The Manufacture of an Improved Detachable Cover for Pneumatic Tyres.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
The Manufacture of an Improved Detachable Cover for Pneumatic
Tyres.
We, THOMAS CALDWELL, of 137, Blackburn Road, Bolton, Cycle Agent, and
WILLIAM CALDWELL, of Vicarage Square, Leigh, Cotton Mill Manager, both in
the County of Lancashire, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object improvements in or relating to detachable
covers for pneumatic tyres and the manufacture thereof and is designed to pro-
duce a cover which (when the tyre is inflated) will firmly hold onto and remain
on a concave wheel rim without any side wires or thickened edges or parts to
lock or engage into the rim in fact without adding any holding-on devices at all.
Our present invention is as follows:
First of all we employ any suitable textile fabric-advantageously a woven
cotton cloth or canvas of sufficient strength and resilience-formed somewhat
V-shaped or U-shaped in cross section and also curved (as to its length) of or
about the radius of the tyre to be made such shaped fabric being woven or produced
in any suitable manner (for instance by weaving in the manner and by the means
set forth in the specification of another application for Letters Patent which we
are filing concurrently herewith) and this specially formed fabric we now proceed
to stretch advantageously in a circular direction-so as to take all stretch out
of the fabric or to take so much of the stretch out as to answer our purpose although
we consider that the more stretch taken out of the fabric the better and this severe
stretching operation should advantageously be effected before rubbering or forming
the tyre cover.
This stretching of the fabric in a circular direction is advantageously effected
by lapping the fabric one or more times around a circular expansible apparatus or
expanding mandril and having secured the ends of the fabric we then expand the
mandril or apparatus by any suitable means and thereby the fabric is stretched
in a circular direction and having thus stretched same we may now wet the fabric
while thus stretched the shrinkage consequent on the wetting being prevented
owing to the fabric already stretched tightly on the expanding mandril.
Or if desired before lapping the fabric on the expanding mandril as described
it may advantageously be wetted the stretch being got out of the fabric with less
effort than when stretched dry.
Instead of expanding the fabric as above described we may lap it in a suitable
fixed mandril of about the diameter of the wheel for which it is designed and
subject it to the treatment known as mercerising or to a mercerising liquid.
Or the fabric may first be stretched on the expanding mandril before mentioned
and while at its stretch subjected to the action of mercerising liquids as afore-
said

page_text: In all cases and procedures it is the object of this invention more particularly
near thereto
to take the stretch out of the edges or
or sufficiently
take out the stretch to obtain the objects of the present invention; and the
sufficiency of the stretching can be easily ascertained by feeling or testing the
edges of the fabric while on the aforesaid mandril or may be ascertained in any
other suitable manner or means.
The fabric is stretched to such a degree that when in use the pressure of the air
tube will be insufficient to blow off the cover for instance to make a cover for a
28 in. wheel we have found in practice that with a piece of fabric woven as
aforesaid we cut off a length of such fabric say 44 yards and stretch this until
said cloth measures some 12 inches longer that is we lap such fabric on an
expanding mandril 26 inches outside diameter and expand same with the
fabric lapped thereon to 29½ inches outside diameter, and we then take off said
fabric from the expanding mandril and wind same round a collapsible man-
dril 27 inches in diameter to allow 1/8 inch all around for rubber to thus make
28 in. outside diameter of said cover for a 28 inch tyre although we would here
state that it is desirable in stretching the fabric for a cover that the operation
should be started at such a diameter as shall leave the fabric when fully stretched
of the same diameter as that of the making up mandril (hereinafter referred to) so
as to obviate any puckering or slackness on the edge of the finished cover.
Having thus stretched the fabric as and for the purposes stated we then lap said
fabric once, twice, or more (according to the character of the cover desired)
around a collapsible mandril and having now (permanently) secured the ends of
said fabric in any suitable manner we proceed to rubber same or make up said
fabric into the finished cover in any desired or suitable manner advantageously
in the following manner;-
The fabric is wound round the mandril and treated with rubber solution which
sticks the layers together and also gives a surface for the final separately manu-
factured and vulcanised circle of rubber to adhere to; and this moulded strip or
ring may have projections on it or be ribbed or corrugated or otherwise suitably
formed to prevent side-slip.
The mounting of said fabric on said collapsible mandril while same is rubbered
or otherwise treated having the effect of preventing the rubbering causing any
shrinkage or alteration in said fabric and when the cover is finished (and dry
or set) the mandril is collapsed (any suitable apparatus being used for this purpose)
and this enables the cover to be removed from said mandril and said cover is now
ready for use.
