An Improved Case for Electrical Transformer Connections, also applicable to Street Electric Light Standards.
Year: 1899

page_text: Date of Application, 6th Mar., 1899-Accepted, 8th Apr., 1899
An Improved Case for Electrical Transformer Connections, also
applicable to Street Electric Light Standards.
I, GEORGE WILKINSON, of 12, Dragon View, Harrogate, in the County of Yorks,
Electrical and Mechanical 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:—
My invention relates to an improved case for electrical transformer connections
whereby the high tension connections are entirely enclosed, and the surrounding
carcass and framework suitably earthed to comply with the regulations, the
terminals and connections being only accessible by means of a key, fitting a lock
of good construction.
This arrangement is especially adapted to concentric systems of wiring, and
provides a complete closure of the high tension circuit from the main or branch
lead to the transformer which may be of any known type or make. The secondary.
or low tension connections are accessible outside the box, and independently of
the lock and key, or they may also be enclosed within the metal box or they may
be enclosed in a separate box to themselves if desirable, the low tension cables
being brought out therefrom through suitable holes therein. I have modified
the arrangement of parts to render the invention applicable to hollow electric
light standards.
In order that my said invention may be the better understood, I have appended
the accompanying sheet of drawings in which Figure 1 represents a part sec-
tional elevation of a box or case fitted upon the top of a transformer for house,
domestic or other purposes, and Figure 2 is a plan view thereof. Figure 3 is a
sectional elevation of the lower part of an electric light standard, showing the box
in section, and the transformer only in part, for obvious reasons. Figure 4 is a
sectional plan upon the line A B. Similar letters of reference indicate corre-
sponding parts throughout the several views.
In carrying my invention into effect. I construct a metal box C, which in
Figure 1 and 2 fits upon the transformer D. The studs or bolts for attachment are
not shown, but in any case they are only accessible from the interior. The con-
centric conductor E terminates in a nozzle F of a well-known type. having been
previously passed through a metal can G which is attached to the box or case C
by one or more bolts a which are preferably rounded at the head, and squared or
otherwise shouldered to prevent turning, in order that the fixture to the box C
should be inside and not accessible from the exterior. One high tension primary
lead bis led to the transformer D off the nozzle F, and the other lead c through
an insulating bush f, and through a high tension safety fuse d also to said trans-
former. The secondary, or low tension conductors may lead through an external
switch H and any other instrument or mechanism placed outside the box C. There-
fore, according to this construction, the concentric lead is entirely enclosed, the
space e being filled in with lead or other metallic tamping which fulfils the pur-
poses of sealing and also of "earthing" the main or branch lead and the
transformer carcass or framework. A door I is suitably hinged, and fitted with a

page_text: safety lock and key, so that the enclosed high tension connections cannot be
tampered with except by officials in charge.
A modification of this device is shown by Figures 3 and 4, and is especially
applicable to electric light standards. Referring to these figures K is the base
of a standard, having a hinged door L, shown in section by the plan view
Figure 4, and-by dotted outline Figure 3. Through this door the transformer is
passed in, and preferably suspended by the eye until the box C upon which it
is to rest is adjusted. Said box is provided with claw webs i on one side, and a
centre pointed screw stud g on the other, engaging with a screwed lug h attached
to or forming an integral part of the box C. Thus, an ordinary centre counter-
sunk in the standard K at the proper height allows of the adjustment of the box C.
The transformer D is then lowered and fixed upon it, and is preferably furnished
with a conical roof and case as shown for protection against humidity of the atmos-
phere. The concentric lead E is passed through the cap G and the connections
made as herein before described. The metallic tamping shown by e in Figures 1
and 2 need not be carried out in this case, and the orifice may be closed by any
other means, the necessary "earthing” being provided by the buried root of the
metal lamp standard. The low tension switch H readily accessible by means of
the door L, but the high tension connections, such as the safety fuse d are enclosed
within the box C, and only accessible to the possessor of the key controlling the
door L.
Thus, according to my invention, the entry of the concentric cable or lead to the
transformer and its subsequent subdivision, through fuses or any other devices,
are entirely enclosed, and cannot be disconnected or tampered with without the
proper possession of the key, and further, the subdivision of the high tension
leads are so arranged that the concentric cable is practically led to the transformer
without the intervention of terminals or separately insulated wires. It is obvious
that transformers arranged and fitted as above described can be safely installed
in buildings without the necessity of a special brick or iron chamber as hitherto
used in such cases.
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:-
First. A metal box or case with a hinged and locking door adapted to an
electrical transformer, and holding enclosed all high tension connections and
appliances, in combination with a metal covering cap having internal attach-
ments and carrying a concentric cable with or without a metallic tamping for
sealing and earthing, substantially as herein described and shown by the appended
drawings.
Second. A metal box or case with a locking door as referred to in the preceding
claim having extended webs and an adjusting screwed stud for fitting the interior
of electric lamp standards substantially as and for the purposes set forth and
shown by the accompanying drawings.
Third. The combination of a transformer D, box or case C, cap G and concentric
conductor E substantially as and for the purposes herein set forth and shown by
the appended drawings.
Fourth. The combination of a transformer D box or case C and cap G with a
hollow lamp standard K having a door L substantially as herein described with
reference to Figures 3 and 4 of the appended drawings.
1
1. 1 Manch 1000
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E..
Agent for the Applicant.