Improvements in or applicable to Pneumatic Tyres for Wheels.
Year: 1899

page_text: Date of Application, 23rd Sept., 1899
Complete Snorification Loft 16th June. 1900-Accepted. 22nd Sept.. 1900
PROVISIONAL SPECIFICATION.
Improvements in or applicable to Pneumatic Tyres for Wheels.
I, ROBERT JOHN CHADWICK MITCHELL, of Albert Works, Waterfoot, in the
County of Lancaster, Felt Manufacturer, do hereby declare the nature of this
invention to be as follows:-
:-
"
This invention relates to that class of pneumatic tyres for the wheels of bicycles
and other vehicles which are composed of an inner inflatable annular tube of
india rubber or other material, and an outer removable cover or tread" usually
composed of a combination of india rubber and canvas or other woven fabric
secured in the rim or felloe by endless wires.
"
My improvements relate to the construction of the outer removable cover or
tread" of the tyre the objects of the said invention being to make such covers
more durable and less costly than heretofore, and to prevent entirely the side-
slipping" and puncturing of the tyre to which the ordinary india rubber surface is
liable, and which (especially in bicycles) is a frequent cause of accident.
According to my invention I make such tyre covers and treads" entirely
of a single seamless piece of hardened and milled felt in the following manner:
I first manufacture, by felting and hardening upon a suitable cylindrical bed
former," a cylinder of solid felt, of the required diameter and thickness for
the tyre cover, and of any convenient width, and I cut from this cylinder a series
of flat bands of a sufficient width to form the tyre cover.
or
These flat bands, I then mould whilst wet and pliable into an arched or horse-
shoe form in cross section so that their edges approach each other or nearly touch
as may be required. The flat bands are stretched and moulded over moulds or
"formers" of the required shape and size made of wood or other suitable material
the said bands being secured thereto by twine or other similar means to prevent
the felt from getting out of shape when drying.
When the felt is thoroughly dried it can be removed from the mould or
"former" and be submitted to a further process of milling which will cause it to
permanently retain its shape.
In some cases it may be found necessary to make the moulds or formers in two
or more parts to facilitate their removal from the inside of the felt covers when
dried and hard, but excepting for covers for motor car tyres or other very thick
strong tyres it will not be necessary.
If the felt is hardened and milled to a sufficient degree to resist moisture the
covers may be used without any further preparation but in other cases it may
be made waterproof by the application thereto of a solution of india rubber or
other known water repellant solution or composition.
To insert the binding wires I cut a slit in each edge of the cover all round and
I insert the endless wires therein and fix them in place by stitching through the
felt on the outer side of the wire, or on both sides if preferred.
66
These seamless or jointless outer covers or treads" for pneumatic tyres will

page_text: be found to be quite as resilient as the ordinary covers, more durable, and less
costly and will entirely prevent the tendency to side-slipping and puncturing.
Dated this 22nd day of September 1899.
GEO. DAVIES & SON,
Agents for the Applicant,
4, St. Ann's Square, Manchester.
Improvements in or applicable to Pneumatic Tyres for Wheels.
I, ROBERT JOHN CHLADWICK MITCHELL, of Albert Works, Waterfoot, in the
County of Lancaster, Felt 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 relates to that class of pneumatic tyres for the wheels of bicycles
and other vehicles which are composed of an inner inflatable annular tube of
india rubber or other air-proof material and an outer removable cover, or pro-
tecting tread," which latter is usually composed of a combination of india rubber
and canvas or other unstretchable woven fabric or material, such removable
cover being secured in its place on the metallic rim or felloe of the wheel by
endless wires.
My improvements relate to the construction of the outer removable cover or
"tread" of such pneumatic tyres, the objects of the said invention being to make
such covers more durable and less costly than heretofore, and to prevent entirely
the "side-slipping" and puncturing of the tyres to which the ordinary india
rubber surface is liable, and which (especially in bicycles) is a frequent cause
of accident.
The manner in which my said invention is to be performed or carried into
practical effect will be readily understood on reference to the sheet of drawings
hereunto annexed and the following explanation thereof.
According to my invention I propose to make such tyre covers and "treads "
entirely of a single seamless piece of hardened and milled felt in the following
manner :-
"
I first manufacture by felting, hardening, and milling wool, upon a suitable
cylindrical bed or "former a cylinder of solid felt, of the diameter and thickness
required for the cover, and of any convenient width (as represented in longi-
tudinal section at Fig. 1 on the drawings, and in transverse section at Fig. 2)
and I cut from this cylinder a series of flat endless bands a of a sufficient width
to form the tyre covers, as indicated by the dotted lines on Fig. 1.
66
These flat endless bands of felt I then mould, whilst wet and pliable, into an
arched or horse-shoe form in cross section (as shown at Fig. 3) so that their edges
approach each other, or nearly touch, as may be required. The flat felt bands a
are stretched and moulded whilst wet over suitable moulds or formers" of the
required shape and size, made of wood or other suitable material, the said bands
being secured thereto by twine, or other similar means to prevent the felt from
getting out of shape whilst drying.
When the felt band thus moulded is thoroughly dried it can be removed from
the mould or "former" and submitted to a further process of extra milling which
will cause it to permanently retain its shape.
"formers
"
In some cases it may be found necessary to make the moulds or
in two or more parts to facilitate their removal from the inside of the felt covers,

page_text: when dried and hard, but except for covers for motor car tyres, or other very
thick strong tyres it will not be necessary.
If the felt is hardened and milled to a sufficient degree to resist moisture the
covers may be used without any further preparation (excepting wiring as herein-
after described) but in other cases it may be made waterproof by the application
thereto of india rubber solution or other known water-repellant solution or
composition.
To insert the binding wires I cut a slit b in each solid edge of the hardened
and milled felt cover a all round (as shown at Fig. 4) and I insert the endless
wires therein and fix them in place by stitching through the felt on the outer
side of the wire, or on both sides if preferred.
Or, in some cases where the "milling" is not carried to too great an extent
I may dispense with the moulding or 'forming" process above described and
cut the slits b in the solid edges of the endless bands a of hardened and milled
felt, in the flat form, as shown at Fig. 5, and taking an endless wire of smaller
circumference or circle than that of the flat band the operator lays one portion
of the same in one of the slits b and commences to sew it therein.
As this operation proceeds the operator will force the edge of the felt from
time to time endwise along the wire slightly compressing and crimping the
same by pressure of the fingers, so that the edge b of the felt band becomes gradu-
ally contracted to a smaller circumference or circle than the central portion
thereof, until eventually the edge of the band becomes so contracted that, by the
time the stitching is completed all round, the whole of the endless wire will be
covered in and the edge of the felt contracted to such an extent that when both
edges have been thus wired the flat band will assume the horse-shoe form shown
at Fig. 4.
These improved seamless or jointless outer covers or
"treads" for pneumatic
tyres made from a single piece of solid hardened and milled felt will be found
to be quite as resilient as the ordinary covers, more durable, and less costly,
and will entirely prevent the tendency to side-slipping, and puncturing to which
the ordinary tyre covers as now made are so liable.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. The improved process of manufacturing seamless and jointless removable
covers or treads," for the pneumatic tyres of wheels, from a single piece of
hardened and milled felt substantially as hereinbefore described and illustrated
by the drawings annexed.
2. I claim as a new product or manufacture a seamless and jointless removable
cover or "tread" for the pneumatic tyres constructed from a single piece of
hardened and milled felt substantially as hereinbefore described and illustrated.
Dated this 15th day of June 1900.
GEO. DAVIES & SON,
Agents for the Applicant,
4, St. Ann's Square, Manchester.