Improvements in Electric Conductors and in Appliances for Making Connection with same.
Year: 1898

page_text: Improvements in Electric Conductors and in Appliances for Making
Connection with same.
JOSEPH DEVONPORT FINNEY ANDREWS, 45, Fulham Park Gardens, Fulham, S.W.,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the construction of electrical conductors & the means
of connecting them together for electric lighting & other purposes. When wires
are stranded together to constitute a core of an electric cable there is usually
a straight or nearly straight line of wires across any diameter. In order to
make two insulated conductors of such a strand of wires, I substitute the wires
across one diameter by wires of insulating material or instead of wires I may
use a strip or tape of insulating material to occupy the same space as the line
of wires. When I desire more wire than two independent conductors I may
introduce insulating wires or strings or tapes into the strand to suit. I may
make each wire forming the strand up of several wires stranded together. Instead
of stranding the 2 conductors & the insulation together I may lay wires together
parallel preferably in the form that when two or more sets are placed together
they would form a round cable, I may lap each set of wires with insulation
before forming them into the cable. After building up the cable with the sets
of wires I would twist them together & I would preferably provide in insulating
material over all. I may add a lead or other metal covering or tubing to the
cable thus formed, or I may surround it with an armouring of wires of any
suitable metal. When I wish to join two lengths of cable together or a length
to a branch I prefer to employ a metal box with nozzles one for each cable & a
cover screwed into the open side. I prefer to solder the outer metal covering of
each length of cable one into each nozzle, the conductors being carried up the
centre of the box & the respective ends soldered together. The ends being pre-
ferably turned towards the open side & bound together with wire before soldering.
A disc of insulating material preferably porcelain would be placed in the bottom
of the box & a cap of insulating material placed on each pair of united ends. In
order further to improve the insulation I may coat the ends of the conductors &
the caps & the porcelain disc with an insulating material such as vaseline or
parafin wax or I may fill the box with an insulating compound. I should specially
prefer to do this if the insulating material of the cables could not stand exposure
to air. When I wish to fix my joint boxes to the wall or the like I provide one or
more holes in the wall of the box to receive screws. Likewise if I wish to attach

page_text: a switch to my box I arrange the fixing screws to be in the wall of the box.
When I wish to make provision in making a joint to avoid damage in the event
of possible injury or disturbance to the conductors & a consequent excess of
current I provide a fuse preferably constructed by casting or forming plaster of
Paris or other mineral or cement or insulating material onto the wire over its
entire length except on a small portion preferably in the centre which I leave
entirely free from touching the insulating material but surrounded by it on all
sides except in some modifications in which I preferably leave one side open to
permit of the escape of the products of fusion. I may however close this opening
with a mica window or with wire gauze or I may leave the surrounding space
large enough to permit of the fuse being entirely surrounded by the insulating
material I may make more than one such space round the wire in one fuse
& when there is more than one space I would preferably bend the wire so
that a loop passed through each space or opening. When I desire to
reduce the fusing effect to a minimum I employ two
or more wires & I
expose a different length of each, the result would be that by an excess of
minimum I employ two or more wires, one preferably larger than the other,
and I expose a different length of each, the result would be that by an excess
of current the wire with shortest piece of its length exposed which I would
prefer to be the largest wire would become interrupted without violent fusion and
so on each wire with a shorter piece of its length exposed than another remaining
would fuse slowly in succession until the last one, which would fuse quickly, I
would prefer to make the last one or last ones of finer wires. I may prefer to
employ wires with the portion exposed thinner than the rest of the wire or a
strand of wires with fewer strands at the place exposed or I may surround the
fusible wire with a metal tube or lap another wire round it at all points except
where it is exposed.
I may expose each wire in a separate recess in the insulating material. I may
fix the ends of the conducting wires leading to and from the fusible junction into
the insulating material or I may provide terminals fixed into the insulating
material attached to the fusible connection to receive the cable conductors.
1 1000
Improvements in Electric Conductors and in Appliances for Making
Connection with same.
JOSEPH DEVONPORT FINNEY ANDREWS, 45, Fulham Park Gardens, Fulham, S.W.,
Electrical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to the construction of electrical conductors and the means
of connecting them together for electric lighting, and other purposes. When
wires are stranded together to constitute a core of an electric cable there is
usually a straight or nearly straight line of wires across any diameter of the
cross section. In order to make two insulated conductors of such a strand of
wires I substitute the wires across one diameter by wires of insulating material.
When I wish to join two lengths of cable together or a length to a branch I solder
the respective ends together, the ends being preferably turned up and bound
together with wire before soldering, and a cap of insulating material placed on
each pair of united ends. When I wish to make provision in making a joint
to avoid damage in the event of possible injury or disturbance to the conductors