The cover is made of a size to fit closely within the groove or channel in any
suitable concave rim and of a size which will just allow it to be put on (forced
over) said rim and an ordinary or any suitable air tube is placed inside said
cover and then inflated and it will be found that owing to the character and
structure of the cover manufactured as aforesaid same cannot be forced off the
rim either by inflation or use.
We
may
if desired form a cover out of this stretched fabric without any rubber-
ing etc. or if desired we may form non-slipping covers of a single thickness of
thin canvas formed and stretched according to our present invention to fit over our
aforesaid covers or any other pneumatic tyre (tube tyre, tubeless tyre, or tyre with
inner air tube and detachable outer cover) to which same may be applicable
simply for use as a non-slipping surface.
Or such canvas covers may be formed and used simply for the purpose of
putting over new tyres to protect same during transit, storage, etc.

page_text: COMPLETE SPECIFICATION.
The Manufacture of an Improved Detachable Cover for Pneumatic
Tyres.
We, THOMAS CALDWELL, of 137, Blackburn Road, Bolton, Cycle Agent, and
WILLIAM CALDWELL, of Vicarage Square, Leigh, Cotton Mill Manager, both in
the County of Lancashire, 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 improvements in or relating to detachable
covers for pneumatic tyres and the manufacture thereof and is designed to pro-
duce a cover which will firmly hold on to and remain on a wheel rim of any
suitable concavity without the help of side wires or thickened edges or parts to
lock or connectedly engage with the rim or any other holding-on devices.
Our present invention is as follows:-
First of all we employ a textile fabric (advantageously a woven cotton cloth or
canvas of sufficient strength and flexibility) formed somewhat V-shaped or
U-shaped in cross section and also curved (as to its length) to or about the radius
of the tyre to be made, such shaped fabric being advantageously woven or produced
in the manner and by the means set forth in the specification of our application
for Letters Patent No. 9631 of 1898 concurrent herewith.
This fabric we stretch-advantageously in a circular direction as hereinafter
described or otherwise treat so as to take all or substantially all
of the fabric.
"
stretch" out
This stretching should be effected before such fabric is rubbered or finally
formed into a tyre cover.
And in order that our invention may be understood and carried into practice
we will describe the same with reference to the drawings hereunto annexed, in
which;-
-
Fig. 1 shows a short length of the woven fabric.
Fig. 2 being a cross sectional view thereof on line 2-2 Fig. 1, and
Fig. 3 similar view showing the shape in cross section which said fabric assumes
when in use.
Fig. 4 is a side view and Fig. 5 an edge view of an expanding mandril or
apparatus suitable for stretching the aforesaid fabric in a circular direction
such apparatus consisting of a strong radial frame a each said radial arm a having
guided therein or thereon the sliding guide rods b the upper ends 6* whereof are
screw-threaded and pass freely through eyes in the overhanging ends c¹ of a
plate e fixed on the outer end of each arm a.
By screwing a nut d (winged or otherwise) on each side screw 6* as shown the
said guide rods b can be moved radially and slide through the eyelets a* (on
the frame a) by which latter and the ends c¹ of the plate c said rods 6 are guided.
From each said rod b an arm 6 extends laterally and carries cross arms b
which latter are connected at 63 rigidly to the quadrant e four quadrants being
thus mounted on each side of the frame a to form two separate and independent
expanding mandrils.
Each quadrant piece e has hinged to it at f¹ a metal flap f which embraces the
next adjoining quadrant and serves to bridge over the gaps formed between the
ends of the quadrants e as the latter are drawn apart when the mandril is ex-
panded.
Figs. 6 to 9 show another form of collapsible mandril upon which the cover is
finally built up and finished. The mandril can be collapsed in order to enable
the finished cover to be removed from said mandril.

page_text: Fig. 6 showing the mandril rigid and of fixed diameter ready for the fabric to
be lapped around same.
Fig. 7 is an edge view thereof.
Fig. 8 is a cross sectional view on line 8-8 Fig. 6.
Fig. 9 is similar view to Fig. 6 showing the mandril collapsed
hh are two similar segments of a circle the circumferential edges whereof are
convex in cross section and advantageously of a size less than the size the cover
will assume when inflated and of a radius equal to the radius of the cover to be
nade thereon.
i and jare stretcher boards arranged on opposite sides of the segmental
pieces and provided with clamping screws k passing right through same as
shown in Fig. 8 with winged nuts on said screws.
m is a central aperture on which the mandril can be mounted on a pin or
spindle so as to be free to revolve while in use.
n is a removable segment attached to the board i which latter by means of the
slots therein.can be readily removed from the screws kk when the pinching
nuts are slacked. When the said segment n and cross-bar i have been removed
the two segments h can by means of the slots h¹ therein be moved towards one
another the taper sides of the 4th segmental piece o permitting this as shown in
Fig. 9, the lateral pins o¹ keeping the segment o in position.
