Glossary - Mondolfo Ferro AS 924 Manual De Uso

15. GLOSSARY

Wheel and tyre assembly
Assembly consisting of:
Tyre
Wheel: rim and disc coupling
Inner tube (if present)
Pressurised air
I - Tyre The tyre is the main part of the complex that is
in contact with the road and is therefore designed to
support the internal air pressure and all other stress
arising from use.
This cross section of the tyre illustrates the different
parts making up the tyre itself.
The tyre must:
- withstand a load,
- ensure driving power,
- steer the vehicle,
- aid handling and braking,
- aid vehicle suspension.
1 - Tread. This is the part in contact with the ground
when the tyre rolls. It comprises a rubber compound
and a "pattern" suitable for ensuring good resistance
to abrasion and good grip in dry and wet conditions,
as well as quiet operating conditions.
2 - Edge or bracing. This is a metal fabric or textile
insert, in the area of the outer bead part It protects
the casing plys from rubbing against the rim.
3 - Casing. This is the resistant structure and comprises
one or more layers of rubber plys. The way the plys
comprising the casing are arranged give the structure
its name. The following structures are possible:
Conventional: the plys are inclined and arranged so
that the strands comprising a ply overlap with those
of the adjacent ply. The tread, which is the part of the
tyre in contact with the ground, is part of the sidewalls
and so during rolling, sidewall flexure is transmitted
to the tread.
Radial: the casing consists of one or more plys with
the cords in a radial direction.
A radial casing in itself is quite unstable. To make it
stable and prevent incorrect tread movement in the
area of contact with the ground, the casing and the
tread are reinforced with an annular structure, usually
122
I
II
AS 924 - AS 924 A Operator's Manual
III
IV
1
13
12
8