Year: 1886

page_text: Date of Application, 9th Mar., 1886.
Complete Left, 9th Dec., 1886.
Complete Accepted, 25th Jan., 1887.
I WILLIAM HENRY TRENTHAM of 33 Portland Road Notting Hill in the county of
Middlesex do hereby declare the nature of this invention to be as follows:-
This invention has for object to enable an arc lamp regulated by solenoids and iron
cores without the intervention of clock work, train of wheels, or system of levers to
burn double the usual time that is to say to make a double lamp and that without
duplicating all the parts.
The solenoids are arranged side by side, each being wound with large wire for the
main circuit, and small wire of high resistance for the shunt circuit in manner as is
well known.
I use two sliding frames one on each side of the guide rods to support the bottom
carbons and instead of having a pair of guide rods for each frame I arrange one sliding
frame above the other, the positive frame that is that frame which supports the carbon
that first burns being arranged to slide upon the same guide bars but above the other
frame.
I use the guiding wheels which carry the cords which support the upper carbon
rods and also the lower sliding frame in position in the upper portion of the lamp at
an angle to the carbon rod instead of being set coincident with the same vertical plane
so as to get the requisite double set of wheels within the available space and so as to
bring and work the cords of the frame vertically over the ends of the said frames, and
these wheels are supported or pivotted on pointed steel screw centres instead of
ordinary wire pins as is usual.
I also use a mechanical "cut-out" or switch which "cut-out" operates when the
carbon which has first been burned is exhausted to automatically switch the current
from the said first carbon to the other without breaking the circuit.

page_text: An arbor is mounted upon insulated brackets set on the frame of the lamp said
arbor having attached thereto a lever arm which arm is when the lamp is set acted
upon by a spring catch engaging with said arm to hold same down during the time of
the burning of the first set of carbons. When the first set of carbons are burned down,
the carbon rod thereof will have been lowered and an insulated stud fixed upon the
carbon rod will come in contact with the spring catch and so will depress same and
release the lever of the arbor. A spring acting upon the lever arm of the arbor will
then act to throw the arm up and turn the arbor partially around so bringing into
action a brush "contact" which will establish circuit with the second set of carbons
which will in their turn be immediately available for consumption or use.
By these means with but little alteration of the ordinary construction of lamps of
this type a lamp is provided that will burn for double the time hitherto attainable.
WALTER A. BARLOW,
6, St. Paul's Churchyard, E.C.,
Applicant's Agent.

page_text: I WILLIAM HENRY TRENTHAM of 33 Portland Road Notting Hill in the county of
Middlesex 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 has for object to enable an arc lamp regulated by solenoids and
tapering iron cores without the intervention of clock work, train of wheels, or system
of levers to burn double the usual time that is to say to make a double lamp and that
without duplicating all the parts.
The solenoids are arranged side by side each being wound with large wire for the
main circuit, and small wire of high resistance for the shunt circuit in manner as is
well known.
I use two sliding frames one on each side of the guido rods to support the bottom
carbons and instead of having a pair of guide rods for each frame I arrange one
sliding frame above the other, the positive frame that is that frame which supports the
carbon that first burns being arranged to slide upon the same guide bars but above the
other frame.
I use the guiding wheels which carry the cords which support the upper carbon
rods and also the lower sliding frame in position in the upper portion of the lamp at
an angle to the carbon rods instead..of being set coincident with the same vertical
plane so as to get the requisite double set of wheels within the available space and so
as to bring and work the cords of the frame vertically over the ends of the said frames
and these wheels are supported or pivotted on pointed steel screw centres instead of
ordinary wire pins as is usual.
I also use a mechanical "cut out" or switch which "cut out" operates when the
carbon which has first been burned is exhausted to automatically switch the current
from the first said carbon to the other without breaking the circuit.
In order that ny said invention may be readily understood I have hereunto annexed
a sheet of drawings whereof.
Fig. 1 is front view of an are lamp constructed according to this invention.
Fig. 2 is side view of Fig. 1.
Fig. 3 is plan at zz Fig. 1 showing the "cut out" or switch.
Fig. 4 is view to the right of line y y Fig. 3.
The two circular plates A and B are bolted to and held together by the rods a, b, c, d
and constitute the framing for carrying the various parts.
C and D are the solenoids arranged side by side and supported by standards fixed to
the plate B.
E and F are the sliding frames carrying the lower carbons working on opposite
sides one above the other between the guide rods G, H.
The two sets of guiding wheels 1 K are supported in their brackets at an angle to
the carbon rods and carry the cords ik which are attached at one end to the lower

page_text: portion of the brass tubes M M³ which contain the tapering iron cores carrying the
upper carbons, and the other ends of said cords carry the weights W which are in
their turn connected by cords to the rods m, n attached to the frames E, F carrying
the lower carbons.
The mechanical "cut out or switch is constructed as follows: An arbor o having
at either end the brushes a¹, is mounted upon insulated brackets ppl set on the
frame rods a b, said arbor o having attached thereto the lever arm which armis
when the lamp is set acted upon by the spring catch s engaging with said arm to
hold same down during the time of the burning of the first set of carbons. When the
first set of carbons are burned down the carbon rod M. will have been lowered and the
insulated stud fixed upon said carbon rod M will come in contact with the lever end
of spring catch s and so will depress same and release the catch from the lever of the
arbor. The spring then acts upon the lever arm to throw it up and turn the arbor
partially around so bringing into action the contact brush (at same time throwing
out of action the brush contact ) and so will establish circuit with the second set of
carbons which will in their turn be immediately available for consumption or use.
The two ends of the arbor o must be of necessity insulated from one another.
It will be seen that by these means with but little alteration of the ordinary
construction of lamps, of this type a lamp is provided that will, burn for double the
time hitherto attainable.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
Firstly. The construction of a double arc lamp wherein the solenoids are arranged
side by side having tapering iron cores free to slide lengthwise therein said cores
carrying at their lower ends the top carbons of the lamp, in combination with the two
sliding frames carrying the lower carbons said frames working on opposite sides one
above the other on the same guide bars as herein described and shown in the drawings.
Secondly. The mechanical" cut out" or switch for automatically switching the
current from the first carbon burned to the second without breaking the circuit as
herein described and as shown in Figs. 3 and 4 of the drawings.
AUTY T GOGIKARTH C