Improvements in Conduits for Electric Conductors.
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by ARTHUR LORD, of Plymouth, Massachusetts,
United States of America.]
Improvements in Conduits for Electric Conductors.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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 :-
It is desirable in many places, especially arranging electric wire in houses, to
have the electrical conductors in conduits or pipes, and my invention relates to
conduits which are especially adapted for that use, but are of course of more
general application.
My invention comprises a conduit formed of short tubes which are held end to
end by means of a flexible pipe or hose the whole forming a flexible conduit one
advantage of which is that it is readily drawn into place behind the plastering;
it is also strong and in all respects admirably adapted for the reception of electrical
conductors.
In the accompanying drawing
Figure 1 is a lengthwise section of a short length of my conduit.
Figures 2 and 3 are cross sections on lines 2, 2 and 3, 3 of Figure 1.
Figure 4 is an elevation showing a construction which adapts the conduit to be
cut into lengths.
A represents short tubes of porcelain or other proper material. These tubes are
preferably non-conductors of electricity and shaped as shown, so that when put
together end to end each will move readily with relation to the other for
enough to give flexibility to the finished conduit, and yet not interfere with
the introduction of conductors, that is the bore of one tube cannot get cross-wise
of the bore of the neighboring tubes. These tubes are held together by the
flexible pipe B which is preferably manufactured in place on the tubes A; but
of course, a suitable hose may be packed with these tubes, especially when some
of them are formed with a groove as shown in Figure 4, by means of which the
hose B may be firmly secured to the tube A. so grooved by a binder a. In all
cases I prefer to use a pair of grooved tubes every yard or two in the length of
the conduit so that it may be cut into suitable lengths, as will be clear from
Figure 4. Of course all the tubes may be grooved if desired and with proper
machinery for weaving the hose in place and contracting it about the grooves
this is desirable but where wire or cord binders a are used it answers well to
secure the hose B to the tubes A only at such intervals in the length of the
conduit as will answer for adapting the conduit to be cut into lengths.
The hose or flexible pipe B is preferably water proofed by a rubber covering
but that is a matter too well known to require description.
I am
aware of United States Letters Patent No. 283,763 of 1883 and
No. 421781 of 1890 also the British Patent No. 800 of 1861 and disclaim all
that is shown in them, my conduit consisting of a flexible tube or pipe lined with
short tubes each of which is independent of its neighboring tubes and each of
which is flared at both ends. The beads, discs or tubes of United States Patents
Nos. 283763 and 421781 and of the above mentioned British Patent are strung
upon the conductor and the bore of these beads discs or tubes are substantially
uniform except in United States Patent No. 421781 where the tubes are not
independent but articulated that is, a portion of one tube fits into a socket formed
in the other tube to receive it. In short the main function of the parts comprising
my conduit or compound tube is to preserve the bore so that a flexible wire passed
[D017

page_text: endwise into my compound tube will be guided by the small central part of the
bore of each short tube into the mouth of the next short tube even when the com-
pound tube is bent and hence the articulation of the short tubes as in United States
Patent No. 421781 or in any other way must be avoided in making my conduit or
compound tube and the difference in diameter between the middle and end portions
of the bore of the short tubes must be large, instead of merely that slight flare
which enables the tubes to be strung more readily upon a wire or which enables
the tube to move somewhat upon a wire which fills the middle part of its bore.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
First. A conduit for electrical conductors made up of a number of short tubes A
having an inner diameter at the ends greater than at the middle portion and each
independent of the others and a flexible pipe B; the pipe B holding the tubes A
end to end and the whole constituting a conduit substantially such as described.
Second. A condiit for electrical conductors made up of a number of tubes A some
of which are grooved substantially as described held together by a flexible pipe B
which is contracted to fill the grooves about the grooved tubes all substantially as
described.
Dated this 13th day of January 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.