Improvements in Junction Boxes, Switches, Wall Plugs and Distribution Boards for use in Electric Wiring.
Year: 1898

page_text: Date of Application, 13th Dec., 1898
Complete Specification Left, 15th May, 1899-Accepted, 22nd July, 1899
Improvements in Junction Boxes, Switches, Wall Plugs and
Distribution Boards for use in Electric Wiring.
We, GEORGE ALEXANDER CLARK, WILLIAM MCAULAY, and JOHN ALEXANDER
MCLAREN, all of the Firm of. McAulay, Clark and McLaren, Electrical Engineers,
182, West George Street, in the City of Glasgow, do hereby declare the nature
of this invention to be as follows:-
-
This invention has for its object to provide improved junction boxes, wall
plugs, main switches and distribution boards, insuring high insulation in elec-
trical wiring especially of the class wherein two separate insulated conductors
are carried in metallic piping or sheathing in lieu of the ordinary wooden casing.
The cable employed in conjunction with the improved junction boxes, main
switches, wall plugs and distribution boards may be round or oval in section and
consist of two single wires or groups of wires each insulated by paper rubber, or
other insulating material placed together and enclosed in one sheathing, special
arrangements being made to ensure water tightness at points of junction of the
cables with the switches, wall plugs, fuses and distribution boards as hereinafter
described.
In junction boxes two distinct forms of junction are used in joining cables
known respectively as "blind" and "fitting," the blind form of junction being
used where it is merely necessary to connect two or more cables together; and
the fitting form when it is desired to attach a pendant or bracket fitting to the
cable, and these have each four separate forms for special purposes hereinafter
described.
"
In the case of the "blind form of junction, the junction box may be either
a two-way junction box, when two cables having the same direction are to be
joined; a tee" junction box for joining together two or three cables at right
angles, connection being made with both positive and negative sides to fulfill the
operation known as teeing off" a three-way switch junction box for joining
together two or three cables, connection being made with one cable at right
angles to the other one, or two on the positive or negative sides only, to fulfil the
operation known as "running down to a switch" ; and a four-way junction box,
for joining together two, three, or four cables to fulfil the operation "teeing off"
in different directions. These junction boxes all consist of the following essential
parts:-
The box is made of brass, stamped, cast, or spun and has two, three, or four
'sweating pockets" for the cable according to the form of junction desired; a
disc of fibre, mica, or similar insulating material, cut to the same size and shape
as the bottom of the box; a second disc similar to the first mentioned disc, but
cut so that it may be shoved between the two conductors forming the cable and
serve to keep them mechanically and electrically apart; a third disc exactly the
same is the first mentioned; and a tinned disc consisting of a sheet of tin, tinned
brass, or other suitable and easily soldered metal cut to the shape of the top of the
box.

page_text: Assuming the desired junction to be a "tee" junction, the lead sheathing of
the cable is first of all cut away for a distance equal to a very little more than
the distance between the inner ends of the "sweating pockets" inside the box.
The outer covering of insulation wrapped round both wires is then cut away for
a distance slightly less than the above distance on either side, and finally the
insulation of each wire is cut away for a short distance in the centre and the
copper conductor cleaned and tinned. The cable to be connected to the above
cables is then similarly prepared, and the two cables are soldered together either
in a sleeve or on a plate. The bottom disc is then placed in the bottom of a
junction box, the separating disc inserted between the two wires, and the cable
placed in position in the box. The "sweating pockets" of the box are then
filled with solder till the outer sheathing of lead and the box forms a continuous
metal sheathing. The top disc is now placed above the upper conductor, the
tinned disc being placed in position above this, and sweated to the top of the box
rendering the whole water-tight.
In the case of "fitting junctions," four forms of junctions are also required,
namely:-
66
66
A flanged butt" which is employed in attaching a pendant to the end of the
branch cable, the junction box being fixed to the ceiling or to a back block; a
"suspension butt' for the attachment of a pendant or a bracket to the end
of the branch cable when the branch cable is clipped to a suspending wire; a
flanged throughway" for the attachment of a pendant or a bracket to the branch
cable, the cable passing on to feed another pendant or bracket, and the box being
fixed to the ceiling or to a suitable back block;
and a suspension throughway
for the attachment of a pendant or a bracket to the branch cable, the cable passing
on to feed another pendant or bracket, and being clipped to a suspending wire.
