Abstract A tire suitable for use with a fast vehicle, a vehicle carring a heavy load, or a vehicle exerting a high torque having a tread, an outer portion of the tread being sculptured and having hollows, a carcass and a reinforcing member having an outer face spaced radially from the level of the bottoms of the hollows of the sculptured portion, whrein there is a second portion of the tread between the level of the bottom of the sculptured portion and the outer face of the reinforcing member which second portion is made of a rubbery mixture having a high modulus of elasticity at least equal to 40 kg/cm2 at 100 percent elongation, whilst the sculptured outer portion of the tread is made of a rubbery mixture having a less high modulus of elasticity. This tire displays high resistance to any tendency of the sculptured portion to be worn away or stripped off whilst retaining its other essential qualities.
A tire for a high speed and/or heavy duty vehicle comprising a carcass, a bead in each edge of the carcass, a reinforcing tread member in the crown region of the tire, and a tear resistant tread comprising an anti-skid outer tread portion made of wear resistant rubber compound having a relatively low modulus of elasticity in the range of 20 to 25 kg/cm2 at 100 percent elongation, hollows extending from the outer tread surface into the tread, and an inner tread portion only in the area of the tread extending from the reinforcing tread member to the level of the bottom of the outer tread hollows, said inner portion being made of a rubber compound having a substantially higher modulus of elasticity at least equal to 40 kg/cm2 at 100 percent elongation.
Claim 2
Dependent Claim
133 words
A tire for a high speed and/or heavy duty vehicle comprising a carcass, a bead in each edge of the carcass, a reinforcing tread member in the crown region of the tire, and a tear resistant tread comprising an anti-skid outer tread portion made of wear resistant rubber compound having a relatively low modulus of elasticity in the range of 20 to 25 kg/cm2 at 100 percent elongation, hollows extending from the outer tread surface into the tread, and an inner tread portion only in the area of the tread extending from the reinforcing tread member to the level of the bottom of the outer tread hollows, said inner portion being made of a rubber compound having a substantially higher modulus of elasticity at least equal to 40 kg/cm2 at 100 percent elongation.
Claim 3
Dependent Claim
34 words
A tire according to claim 1 in which the second portion of the trEad has a thickness equal to a least a quarter of the thickness of the sculptured outer portion of the tread.
Claim 4
Dependent Claim
23 words
A tire according to claim 1 having a carcass in which the reinforcing member is a relatively non-extensible belt placed on the carcass.
Claim 5
Dependent Claim
24 words
A tire according to claim 1 in which the second portion is made of a rubbery mixture containing a high content of reinforcing material.
Claim 6
Dependent Claim
20 words
A tire according to claim 4 in which the reinforcing material comprises fibres having a diameter less than 0.03 mm.
Claim 7
Dependent Claim
32 words
A tire according to claim 1 in which the rubbery mixture of the second portion includes reinforcing material which includes a finely divided polyolefin having a molecular mass of at least 500,000.