Abstract: Coextrusion apparatus for forming tubular elastomeric ply made up of first, second and third concentric streams of elastomeric material and a pair of coaxial helical patterns of individual reinforcing elements wound in opposite direction with respect to each other contained within the first and third streams of elastomeric material and separated by the second stream of elastomeric material. A pair of reinforcing element guides are rotatably mounted within the apparatus between stationary flow channels for the three streams of elastomeric material, and are rotated in opposite directions with respect to each other. The two helical patterns of reinforcing elements and three streams of elastomeric material merge together substantially simultaneously in concentric circles which lie in a plane generally perpendicular to a central axis of the coextrusion apparatus to form the tubular ply. A method for producing such a reinforced tubular elastomeric ply also is presented.

Abstract: A process for manufacturing a second stage tread assembly (1) of a road vehicle tire, whereby a green annular tread cap (2) is fed onto and stitched internally against, the inner annular surface (23) of an annular forming body (18) negatively reproducing the final outer annular surface (3) of the tread cap (2). A number of further annular components (7,14), comprising a reinforced annular tread belt (14), are successively fed into the annular body (18) and onto a barrel-shaped inner annular surface (5) of the tread cap (2).

Abstract: A body ply splice width monitor is provided to sense the leading and trailing edges of a lateral splice in a web of tire body ply material and to produce an indication upon a monitor as to whether such splice satisfies certain dimensional criteria. A first pair of sensors is maintained along one edge of the web, while a second pair of sensors is maintained along the opposite edge. An encoder tracks the movement of the web through the array of sensors and provides output pulses corresponding to finite dimensional lengths of the web. The number of pulses between the sensed leading edge and sensed trailing edge of the splice is used to indicate and determine the total splice width.

Abstract: A compact and precision extrusion system for extruding strips of rubber compounds with profiles of accurate dimensions. Strips of rubber compound are uniformly heated and mixed in an extruder and then passed through a low pressure drop strainer to remove foreign matter. The strained compound then is fed directly into a gear pump which delivers precise volumes of the rubber compound immediately into the spread chamber of an extrusion head after which it passes through a die to form a precise strip of the rubber compound. The strainer and extrusion head are movably mounted with respect to the gear pump for axial separation from the gear pump for easy removal of the rubber compound from the various components of the system to facilitate compound changes. A control system regulates the speed of the extruder to provide a near constant pressure at the entrance port of the gear pump to precisely regulate the rate of extrusion of the compound from the extrusion head.

Abstract: An extrusion head (1) defined by a number of superimposed plates (7,8,9,10) and by a casing (55) housing the plates (7,8,9,10) and defining two shoulder surfaces (68,69) forming an angle and perpendicular to the plates (7,8,9.10); the plates (7,8,9,10), when packed together, defining an intermediate guide duct (35) for guiding reinforcing wires and two supply ducts (11,23) for supplying extruded elastomeric material located on opposite sides of the intermediate duct (35), and providing for locking together a wire guiding device (36) and a die (37) presenting respective flat shoulders (42,43;50,51) parallel to a first (68) of the shoulder surfaces (68,69) and pressed by the plates (7,8,9,10) into contact with one another and with the first shoulder surface (68), with the die (37) located between the first shoulder surface (68) and the wire guiding device (36).

Abstract: A method and device (1) for stabilizing a tire extracted at a relatively high temperature from a tire curing mold, whereby the tire (2) to be stabilized is inflated to a given pressure by a pressurized fluid, and cooled from the inside by circulating the pressurized fluid along a closed circuit (44) defined, at least partially, by the tire (2) and by a radiator (45) located outside thereof.

Abstract: An apparatus and technique for measuring and analyzing the tread wear of a pneumatic tire. The tire is indexed about its axis. Between the indexing steps, a laser scanner obtains data from the tread surface. This data is normalized to eliminate any out-of-roundness of the tire data. Noise spikes are removed and replaced with values attributable to valid data. From the data, a reference curve corresponding to a lateral sector of the tire is devised. The data from actual lateral sectors is then compared to the reference curve by a curve-fitting process and the deviation between the actual data and the reference curve establishes the degree of irregular wear of the tire at that lateral point.

Abstract: A method and apparatus for circumferentially measuring tread wear on a tire. A laser probe sequentially scans each of the ribs of a tire, obtaining data respecting the tread depth at various points therealong. This data is employed for each rib to determine heel-to-toe irregular wear of the lugs thereof and to also determine a total wear index indicative of the degree of wear of the lugs. The method and apparatus is also adapted to laterally scan the tire sidewall to obtain data therefrom for the ascertaining of anomalies therein.

Abstract: A method for the vectorial assembly of green tires (2) in a curing unit (4), whereby a processing unit (12), after performing a first step consisting in determining the origin of a tire (2), i.e. the machine on which it was produced, and the curing unit (4) in which it is to be cured, extracts memorized data relative to the asymmetry of the curing unit (4) and the average tire (2) produced on the machine, and positions the tire (2) angularly in relation to the curing unit (4) so as to compensate for both asymmetries according to a given program.