These junctions all consist of the following essential parts:
"
A box is made of brass, cast, stamped, or spun and has one, or two sweating
pockets" for the cable according as the junction be a butt or a throughway the
lower rim of the box being screw-threaded; a disc of fibre, mica, or other insulat-
ing material cut to the size and shape of the bottom of the box, this disc having
two circular holes stamped in it; a circular disc of porcelain, fibre or other
insulating material with two holes screwed at the top to take the sockets herein-
after described; two sockets, the tops of which are grooved to receive the con-
ductors, the bottom ends of the sockets being also bored out, so as to form
sockets for the plug terminals of the fitting; a second disc exactly the same as the
bottom disc, but without holes; a disc of tin, tinned brass or other suitable and
casily soldered metal cut to the shape of the top of the box.
Assuming the junction, it is desired to form, to be a throughway junction, the
mode of operation is as follows:-
The lead sheathing of the cable is first of all cut away for a distance equal to
very little greater than the distance between the sweating pockets inside the box.
The outer covering of insulation wrapped round both wires is then cut away for
a distance slightly less than the above distance on either side and finally the
insulation of each wire is cut away for a short distance in the centre and the
copper conductor cleaned and tinned. The cable is then opened out, the bottom
disc being placed in the bottom of the box, the socket passed through the holes
and screwed into the porcelain piece, and the cables placed in position. The outer
sheathing of lead is then soldered into the sweating pockets at either end, and the
conductors at the bare parts placed in grooves in the socket heads and soldered
therein. When the joint is made, the top disc is placed in position, and the tinned
disc placed above it, and soldered round the edges of the brass box thus rendering
the top of the box water-tight.
In a junction for an electrolier, small contact plugs consisting each of a short
length of brass tube are soldered to the end of the flexible cord, which forms the
pendant, or with which the pendant, bracket or electrolier is wired. In wiring
a fitting the cover is first of all passed over the flexible cord, then screwed at the

page_text: base, to fit the screw on the outside of the junction box. The two ends of the
flexible cord are then passed through five small holes in a circular disc of fibre,
or other insulating material cut to the same diameter as the porcelain piece,
which holes are too small to admit of the contact plugs passing through them.
The ends of the flexible cord are then soldered into the contact plugs, and the
contact plugs are inserted into the sockets to fix the fitting and the cover finally
screwed up. The weight of the pendant even if it be a heavy one, is carried by
the disc cord grip arrangement inside the cover of the box, the cover when
screwed bearing with a flange on the disc of fibre already referred to.
The arrangements for rendering a switch box water-tight consists of the follow-
ing essential parts:
A box consisting of a brass ring, having two sweating pockets one at either side,
bored out as required, the top of the box being screwed externally; a porcelain
piece upon which is mounted the working parts of the switch; sweating sockets
into which the wires are sweated; a cover screwed internally at the base, in order
to be screwed on to the outside of the box. The top of this cover has a hole
bored in it to admit of the knob of the switch projecting through it. When the
cover is screwed up a flange which projects internally above the screwed portion
of the cover bears on the porcelain piece, thereby preventing any movement.
wooden ring may be passed over the box underneath the cover for ornamental
purposes.
A
In the case of a wall socket and plug, the arrangements for rendering the wall
socket water tight consist of the following essential parts. A box similar to that
used for the switch; a porcelain piece suitably shaped and having two holes
screwed at the top for the socket piece; sweating sockets which also form the plug
contacts; plug contacts each of which consist of two contact rods firmly secured
by a couple of nuts to a disc of fibre or other insulating material, to which a
wooden top is fixed. The flexible cable is attached to the plug in the usual method
by pinching the flexible between the two nuts on the top of the contact rod, and
a sleeve of insulating material passed over the top portion of the plug contact
rods, so that when the rods are still in contact with the sockets all that portion
of the rod which is projecting from the socket is insulated, thereby rendering a
short circuit impossible. The cover of the socket is practically the same as that
of the switch, an internal flange above the screwed portion of the cover bearing
on the top porcelain piece, when the cover is screwed up.
