Improvements in Automatic Disconnectors for Overhead Conductors.
Year: 1892

page_text: Date of Application, 8th Feb., 1892-Accepted, 12th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Automatic Disconnectors for Overhead Conductors.
I, ANDREW LANGSTAFF JOHNSTON, of Richmond, in the County of Henrico,
and State of Virginia, Electrician and Civil Engineer, 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 certain new and useful improvements in disconnectors
for electrical conductors, and is more especially designed to be used in circuits for
electric lighting, and for electric railways.
The object of this invention is (on the breaking of the wire) to automatically cut
out the current, so that the wire in its contact with anything or anyone, will be
incapable of injury, but can be immediately seized and put out of the way, without
exposing the person so employed, to danger.
In the accompanying drawings, forming a part of this Specification, and on which
same letters of reference indicate the same or corresponding parts,
Fig. 1 represents a side elevation, with a part of the conductor broken away so as
to illustrate the interior mechanism.
Fig. 2 is a top view thereof.
The letters A and B indicate two cylindrically shaped metallic sections, similar
in shape, and bolted at their inner end C to the post D, which may be formed of
any insulating material. These inner ends C are provided with fulcrum bars E, in
the jaws of which are pivotally mounted the switches F, their upper ends terminating
in the hatchet-shaped head G, and their lower ends H, formed so as to be operated
by the knock bars I.
In order to prevent the lever heads G from jarring loose, the opposite sides of
each head are provided with recesses G¹, which receive beads or projections M' on
the inside of the jaws, which are spread apart slightly so that they will spring into
engagement with the head when it enters. This provision is especially desirable on
bridges and other places where the parts are subjected to violent vibrations.
This disconnector in actual practice is suspended by the eye J, formed integral
with the cap E, which covers the upper portion of the insulated block D. This
cap is made of metal, and is provided at any convenient point with the wire posts L.
This cap on either side of and just above the sections, is provided with V-shaped
jaws M, composed of any good material which is an especially good conductor of
electricity, and into which the lever heads G are thrown when it is desired to make
electrical connections with the line.
The hollow sections B are provided with a hinged portion, which can, on the
removal of the screw O, be taken entirely off the section, and allow the operator to
easily and readily put the line wire in its proper position, in the sections, and screw
it into the metallic travelling head P, into the inner end of which is screwed the
knock bar I.
The sections A and B are further provided with a pin Q, to which one end of
the spiral spring E is fastened, the other end thereof being secured to the travelling
head P.
When the line wire S is secured into the head P, the hinged section N is closed
and held tight by the band T, and the travelling head P, by the tension of the line
wire, is pulled in the direction of the arrow in Figure 1, and the lever heads G are
then firmly pushed into the jaws M, and the current of electricity entering the
post L, proceeds along the base of the cap and the jaws M into the lever, through
the fulcrum into the section, and thence down to the line wire.
Should the line wire become broken in any way, then the tension of the spring
draws the bar I forcibly against the lower end of the lever, and throws its head G

page_text: out of engagement with the jaws M, and the cap K being mounted upon the
insulated base D, the current is unable to pass down to the line wire, and said wire,
as a consequence, is dead.
It will be observed with the construction here shewn and described, that, when
the levers are thrown out of engagement with the jaws on the cap, that even should
a tension be exerted on the wire, as would be the case when the lineman repairs the
same, the levers would not be thrown back into the position they formerly occupied
in the jaws, and the current thus re-established, but all repairs etc., can be made
without any danger or inconvenience whatsoever, and when completed and all
danger is over, the levers are then returned to normal position by the lineman.
Although my device is described as especially applicable for overhead wires, yet
it is evident that it could be applied to all kinds of electrical conductors.
And it
is also apparent that my device could be varied in many ways that would suggest
themselves to a skilled mechanic, therefore I do not limit myself to the exact
construction herein shewn, but consider myself entitled to all such variations as
come within the spirit and scope of my invention.
The letter Z represents a hood, used to protect the parts from the weather.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. In an automatic disconnector for overhead conductors or other wires, the
combination of the body thereof provided with an insulated cap having jaws, of the
switch bars mounted on the body of the disconnector having heads at their upper
ends, said heads being adapted to be thrown out of engagement when the wires are
slackened, as stated.
2. In an automatic disconnector for overhead conductors or other wires, the
combination with the body having an insulated cap with the jaws on either side, of
the switch bars pivotally mounted on the body and provided at their upper ends
with hatchet shaped heads, which are automatically thrown out of engagement
when the wires are slackened, as specified.
3. In an automatic disconnector for overhead conductors or other wires, the
combination with the body thereof provided with an insulated cap having jaws, and
lever switch bars mounted upon the body so as to be thrown into engagement with
the jaws, of the hollow sections having springs secured thereto at one end, and the
line wires connected to the other ends of the said springs and knock bars also
connected to the said springs and adapted to be thrown into engagement with the
lever switches when the wires are slackened, as described.
4. In an automatic disconnector for overhead and other electrical conductors, the
combination of a hanger substantially as described, provided with circuit breakers
having interlocking devices arranged to hold the breakers in closed adjustment, as
set forth.
5. The combination in an automatic electrical disconnector for overhead and
other conductors, of a hanger or suitable support provided with a pair of pivoted
levers having hatchet shaped heads, and jaws adapted to receive the heads, of
interlocking beads or projections, and recesses adapted to receive the beads and
hold the heads in place, for the purpose described.
Dated this 8th day of February 1892
A. L. JOHNSTON,
By L. W. per F. B.