Improvements in Pneumatic Tyres for Bicycles.
Year: 1897

page_text: Date of Application, 10th Aug., 1897-Accepted, 25th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres for Bicycles.
I, ISAAC SEAMAN M'GIEHAN of 26, Cortland Street, City, County and State of
New York, United States of America, Counsellor at Law, 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 Pneumatic Tires for bicycles, and has for its object to
provide an armor located on the tread side of the tire which will render it puncture
proof, and at the same time increase the resiliency of the tire as will be hereinafter
explained.
In the accompanying drawings which form a part of this specification, my inven-
tion is fully illustrated with similar letters of reference to indicate corresponding
parts as follows:-
Fig. 1 represents a plan view of the armor a which is usually composed of raw
hide and formed like a flattened helix.
Fig. 2 represents a similar view showing the armor provided with holes in its
center through which the inner and outer coverings of rubber are united.
Fig. 3 represents also a similar view showing the effect produced when the
armor is stretched lengthwise.
Fig. 4 represents a transverse section through the armor a at the linear,
Figure 2, showing the upper and lower laps m and n before the armor is concaved
to fit the tire.
Fig. 5 represents the armor after it is concaved, showing the crimpings m³ which
reinforces the raw hide on the inside lap m, and causes the laps to lay closely
together and retain their concavity independent of the outer covering.
Fig. 6 represents a transverse section through the pneumatic tire showing the
armor a in place on the tread side and particularly showing that the concavity of
the armor is greater than the transverse curvature of the outer covering e.
This figure represents a tire as it would appear if the inner and outer coverings d
and e were not vulcanized together.
Fig. 7 represents the same when the tire is completed, showing at c¹ the manner
in which the inner covering d is pressed down over the edges c c of the armor a
in forming the tire.
Fig. 8 represents the same section at a point of the tire. where it would intersect
one of the holes through the armor a, say at the line y y, Figure 2, to show the
manner in which the inner and outer coverings d and e are united through the holes s.
This figure also shows the backing 9 which is inserted when the tire is intended
for heavy service.
The majority of armors heretofore created have usually been so rigid as to
destroy the elastic nature of the tire, and others have been so soft as to destroy the
life of the tire and make it less resilient. The object of this invention, therefore,
is to create an armor which will prevent the fire from being punctured, and at the
same time retain all of its elasticity. An armor to do this of course must be
capable of being bent in any and all directions while in use, and to stretch with
1. I

page_text: the tire when inflated; in other words, contract and expand and move in any and
all directions with the rubber.
The armor a is made by taking a long narrow strip of raw hide or similar sub-
stance, about the size shown in the drawing, and while it is wet wind it over a
round mandrel with the edges joined close together in the form of a spiral; as soon
as it is partly dry, it is slid off the mandrel and placed under a heavy press where
it receives sufficient pressure to eject all the moisture and make it very flat as
shown in Figures 1 and 4; after the moisture is thoroughly squeezed out, the
armor is placed under the concaving dies where the inner lap m is crimped, as
shown at m¹, Figure 5, and the outer lap n is stretched. It is then left to dry
under a very heavy pressure. When the armor is prepared in this way, it will
stand almost any pressure without losing its concavity in the least.
After the armor is formed as above described, a series of holes are cut through
the armor directly upon the seam formed where the laps m join on the upper side,
which brings the hole directly in the center of the lap n on the bottom side, as
shown at s and s¹, Figures 2 and 3. The armor is then ready to be inserted in the
tire which is usually accomplished as follows;
The regular wrapping of canvas and rubber which forms the inner covering d
is wound over a mandrel of the correct diameter and length, the armor being
coated with rubber cement is then laid lengthwise on the mandrel over the first
wrapping on the side which is intended for the tread, after which the outer
covering e is wound over the armor in the usual manner: the ends are then
brought together and vulcanized, and the tire properly moulded.
In moulding the tire, the rubber will of course adhere to the outer, surface of the
armor, both on the concave and convex sides; but where the armor is lapped one
portion over the other, the inside surface of the lans will not of course adhere to
each other and it is not intended that they should, as if this was so, the armor
could not stretch with the tire when it was inflated-thus to prevent a continuous
separation of the laps, it is thought advisable to unite the inner and outer coverings
through the center in such a way as not to interfere with the stretch of the armor:
the raw hide armor, when finished, is pressed to a thickness of less than 1/16 of
an inch; thus it will be readily understood that the soft rubber on the inner and
outer coverings d and e will stick together and form a union or connecting point
through each of the holes in the center of the armor.
It is quite impossible at times to shave the strips of raw hide so that the whole
strip will be of uniform thickness and strength; thus when the armor is finished,
one portion of the armor is likely to be weaker than another and when the tire is
inflated, the armor would be apt to stretch most at the weak place, but when the
inner and outer coverings d and e are united at regular intervals through the
holes s, the strength of the armor will be limited to the exact stretch of the cover-
ings between the united points and it is thus equalized throughout the circumference
of the tire.
It will be particularly noticed that in making the holes s, a solid piece is cut
from the center of the lower lap n, while only a semi-circular piece is cut from
each edge of the top lap m, as shown at s¹, Figures 3 and 2; this gives us the
proper fastening of the covers and practically seals the bottom lap n to the outer
cover, but it leaves the ton lap m free between the secured. points so that the
fastening in no way interferes with the universal stretch of the armor.; in Figures 3
and 8, t represents the united portions of the outer coverings d and e.
When any substance sufficiently hard to resist a puncture is inserted as an
armor, its tendency is to flatten out laterally when pressure is exerted against the
tread portion. This is so because the air is compressed vertically and must expand
laterally; thus in all armored tires of this kind, the edges of the armor extending
along the sides of the tire will soon cut the outer covering. To guard against
this, I concave the armor to a curvature which is greater in a transverse direction
than the outer covering e of the tire, so that the edges of the armor before, the
covers d and e are vulcanized together, would stand out and away from the sides

page_text: and consisting of a flattened helix composed of a non-puncturable material as raw
hide, substantially as described.
11. A Pneumatic Tire for bicycles provided with an armor on its tread side and
thrust pieces as g, Figure 8, to receive the pressure from the edges of said armor
as set forth.
ated this 10th day of
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.