Improvements in Junction Boxes.
Year: 1893

page_text: Date of Application, 25th July, 1893-Accepted, 2nd Sept., 1893
COMPLETE SPECIFICATION.
Improvements in Junction Boxes.
I, EDWARD JOHN MCEVOY, of 318 East Thirty Seventh Street, in the City of
New York, County of New York, State of New York, United States of America,
Electrician, 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 :-
My invention relates to that class of moisture-proof boxes which are employed
in connection with systems of electric conductors, or wiring, to receive the
terminals of main and branch wires, and within which connection is made between
said main and branch wires.
The invention comprehends improvements in both single-branch and double-
branch junction boxes, and is of especial applicability in connection with the wiring
of ships, although it is applicable to systems of wiring employed in and connected
with buildings.
In the wiring of ships, to which, as stated, my invention has especial relation, the
junction boxes heretofore employed to receive the terminals of the various main
and branch wires, have been of cubical or quadrangular forin, and employed in
connection with moldings which have encased or enclosed and protected the wires
and been caused to abut against the flat ends or sides of the boxes, the joints
having been made as close and perfect as possible, but having been open or "butt
joints, the extremities of the moldings have been squared off to present plane
surfaces correspondent respectively with the plane surfaces of the sides and ends of
the boxes.
"
By reason of the constant vibration to which ships at sea are subject, it has been
found that the joints between the moldings and the boxes, no matter how securely
the boxes on the one hand and the moldings on the other may have been secured to
the ship, have worked loose, and that the wires have become either broken at the
joints or shaken loose or disconnected within the boxes.
It is the object of my invention to prevent this working of the joints, with its
attendant disadvantages, and, in addition, to improve the construction of the base-
blocks with which the junction boxes have been provided, and of the conductors or
wire-connecting bars with which the basc-blocks have been equipped, and which
serve to electrically connect particular wires, in such manner that in the application,
connection, disconnection, or removal, of the wires and connecting bars, all chance
of short circuiting will be avoided.
In the accompanying drawings I have represented, and hereinafter I describe,
preferred embodiments of my invention, the subject-matter which I claim as novel
being definitely specified in the claiming clauses.
In the accompanying drawings,
Figure 1 is a top plan view of a single-branch junction box embodying my
improvements, and shown in its application to its moldings; the cover of the box
and the cover strips of the moldings being supposed removed in order the more
clearly to exhibit the construction of the box and the mode of its application to the
moldings.
Figure 2 is a view in perspective of the base-block represented within the
junction box of Figure 1, removed therefrom.
Figure 3 is a view in perspective of the connecting bridge bars represented in
Figure as in place within the base-block, removed therefrom, but so relatively
disposed with regard to pictorial representation that they may be readily imagined
as in place within the aforesaid block as shown in perspective in Figure 2, the

page_text: representation of the grooves or channels within which they would obscure were
they actually drawn in place.
Figure 4 is a view in perspective of the double-branch junction box represented
in Figures 9 and 10, removed from its moldings.
Figure 5 is a view in perspective of the end portion of a molding of the
character employed, for instance, in connection with the junction box represented
in Figure 4.
Figure 6 is a view in perspective of a double-branch junction box embodying my
improvements in a slightly modified form, and shown as applied in connection with
moldings suitably recessed to receive it.
Figure 7 is a top plan view of a double-branch junction box embodying my
improvements in a slightly modified form, and shown as applied in connection with
moldings from which the cover strips are supposed removed.
Figure 8 is a view similar to Figure 7, of a single-branch junction box, of the
character, for instance, of that shown in Figure 1, the recessing of the moldings
being, however, slightly different, and their cover strips being omitted.
Figure 9 is a top plan view of a double-branch junction box, such, for instance,
as that represented in Figure 4, the cover being removed, and the moldings
uncovered or sectioned to exhibit the mode of their application.
Figure 10 is a central, vertical, longitudinal, sectional elevation through the box
and moldings of Figure 9, in the plane of the dotted line x-x on said figure, and
sight being taken in the direction of the arrows upon said line.
