Abstract: A process for preparing high molecular weight water soluble polymer gels having relatively narrow molecular weight distributions is disclosed. An aqueous reaction mixture comprising a solution of a water soluble vinyl monomer and a suitable catalyst system is polymerized in a reactor comprising a tube or bag of an oxygen-impermeable film in the substantial absence of oxygen.

Abstract: An improved bladder lubricant composition is disclosed which provides durable release of bladders from cured rubber tires in the manufacture of the latter. The composition comprises (A) an organopolysiloxane resin consisting essentially of phenylsilsesquioxane units and dimethylsiloxane units; (B) an organosilane having trioxime or trialkoxy functionality; (C) a condensation catalyst; and, optionally, (D) at least one diorganopolysiloxane having hydroxyl or alkoxy terminal groups.

Abstract: A method and an apparatus for vulcanizing an elastomer product, such as automobile tires, wherein the elastomer product is placed in a vulcanizing chamber in a mold steam at an elevated pressure is supplied to the vulcanizing chamber to heat and pressurize the elastomer product until the elastomer product reaches a prespecified temperature or for a prespecified period of time, the steam supply is stopped and a pressurizing gas, at a pressure not lower than the steam supply pressure, is supplied to the vulcanizing chamber until the end of a heating period, said steam being blown in and supplied from an upper position of the center of the vulcanizing chamber in a horizontal direction or in an inclined downward direction, said steam being blown in and supplied from a lower position of the center of the vulcanizing chamber toward an upper region of the vulcanizing chamber.

Abstract: In order to form shaped convex non-extractable pieces made of a composite material, a partially polymerized (stage B) preform strip (10) is placed in a forming tool (16) along a cylindrical surface having one rectilinear generator and one convex directrix curve whose shape coincides with the shape of the piece to be embodied. The particular section of the piece is obtained with the aid of an inflatable bladder (22) pressing the preform strip against a forming die (24). In this way, the area contractions are kept to a minimum, which avoids may undulations of the fibers and any falling off of the mechanical characteristics of the pieces which may accordingly arise.

Abstract: A method for vulcanizing an elastomer product includes heating under pressure an elastomer product placed in a mold by supplying a heating medium such as steam, stopping the supply of the heating medium when the elastomer product rises to a predetermined temperature or after the lapse of a specified period of time, supplying a pressurizing medium such as nitrogen gas at a pressure equal to or higher than that of the heating medium until the heating process is completed, and discharging the vulcanizing medium after the heating process. The heating and pressurizing medium are supplied through respective blow supply means with the heating medium being blown to a lower portion of the vulcnizing chamber and the pressurizing medium being blown to an upper portion of the vulcanizing chamber.

Abstract: An apparatus for vulcanizing an elastomeric product includes a mold in which the elastomeric product to be vulcanized is disposed, a piston gland having a first supply passage for supplying a heating medium, and an annular junction chamber. The first supply passage communicates with the interior of the junction chamber. The junction chamber has an outer wall which separates the junction chamber from the interior of the product, and a nozzle in the outer wall directs heating medium from the junction chamber into the interior of the product in a downward direction toward the lower portion of the product. An enclosure overlies the junction chamber. The piston gland has a second supply passage for supplying a pressurizing medium which communicates with the enclosure to supply pressurizing medium to the enclosure, the pressurizing medium passing from the enclosure to the interior of the product.

Abstract: A split tire mold having a tread ring in which provision is made for venting air circumferentially across the inner surface of the tread ring so that the air escapes from the parting line of the mold halves, dispenses with widely used, conventional, radially protruding vent stubs. The air is vented through "butterfly-shaped" or "double-wedge-shaped" arch-vents which provide passage for trapped air above each tread block of the tread as it is moved against the inner surface of the tread ring. The shape of the arch-vent passages and the angulation of the wedges is critical to the effectiveness of the arch-vent which forms an arch-vent bridge of cured rubber in a cured tire. The configuration of the bridge allows as cured tire to be easily removed from the mold cavity without leaving a broken-off piece of the rubber bridge to plug the arch-vents. This arch-vent design leaves unobtrusive flat-sided, narrow wedge-shaped pieces of rubber as the arch-vent stubs, tapered in two directions.

