Improvements in or relating to Inflatable Tubular Rings.
Year: 1897

page_text: Date of Application, 21st Aug., 1897-Accepted, 29th Jan., 1898
COMPLETE SPECIFICATION.
Improvements in or relating to Inflatable Tubular Rings.
I, FRANK WYNNE, of 13, Ashley Gardens, in the City of Westminster, Civil
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:
This invention has reference to a construction of tubular inflatable closed ring
the diameter of which can be readily increased by inflation beyond its normal or
initial diameter against an elastic resistance so that if it be then placed around a
body of larger diameter than the said normal or initial diameter and be afterwards
deflated, it will, by contraction, exert a centripetal or sphincter like action around
and upon the body to which it is applied and which interferes with its reverting
to its original state. Such a ring, which (besides other applications) is specially
suitable for securing an inflatable tyre around and upon a wheel and making
an air tight joint all around the inner periphery of such tyre, as described in the
specifications of other applications for Letters Patent filed by me No. 27808 of 1896
aud No. 385 of 1897; is herein called an inflatable sphincter grip ring. Such a
ring is composed of a tube of air tight material, for example india rubber, so
constructed as to be capable when subjected to internal fluid pressure, of extension
along or parallel to its axis, (hereinafter called axial extension) at all points
around its circumference, but not of circumferential extension (hereinafter called
distension) so that the tube, as distinguished from the ring, can increase in length
without increase, except perhaps to a small extent, in cross sectional area; or in
some cases the axial extension may even involve slight reduction of cross sectional
area. The said ring may conveniently be made by wrapping a tube of india rubber
with suitable material such as a thread or ribbon arranged spirally or in the form
of parallel rings on or in the substance of the tube so that it will limit the dis-
tension of the circumference of the tube while permitting axial extension of the
tube and consequent increase in the diameter of the ring formed thereby, when the
tube is sufficiently inflated with fluid under pressure which is introduced through
an inflation tube that is provided with an air valve and is adapted to be connected
to an air pump. . I do not limit myself to the exact direction or arrangement of
the thread or ribbon of the inserted or wrapping material so long as such material
will limit the distension of the tube whilst leaving it free to be extended in an
axial direction under the action of internal fluid pressure.
In the accompanying illustrative drawings, Fig. 1 is a side elevation of an
inflatable sphincter grip ring according to this invention. The dotted lines shew
by way of example, the same ring but increased in diameter by inflation with air
under pressure. Fig. 2 shows in longitudinal section and to a larger scale than
Fig. 1, a portion of such a ring. Fig. 3 shows a cross section on the line x x of
Fig. 2.
In this example, the inflatable sphincter grip ring is made of a suitable length
of good air tight india rubber tubing 1 the ends 1° of which are suitably united
together to form an endless ring. For this purpose the ends of the tube may con-
veniently be butt jointed by a junction piece 2 consisting of a short length of

page_text: india rubber tubing (Fig. 2) inserted, within and secured to them by cement or
otherwise.
Or instead of being of india rubber, the juncture piece 2 may consist of a piece
of metal tubing, which, as shown in Fig. 24, is preferably corrugated for con-
venience in fastening the ends of the rubber tube 1 to it. To the tube 1 is secured,
preferably at the part where its ends are connected together to form the complete
ring, an inflation tube 3 which may conveniently be of india rubber and is pro-
vided with a fitting 3 by which it can, when desired, be readily connected to an
air pump. The inflation tube may be fitted with a non-return valve of known kind
for retaining the pressure in the ring until it is desired to deflate the same.
inflation tube may be connected to the inner or outer periphery of the ring, or to
either side thereof, as may be desired. In some cases such inflation tube may be
of metal:
The
The tube 1 is supported in a tangential ¿.e., circumferential direction by a practi-
cally inextensible thread such as sewing or pack thread, which is wound spirally
around the tube with the convolutions near together so as to effectually support
the tube circumferentially and prevent its distension when inflated, without
materially interfering with its power of axial extension. The winding on of the
thread can be effected whilst the tube is partially or sufficiently inflated to cause
the tube to retain its original circular form in cross section during the winding
operation and enable the thread to be laid around it in a regular and even manner
which should be done without much compression of the india rubber tube.