In the case of distribution boxes, the distribution board is contained in a
cast iron box, having the fuses mounted on slate bases suitably secured inside
the box. At the points where the cables enter the box, brass couplings are soldered
to the sheathing of lead, the lead sheathing being cut off inside the box, and a
suitable sweating socket soldered on at a convenient point to each conductor.
The two poles of the box are separated by a sheet of fibre or other insulating
material, and the fuse passes up the middle of a glass tube, which has suitable
contact pieces soldered on at each end. The contact pieces are ventilated at each
end to admit of the expansion of the air when a fuse blows.
In the case of a main switch and fuses, these are of the ordinary form, but are
mounted in cast iron boxes, and where the cables enter the box the outer sheathing
of lead is soldered into suitable couplings as hereinbefore described with reference
to the distribution boxes.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicants.

page_text: Improvements in Junction Boxes, Switches, Wall Plugs and
Distribution Boards for use in Electric Wiring.
We, GEORGE ALEXANDER CLARK, WILLIAM MCAULAY, and JOHN ALEXANDER
MCLAREN, all of the Firm of McAulay, Clark and McLaren, Electrical Engineers,
182, West George Street, in the City of Glasgow, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement;-
-
This invention has for its object to provide improved junction boxes, wall plugs,
and switches, insuring high insulation in electrical wiring especially of the class
wherein two separate insulated conductors are carried in metallic piping or sheath-
ing in lieu of the ordinary wooden casing.
The cable employed in conjunction with the improved junction boxes, switches
and wall plugs may consist of two single wires or groups of wires each insulated
by paper, rubber, or other insulating material placed together and enclosed in
one sheathing, special arrangements being made to ensure water tightness at
points of junction of the cables with the fittings, switches and wall plugs as
hereinafter described.
In junction boxes two distinct forms of junction are used in joining cables
known respectively as "blind" and "fitting," the "blind" form of junction
being used where it is merely necessary to connect two or more cables together
and the "ntting" form when it is desired to attach a pendant or bracket fitting to
the cable, and these have each separate forms for special purposes hereinafter
described.
66
In the case of the "blind" form of junction, the junction box may be either
a two-way junction box, when cables having the same direction are to be joined;
a tee" junction box for joining together two or three cables at right angles,
connection being made with both positive and negative sides to fulfil the operation
known as teeing off"; a three-way switch junction box for joining together
two or three cables, connection being made with one cable at right angles to the
other one or two, on the positive or negative sides only, to fulfil the operation
known as 66
running down to a switch"; and a four-way junction box, for join-
ing together two, three or four cables to fulfil the operation known as teeing
off in different directions.
"
"
tee
" tee"
The invention is illustrated by the accompanying drawings, Figs. 1 and 2 being
a horizontal longitudinal section and vertical section, respectively, of a
junction box for twin wiring with sweating pockets, and Figs. 3, 4 and 5 a
junction box without sweating pockets. Figs. 6, 7 and 8 are respectively hori-
zontal longitudinal section, vertical section, and transverse vertical section of a
tec junction box with sweating pockets adapted to a three wire system, and
Fig. 9 a transverse section with the box removed of like arrangement showing two
of the three wires teed off. Fig. 10 is a vertical section through a screwed junction
box with sweating pockets arranged for use on a three wire system in which cables
are used having two conductors each insulated from each other and from earth
enclosed in a sheathing or armouring which sheathing or armouring is used as
a conductor, the pendant wire being of the ordinary concentric pattern with earthed
outer. Figures 11 and 11 are plan and vertical section respectively of a screwed
junction box with sweating pockets adapted for attaching a pendant or bracket
thereto, and Figures 12 and 13 are similar views of a box without sweating
pockets, Figure 14 being an elevation of the same showing the two portions of
the box. Figure 14* is a plan of a screwed junction box with sweating pockets
adapted for use with a three wire system in which all three conductors are insu-

page_text: lated from each other and from earth. Figure 14" is a section on the line AB
showing the arrangement of the porcelain used in this junction box. Figure 15
is a vertical section of a wall switch with sweating pockets and Figures 16 and 17
are plan of underneath portion and transverse vertical section of the box for
same without sweating pockets, which box may also be used in connection with
the wall sockets immediately hereinafter mentioned. Figures 18 and 19 are
vertical sections of two forms of wall socket both with sweating pockets. Figure 20
is a vertical section of an attachment for an arc lamp and Figure 21 a section
showing a detail of the same. Figure 22 is a plan and Figure 23 a vertical
section of an electrolier junction with sweating pocket.
