An Improvement in Flexible Tubing.
Year: 1890

page_text: Date of Application, 19th Aug., 1890-Accepted, 20th Sept., 1890
COMPLETE SPECIFICATION.
An Improvement in Flexible Tubing.
I, ALEXANDER MELVILLE CLARK of the firm of A. M. and Wm. Clark, of
53, Chancery Lane in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this invention (a communication to me
from abroad by Thomas Richard Almond, Machinist, of 343, West 23rd Street, and
Edwin Gale Freligh, Physician, of 11, West 34th Street, both in the City County and
State of New York, United States of America) and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to an improvement in flexible tubing and is particularly
designed as an improvement on a former Patent dated the 25th day of March 1890,
No. 4664.
The invention consists essentially of combining a coil of substantially triangular
cross-section with any other suitable coil between the convolutions of which the
triangular windings of said triangular coil are forced. It also consists in concaving
the faces of said triangular coil and combining therewith peculiar shapes of any other
suitable coil, as hereinafter more fully specified.
Reference is to be had to the accompanying drawings forming part of this
Specification, in which
Figure 1 represents an adaptation of the tube having a tapering form, to gas piping
and the like.
Figure 2 is an adaptation to an electric light support.
Figure represents a longitudinal central section, on a larger scale, of a flexible
tube embodying the invention shewing it on the mandrel.
Figure 4 is a similar view of said tube, partly in face view, with the mandrel
removed.
Figures 5, 6, and 7 are sectional diagrams shewing different forms of parts.
In the Specification of my former Patent referred to, a flexible tube was described
as composed mainly of two coils of circular cross-section one of which was placed
around the mandrel, the other being forced into the interstices between the con-
volutions of the first coil so as to enter between said convolutions and reach contact
with the mandrel.
One advantage which a triangular coil has over this arrangement is that the pipe
may be made with a substantially smooth outer surface, as shewn in Figures 1, 2,
and 4. An outer coil A of substantially triangular cross-section is therefore adopted,
which outer coil is forced between the convolutions of the inner coil D while the said
coil A bears on the mandrel B so that the tapering or wedge-like edges of the outer
coil A will at all times keep the inner coil D under tension.
The triangle of the outer coil A may be equilateral and straight sided, as in
Figure 6, to produce a semi-flexible tube or a tube which will, on account of the large
amount of friction between the coils, support itself, as shewn in Figures 1 and 2.
To produce a tube which shall possess great flexibility, the contact faces a a which
outt against the coil D are made of concave form, as shewn in Figures 5 and 7. This
coil, consisting of a concave triangular form, as shewn in Figure 5, has also the.
dvantage of producing a tighter joint. Figure 7 shews another form in which the
nner coil D has contact faces bb on the same curve as the contact faces a a of
he concave faces of the coil A.
A convenient method of making this improved tube is to first place the coil D
round the mandrel B and then to force between the convolutions of the said coil D
he triangular coil A so that the wedge-like convolutions of the coil A will enter
etween the convolutions of the coil D, spreading said convolutions apart, and make a
ight joint. The mandrel is then removed, and the tube ready for use. It is found
Pin 1

page_text: convenient to diminish the weight of the outer end of the tube, for some purposes, by
making it of tapering form, as shewn in Figure 1.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
1. The flexible tube composed of a coil D combined with a coil A of substantially
triangular cross-section, the convolutions of which are interposed between the
convolutions of the coil D, substantially as herein shewn and described.
2. A flexible tube composed of the coil D combined with the coil A. of substantially
triangular cross-section having concave faces a a the convolutions of the said coil A
being interposed between the convolutions of the said coil D, substantially as herein
-shewn and described.
3. A flexible tube composed of the coil D combined with the coil A. of substantially
triangular cross-section having the concave faces a a, the coil D having curved
faces b b corresponding to the curved faces a a of the coil A the convolutions of the
coil A being interposed between the convolutions of the coil D so that the concave
faces a a shall contact with the curved faces b b, substantially as herein shewn and
.described.
Dated th: 10th L
1000
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.