Improvements in Means of Supporting and Insulating Electric Conductors within Culverts or like Conduits.
Year: 1895

page_text: Date of Application, 1st Oct., 1895.
Complete Specification Left, 1st July, 1896-Accepted, 8th Aug., 1895
PROVISIONAL SPECIFICATION.
Improvements in Means of Supporting and Insulating Electric
Conductors within Culverts or like Conduits.
I, ROOKES EVELYN BELL CROMPTON, of Mansion House Buildings in the
City of London, Electrical Engineer do hereby declare the nature of this
invention to be as follows:-
My invention relates to improvements in insulators and supports for insulators
for use in connection with underground mains for distributing electricity. My
system is described in my Patent Specification No. 7655 of 1888 and my present
invention relates more particularly to the supporting and straining insulators
therein described. Also in the Patent Specification of myself and William
Ashcombe Chamen No. 14698 dated Sep. 17 1890 wherein special forms of
insulators and supporting bars are described. In place of the older forms of
supporting insulators and supporting bars for certain purposes particularly where
much moisture is met with in the culverts or like conduits I prefer to use cast iron
supporting bars on which the insulators are mounted in a manner which I will now.
proceed to describe.
The supporting bars consist of cast iron bars of a T shaped section from which
rise spaced at a convenient distance apart a number of pins or short pillars which
are cast solid with the bar itself. Over these pillars I drop either a succession of
short perforated slabs of porcelain or one long slab perforated with holes to
correspond with the pillars in such manner as to entirely cover the whole of the
upper portion of the cast iron leaving the pillars projecting up through it and thus
prevent any accident due to short circuit from one or more of the bare copper
conductors falling on to the cast iron. In place of the insulators I have hitherto
used and described in my former patents I prefer to use what are technically
called "double shedded insulators provided with an internal cylindrical recess
which can fit on to the tops of the cast iron pillars above mentioned and be held
sufficiently firm in position thereon by a ferrule or cap made of vulcanized Indian
rubber or other material sufficiently elastic for the purpose. By this means
I obtain a double shedded insulator having an extended surface and this greatly
improves the insulation of the system. I use this same arrangement of cast iron
pins and double shedded insulators for my straining insulators the straining beams
in this case being of cast iron, cast steel or of other suitable material provided with
pillars or pins which in this case are placed horizontally, the horizontal insulators
being fitted to them by recesses and rubber ferrules and pads as before described.
In order to prevent accident due to short-circuit from a strip falling aud coming
into contact with the lower portion of the straining beams in some cases I provide
a piece of porcelain which fits on to and protects the whole of the exposed surface
on which the copper strip could fall.
Dated the let dan of
1005
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, W.C., Agents for the Applicant.

page_text: Improvements in Means of Supporting and Insulating Electric
Conductors within Culverts or like Conduits.
I ROOKES EVELYN BELL CROMPTON of Mansion House Buildings in the
City of London, 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 ascertained in-and by the following. statement :-
My invention relates to improvements in insulators, and supports for insulators,
such as those intended for use in connection with underground mains for
distributing electricity, and more particularly to the further improvements in the
system described in my Patent Specification No. 7655 of 1888 that is to say in
regard to the supporting and straining insulators therein described also to Patent
Specification of myself and William Ashcombe Chamnen dated Sep. 17th 1890
No. 14698 wherein special forms of insulators and supporting bars are described.
In place of the older forms of supporting insulators and supporting bars, wherever
much moisture is likely to be met with in the culverts, I prefer to use, in place of
wooden supporting bars, cast iron, cast steel, or such like material supporting bars
of a special form on which improved insulators are mounted in a manner which I
will now proceed to describe.
Figure 1 shows in side view and Figure 2 in end view a cast iron supporting bar
arranged for three lines of conductors (i.e. for a three wire system, but of course
any number of lines of conductors up to 10 or 12 may be mounted in a similar
manner) the cast iron bar a being strengthened in proportion to the extra number
of insulators mounted on it. This supporting bar a is most conveniently made of
cast iron of good quality and of T form of cross section as shown in Fig. 2. On
its upper surface are cast three conical pillars or projections b the lower portion
being slightly conical and the upper portion being cylindrical. d shows in cross
section a double shedded insulator which may be made of glass, porcelain, woodite,
vulcanite, compressed and moulded tnica, or any of the well known materials used
for such insulators. This insulator d is a loose fit on the pillar b an annular space
being left between the cast iron pillar and the insulator for the insertion of a
special form of india rubber thimble e shown in full size in cross section and plan
view. Fig. 3. The upper part of the insulator d has a cylindrical projection fon to
which a gunmetal crutch or cap g is dropped, the copper strip or conductor lying
in a rectangular notch formed in this crutch. cis a strip of porcelain having
perforations to correspond with the pillars bbb this strip of porcelain is of a width
equal to that of the supporting bar a and is dropped over the pillars in the position
shown in the drawing before the insulators are placed in position the object of this
strip is to prevent a possible short circuit if accidentally one of the conductors
becomes dislodged and falls. down in the space between the insulators. Another
method of obtaining this. object is in place of providing the separate porcelain
strip c to coat the upper surface of the bar a with vitreous enamel in some cases I
may continue this enamel all over the surface of the bar so as to protect it from
oxidation and also give extra insulation to the system. The object of forming the
rubber washer with projections or wings (here shown as cruciform) as shown at
Fig. 3 is to make it easily adapt itself to slight variations in the internal diameter
of the recess in the insulators as whenever these are made of glass or porcelain it is
not easy to make this recess exactly to gauge. This cruciform section touching
the insulator only in four points also adds to the insulating qualities of the
system..
.
Figures 4 and 5 show the same form of insulator adapted as a means of taking
the horizontal strain of my strained up system of conductors; in this case the

page_text: horizontal strain is taken by a pair of bars of I section placed on their sides; these
may be of cast iron as in the former case and the pillars are cast on them and insulators
fitted to them almost precisely as in the case of the vertical insulators in Fig. 1..
kk shows these horizontal straining bars or girders in end view and cross section ;.
1 is the bridge piece supported against the ends of the horizontal insulators; m is a
piece of insulated material dropped on to the upper surface of the lower girder so
as to prevent accidental short circuit from contact with any part of the conductors
with this lower straining girder but as in the case of supports this object may also
be attained by covering the girder with a sufficiently thick coating of vitreous.
enamel.
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 in respect of supporting and insulating devices for electric conductors within
culverts or like conduits is :-
1. The combination of a supporting bar provided with pillars, shedded insulators,.
elastic washers and crutches, substantially as herein set forth and for the purpose
described and shown on the drawing Figures 1, 2, 3.
2. The apparatus similar to that described in Claim I used as a means of
straining insulators, as set forth.
3. The use of metallic supporting bars protected against accidental short
circuiting by insulating strips or coatings of enamel, substantially as herein.
described.
4. The construction and use of washers of elastic material as india rubber, as and.
for the purpose set forth.
5. The construction and arrangement or combination of parts of supporting and
insulating electric conductors within culverts, or like conduits, so as to improve the
insulation, equalize strains and prevent the breakage of insulators due to unequal
and bad fitting of the supports for the porcelain insulators, and simplification of
construction substantially as set forth.
Dated the 30th day of June 1896.
WM. BROOKES & SON,
55 & 56 Chancery Lane, Loudon, Agents for the Applicant.