The cables we use consist of two or more conductors insulated from each other
and from earth, laid together and enclosed in a common sheathing metallic or
otherwise, or we may use cables having two or more conductors insulated from
each other and enclosed in a metallic sheathing or armouring which sheathing
or armouring is not insulated and is used as a conductor. The insulating sub-
stance may be non-hygroscopic material such as india rubber and its compounds
or hygroscopic material such as paper impregnated with an insulating oil.
Where it is desired to join two or more cables, a junction box is used and
where the conductors are enclosed in a sheathing of lead or other metal in places
likely to be exposed to contact with water or in a more than usually damp atmos-
phere, we may employ a metallic junction box provided with suitable sweating
pockets at the points where the cables enter and leave the boxes such pockets
being similar to those used in Mavor & Coulson's CC concentric system of wiring.
This concentric system of wiring consists in forming the cable with a central
copper core and insulating it by india rubber material from the outer conductor
which is stranded over the rubber, the whole being enclosed in a solid drawn
sheathing of lead.
A box arranged for twin cables is shown in Figures 1 and 2. A is a metal box
with two, three or four sweating pockets B as required, and C is a disc of mica
or other insulating substance, of the same shape and size as the bottom of the
box and placed therein to insulate the conductor from the bottom of the box;
D is a similar disc inserted between the two conductors 12 of the cable to insulate
them from each other; E a third similar disc and Et a disc of brass or other
easily soldered metal soldered to the top of the box in the usual way making it
water-tight; or when conductors enclosed as last mentioned or enclosed in any
non-hygroscopic substance are used in places not likely to be exposed to contact
with water, or unusually damp atmosphere, or when conductors are used having a
non-hygroscopic insulation and enclosed in any common sheathing whatever,
we may use the junction box shown in Figures 3, 4 and 5. This box we make
in two parts A, A1, and may bind the parts together by screws as shown in Fig. 5
after the conductors D2 have been joined and insulated from each other, as shown
in Figs. 3 and 4, and from the box as above described. When the sheathing of
the cable need not necessarily be metallic, we may make the box shown in
Figs. 3, 4 and 5, out of non-metallic substance, and if the insulating properties
of the material of which the box is made be good, we may dispense with the top
and bottom discs. Where it is desired to join cables having three conductors D³
each insulated from each other and from earth the boxes are modified as shown
in Figs. 6, 7 and 8, and where it is desired to join a cable having three con-
ductors D2 each insulated from each other and from earth to a cable having two
conductors 12 so insulated, the arrangement is modified as shown in Fig. 9 and
where it is desired to join cables having two conductors each insulated from the
other and from earth and enclosed in a metallic sheathing or armouring, which
sheathing or armouring is used as a conductor, the box we use is the same as
shown in Figs. 1 and 2, and so on with similar modifications to suit cables having
any number of conductors.
