Improvements in and relating to Pneumatic Tyres.
Year: 1897

page_text: Date of Application, 15th June, 1897-Accepted, 20th Nov.,
1897
COMPLETE SPECIFICATION.
Improvements in and relating to Pneumatic Tyres.
I, PETER KRUMSCHEID, of 32 Marcella Street, Boston, Massachusetts, in the
United States of America, Machinist, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
The nature of my invention is involved in a fabric to be used as a part of a
bicycle tire; also in the manner of attaching the tire to the rim of the wheel.
The invention relates to a fabric especially adapted for bicycle tires, but the fabric
may be applied to other uses. The above product is a new elastic unwoven sheet
the elasticity of which being different on different lines, that is, in some direc-
tions the sheet is almost totally inelastic while on other directions it is very elastic.
The invention also relates to the form of the rim and to the fastening of the tire
to the said rim of the wheel by means of a peculiarly formed groove made in
the rim and adapted to receive and hold the reinforced folded edge of the fabric.
My invention is illustrated in the accompanying drawings, in which :-
Figure 1, shows in cross section my fabric as it appears when in use, also
showing how it is attached to the rim. And a part of the rim itself.
Figure 2, shows in elevation the edge reinforcing piece.
Figure 3, illustrates the method of folding the border of the fabric about the
reinforcing piece.
Figure 4, illustrates the method of arranging the threads in the fabric.
Figure 5, shows a modification that may be used in making my fabric.
The drawing Figure 4, that I have used to illustrate my improved fabric is
diagrammatic in its nature and is intended to show the relative positions of the
threads in the fabric.
In the manufacture of my fabric I proceed as follows:-A sheet of thin rubber
has applied to each of its sides threads aligned substantially as shown in the
drawings, said threads are pressed into the sheet rubber so as to be held in place
by it.
The threads of one side of the sheet are represented in the drawings by full
lines H, H, H³, H³, H', 'and the threads of the other side by dotted
lines K, K¹, K2, K³, K. The several threads of the opposite sides cross each
other at varying angles as shown in the drawing. The piece shown in the drawing
is supposed to be cut crosswise from a long sheet; the width of the sheet should
be so great as to admit of cutting a strip crosswise that will be long enough for
a tire, the width of the tire strip is represented on the drawing by the lines P, P,
and N, N.
My object in placing the threads in the manner shown, is to obtain two of the
most essential features in a good tire, viz.-Elasticity longitudinally and laterally,
greater in the former; and great rigidity. The latter prevents the tire from
swaying or rolling from side to side while riding. The first, I obtain by crossing
the threads at an acute angle on the middle line. The second, by crossing them
at an obtuse angle on the sides. The angles vary gradually, from acute on the
middle line, to right angles on the sides.

page_text: This arrangement of the angles also imparts to the tire a gradually increasing
resisting power, to absorb the force of a sudden shock while riding over rough
roads; it being greatest at a point nearest to where the tyre comes in contact with
the rim.
In my method, the rubber serves a double purpose, viz: To lock the threads
together, and to equalize the tension on the threads. The threads pulling in
opposite directions compress the rubber between them which relieves them of
the strain. The latter office it could not perform if one system of threads run
straight across the tyre.
Fig. 5 illustrates a modification of my fabric, in which the sheet of rubber is
omitted and the fabric is made up of alternate threads of spun fibres, S S and
strips of rubber W, W, laid parallel to each other and diagonal to the length of
the fabric, which is in fact double; the threads and strips of one side, crossing
those of the other side. This method of laying the threads and strips produces
a double thick fabric. The threads and strips are all connected together by heat-
ing so as to cause the rubber strips to adhere to the threads, or by heating the
whole to a solution of rubber.
The manner of connecting the fabric to the rim of the wheel is illustrated in
Figures 12 and 3. The rim has a section as shown at A, with grooves L, L, these
grooves extend under the material of which the rim is composed as indicated
at R, R, so as to hold the reinforced edge E, of the fabric in place. The reinforced
edge E, (see Figure 3) of the fabric is made by folding the border of the fabric
about a strip F of firm material having alternatingly arranged lateral incisions as
at T.. T. Figure 2. The reinforced edge is shown in Figure 3. The rein-
forced edges of the fabric can be readily inserted (before the tyre is inflated)
into the grooves L L; but when the tyre is inflated then the strain will be in
the direction of the arrows and the reinforced edge cannot be drawn out as the
strain will have a tendency, to turn the edge against the overhanging part R,
which will effectually prevent it from turning, and as it cannot turn and cannot
be drawn out in the line of the arrows, see Figure 1, it must stay in place so long
as the tire is inflated. When the tire is not inflated the outer part of the edge
may be turned inward and easily removed from its grooves.
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 :-
1st. As a new article of manufacture a fabric consisting of a sheet of rubber
having embodied in its sides, series of threads curved so as to form. U shape lines
the ends of the thread being at the edges of the fabric and the bow part at the
middle. The threads being so located that the lines on one side of the fabric
cross those of the other side at an angle, the angles at the edge of the fabric being
obtuse and those at the centre acute, whereby the greatest longitudinal elasticity
is obtained at the centre and the greatest lateral elasticity is obtained at the edges,
substantially as and for the purpose set forth.
2nd. A bicycle rim and tire, consisting of a rim A, having undercut grooves on
its outer face adapted to receive and hold the reinforced edges of the tire fabric,
and a tire fabric having its border folded about a flat laterally incised strip to
form a reinforced edge, and the said incised strip, substantially as and for the
purpose set forth.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.