improvements in cut out apparatus
Year: 1888

page_text: Date of Application, 11th Dec., 1888
Specification Accepted, 29th Jan., 1869
improvements in cut out apparatus
A communication from abroad by CHARLES HEISLER, of St. Louis, in the State of
Missouri, United States of America, Electrician.
I, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents; 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 relates to means for short circuiting an electric lamp when the lamp
fails to operate normally, and it consists in providing electro magnetic and thermal
devices which mutually co-operate in assuring the continuity of the line, and thereby
promote the efficiency of the electric lighting system.
The particular form in which the invention is embodied is illustrated in the accom-
panying drawings in which :-
Fig. 1 is a view of the cut out with a single incandescent lamp attached thereto.
Fig. 2 is a view taken from the left of Fig. 1, the lamp and a part of the frame of
the cut out being removed.
Fig. 3 is a similar view taken from the right of Fig. 1.
Fig. 4 is a plan of the cut out with the cap removed.
Fig. 5 is a bottom view of the cut out.
-
-
Fig. 6 is a section through line <
of Fig. 3, looking to the left, and
Fig. 7 is an enlarged view of the cut out with the lamp attached, modified as to
some of its details, and designed especially to show the circuits.
A represents a cut out, and B an electric incandescent lamp attached to the bottom
thereof. The cut out is attached directly to an insulating base C, which base also
supports the screw posts c, c, to which a cap D is attached. The cap D has a screw
threaded socket D', by means of which it may be secured to a fixture or support.
Upon the base C is mounted a frame E which is formed at one end into a post or
standard E, which supports an electro magnet F. The frame extends thence across
the upper surface of the base under the electro magnet, and is formed at the other
end into a broad standard E' as shown most clearly in Fig. 6. Within the frame

page_text: formed by the parts E, E and E2, but insulated therefrom, is a frame or bar G which
extends alongside the electro magnet, and between the standard E2 and the armature l
of the magnet frame E is connected a binding screw e on the post E¹ to one end of
the line circuit, and the frame or bar G is connected at binding screw I with the
other end of tho line. It is evident therefore that the circuit of the cut out will be
complete whenever there is electrical connection between the frames E and G. In
the normal condition of the apparatus, connection is made between the frames by the
two paths, one through the electro magnet F, the terminals of. which are connected
respectively to the post or standard E¹, and the frame G, (see Fig. 4) and the other
through the lamp B by a course presently to be described. The magnet F is of very
high resistance so that the greater portion of the current shall normally flow through
the lamp and render it incandescent.
The lamp connections, which admit of the passage of the current through the lamp
itself will now be set forth.
The lamp may be of any ordinary construction and have terminals of any desired
shape. The lamp represented has a braided filament b, and post terminals f, f¹.
Corresponding to the post terminals on the bottom of the cut out are socketed posts H
and I, for the reception of the post terminals and f¹. The post I is secured in a
fixed position by a screw i which connects it mechanically and electrically with the
frame or bar G. The screw i is insulated from the frame E which it passes through.
The post H is adjustably connected with the frame E through the bar H, nut h', and
screw (see Figs. 2 and 5). By loosening the nut the post HI may be moved into
any desired position. The object of this is to allow for .variations in the construc-
tion of lamps having post terminals. The post H being connected with the frame E,
and the post I to the frame or bar G, it is evident that the circuit will normally
be complete through the cut out and lamp unless the parts are for some reason
out of order. The current entering at binding poste will divide, part of it passing
through the high resistance magnet F, and part through the frame E, screw,
bar H, socketed post H, lamp terminal f, filament b, lamp terminal.1, socketed
post 1, screw i, frame or bar G, and binding post g, to the line. The armature of
the electro magnet F is attached to a spring which is secured to the frame E by
the same screw which connects the latter with the post H. The spring tends to
keep the armature away from the magnet core. The backstop extends behind
the armature from a post k formed on frame E. The armature is bent back a
little at the top and on the bent back portion of it rests the end of an arm m-which
is pivoted in uprights on the standard E. The spring n tends to throw the outer
end of the arin m downward in an obvious manner. Directly below the arm m, and
secured to the frame or bar G, is a part of spring contact arms o, o. Whenever the
end of the arinature is removed from under the arm m, the latter is pressed downward
into contact with the spring arms o, o, and thereby makes a short circuit between
the frames G and E, with, which respectively, the spring arms and the arm m are
connected. This happens whenever for any reason the lamp becomes inoperative.
The current is then forced to pass through the magnet causing it to attract its
armature; and to release the spring actuated arin as above described. By the
completion of the short circuit the line is kept in order, and no, other lamps are
disturbed. Besides the short circuiting device operated by electromagnetism there
is provided a thermal cut out which will operate in case the electro magnetic device
fails to act properly from accidental causes. To-an-arm e-running out froin the
standard E¹ there is attached a rod P made of a fusible alloy, and this is run along
beside the coils of the magnet. To the 'free' end of, this rod is attached a link qand
this is connected by a spiral metallic spring to a post Es formed in one piece with a
standard E². When in position the link q surrounds a rod or pin r without however
touching it. The rod or pin is fixed in the frame or bar G. There is also attached
by solder or other means, a pointed metallic piece s to the bar G, so arranged that
the pointed end shall rest close to the fusible rod P. The cut out here described is
brought into operation whenever the rod P is melted, in, that event the link q falls
"or is drawn by the metallic spring into contact with the pin r, thus completing
rai

