Improvements in Connections for Electrical Conductors.
Year: 1887

page_text: Date of Application, 23rd June 1887.
Specification Accepted, 26th July, 1887.
Improvements in Connections for Electrical Conductors.
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I, ROBERT ORD RITCHIE, of 50 Old Broad Street, in the City of London, 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 means of holding near together the ends of electrical
conductors that are to be connected by a safety fuse or otherwise, and has for its
object the dispensing with all connecting screws, terminals, connecting pieces, or
other loose and separate parts, each and all of which not only serve to increase the
electrical resistance of the circuit in which they are employed but also, should they at
any time work slack, or be in the first instance a bad fit, greatly increase the fire risks
due to the tendency to flash or "arc" that would be thereby set up.
Taking as a typical illustration of these defects an ordinary fusible cut-out, as
heretofore constructed. This consists essentially of a base of slate, or other suitable
insulating material, on which the necessary connecting devices are mounted, these
latter usually consisting of two screwed terminals and a binding plate, or other
suitable connecting device, for each point of contact. Thus in a cut-out for a pair of
wires, lead and return, eight screwed terminals and four binding plates, or other
devices, are used, the whole adding greatly to the resistance of the circuit and to the
fire risks. Now in fusible cut-outs constructed in accordance with this my invention
no screwed terminals, binding plates, or other similar devices are employed, and thus
no unnecessary electrical resistance is put in circuit, while all liability to flash or
"are," together with the attendant fire risks therefrom, is done away with. I will
now proceed to describe one of the methods of, and means employed for, carrying my
invention into effect, where it is desired that the connections should be of a permanent
nature.
In a base of any desired shape or configuration, made preferably of porcelain, or
baked earthenware, though any other suitable insulating material may be employed,
there are formed grooves or channels for the wires or leads to lie in, and at a distance
from each end of these grooves or channels, coinciding with the positions that would
be occupied by the usual terminals, suitable holes or recesses are inade. These holes
or recesses are carried down for such a distance only as to ensure their not passing
through the base, and they are so made as to extend conically inwards. These conical

page_text: holes are filled in with any suitable metal, or metallic alloy, the same being melted
and run into the holes until they are quite full.
If now any wire which it is desired should terminate on the base has its end bent
at approximately a right angle, so as to form a hook like projection, having a length
slightly less than the depth of the hole or recess, then on allowing the point of a hot
solder iron or the flame of a blow lamp, or other convenient source of heat, to act on
the metallic plug in the hole or recess, for a sufficient length of time to melt it, the
hook like projection may be inserted in the hole or recess, and being retained there
until the metal cools it will then be found to be firmly retained in place.
In a second form of connection designed to be used where a permanent attachment
is not desired, the base, formed of porcelain or other suitable insulating material, is
provided with suitable channels or grooves extending for its whole length. At a
certain distance from each end of each groove or channel, corresponding to the
positions of the usual terminals, smaller grooves or channels, extending at right angles
from, and on each side of, the main grooves or channels, are formed. These smaller
grooves or channels are formed in planes perpendicular to the main grooves or
channels and extend for a sufficient distance on each side of them, and for a sufficient
distance below them, to allow of cross pieces, rigidly attached to the ends of the leads
or wires, being placed therein. The tops of these cross pieces come flush with the top
of the base, hence when the lid or cover is screwed on they cannot be withdrawn, and
the ends of the leads or wires are thereby firmly secured.
Having thus indicated the nature of my said invention I will now proceed to more
particularly describe the same as applied to a fusible cut-out, reference being made to
the accompanying sheet of drawings.
Figure 1 shows an end sectional elevation of a cut out for a pair of leads, Fig. 2
being a longitudinal section of the same taken on the line a b, and Fig. 3 a plan of the
same. Fig. 4 is an end sectional elevation of a similar cut-out having the lid or
cover so constructed as to bear upon the top of the hook like projection when
embedded in the metallic plug, the object being to retain the metallic plug in place
should it at any time become slack in the conical recess. Fig. 5 is a plan of the
underside of the lid or cover, and Fig. 6 a longitudinal section of the same taken on
the line cd. Figs. 7, 8, and 9, show respectively three forms of fusible attachments,
hereinafter described.
Referring now to Figs. 1, 2 and 3, it will be seen that the base or body A, A, of
the cut-out is formed with two grooves or channels, B, B, into which the leads or
wires F, F, pass, and is provided with a suitable lid or cover C, retained in place by
the bolt and thumb nut D. The body of the cut out is made preferably of porcelain,
or other similar suitable material, and has formed in it during the process of moulding
the conical holes or recesses E, E; which, after the cut out has received the necessary
amount of baking, are filled in with the metallic alloy as hereinbefore described.
Assuming the respective wires to be placed, and secured, in situ as indicated by
Figs. 2 and 3, then each pair would be connected together by one or other of the
fusible connections shown in Figs. 7, 8, and 9, the first of which (Fig. 7) is a plain
wire, or strip, of any suitable metal, or alloy, whose ends are simply soldered one to
each wire. Fig. 8 is a similar wire, or strip, attached to the leads in the same way
as Fig. 7, but having its ends enlarged so as to ensure fusion (on an excess of current)
at a point remote from the metallic plugs E, E, thereby avoiding the risk of
locally heating them sufficiently to cause them to release the ends of the leads or
wires F F.
Fig. 9 shows a wire, or strip, similar in its composition to the preceding, but
provided at each end with a spring clip arrangement to facilitate its attachment to the
ends of the leads or wires F, F.
Referring now to Figs. 4, 5 and 6, it will be seen that the lid or cover C is provided
with a number of projections e, e, e, e, corresponding in number with the number of
terminals on the base A. These project from the lid or cover C for such a distance as
will ensure their bearing on the leads or wires and thereby retain the metallic plugs
in the conical holes or recesses E, E. These projections may be flat on their faces, or