The india rubber tube 1 is conveniently a ready vulcanized one but it may be
of natural rubber. It is coated on its surface with rubber solution previous to
the packing thread being wound thereon in order to prevent the thread from
shifting. This serving of packing thread is then covered with a thin layer 5 of
vulcanized rubber, either in the form of a spiral ribbon or a sheet, the straight
joint in the latter case being placed where it will least interfere with the operation
of the sphincter grip ring in making a joint, for example in a pneumatic tyre, that
is to say, away from the body upon which the ring is to contract.
In some cases,
as for example in which the sphincter grip ring is solutioned to the upper or
radially outer side of an overlapping margin of a tyre cover or air tube around
which it is to contract, as described in my said former specifications, and does not
come into contact with any other part, the thread on the ring may be wrapped
with a layer 5 of unvulcanized rubber, or it may even be left unwrapped with such
a layer of rubber. Or when a wrapping of unvulcanized rubber is used, it can be
vulcanized in place on the tube if desired.
The exterior of the ring prepared as described is preferably smooth, especially
when the ring itself has to make an air tight joint with the smooth rubber
surface on the inside of a pneumatic tyre and is not solutioned fast thereto. When
the material used to prevent distension of the tube 1 is in the form of a ribbon
wound spirally round the said tube, whether this is of vulcanized or unvulcanized
rubber, and the ribbon is solutioned on its inner side to the tube leaving the
outside plain, no additional outer covering need be employed in cases where it
is not desired that the outside surface of the sphincter grip ring should make an
air tight joint with the pneumatic tyre or other body around which the ring is
to contract.
Instead of winding the tube with thread or ribbon after being made up into
a ring and partly inflated as herein before described, it can be more conveniently
wound whilst in the form of a straight tube supported internally by a collapsible
mandrel which may consist for example, as shown in cross section and longi-
tudinal section, in Figs. 4 and 5 respectively, of a number of rods 6, conveniently
six in number, arranged around a central core 7, preferably made in two lengths,
the arrangement being such that upon withdrawing the core 7, which may be
lubricated with plumbago, from between the rods 6, the latter can be readily
loosened and withdrawn from the wrapped tube 1.
Fig. 5 is a cross section showing another form of mandrel made of a thin metal

page_text: tube 6 parted or split longitudinally and having a sett or bias tending to make
it collapse, or to make its margins overlap to a greater extent than shown. This
metal tube is inserted in the tube 1 which has to be "served" and inside it is
placed an inflatable tube which by suitable means is inflated until it gives the
required support to the wall of the tube to be "served."
Fig. 5 shows another form of mandrel consisting of a split metal tube the
longitudinal margins or edges of which are adapted to be hooked together as
shown so as to limit the possible distension of the tube which in this case has a
bias to expand or open out but can be readily collapsed to facilitate its being
inserted within and removed from an india rubber tube. This form of mandrel
may be used when serving very thin rubber tubes.
Fig. 6 shows a piece of a sphincter grip ring supported circumferentially by
thread 4 of the kind mentioned, wound spirally on the exterior of the tube and
uncovered. Fig. 7 shows a piece of a sphincter grip ring upon which is spirally
wound a tape or ribbon 4" of silk, cotton or like practically inelastic material.
Fig. shows a modified construction in which spiral tapes or ribbons 4ª of the
kind mentioned are embedded in the wall of the tube, during the manufacture
thereof. In Fig. 9 the rubber tube 1 is provided externally with a series of
supporting rings 4b which are arranged parallel and close to one another and which
are of suitable material, for example textile material that will, under the conditions
to which it will be subjected in use, be practically inextensible.
The threads 4, ribbons 4" or rings 4 should in all cases be arranged sufficiently
close together to prevent any liability of the india rubber between the consecutive
convolutions or rings being blown outward when the ring is inflated with. air
under pressure sufficient to increase its diameter to a suitable and moderate extent..
For use in a pneumatic tyre as described in my said former specifications, the
sphincter grip ring may be made of an india rubber tube having a diameter of
say inch and a thickness of wall of say 1/12 inch, its initial or normal diameter,
for use in a 28 inch tyre being about 21 inches. It is however to be understood
that I do not limit myself to these dimensions as the same may be considerably
varied, and are merely given, as an example.
