Improvements in or relating to Air Tubes for Pneumatic or Air Tyres.
Year: 1892

page_text: Date of Application, 29th June, 1892
Complete Specification Left, 25th Mar., 1893-Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Air Tubes for Pneumatic or
Air Tyres.
I, WILLIAM JAMES of The Woodlands, Clifton Park, Birkenhead in the County
of Chester, Cycle Manufacturer, do hereby declare the nature of this invention to
be as follows:-
The invention has for its object an air or inflation tube for pneumatic tyres or
the like, which, while having all the advantages of the ordinary air tube, will avoid
the defect so objected to in the latter, that it is liable to be rendered useless by
being cut or punctured by thorns, pins, nails, pieces of broken glass, etcetera.
By my invention, I employ an air tube, the material of which (when the tube is
inated) is in compression instead of in tension. This plan possesses advantages
over the air tubes hitherto used, as the resiliency is not impaired, and yet the tube
is not so liable to be cut, or, if cut, will immediately close up again, preventing any
escape of air.
In carrying my invention into effect, I form my air tube of corrugated rubber or
of other suitable material. These corrugations may be formed longitudinally,
transversely, spirally, or the like, or in the manner hereinafter mentioned. The
tube thus formed is placed in the tyre, and, when the tube is inflated, the
depressions or valleys of the corrugations are forced outwards, by the pressure of
the air, until all the corrugations are merged together, into an approximately
circular tyre, whereby the material is brought into a high state of compression,
and any cutting of the tube is prevented, or, if cut, it will immediately close up.
As the tube is put inside the tyre, the latter prevents any undue expansion of
the tube.
Instead of the tube being corrugated, it may, if desired, be formed with swellings,
protuberances, wrinkles or in other similar manner, exactly the same results and
advantages being obtained by this construction as when a corrugated tube is
employed.
The corrugations, protuberances, etcetera, may be formed by means of dies,
moulds, or their equivalents.
THIS GOT way
1333
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Air Tubes for Pneumatic or
Air Tyres.
I, WILLIAM JAMES of The Woodlands, Clifton Park, Birkenhead, in the County
of Chester, Cycle Manufacturer, 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 for its object an air or inflation tube for pneumatic tyres or
the like, which, while having all the advantages of the ordinary air tube, will avoid
the defect so objected to in the latter, that it is liable to be rendered useless
by being cut or punctured by thorns, pins, nails, pieces of broken glass, and
the like

page_text: My invention is best described by aid of the accompanying drawing, in
which―
Figure 1 is a view of an elevation of a portion of the tube, and
Figure 2 a transverse section.
By my invention as herein shown, I employ an air tube, the material of which,
when the tube is inflated, is in compression instead of in tension. This is effected
by forming the tube with a series of corrugations concave outward as shown, and
enclosing it in a sheath of no larger internal diameter than the circle in which the
corrugated tube is inscribed. The result is when the pneumatic tube is inflated the
tendency is to flatten each of these corrugations and thus put the entire tube under
compression. The resiliency of the tube is not impaired and yet it is not so likely
to be cut, or if cut will immediately close up again owing to the tyre being in
compression, thus preventing escape of air.
I prefer to form my tube of corrugated rubber, but other well known substitutes
can be used.
The corrugations can be of any desirable shape and be formed longitudinally,
transversely or even spirally, or to any desired pattern. In using my invention for
bicycles, the tube thus formed is placed in the tyre and inflated, the depressions or
valleys of the corrugations are forced outwards, by the pressure of the air, until
all the corrugations are merged together, into an approximately circular tyre,
whereby the material is brought into a high state of compression, and any cutting
of the tube immediately closes up. As the tube is placed inside the tyre, the
latter prevents any undue expansion of the tube. Instead of corrugations,
swellings or wrinkles, protuberances or other variations under the surface can be
used whereby the same advantage is obtained. The material can be brought to
this shape in any well known manner.
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 :-
The improvement in air tubes for pneumatic tyres which consists in forming the
tube with corrugations, wrinkles, elevations, depressions or the like, or in such form as
to have naturally a greater area of outside surface than the area of surface of the
containing sheath or tyre, whereby when inflated its material has a strong com-
pressive strain upon it, substantially as described.
Dated this 24th day of March 1893
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham and London, Patent Agents.