Abstract: A mold for curing a green tire which is made of an elastomeric material capable of flowing prior to curing. The mold includes a surface defining a cavity in the mold for receiving the green tire. A passage communicates the cavity with the exterior of the mold. A vent plug is located in the passage. The vent plug has an opening extending therethrough communicating the cavity with the passage. Elastomeric material may flow into the opening to form a projection extending from the tire as the green tire is pressed against the surface defining the cavity during a molding operation. The vent plug has a portion extending into the cavity a predetermined distance from the surface to form a recess in the tire adjacent the projection. The recess provides a space that the projection may deflect into to prevent shearing off of the projection during removal of the tire from the mold.

Abstract: In a method of controlling a tire vulcanization by controlling a heat supply to a vulcanizing machine including a mold unit and a bladder unit, temperatures at points on a boundary between the mold unit and a tire are measured by means of temperature sensors, a temperature at a center post assembly of the bladder unit is measured by a temperature sensor arranged at the center post assembly. The method includes calculating temperature profiles within the tire from the measured temperatures by using the finite difference method, estimating vulcanization profiles within the tire from the temperature profile, deriving the least vulcanization within the tire from the vulcanization profiles, and producing a stop signal for the heat supply to the vulcanizing machine in accordance with the least vulcanization thus derived.

Abstract: A method and apparatus for vulcanizing pneumatic vehicle tires having heads that in the mounted state are disposed on the radially inner periphery of a rim. In order for such tires to achieve a satisfactorily contoured vulcanization, and in order at the same time to produce sealing surfaces with great precision, the tire is vulcanized with its beads in their operating position. During the vulcanization, the radially outwardly disposed surfaces of the tire beads are shaped with the aid of rigid, one-piece, shaped molding rings.

Abstract: A method of setting a crude tire into a space between upper and lower molds in a tire vulcanizing press having upper and lower mold units movable relative to each other includes the steps of pushing an upper bead of the crude tire into a bead of the upper mold by a vertically movable device which supports the upper bead of the crude tire, introducing gas into a bladder to expand the bladder while restricting the elevation of an upper portion fixing ring of a bladder holder mechanism attached to the lower mold unit, and pushing a lower bead of the crude tire into a bead of the lower mold by utilizing the expansion forces of the bladder. With the bladder enclosed air-tightly, the tire lower bead can efficiently be pushed into the lower mold bead.

Abstract: Apparatus for vulcanizing an elastomeric product includes separate passageways for supplying a heating medium to a lower portion of the vulcanizing chamber and an inert gas pressurizing medium to the upper portion of the chamber. The mixing of the fluids minimizes the temperature difference in the inner space of the product and ensures a uniform vulcanization.

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: A hollow, fiber reinforced composite product having a substantially continuous outer surface and a minimum of discontinuities in the fiber reinforcement material and method for manufacturing the product. The product is manufactured by inserting a tubular bladder inside a length of composite material in tubular form so that the bladder ends extend out the corresponding ends of the composite material. An opening is formed in the side of the composite material at a location spaced apart from one of the ends thereof. Both ends of the bladder are passed through the side opening from the inside thereof. A hollow preform is formed by overlapping the ends of the composite material so that the ends of the fiber reinforcement in the composite material overlap. One of the ends of said bladder is sealed and the preform is placed into a mold. The preform is molded into the desired hollow continuous annular shape by curing the preform within said mold while inflating the bladder through its nonsealed end.

Abstract: A method of manufacture of pneumatic tires having a tread T with grooves therein in which the grooves are formed by use of cylindrical network grid 10. The grid 10 is filled with tread compound T, and is then located concentrically to surround a tire carcass assembly C to assemble the carcass to the tread. Other tire components such as sidewalls S are added to the carcass C with the grid in situ, and the assembled tire is then cured with grid in situ, the grid being subsequently stripped from the finished tire. Apparatus for above method include a tread mould body (23) having an inner mould surface (24) in which the closely fitting cylindrical network grid (10) is located. The grid (10) is separate from the mould body (23) and has at least one axial split therein to allow removal of the grid (10) from the finished tire.

Abstract: The heat-sink capacity of a well-insulated dome curing press lends itself to saving external steam (flowed over the exterior of a mold in the press) when curing an article. Despite shutting off the external steam at about the half-way point in the normal heating cycle, or sooner, the temperature swing at a point 2 inches within the mold is less than 10.degree. F. This small swings allows the point of least cure (PLC) to receive the required number of cure equivalents long after the external steam supply is shut off, that is, while the press is "coasting". In the mean while, the internal heating and cooling cycle of the press may also be shortened for maximum energy savings, or left unchanged. Though the external steam is shut off before the PLC has received the required or specified number of cure equivalents at the PLC, the press-open to press-close cycle remains the same, and the quality of the cure is not measurably affected.

