Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.

Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.

Abstract: The invention relates to the lugs of tires intended to be mounted at least on the driving wheels of agricultural and industrial tractors; said lugs have the front sidewall, with respect to the running direction of the vehicle when in service, shaped according to a curvilinear profile which produces considerable advantages as regards the wearing-out, the efficiency, and the lifetime of the tire itself. This curvilinear profile is expressed by the equation:y=Ax.sup.3 +Bx.sup.2 -Cxwhere A, B and C are constants linked to the geometry of the lug.