In order to supplement the contractile action of a sphincter grip ring of the kind
hereinbefore described, I sometimes combine with such a ring, as shown in Figs. 10.
and 10, which are elevations at right angles to one another and each partly in
section, an endless ring 8 of spring wire bent into a corrugated shape or, as shown
in Fig. 11, into a spiral shape so as to form a supplementary sphincter grip ring
of resilient character but which is not self operative, that is to say, it does not
include in itself the means of expansion by pneumatic or other fluid pressure,
but being conjoined to the pneumatically expansible sphincter grip ring will
share in the axial expansion thereof and will contract with such ring on deflation
and add its contractile force to that of the said ring. Such a resilient sphincter
grip wire ring may conveniently be combined with the elastic material of an in-
flatable sphincter grip ring such as hereinbefore described, by including it in or
wrapping it around the elastic wall of such a ring as shown in Figs. 12 and 13
respectively, but it is desirable that in every case the corrugations or spirals should
have a comparatively large pitch so that a comparatively thin and light wire can
be employed. The length of wire to form the supplementary sphincter grip ring
after being corrugated, coiled or otherwise bent to the desired shape is inserted
in the rubber tube 1 before the ends thereof are connected together, and upon
pressing back one or both of the ends of the tube, the ends of the wire ring can
be conveniently connected together in any suitable way as for example by welding,
after which the ends of the tube can be connected together as herein before
explained.
When the sphincter grip ring is constructed with a supplementary sphincter
grip ring, its initial or normal diameter relatively to the internal diameter of
the pneumatic tyre or other body with which it is to be used, can be greater than
would otherwise be desirable.

page_text: I am aware that it has heretofore been proposed to make elastic
tyres with coiled metal springs embedded in their walls; also to make
tyres of woven material covered with india rubber and of which the warp
threads, or some of them, extending around the tyre, are of elastic material whilst
the weft threads, extending around the tube of which the tyre is made, are of
inextensible material, but such constructions, which I do not claim, are not
adapted and were not intended to be used as inflatable sphincter grip rings such
as herein described.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. An inflatable sphincter grip ring constructed and adapted for use substantially
as herein before described.
2. An inflatable sphincter grip ring made of a tube of elastic material supported
circumferentially against distension by a thread or ribbon of practically inelastic
material applied as described, and provided with means whereby it can be inflated
with air under pressure and deflated, substantially as and for the purpose described.
3. An inflatable sphincter grip ring made of a tube capable of extension in an
axial direction but not in a circumferential direction and provided with an inflation
tube and with a valve so that the ring can be inflated with air under pressure to
increase its diameter and can afterwards be deflated to cause it to contract on the
body to which it is applied, substantially as described.
4. The combination with an inflatable sphincter grip ring of the kind herein
described, of a supplementary sphincter grip ring of bent or coiled wire, substan-
tially as and for the purpose specified.
5. An inflatable sphincter grip ring such as herein referred to composed of a
circumferentially supported tube of elastic material having its ends butt jointed
together and provided with an inflating tube at the jointed part, substantially as
herein before described with reference to and shown in Figs. 2 and 24 of the drawings
annexed.
6. The manufacture of an inflatable sphincter grip ring substantially in the
manner and by the means hereinbefore described with reference respectively to
and shown in Figs. 2 to 5 inclusive or modified according to Fig. 5^ or to Fig. 5"
of the drawings annexed.
7. An inflatable sphincter grip ring constructed substantially as hereinbefore
described with reference to and shown in Figs. 1 to 3 inclusive or modified as
described with reference respectively to and shown in Fig. 6; in Fig. 7; in Fig. 8;
and in Fig. 9 of the accompanying illustrative drawings.
8. Combined inflatable and supplementary sphincter grip rings constructed
substantially as hereinbefore described with reference respectively to and shown
in Figs. 10, 10 and 11; in Fig. 12 and in Fig. 13 of the drawings annexed.
Dated this 21st day of August, 1897.
1897.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
Dated this 21st day of August, 1897.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.