page_text: electrical connection between the two frames. Suppose now that the lamp should fail
to operate, and the electro magnet for any reason fail to attract its armature at once,
as by reason of the latter becoming accidentally caught, the magnet coils will become
heated, and by fusing the alloy, close the short circuit as above indicated. In case of
a total interruption of the magnet circuit (in which case the coils will not become
heated) a spark will cross beneath the point of the pieces and the rod P, fusing the
latter and closing the short circuit as before.
It is of course necessary in all apparatus of this kind to provide in addition to the
automatic short circuiting devices, means whereby the lamp can be cut out at will
from the main circuit. The means which are employed are shown most clearly in
Figs. 3 and 4. Referring to these figures it will be seen that an arm T is pivoted
on an extension of the back stop between the posts k and v. On the top of the
lever T is a projection t, upon which presses normally a spring w mounted on a post e
formed on the frame E. The free end, of the spring rests over the inner end of the
binding screw g, but is kept out of contact with it by the projection t. The lever T
has pivoted to it a handle V which extends down through a hole in the base C into a
position where it can be easily reached by the hand. When it is desired to cut out
the lamp, the handle is raised carrying with it. the lever T, and removing the
projection t from under the spring w. In consequence of this, the spring comes in
contact with the screw 9 and thus closes at once a short circuit around the lamp and
the electro magnet. The position of the parts when the manual cut out has been
operated is shown in dotted lines in Fig. 3. A special advantage of this form and
arrangement of cut out is that the operating parts thereof are situated below the
point of attachment of the lamp shade, and can be reached without difficulty. In
Fig. 3 are shown the details of a restoring device for the arm m. It consists of a
rod u which is capable of being moved up and down in perforations in the base C,.
and the frame E. A. cap y is attached to the lower end of the rod, and a spring u¹
located within the cap and pressing against the end of a sleeve z, which surrounds
the rod and extends for a short distance into the cap, tends to keep the rod down
out of the way of the arm m. The arm is raised by pushing up on the cap y, and
the actuating rod is returned automatically by the spring. This restoring mechanism
also can be operated from beneath the lamp shade.
In order to secure the necessary attractive power, and also the necessary
resistance for the inagnet, it is wound partly with copper and partly with German
silver wire. In the present instance the German silver wire (which is wound on
the outside of the coil) serves not only as a magnetic medium and a rheostat but
also as a means of fusing the rod P in case the electro magnet fails to operate with
sufficient rapidity. It will thus be seen that the devices in question do not simply
operate alternatively but co-operate to the same end. The cut out is shown as applied
to a single incandescent lamp, but it may with equal advantage be applied to two or
more lamps having two or more filaments. In fitting the cut out for application to
two lamps, a socketed screw post similar to I would be substituted for the nut h¹,
and a fourth socketed' post would be added capable of adjustment for reasons
stated above.
The contact arms may be of copper and the pivots may be of steel or any
preferred metal. With this construction there is the smallest possible danger of
the derangement of the devices from corrosion. In general a cylindrical casing
as e will surround the parts, fitting into the cap D.at one end and secured to the
base C by a screw.
The device might be applied to an arc lamp or a group of arc lamps without
departing from the spirit of the invention. The lamp shade (not shown) will be
applied above or to the body of the cut out by any suitable means.
In Fig. 7 both the binding posts at the bottom of the cut out are represented as
stationary, moreover, the armature of the magnet is shown as attached to a forward
extension of the standard E, and as being held away from the magnet by a retractile
spiral spring. This and other minor alterations are made so that the parts can be
arranged to show, the circuits more clearly.

page_text: Having now particularly described' and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is:-
1. .The combination in a single device, of a thermal and. an electro magnetic cut.
out in operative proximity to each other, the thermal cut out being brought into
operation by the overheating of the coils of the electro magnet resulting from the
imperfect action of the said magnet, or its total failure to act, substantially as
described.
2. The combination in an automatic cut out for electric lamps with an electró magnet
and means operated by its action for short circuiting the lamp, of a fusible rod or
piece located. near the magnet coils, short circuiting devices released by the fusing of
the rod or piece, and a metallic point located near the rod and connected to the
opposite pole of the lamp, whereby on the failure of the electro magnet to act, a short
circuit will be formed, by the fusing of the rod or piece, either by the heating
of the magnet coils or by a spark from the metallic point, substantially as
described.
3. In combination with an electric lamp an electro magnet, the connections with
the line substantially as described, whereby the electro magnet short circuits the
lamp when said lamp fails to operate, an easily fusible piece or rod, a second short
circuit for the lamp held open by the easily fusible piece or rod, and a conducting
point located near the easily fusible piece or rod, and connected to the opposite pole
of the lamp, whereby on the failure of the magnet switch a second short circuit
may be closed by the spark from the point melting the piece or rod, all substantially
as described.
Dated this 11th day of December 1888.