Improvements in Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 8th Aug., 1893-Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres.
We, WILLIAM SAMUEL CALLAGHAN, Machinist, and CHARLES THOMAS
HOLLOWAY, Manufacturer, both c/o Mann & Co., Equitable Building, in the City
of Baltimore and the State of Maryland, United States of America, 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:
The object of this invention is to render pneumatic tyres such as used on
bicycles, sulkies and other vehicles, impervious to penetration. Various expedients
have been resorted to for the accomplishment of this object, as for instance by the
interposition of non-penetrable material covering the inflated tube of the tyre.
But such a cover or lining, being non-elastic destroys the elasticity of the tyre
itself. I contemplate surmounting this difficulty by making such cover loose on
the tube and open, and I accomplish this result by the construction shown in the
accompanying drawings, in which,
Figure 1 shows a cross-section of the complete tyre;
Figure 2, a sectional view of the inner tube which contains the compressed air,
and the non-penetrable cover depending.by its point of attachment to said tube to
illustrate the relation of said cover to the tube.
. Figure 3 shows a perspective view of the said cover.
Figure 4 shows a section view of the inside tube with the cover in its proper
position around it, and a dotted representation illustrating the expansion of the
tube under pressure and the adaptation of the cover to such expansion.
The letter, A, designates the metal rim of the wheel which rim is dished in the
ordinary way to receive the pneumatic tyre, and is attached to the spokes, B.
The outside rubber tube, C, of the tyre, which receives the direct impact under
action, is split at, a, on the inner side to receive the inner tube, D, which contains
the charge of compressed air. The said outer tube, C, engages the dished metal
rim, A, and is fastened thereto by cement or otherwise with its edges at the
split, a, abutting; thus it completely incloses the inner tube, D.
A cover, E, of raw-hide or other non-penetrable material surrounds the inner
tube, and is split at, b, and fastened to the tube at one side of said split, this point
of attachment being designated by the letter, c, and being the only place where
the said cover is attached, the remainder of it being loose on the tube.
In the normal condition of the inner tube,-i.e., before it is charged with
compressed air,-the cover, E, will extend entirely around it as illustrated in
Figure 4. When the charge of compressed air is introduced and the tube expands,
as illustrated by the dotted line, d, in said Figure 4, the cover, E, opens at the
split, b; the cover in this state is designated by the dotted line, e.. Hence such
expansion is not in any way restricted by the non-elastic cover, and the flexibility
of the tyre is not disturbed in the least. When the inflated tube is introduced
into the outer tube it is set so that the split, b, is behind the metal rim, A, as
shown in Figure 1, whereby there will be no possibility of penetration of the inner
tube through the said split, and the said iuner_tube is fastened to the outer tube
by cementing or otherwise attaching the cover, E, to said outer tube at the point, f,
the same place of attachment of the cover to the inner tube; this is to prevent
possibility of the inner tube slipping around to a position where the split, 6, would
be exposed. The inflated tube also stretches under action, and here again the
advantage of this arrangement is apparent, for the open loose cover does not in
any way interfere with the perfect freedom of the tyre în expanding and contracting
under such action.

page_text: It will now be seen that this construction does not affect the elasticity of the
tyre in the least, and yet it renders the tyre invulnerable.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :
1st. In a pneumatic tyre, the combination of an inner elastic tube; an outer
elastic tube and an impenetrable cover inclosing the inner elastic tube, and
having a split extending in a peripherical direction entirely around it on that side
adjacent the metallic rim of the wheel, one edge only of the split being cemented
or otherwise secured to one of the elastic tubes-the rest of the cover being
unattached and loose, for the purpose described.
2nd. In a pneumatic tyre, the combination of an inner elastic tube; an outer
elastic tube; and an impenetrable cover inclosing the inner elastic tube, and having
a split extending in a peripherical direction entirely around it on that side adjacent
the metallic rim of the wheel and arranged to avoid restricting the expansion of
the inner tube, as set forth.
Dated this 25th day of July 1893
WILLIAM SAMUEL CALLAGHAN.
CHARLES THOMAS HOLLOWAY.