Abstract: A system for curing a green tire made from elastomeric material includes a tire mold with a surface defining a cavity for shaping the tire. A plurality of vent passages communicate the cavity with the exterior of the tire mold. An inflatable bladder presses the tire against the surface defining the cavity for a predetermined time in response to fluid pressurization. A fluid pressure source pressurizes the bladder. A conduit communicates the fluid pressure source with the bladder. A restrictor member is located in the conduit for restricting the rate of increase of fluid pressure in the bladder to a predetermined rate of increase during the first one-third of the predetermined time. During the first one-third of the predetermined cure time, portions of the tire adjacent the plurality of vent passages cure and restrict the flow of other uncured portions of elastomeric material into the vent passages.

Abstract: An apparatus is disclosed for measuring tire force and tire tread motion in a common area of a tire under test. The apparatus comprises a tire test block having a bearing surface over which a tire to be tested is rolled. A force sensor is received in an opening in the block and adapted to be engagable by the tire under test. The force sensor includes a longitudinally extending member having a longitudinally extending opening therein. The member has a central axis, the central axis being oriented substantially perpendicular to the bearing surface of the test block. The force sensor further includes strain gages secured to the member and having an electrical characteristic indicative of force applied to the member by the tire under test. A motion sensor is located within the longitudinally extending opening in the member.

Abstract: A curable rubber bladder stock containing esters of ricinoleic acid or derivatives thereof has reduced viscosity as compared to stocks containing castor oil. The rubber stocks of the present invention generally retain a very high percentage of the initial cure tensile strength and have improved modulus as compared to castor oil, both upon initial cure and upon aging. Lower viscosity and higher modulus of the rubber stocks of the present invention readily permit the production of thinner bladders. The bladders can fit within an article such as a tire during vulcanization of the tire as in an automatic vulcanizing press. Thinner bladders effect a greater heat rate and result in shorter cure times for articles such as tires. The esters of ricinoleic acid and derivatives thereof have the formula ##STR1## where R is H or ##STR2## where R.sup.1 is an aliphatic, preferably an alkyl, having from 1 to 12 carbon atoms, desirably from 1 to 4 carbon atoms, and preferably 1 carbon atom, i.e., methyl, and R.sup.

Abstract: Determining the rate of change of fluid pressure in a tire comprises mounting the tire in an inflated condition. A tire pressure sensor senses fluid pressure in the tire and generates an electrical signal in proportion to the fluid pressure sensed in the tire. A temperature sensor senses the temperature adjacent the tire and generates an electrical signal in proportion to the temperature sensed adjacent the tire. A data acquisition system is in electrical communication with the sensors. The data acquisition system receives the electrical signals from the respective sensors at a substantially simulatneously time and converts the electrical signals into digital information. An electronic digital computer is an electrical communication with the data acquisition system for receiving the digital information and for calculating a value representative of a corrected pressure in the tire as a function of the digital information received. A plurality of the corrected pressure values are stored.

Abstract: An improved of processing a tire on a uniformity machine comprising the steps of sensing the radial force variations in a tire and generating a composite waveform corresponding to the sensed force variations, converting the composite waveform into a special function waveform selected from the class of waveforms which includes filtered partial square waves, partial sine waves and full sine waves, selecting either from a table or adaptively one of the special function waveforms and grinding of the tire in response to the selected special function waveform.

Abstract: The heat-sink capacity of a thick-walled article being cured with a hot liquid supplying heat to one side of the wall, allows the point of least cure (PLC) to receive a higher rate of cure equivalents even after the hot liquid is replaced with a cold liquid. In the mean while, the other side of the wall continues to be heated. Because such a change-over is effected before the PLC has received the minimum number of cure equivalents required to effect a cure at the PLC (a "pre-cure change-over"), a valving arrangement is provided which allows the change-over to be effected without permitting a pressure drop in the bladder sufficient to permit the tire to "blow" because it is as yet uncured when the change-over is effected. Such a pre-cure change-over cannot be made when steam is replaced with water at ambient temperature.