Similar letters of reference indicate corresponding parts.
It is proper to explain that I have, for clearer illustration, omitted from the
junction boxes represented the fuse devices which are usual in boxes of this class,
and which may, of course, be applied in any preferred manner in connection with
boxes embodying my improvements.
Referring, first, to those features of my invention which are concerned with the
prevention of the working of the joints between the box and its moldings, it is
proper to explain that I accomplish the desirable result by so correspondently
forming and recessing the box and its moldings, and relatively applying them, that
they are respectively adapted and caused to overlap, or "take" the one within the
other, somewhat after the manner, for instance, of the respective members of a
tenon joint, a rabbet joint, an angle joint, or other kindred lap joint.
Referring, first, to the double-branch junction boxes represented in Figure 4:-
The body of the box is designated by the letter A, and is shown as of quadrangular
form and as provided with lateral wings or extensions, designated A¹ A² A³ A₁
respectively of quadrangular form, and respectively projecting from the respective
sides of the body integral with which they actually or in effect are.
Portions of the main wires B B*, and of the branch wires C Cx, are shown as
respectively protruding from the wings A' A2 and A³ A¹.
In Figure 5 is represented the end portion of a molding D, having a cover
strip d, and a longitudinal wire-receiving channel or recess d*, of such dimensions
as to conform it to snugly receive within it, for instance, the wing A' of the box of
Figure 4, and also to receive and enclose the main wires B B* which protrude from
said wing.
Obviously when the wing A¹ is introduced within the recess of the molding, and
the end face of said molding caused to abut against that side of the body of the
box from which said wing springs, a solid and tight joint will be formed between
the box and the said molding, which will prevent any possible working of either
with respect to the other, and assure the maintenance of the enclosed wires without
injury or liability of disconnection.
Regarding the construction of the box represented in Figure 4, and just described,
-in which the wings or extensions of the body are of less vertical and transverse
dimensions than those of the respective sides from which said wings respectively
spring, in the light of an extreme illustration of the construction of the box with
lateral extensions conforming to and adapted to be entered within recesses in the

page_text: mouldings, it will be apparent that the idea will be equally embodied in, for
instance, the form of box represented in Figure 6, in which the extensions both as
to depth and width correspond with the depth and width of the body, the box as an
entirety being in the form of a Greek cross; and that the same result of the
prevention of working will be accomplished when a box of such form is applied in
connection with moldings recessed as at d in the manner represented in said
Figure 6, with respect to the interior wire-enclosing recesses of which the entire
extensions are not entered and enclosed.
Obviously the invention, so far as it relates to the prevention of the working of
the joints, is embodied in either the form and mode of application represented in
Figures 4 and 5, or in the form and mode of application represented in Figure 6,
or, in fact, in many other well known forms of lap or kindred joints of which the
box and molding are the respective members.
In any case the moldings are, of course, firmly affixed to the wall or ceiling to
which they are applied, and the box firmly affixed either to the wall or ceiling or
to portions of the moldings. The fixation is most conveniently performed by
screws.
In the junction box represented in Figure 7, a modified form of my invention is
represented, in which the body of the box is cylindriform and not quadrangular,
the extensions, however, being quadrangular, although they may be of other forms.
The single-branch junction box represented in Figures 1 and 8 embodies the
same features of extensions for application relatively to the moldings, that the
double-branch boxes of Figures 4, 6, 7, 9, and 10, embody, the only difference
being the omission of one of the branch extensions.
The material of which all of the junction boxes represented and described
are composed, is preferably. metal, and their mechanical construction such as
convenience of manufacture may dictate, although they are usually made as
castings. All of them are provided with covers a conveniently secured by
screws a¹, or otherwise if desired; and all of them are provided with the usual
lateral threaded apertures a² for the entrance of the wires, to which are applied the
usual tightening-up threaded thimbles a³ which compress the annular packings a*
with respect to the apertures and wires, and render the box as an entirety moisture-
proof.
