Appeal 2007-0163
Application 10/318,898
STATEMENT OF THE CASE
The subject matter on appeal is directed to a radial ply pneumatic
truck tire having a circumferential decoupling groove designed to prevent
irregular tread wear, particularly in the shoulder region of the tread
(Specification 1-2). Further details of the appealed subject matter are recited
in representative claims 1 and 7 reproduced below:
1. A pneumatic radial ply truck tire for use on steering axles,
comprising a tread, a casing, the casing having two sidewalls, one or more
radial plies extending from and anchored to two annular beads, a belt
reinforcement structure located radially between the tread and the plies, the
tire characterized by the tread having a plurality of circumferentially
continuous grooves, a pair of radially recessed ribs, the radially recessed ribs
being radially recessed and non-road contacting under static load, a pair of
full radius circumferentially continuous decoupling grooves, one full radius
circumferentially continuous decoupling groove being adjacent each
recessed rib, and a plurality of tread ribs, including a pair of shoulder ribs,
one shoulder rib being adjacent each circumferential decoupling groove, the
radially outer surfaces of the plurality of tread ribs defining a radially outer
tread surface, the outer tread surface being adjacent to and extending
between the pair of full radius circumferential decoupling grooves, the
distance halfway between the decoupling grooves defining the centerline of
the tread, in a cross section of the tread, the radially outer tread surface has a
maximum diameter D at the tread centerline and a constant radius of
curvature R, R extending laterally toward each circumferential decoupling
groove, the constant radius of curvature R originating on the centerline of
the tread, the axial width of the tread being W as measured between
lateral edges of the shoulder ribs; the belt structure having a plurality of belt
layers, a first radially inner belt layer, a second intermediate belt layer, a
third intermediate belt layer and a radially outer belt layer each belt layer
having an axially outer end; and
wherein each decoupling groove is defined by an axially innermost
sidewall intersecting an axially outermost ground-contacting edge of the
tread and an axially outer rib of reduced radial height, the groove further has
a full radius of curvature RG, RG being at least 2.0 mm and at a point C
2
Page: Previous 1 2 3 4 5 6 7 8 9 10 Next
Last modified: September 9, 2013