page_text: and a consequent excess of current, I provide a fuse preferably constructed by
casting or forming plaster of Paris or other mineral or cement or insulating
material on to the wire over its entire length except on a small portion preferably
in the centre which I leave entirely free from touching the insulating material,
but surrounded by it on all sides except in some modifications in which I pre-
ferably leave one side open to permit of the escape of the products of fusion.
I may however close this opening with a mica window or with wire gauze, or I may
leave the surrounding space large enough to permit of the fuse being entirely
surrounded by the insulating material. I may make more than one such space
round the wire in one fuse, and when there is more than one space I would
preferably bend the wire so that a loop passed through each space or opening.
When I desire to reduce the fusing effect to a minimum I employ two or more
wires, one preferably larger than the other, and I expose a different length of
each, the result would be that by an excess of current the wire with shortest piece
of its length exposed which I would prefer to be the largest wire would become
interrupted without violent fusion and so on each wire with a shorter piece of
its length exposed than another remaining would fuse slowly in succession until
the last one, which would fuse quickly, I would prefer to make the last one, or
last ones of finer wires. I may prefer to employ wires with the portion exposed
thinner than the rest of the wire, or a strand of wires with fewer strands at the
place exposed, or I may surround the fusible wire with a metal tube, or lap
another wire round it at all points except where it is exposed.
I may expose each wire in a separate recess in the insulating material. I may
fix the ends of the conducting wires leading to and from the fusible junction into
the insulating material, or I may provide terminals fixed into the insulating
material attached to the fusible connection to receive the cable conductors.
In Fig. 1 I illustrate a form of my conductor in which there are seven strands,
three of which A are of insulating material which divide the remaining strands
which are of metal, into two separate conductors B & C. The whole of the other
strands, insulating and metal, are stranded together in the usual way as if they
were all metal.
In Figs. 2 & 3 I represent my method of jointing conductors as above described,
or other sheathed conductors. Fig. 3 is a plan of a joint box with the lid removed,
A A A are twin sheathed conductors. The conductors of the cables are taken
into the interior of the box and the ends which are freed from insulation are bent
towards the opening, the ends that are to be joined together are arranged together
as at C & D and soldered and a porcelain thimble E is placed over each. Fig. 2
represents an elevation of the box with the cover F fixed ón with screws G.
In Fig. 4 I represent my fusible connections; A A are conducting wires joined
together by a fusible wire B. Around the whole I cast or form a block of cement
or other suitable material C with a recess around the fusible wire at D. I may
strengthen the cement on the outside in any suitable way.
Fig. 5 represents a fusible connection in which there are two recesses A & B
for the fusible wire or portions of them in a block of cement, porcelain, or other
suitable material. C & D are the portions of the fusible wire that would fuse first
by virtue of their being thinner than the rest of the length. The wire C is
thicker and shorter than the wire D, and in consequence of its greater diameter
and shorter length it will take a correspondingly greater proportion of the
current, and will melt before the fine wire, and it will do so without an emission
of sparks; as soon as the heavy wire is fused the fine wire will receive the
whole of the current and will blow with a flash. Mica or other suitable windows
may be used as a cover to the recesses.
In Fig. 61 illustrate a form of my fusible connection consisting of two con-
ductors A & B held together by a piece of insulating material, C, D & E are the
fusible wires connected to the conductors A & B by pins F. The wire D is
heavier and shorter than the wire E and will consequently fuse first without
violence, the wire E fusing quickly as described in relation to Fig. 5.

page_text: 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:
1st. The construction of cables as described and illustrated in Fig.. 1.
2nd. The construction of a joint for electric conductors in which there is no
insulative lapping on the wires at the point of junction, but instead a collar
or thimble of china, or other suitable material, substantially as described and
illustrated in Figs. 2 and 3.
3rd. The construction of an electric fusible connection in which the wire is
surrounded by a suitable cement or porcelain with a recess at the point to be
fused substantially as described and illustrated in Fig. 4.
4th. The construction of an electric fusible connection in which a fine wire
bridge is employed over the wire to be fused. The wires being held in recesses in
cement, or china, or attached to terminals on the conducting wires substantially
as described and illustrated in Figs. 5 & 6.