The stretching of the fabric in a circular direction is advantageously effected
in the manner set forth in Patent Application No. 23135 of 1898; or by lapping
the fabric one or more times around an expanding mandril (advantageously a
circular mandril) in which latter case the ends of the fabric having been tem-
porarily secured the mandril is expanded and thereby the fabric is stretched in a
circular direction.
The fabric whilst thus stretched may be wet with water the shrinkage conse-
quent on the wetting being prevented owing to the fabric being already stretched
tightly on the expanding mandril.
If desired the fabric may advantageously be wetted before it is placed on the
expanding mandril.
If the fabric is stretched in the wet condition the stretching of the fabric takes
place very readily.
The fabric may also be first stretched and while so stretched subjected to the
action of mercerising liquids as aforesaid.
The object of this invention is in all cases to sufficiently take out the stretch
so that when in use the pressure of the air tube will be insufficient to blow off
the cover.
To make a cover for example for a 28 inch wheel we lap the fabric which has
been woven of the shape aforesaid on an expanding mandril 26 inches outside
diameter and expand same with the fabric lapped thereon to 29 inches outside
diameter. We then take off the stretched fabric from the expanding mandril and
wind it round a collapsible mandril 273 inches in diameter so as to allow 1/8th inch
all round for rubber thereby making the outside diameter of the cover 28 inches.
It is desirable in stretching the fabric for a cover that the operation should be
started at such a diameter as shall leave the fabric when fully stretched of the
same radius as that of the making up mandril (hereinafter referred to) so as to
obviate any puckering or slackness.
Having thus stretched the fabric we lap the stretched fabric once, twice, or
more (according to the character of the cover desired) around a collapsible mandril
(such as that shown in Figs. 6 to 9) and permanently secure the ends of the
fabric in any suitable manner and rubber the same or make up the said fabric
into the finished cover in any usual manner or advantageously in the following
manner:-
The fabric is wound round the collapsible mandril and treated with rubber
solution which sticks the layers together and also gives a surface for the outside

page_text: tread of rubber to adhere to; this outer layer of rubber if desired may have
projections on it or be ribbed or corrugated or otherwise suitably formed to pre-
vent side-slip.
The coating or rubbering of the fabric whilst it is still stretched prevents any
shrinkage of the fabric. The cover when dry or set is released by collapsing the
mandril.
The cover is now ready for use and is practically inextensible in circumference.
The cover is used with any ordinary concave rim and air tube and upon infla-
tion it will be found that owing to the character and structure of the cover
manufactured as aforesaid the same cannot be forced off the rim with any usual
riding pressure.
We may if desired form a cover out of the stretched fabric without any rubber-
ing etc. or if desired we may form non-slipping covers of a single thickness of
thin canvas stretched according to our present invention for and use the same
outside any pneumatic tyre as a non-slipping surface.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:
1. The herein-described method of manufacturing detachable covers for pneu-
matic tyres which consists in taking out the longitudinal stretch from a length
of a textile fabric of suitable width which is shaped in the weaving to the radius
of the tyre or thereabouts and then forming the finished cover therefrom sub-
stantially in the manner and for the purposes set forth.
2. The herein-described method of manufacturing detachable covers for pneu-
matic tyres which consists in taking out the longitudinal stretch from a length of
a textile fabric of suitable width which is shaped in the weaving to the radius
of the tyre or thereabouts and then forming the finished cover therefrom and hold-
ing said fabric in a tightly stretched condition, to prevent shrinkage while
solutioning or rubbering same substantially-in the manner and for the purposes
set forth.
3. A detachable cover-for pneumatic tyres-formed from a woven textile
fabric (such as canvas) shaped in the weaving to the desired radius and from
which fabric the longitudinal stretch has been taken out to such an extent as to
prevent such cover from being forced off a concave rim under riding pressures
substantially as herein before set forth.
4. The herein-described method of manufacturing detachable covers for pneu-
matic tyres which consists in stretching in a circular direction a curved strip of
textile fabric-formed in weaving to the desired curve-to the practical limit of
its extensibility and rubbering said cover while stretched to prevent the same from
shrinking during such rubbering substantially as described.
5. A detachable cover-for pneumatic tyres-constructed and arranged to act
in conjunction with an inner air tube and in combination with a concave rim of a
wheel substantially as and for the purposes herein before set forth.
Dated this 17th day of Fahr 1800
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.