page_text: the faces may be recessed so as to allow of the leads or wires lying in them while the
edges of the recesses bear direct on the metallic plugs themselves.
Figs. 10, 11, and 12, show respectively a sectional end elevation, a longitudinal
section taken on the line g, h, and a plan of a fusible cut out designed so as to allow
of moveable terminals being employed. From these it will be seen that the base A
has two grooves or channels G, G, formed in it. These are slightly enlarged at their
outer ends i, i, to admit the insulated portion j, Fig. 13, of the lead or wire. The
transverse enlargements H, H, form receptacles for the retaining pieces fattached to
each terminal. The retaining pieces are firmly secured to the wire K as at
Figs. 13, 14 and 15, and may be either a plain piece of flat metal screwed or other-
wise suitably secured on a small piece of tube t, or they may be stamped out of, or
cast in, metal as a small tube or thimble having a flange at one end, the end of the
wire K being soldered in the tubular part.
The fusible attachment may be soldered on to the retaining piece direct, or it may
be secured by a screw placed as shown in Fig. 15 either at a, or b, as may be found
most convenient. If placed as shown at ba corresponding recess would be made in
the lid C, to admit the head of the screw. If now the wires are placed in the grooves
or channels so that the retaining pieces fall in the receptacles H, H, and the lid ( is
secured in place by the thumb nut D it follows that the respective terminals will be
securely held in place.
Though shown approximately semi-circular in elevation it will be understood that
any desired form may be given to the retaining pieces, which, as before stated, may
be stamped out of, or cast from, any desired metal, the same being afterwards tinned
or otherwise treated as desired. Further it will be understood, although in both cases
my invention is shown as applied to a double fusible cut-out, that the same is
applicable to a single cut-out, and also to the terminal points of electrical circuits
generally.
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:
First. The herein described method of holding the ends of electrical conductors
that are to be connected by lodging in a recess in a base of insulating material a plug
or collar fused or soldered on each conductor.
Second. A holder for ends of electrical conductors having their terminals fixed
substantially as hereinbefore described and illustrated by Figs. 1, 2, and 3 of the
accompanying drawings.
Third. The modified holder substantially as hereinbefore described and illustrated
by Figs. 4, 5, and 6 of the accompanying drawings.
Fourth. A holder for electrical conductors, having their terminals moveable
substantially as hereinbefore described and illustrated by Figs. 10, 11, 12, and 13, of
the accompanying drawings.
11
00
1000
F. SEATON SNOWDON,
Agent for the Applicant.