Abstract: A device (5) wherein, for splicing the facing edges (4a,4b) of a sheet (4) of unvulcanized rubber using a powered grip fixture (6) with a pressure member (11) and a counterpressure plate (36) for gripping the sheet (4) to a given pressure and imparting a given thrust on the edges (4a, 4b) of sheet (4) for bringing them together, the grip fixture (6) is moved back and forth along a route parallel to the edges (4a, 4b) of sheet (4) and defined by a guide (85) designed to move to and from an operating position wherein the counterpressure plate (36) and the edges (4a, 4b) of sheet (4) are substantially coplanar, and wherein lifting member (41, 64)(41, 65) cooperate with sheet (4) for lifting the respective edges (4a, 4b) onto the counterpressure plate (36) and into engagement with grip fixture (6 ).

Abstract: An extrusion device (1) the extrusion head (2) of which features a number of superimposed shaped plates (9, 10, 11, 12) clamped together by a clamping device (3) located and operating externally of the extrusion head (2) about which it defines a releasable ring device; the extrusion device (1) having an automatic release device (4) for separating the shaped plates (9, 10, 11, 12) when the ring device is released.

Abstract: A method and device for feeding hot portions (4) of extruded tire tread (3) directly to a tire building machine (5), whereby tread portions (4) of given length, obtained by cutting a tread (3) produced continuously by an extruder (2) at a first speed (V1), are fed successively to the tire building machine (5), with no distortion or stretching and at a second speed (V2) differing from the first (V1), by means of a feed device (1) having an input conveyor (11) for receiving the continuous tread (3) at the first speed (V1) and feeding it through a cutting station (12) to an output conveyor (17) at least equal in length to the tread portion (4); during each cycle for feeding each tread portion (4) to the tire building machine (5), the output conveyor (17) undergoes at least four variations in speed, so as to assume, at least once, a speed substantially equal to zero, and three different traveling speeds (V1, V2, V3), of which two (V1, V2) are equal to the first (V1) and second (V2) speeds respectively.

Abstract: An extruder head made up of several segments including a first section made up of at least two plates bolted together. At least one plate is hingeably mounted to another plate in the first section to provide access to an extrudate passage defined by the plates. Downstream of the first section is a pair of mating blocks bolted to the first section further defining the extrudate passage. Inserts of hardened steel are provided and held by the plates and blocks forming the extruder head and the inserts define parts of the extrudate passage. A cooling liquid chamber is provided in at least one insert to cool the wall forming the passage. Although the passage is continuously restricted in the downstream direction, to increase the pressure of the elastomeric melt, intermittent portions of a slightly greater cross-sectional area are provided to allow expansion and thus intermittent lower pressure of the melt as it passes through the passage.

Abstract: An apparatus and method for forming curing envelopes which apparatus and method enable the use of a conventional inner tube mold for making a curing envelope perform in the form of an envelope tube which may have a portion thereof easily removed to provide a curing envelope suitable for use in a tire retreading process. A curing envelope is made by placing an annular tube of uncured envelope material in a curing mold having a center core and a mold insert installed therein. The insert includes a pair of coaxial annular rings projecting radially outwardly from the center core and connecting straps for maintaining the axial spacing between the rings. The mold is closed and heat and internal pressure are applied to the envelope tube for curing the envelope tube and urging the tube against the interior cavity surface with the annular rings penetrating into the inner wall of the tube for forming therein corresponding annular grooves.

Abstract: An extruder for elastomeric material has an axial screw in an extruder chamber defined by a cylindrical housing. Two radial planes of vented kneading pins are provided upstream of the extruder housing succeeded by spaced-apart planes of non-vented kneading pins. Each vented kneading pin includes small apertures at the inlet end of the pin which communicate with a stepped bore of gradually increasing crosssectional area from the inlet to the outlet thereof whereby gases within the elastomeric material can be vented through the apertures communicating with the stepped bore to the exterior of the extruder housing.

Abstract: A pneumatic safety tire, of the type preferably having a section height of five inches or greater, having a pair of crescent shaped elastomeric reinforcing members located between the innerliner and side wall and extending from adjacent the tread shoulders to at least the apex of the bead fillers of the tire. A pair of bias reinforcing plies are located between the elastomeric reinforcing members and the side walls of the tire and extend along the side walls from adjacent the tread shoulders to below the top most turn-up ends of the body ply. The elastomeric reinforcing members preferably are similar in composition to that of the bead fillers and have a low hysteresis value preferably within the range of 0.03 and 0.11, a high modulus preferably within the range of 2600 psi and 2800 psi and a Shore A hardness preferably within the range of between 85 and 91.