Where it is desired to attach a pendant or bracket to such cables as above
described a junction box is used and where the conductors are enclosed in a sheath-

page_text: ing of lead or other metal in places likely to be exposed to contact with water or
in an unusually damp atmosphere we may employ a metallic junction box with
suitable sweating pockets at the points where the cables enter and leave the boxes,
such pockets being similar to those used in Mavor & Coulson's CC concentric
system of wiring. Such a box arranged for twin cables is shown in Figs. 11
and 11. A is the metallic junction box having one, two, three or four sweating
pockets B as required; the lower portion of the box is screwed externally; Cis
an insulating piece of porcelain or other suitable material through which pass
two contact pins D₁ made of brass or other metal. The heads of these pins D
which are slightly larger in diameter than the body, are slotted and into these
slots the conductors D2 are soldered. The underneath portions of the pins are
bored out to form sockets into which the split contact plugs E soldered to the
ends of the flexible wire forming the pendant or to the flexible or other wire
with which the fittings are wired are inserted. F is a disc of fibre or other insu-
lating material with a circular hole just sufficient to let the flexible wire pass
through this cord grip is held in position by the cover G which is screwed
internally and through the top of which a hole is bored. This hole is tapped
and into it in the case of a pendant'an ebonite or similar nozzle is screwed, in the
case of a bracket, the cover is screwed, down over a screwed nipple on the end
of the fitting, the latter being prevented from turning by a jam nut in the usual
way; L is a disc of mica or other suitable insulating material placed above the
contact pins to insulate them from the top M of the box A which is a disc of
brass or other easily soldered metal tinned and soldered to the top of the box in
the usual manner rendering it water-tight.
68
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66
66
In the case of "fitting junctions" two forms of junctions are required, namely
flanged" and " suspension for example, a "Hanged butt" is employed in
attaching a pendant to the end of the branch cable, the junction box being fixed
to the ceiling or to a back block; a suspension butt" for the attachment of a
pendant or a bracket to the end of the branch cable when the branch cable is
clipped to a suspending wire; a flanged throughway" for the attachment of a
pendant or a bracket to the branch cable, the cable passing on to feed another
pendant or bracket, and the box being fixed to the ceiling or to a suitable back
block and a suspension throughway" for the attachment of a pendant or a
bracket to the branch cable, the cable passing on to feed another pendant or
bracket, and being clipped to a suspending wire.
Where it is desired to attach a' pendant or bracket, to conductors enclosed as
last mentioned, or enclosed in any non-hygroscopic substance used in places not
likely to be exposed to contact with water or unusually damp atmosphere, or
when conductors are used having non-hygroscopic insulation and enclosed in any
common sheathing, we may use the junction box shown in Figs. 12, 13 and 14.
This box we make in two parts H, H', and may bind the two parts together by
screws as shown at Fig. 14 after the conductors have been soldered to the contact
pins passing through the insulating piece C¹ Figs. 12 and 13 in the lower portion I
of the box. When the sheathing is not metallic, we may make the box shown in
Figs. 12, 13 and 14 out of some non-metallic substance, and if the insulating
properties of the material of which the box is made be good, we may make the
insulator and box in one part. Where it is desired to attach fittings between
two conductors of a cable having three conductors each insulated from the others
and from earth, the boxes are modified as shown in Figs. 14 and 14", and where
it is desired to attach fittings between one of the inners and the outer conductor
of a cable having two conductors each insulated from the others and from earth
enclosed in metallic sheathing or armouring, which sheathing or armouring is
used as a conductor, the box i modified as shown in Fig. 10 and so on with similar
modifications to suit cables having any number of conductors.
Where it is desired to attach wall switches in places likely to be exposed to
contact with water, we may use the wall switch shown in Fig. 15. I is a metal box
with two flanges I¹, I2, projecting inwards near the bottom of the box.
These

page_text: flanges are hollow underneath, and form cavities. J is the base on which the
switch parts are mounted. This base is made of porcelain or other suitable
insulating material, and has a wall projecting both above and below the base.
This base J is held in position by the cover K of the box I. The cover of the
box may be made of metal polished and lacquered or of any other suitable sub-
stance. The cable enters the box through a hole bored through both the outside
wall of the box and the internal flange. The cavity formed at this point is filled
with solder as described in Specification of Letters Patent No. 2263 of 1885,
rendering the box water-tight at the point where the cable enters. The two con-
ductors 12, are then soldered into suitable sweating pockets B which pass through
the base of the switch. L is a disc of mica or other insulating substance placed
above the bottom wall of the switch base; M is a disc of brass or other suitable
and easily soldered metal, which is soldered round the edge to the bottom of the
box making the whole water-tight.