Abstract: A method of molding and vulcanizing more than 40 rubber products successively by using a curing bladder, which has been treated at the surface thereof with a silicone composition including:(a) 100 parts by weight of a polyorganosiloxane composed mainly of polydimethylsiloxane with a viscosity at 25.degree. C. of from 3,000 to 5,000,000 cst,(b) from 30 to 300 parts by weight of a polymethylhydrogensiloxane with a viscosity at 25.degree. C. of from 10 to 70 cst,(c) from 2 to 25 parts by weight of a finely powderous silica, and,(d) from 0 to 30 parts by weight of an organic acid salt of one or more of metals selected from the group consisting of zinc, magnesium, manganese and cobalt.

Abstract: To obtain and expedite an automatic engagement and disengagement of the bladder with respect to the relative operating mechanism, in particular in presses used for curing pneumatic tires, the movable clamp and the fixed clamp, respectively, which block the beads of the flexible, elastically deformable sleeve constituting the bladder, comprise annular grooves, coaxial with the axis of the bladder, which, in operation interact with the heads of a plurality of pegs situated in the head to be assembled to the movable clamp and in the body of the support to be associated to the fixed clamp, the pegs being radially movable in both senses between two positions, i.e. a work position in the operating condition and a rest position in which said pegs are completely collapsed into the body of said head and of the support so as to allow the axial insertion of the bladder on the mechanism and its removal therefrom.

Abstract: Process for molding and vulcanizing tires and other rubber articles, in which in a press with the aid of a bladder negative shapes are pressed into the tire blank under high pressure and vulcanization is performed, the surface of the bladder having applied thereon a solvent which swells the surface, the swollen bladder being provided with a cross-linked, hardened, tightly adhering, elastic release agent film bonded to the bladder by chemical interactions before carrying out molding and vulcanization to prevent sticking of the molded and vulcanized tire to the bladder, the film comprising more than one thin coating each of which is produced by coating the bladder with an organic solvent solution comprising a mixture of a silicon release agent and a moisture or heat curable silicone rubber and curing the coated mixture through exposure to moisture or heat, and conducting at least 300 molding and vulcanizing cycles without recoating the bladder with the release agent film.

Abstract: A bag control mechanism (or center mechanism) for a tire press in which cross flow of curing medium from the inlet to the outlet is prevented. The center mechanism includes a cylindrical casing having a piston rod reciprocable therein, and an annular fluid distribution member comprising a hub and a distribution cap at the upper end of the casing. The hub has a central bore of larger diameter than that of the piston rod, and inlet and outlet passageways for a curing medium, on opposite sides of the bore. The hub may also have passageways which permit sensing of a condition such as temperature within the tire press. The hub also has lateral passageways from the bore to the outlet passageway, and from the outside surface of the hub to the outlet passageway. The inlet passageway is separated from the bore by a portion of the hub's body. The distribution cap has an opening or passageway aligned with the inlet passageway of the hub, and a cut-out portion aligned with the outlet passageway of the hub.

Abstract: A viscoelastic fluid molding material is injected into a tire tread cavity between the mold and an inflatable tread supporting body. The clearance distance between the mold and the inflatable tread supporting body is varied to increase the flow of the initial amount of fluid molding material into remote portions of the tire tread cavity and provide for the flow of the final amount of fluid molding material into gate portions while the tread supporting body is being deflected.Circumferentially spaced gates may be spaced from the centerplane of the mold and have runners extending toward the shoulders of the tread supporting body for increased flow of the initial amount of fluid molding material into remote shoulder portions of the tread cavity. Sealing rings at the side edges of the tread cavity prevent flow of fluid molding material into sidewall areas of side members of the mold.

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, on 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 changeover 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.

Abstract: A curing bladder containing (A) organic rubber which is surface treated with a curable silicon composition containing (B) polyorganosiloxane, which comprises at least two monovalent substituted or unsubstituted hydrocarbon groups having five or more carbon atoms and a C.dbd.C double bond connected to the silicon atom through at least one carbon atom, and having a degree of polymerization greater than 20.