The covers of the boxes are, if desired, provided with holes through which
access may be had to the interior of the boxes, and these holes are provided with
screw caps as of any preferred character.
The boxes may be conveniently secured with relation to their moldings by
screws a which pass through their bottoms, as shown in Figures 1, 9, and 10.
Referring now to those features of my invention which are concerned with the
base-block and the connecting bridge bars, the general idea is to construct the
base-block with intersecting channels or grooves for the respective main and branch
connecting bridge bars, of different depths, in order that the bodies of these bars,
while lying completely within the channels, may yet respectively lie above and
below each other; and, to the same result, to form the connecting bridge bars
themselves with end lugs of depth or height greater than the thickness of the body
portion of the bars, in order that not only may the respective main and branch bridge
bars when reversely disposed as shown in Figure 3, cross each other with adequate
clearance between them, but also that the openings in the ends of said bars with
respect to which the binding screws operate for the securing of the ends of the
wires, may all occupy a practically common level in a plane parallel with the plane
of the bottom or top of the box, to the further end that all of the apertures in the
walls of the box through which the main and branch wires pass may be formed
upon a common level, preferably in the same plane, so that moldings uniformly
recessed may be employed, and, that, in addition, all of said wires to the extent to
which they exist within the box may occupy a common plane, and not be bent
either upward or downward.
Embodiments of the foregoing construction and relative arrangement of the

page_text: base-block and its connecting bridge bars are especially illustrated in Figures 1, 2,
3, 9, and 10, may be described in the following manner :-
E is a base-block composite of porcelain or other vitreous or non-conducting
substance, to the body proper of which the letter E is particularly applied. This
block is preferably conformed to the interior of the junction box within which it is
to be mounted, and in single-branch boxes conveniently possesses the form repre-
sented in Figures 1 and 2, while in double-branch boxes it is well made when of
the shape represented in Figures 9 and 10.
The block is secured in any preferred manner within the junction box, con-
veniently by being provided with sockets e³, Figure 10, formed in its under surface
and which are adapted to register with respect to the lugs or fillets a, springing
from the bottom of the junction box, screws as, passing through the block, being
threaded into the lugs, as shown in Figure 10.
The channeling of the block varies with its character and form, that is to say, in
double-branch blocks the branch channels as well as the main channels extend
completely across the block, as shown in Figures 9 and 10, whereas in single-
branch blocks the branch channels preferably stop short of one side of the block,
as shown in Figures 1 and 2. Of course where there are more or less than two
main and two branch wires, the channels preferably correspond in number and in
trend with the number of bridge bars required.
Referring now to the single-branch block shown in Figures 1 and 2,-e ex are
the main channels, or those within which the main connecting bridge bars F F* are
entered, and e¹ e² are the branch channels or those within which the branch
connecting bridge bars G G are entered.
As will be observed from a reference to Figure 2, the main channels e ex traverse
the entire length of the block and are conveniently made of a uniform depth,
approximately, for instance, half that of the block; whereas the branch channel e¹
traverses the block to almost its full breadth, and to an extent sufficient to cause it
to intersect both main channels, while the branch channel e² traverses the block to
considerably less than its full breadth, and to an extent sufficient to cause it to
intersect the main channel ex alone.
It will also be observed that both branch channels are of the same depth,
approximately, for instance, three-quarters that of the block.
It is apparent that a block of the foregoing character (and also of the character
represented in Figures 9 and 10) embodies angularly-disposed or intersecting
channels, or sets of channels, which by individual channels, or by sets of channels,
are relatively of different depths.
Good forms of main bridge bars F F and of branch bridge bars G G* are
shown in Figure 1 as in place within the block of Figure 2, and in Figure 3 as
removed therefrom.
It will be observed that each of these bridge bars is formed as a bar of metal,
the ends of which are provided with lugs or heels ff* g g* preferably integral
with the body portions of the bars and all of corresponding breadth or depth.