Where it is desired to attach a wall switch in places not likely to be exposed
to contact with water, we may use the wall switch with the box, shown in
Figs. 16 and 17, without sweating pockets. This box is made in two por-
tions A, A', held together by screws as shown after the conductors have been lead
in and connected as above described. The arrangement otherwise is the same
as Figure 15.
Where it is desired to attach a wall socket in places likely to be exposed to
contact with water, we may use either of the sockets shown in Figs. 18 and 19
which are practically the same as Fig. 15, except the shape of the insulating pieces
inside, which are in these cases shaped practically as shown, and through which in
the case of Fig. 18, the two plug sockets N pass, these sockets N being screwed
into the porcelain J at the lower end and in the case of Fig. 19 the two sockets
carrying buffer contacts pass, and are fixed as shown. The underneath portions
of these sockets are slotted into which slots the conductors D2 are soldered.
Where it is desired to attach wall sockets in places not likely to be exposed to
contact with water, we may use the wall sockets shown in Figs. 18 and 19 with
the box shown in Figs. 16 and 17 without sweating pockets.
Where it is desired to attach an are lamp to a bracket, we may use the socket
shown in Figs. 20 and 21, 0, 0, are two semi-circular insulators shaped as shown.
P, P, two sockets into the top portion of which the conductors are soldered, and
which are bored out underneath to form sockets into which split contact plugs Q, Q,
soldered to the ends of the flexible or other wire leading to the arc lamp terminals
are inserted. These pins are held in position by a cord grip R, consisting of a
disc or fibre or other similar material held in position by the metal cover S,
screwed to the outside of the tube T of the bracket.
Where it is desired to attach to cables having two conductors each insulated
from the other and from earth and enclosed in a common metallic sheathing, an
electrolier the lamps of which are to be controlled by two or three switches, we
may use the junction box shown in Figs. 22 and 23, which box may be either
with or without sweating pockets. In this box A is inserted an insulating piece
of porcelain or other suitable material through which pass four contact pins C¹³,
such as have been already described. Two of these pins, where only two switches
are required, are short circuited. Contact plugs soldered to the ends of the
flexible or other wire with which the fitting is wired are inserted into these con-
tact pins C3 as herein before described. The cover of the boxes may be shaped as
shown so that a hemispherical flange B2 attached to the tube B3 of the electrolier
may bear on the internal surface of the cover and permit the electrolier to hang
vertically when the cover is screwed up.
Having now particularly described and ascertained the nature of our said
nvention, and in what manner the same is to be performed, we declare that what
ve claim is:-
1. A junction for use in joining cables for the transmission of electric enerev

page_text: when cables are used having two or more conductors insulated from each other
and from earth, which junction consists of the combination of a box with rigid
insulating discs insulating the conductors from each other and from the box and
held in position by the walls of the box and so arranged that a longitudinal
section through the conductors and dises when the joint is completed, is solid.
2. A junction for the attachment of fittings to cables having two or more
conductors insulated from each other and from earth, which junction consists of
the combination of a box and an insulating piece held in position by the walls
of the junction box, through which insulating piece contact pins pass and into
one end of each of which pins the conductors are soldered and to the other end of
which the fitting is attached.
3. A water tight wall switch or socket, having the switch parts or the -plug
sockets mounted on an insulating base held in position between two flanges at
the bottom of the box and the metal cover of the box when screwed down, which
base has a wall projecting downwards between the flanges to prevent it turning
round in the box, and also a wall projecting above the switch parts on which wall
the cover of the box bears.
4. A socket for the attachment of arc lamps, having an insulating piece made
in halves between which are inserted plug sockets into one end of each of which
socket the ends of the twin conductors are soldered, the whole being kept in
position by the tube of the bracket from which the arc lamp is suspended, and to
the other end of which sockets the cables leading to the arc lamps are attached.
תתו
1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicants."
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicants.