Improvements in or relating to Pneumatic Tyres.
Year: 1897

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883) as required by
the decision of the Comptroller General of the 6th day of May 1898.
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Tyres.
I, JOHN CRAIG, of 8, Wood Street, Cheapside, in the City of London, India
Rubber Merchant, do hereby declare the nature of this invention to be as follows:-
My invention relates to single tube pneumatic tyres having circumferentially
separable edges which are brought into contact or lie in proximity to each other
when the tyre is in position on the rim of the wheel. The said invention has for its
object to provide a tyre of this class the opposite edges whereof shall be so formed as
to establish a substantially airtight circumferential connection with each other upon
inflation of the tyre without the employment of a dressing or medium of grease
oil glycerine soap or other similar substance as has hitherto been necessary in
order to obtain a satisfactory air tight contact.
According to my invention I provide an endless band of indiarubber or other
suitable material of appropriate form in cross section the said band having one of
its edges bifurcated or duplicated whilst the opposite edge may be tapered or
bevelled so as to lie between such bifurcated or duplicated parts when the edges of
the band are brought together to form a tube and when the tyre is in position. I
prefer that both the single and bifurcated edges shall be so formed as to have a
slight inward curve in cross section. If desired I may form both edges of the said
band with bifurcated or divided portions adapted to engage or interlock with each
other. And if necessary I may divide one or both edges into more than two parts.
I may provide the tapered edge with one or more circumferential beadings or
abutments adapted to lie within a corresponding circumferential groove or grooves
in one or both of the bifurcated or duplicated parts when the tyre is inflated upon
the rim; or inversely the beadings or abutments may be formed upon the inner
surface of either or both of the bifurcated or duplicated parts the corresponding
circumferential groove or grooves being formed in the tapered edge of the tyre.
The tyre having been placed in position upon the rim with its tapered edge
lying between the bifurcated portions of the opposite edge it may be inflated in the
usual way the said bifurcated portions being caused to tightly grip the tapered
edge between them by reason of the pressure exercised by the compressed air on
the one hand and the rim of the wheel on the other hand.
By the above means I provide a single tube pneumatic tyre of that class which is
easily detachable from the rim by being deflated and opened out and whose opposite
edges have a double circumferential contact that is to say firstly between the inner
surface of the tapered edge and the inner portion of the bifurcated edge and
secondly between the outer surface of the tapered edge and the outer portion of the
bifurcated edges.

page_text: I may employ any appropriate means of securing the tyre in place upon the rim
of the wheel.
Dated this 26th day of February 1897
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in or relating to Pneumatic Tyres.
I, JOHN CRAIG, of 8, Wood Street, Cheapside, in the City of London, India
Rubber Merchant, 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:-
My invention relates to "tubeless" pneumatic tyres having circumferentially
separable edges which are brought into contact or lie in proximity to each other
when the tyre is in position on the rim of the wheel. The said invention has for
its chief object to so form the opposite edges of such tyre as to establish upon
inflation of the tyre an air-tight circumferential connection between them, which
shall be more effectual than heretofore.
According to my invention the tyre comprises an endless band of india-rubber
or other suitable material of appropriate form in cross section, with one of its
edges bifurcated or duplicated whilst the opposite edge, which may be tapered or
bevelled, is adapted to lie between such bifurcated or duplicated parts when the
edges of the band are brought together to form a tube. If desired I may form both
edges of the said band with bifurcated or divided portions adapted to engage with
each other. And if necessary I may divide one or both edges into more than two
parts.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the same more fully with reference to the accom-
panying drawings, in which:--
Figure 1 is a transverse section of one form of my improved tyre applied to a
wheel-rim.
Figure 2 is a sectional perspective view of the said tyre removed from the rim.
Figure 3 is a sectional view similar to Figure 1, shewing a modification of the
said tyre.
A is the tyre; B the wheel rim and C the inflation valve.
The tyre is composed of india-rubber and canvas in the usual manner and has
near its edges, beads or enlargements a a to engage with the flanged edges b b of
the wheel rim; the said tyre may however be otherwise formed to engage with the
wheel rim. One edge of the tyre is bifurcated or duplicated to form two
tongues al a while the other edge is tapered or bevelled to form a wedge shaped
piece a³ which is adapted to enter between the tongues a¹ a² of the opposite edge
when the tyre is in place on the wheel rim. On inflation of the tyre the said
tongues are caused, by the pressure of the air within the tyre to tightly grip the
tapered edge a³ between them and by reason of the adhesion thus obtained between
the upper surface of the tapered edge a³ and the lower surface of the tongue a¹ and
between the lower surface of the said edge a³ and the upper surface of the tongue a³,
I provide for a double circumferential contact all around the tyre where it lies
within the wheel rim which produces an effectual air-tight closure of the tyre. At
the same time the tyre on deflation is capable of being very readily removed from

page_text: the wheel-rim for repairs. prefer to locate the inflation valve C at the side of the
rim where the duplicated edge lies as shewn in Figure 1.
I prefer to so mould or form the tyre that when removed from the wheel-rim its
edges will assume approximately the position represented in Figure 2; that is to
say, the said edges will not normally open out or separate to a greater extent than
that indicated in this figure. By so constructing the tyre the circles formed by the
internal extremities a* a* a* thereof will be of smaller diameter than other portions
of the tyre, so that when said tyre is placed on the wheel-rim these extremities
will be stretched circumferentially. Thus in addition to the pressure between the
tongues a¹, a² and the wedge shaped edge a³ due to the air contained in the tyre, a
further pressure independent of that of the air, will be caused to be exerted around
the wheel rim, which will greatly assist in preventing creeping of the tyre.
In the modification illustrated in Figure 3, I have shewn each edge of the tyre
bifurcated. I do not confine myself to the formation of the edges of the tyre with
only two tongues as the number of tongues may be increased if found advantageous.
The said tongues and tapered edge may be moulded in one piece with the tyre
or may be formed separately and joined to the tyre in any suitable manner as by
cementing them thereto.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would state that I am
aware that one of the edges of a tubeless tyre has been provided with a flap which
is adapted to lie over the meeting edges to form an air tight joint, and I am also
aware that a tyre has been formed with protuberances or abutments to engage
with the flanged edges of the wheel rim, such features do not however form part of
my invention nor do I intend to claim them, but what I do claim is:-
An inflatable tyre constructed substantially as described with reference to the
trawings and for the purposes specified.
Dated this 26th don of N
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.