The lugs ff of both ends of the main bridge bars in the arrangement
represented are provided with longitudinal holes or openings f2 f³ with respect to
which are applied binding screws. Into these openings are entered the end
portions of the main wires B B* led into the box as already explained through the
apertures a². Both lugs f and both lugs are of the same depth, and both the
bars F F are similarly disposed in their channels.
The branch bridge bar G is provided with lugs g, and the branch bridge bar G*
with lugs g*, with reference to which the hole in the bar G and the hole g³ in
the bar G are respectively disposed, the binding screws gl serving to secure the
ends of the branch wires C°C when the latter are entered within the holes g' g³.
As will be observed by referring to Figure 2, the branch conductors are disposed
with their lugs extending upward, or in the opposite direction to that in which
the lugs of the main bars extend.
Connection between the branch bar G and the main bar F is effected by a

page_text: screw which passes through the main bar and is threaded into the lug of the
branch bar; while similar connection between the branch bar G* and the main
bar FX is effected by a screw g₁ which passes through the main bar and is threaded
into the lug of the branch bar.
It will be observed that the level of the under faces of the lugs of the main bars
in the arrangement represented in Figure 3, is correspondent with the level of
the upper faces of the bodies of the branch bars G Gx, the under surfaces of the
bodies of said branch bars occupying a lower level or one correspondent with
the level of the floors of the branch channels in the blocks, whereas the level
of the under faces of the lugs of the main bars corresponds with the higher level
of the floors of the main channels.
6
fg are holes formed through the main and branch bridge bars for screws, by
the aid of which these bars may, if desired, be permanently screwed to the block.
By reason of the relatively opposite or reversed disposition of the main and
branch bridge bars when said bars are disposed within their channels in the block,
a clearance of at least the represented depth of the body of a bar is secured
between the main bar Fx and the branch bar G; and by reason, further, of the
fact that when the bars are all in place in their channels in the block, the body
of the latter intervenes in every direction between the respective bars, no
sliding of the screw driver or other tool employed in the connection or dis-
connection of the wires with respect to the bars can bring about such electrical
contact as to occasion short circuiting.
The arrangement of the bridge bars represented in the construction of Figures 9
and 10, is essentially identical with that represented in Figure 3, with the
exception that the branch channels in the block extend completely across it, and
that the bodies of the branch bars are extended to the full length of said
channels, and at their far extremities are equipped with additional lugs and
binding screws.
In the essential particulars of the relatively opposite or reversed disposition
of the bars considered with reference to the direction of the projection of their
lugs, and of the relative depth of the intersecting channels, the constructions are
mechanically identical.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a system of electric wiring, comprising wire-containing moldings and a
junction box, a joint between the junction box and a molding, formed by a
relative counterpart overlap of the box and molding, substantially as set forth.
2. In a system of electric wiring comprising wire-containing moldings and a
junction box, a joint between a junction box and a molding, formed by the com-
bination of a box formed with a lateral extension with a molding provided with an
end recess conformed to said extension, substantially as set forth.
3. A junction box formed with lateral extensions of its body portion, sub-
stantially as and for the purposes set forth.
4. A junction box formed with lateral extensions of its body portion, in
combination with moldings formed with end recesses adapted to said extensions,
substantially as and for the purposes set forth.
5. In combination with a junction box having lateral apertures for the entrance
of electric conductors, a base-block provided with intersecting channels of relatively
different depths, substantially as and for the purposes set forth.
6. In combination with a junction box having lateral apertures for the entrance
of electric conductors,-electric conductors,-a base-block provided with inter-
secting channels of relatively different depths, and connecting bridge bars formed
with heels, reversely disposed within said channels substantially in the manner
described, and connected with the electric conductors, substantially as and for the
purposes set forth.

page_text: 7. In combination with a base-block for a junction box formed with intersecting
channels of relatively different depths, intersecting connecting bridge bars formed
with heels and respectively reversely disposed within said channels, substantially as
and for the purposes set forth.
Dated this 26th day of May A.D. 1893.