the circuit.
This modification is shewn in Figures 2 and 3 of the Drawing, Fig. 2 being a
front view, and Fig. 3 a side view of the lamp; A is the base block to which are
affixed the parallel carbon guides B, B¹, provided with bracket pieces and iridium
tipped rests or supports D, D, as in the former instance. E is an armature pivotted
at e to the underside of the base block. This armature is furnished with a tail
piece to which is attached one end of a spring g, the other end of the spring
being secured by a nut and threaded wire to the underside of the block A. To the
upper side of the armature E is attached a rod or wire carrying a metal block or
contact piece F, and at the back of the base block A. is secured the electro magnet
E¹, one extremity of the wire surrounding which is carried to the terminal G, the
other extremity being secured to the carbon guide B. A wire from the guide B'
connects that guide with the terminal G¹.
It will now be seen that when the current is established, the electro magnet E'
acting on the hinged keeper, will draw back the contact piece F into the position
shewn by dots in Fig. 3, and the arc will then be formed. Should however the
light be accidentally extinguished the circuit will be broken, and the electro magnet
as in the first example ceasing to act, the contact piece will by means of the spring
g fall into the drawn position of Fig. 3 between the carbons, and will thus restore
the circuit. The rod or wire of this contact piece is provided with a cross bar f',
which on one or both of the carbons failing, will come into metallic contact with
the two bracket pieces carried by the carbon guides and will thus close the circuit,
leaving the other lamps in the circuit unaffected.
This arrangement of automatic contact maker is applicable to other arrangements
of electric lamps than that above described, as for example, those in which the
Jablochkoff candle is used, and modifications of the same.
Figures 4 and 5 shew in front and side view a modification of the rests or
supports for the carbon points, by means of which a closed circuit lamp is obtained.
In this example, D is a fixed metallic bar, made by preference of iridium or iridio-
platinum, the opposite ends of which serve to support the carbons Cin place. When
the current is established, the bar D, as well as the carbon points, become incan-
descent, the bar being brought into and maintained in circuit through the carbon
points. In this case, the contact of the carbons with their rests or supports will be
maintained as in the first example by pressure springs or their equivalent.
Referring now to the arrangement shewn at Fig. 2, it will be readily understood
that by withdrawing one of the parallel carbons and advancing one of the rests so
that both may be in contact with remaining carbon, a closed circuit lamp will be
produced in which all undue resistance to the passage of the current will be
removed.
This arrangement is shewn at Fig. 6, in which one carbon only is provided, and
the right hand rest or support D is advanced into contact therewith. The rests in
this arrangement being in circuit as explained with reference to Figures 2 and 3,
the carbon will by filling the space between the rests maintain a closed circuit.
In case of the carbon failing to maintain the circuit, the cross bar f¹ of Figures 2

page_text: and 3 (or its equivalent), will come into action and close the circuit, thereby pre-
venting the failure of this lamp affecting the action of the other lamps on the same
circuit.
Having now set forth the nature of our Invention of "Improvements in Electric
Lamps," and explained the manner of carrying the same into effect, we wish it to be
understood that under the above in part recited Letters Patent we claim,-
First. The arrangement of electric lamps as described with reference to the
accompanying Drawing.
Second. The application to electric lamps of rests or supports for the carbon
points, as and for the purpose above described.
In witness whereof, we, the said John Scudamore Sellon and Henry Edmunds,
have hereunto set our hands and seals, the Fifteenth day of May, in the
year of our Lord One thousand eight hundred and seventy nine.