Abstract: Tire mold vents (34) in communication with a sealed cavity (35) are pressurized for limiting the quantity of rubber entering the vents (34) and for assisting the stripping of the vulcanized tire (28) from the mold. Passages (40) in the mold communicate fluid pressure to the vents (34) and pressure regulators (58,60) control the fluid pressure communicated to the vents (34) during vulcanization and during ejection of the tire (28) from the mold (10).

Abstract: A loading process for a heated tire press is described herein in which a loader takes an unfinished tire from an unfinished tire stand and puts it between the tire forming pieces of the tire press. This loader travels with folded-in clamp jaws into the inside of the unfinished tire from below, engages it with extended clamp jaws inside of the upper bead from below, transports it in this position to the upper tire forming piece and raises it until its upper bead presses against the upper rim ring on the upper tire forming piece. The upper bead is held there by an auxiliary bellows, retaining fastener or the like. Subsequently the clamp jaws are folded in again and the loader retracted.

Abstract: A method of manufacturing pneumatic tires of different tread patterns by vulcanization building in full mold process is disclosed, which comprises providing a pair of mold members separable at a plane inclusive of a parting face perpendicular to the rotary axis of the tire, determining at least two joining position on these mold members at regular intervals, and properly selecting the joining position of each mold member so as to provide a different tread pattern.

Abstract: A method and apparatus for vulcanizing pneumatic vehicle tires where the tire beads, in the mounted state, are disposed on the radially inner periphery of a rim next to the essentially radially inwardly extending rim flanges. In order to obtain tires having a long service life and tire beads with a good sealing quality, it is proposed that the tire be vulcanized in essentially the proper contour for operation. Two, respectively radially segmented, bead-forming rings that have a variable diameter and can be displaced axially are provided. For the purpose of vulcanizing the sealing surfaces disposed in the interior of the tire so that these surfaces will rest on the rim in an airtight manner, the bead-forming rings are introduced, in a radially retracted state, into the interior of the tire blank, whereby at least one of the tire beads is ovally deformed.

Abstract: The invention is a mold adapted for forming a member from a thermoset or thermoplastic resin about a substrate at a distance from the end of the substrate without leaking of the thermoplastic or thermoset material onto the portion of the substrate between the end and the starting point of the member being formed about the substrate, wherein the mold comprises(A) a mold casing adapted for forming a member from a thermoset or thermoplastic material about a substrate at a distance from the end of the substrate,(B) an inflatable seal adapted for forming a seal about the substrate when inflated at a distance from the end of the substrate such that the thermoset or thermoplastic material is contained to the area of the substrate about which the member is to be formed,(C) a means for inflating the seal such that the seal can form a seal about the substrate at a distance from the end of the substrate.

Abstract: A curing press for tires, commonly manifolded to other curing presses in a curing room, are operated with a minimum blowdown time which is variable from one cycle of each press to another cycle. A first signal is generated by a pressure transducer ("PT") in pressure communication with the bladder(s) of each curing press; this first signal is compared to a second signal corresponding to a target pressure, which second signal is stored in a programmable controller ("PC"). The PC controls operation of the press, and is used to provide a variable blowdown period; how quickly this target in the PC is reached, is a function of the pressure in a common blowdown manifold for plural presses.

Abstract: An improved process for molding and vulcanizing rubber products using a curing bladder, characterized in that the bladder is one which is made of a rubber compound containing (A) organic rubber and (B) polyorganosiloxane, the ratio of (A)/(B) being 95/5 to 5/95, or the bladder is one which is produced by surface treating (A) organic rubber with a silicone composition containing (A) organic rubber and (B) polyorganosiloxane, said polyorganosiloxane comprising at least two monovalent substituted or unsubstituted hydrocarbon groups having five or more carbon atoms and a C.dbd.C double bond connected to the silicon atom through at least one carbon atom, and having a degree of polymerization greater than 20.

Abstract: A method for consolidating an annular ring of uncured elastomeric material in a tread ring mould comprising a set of rigid segments in sliding end-to-end relationship to form a consolidation ring having a first small diameter for insertion of the segments into the elastomeric material in the tread mould and a second larger diameter at which the segments form a smooth, continuous consolidating surface, mechanical means for moving the segments from the first diameter substantially to the second diameter and a fluid pressure inflatable bag means which may be inflated behind the segments to apply consolidation force at the second diameter.

Abstract: A tire building machine and method employing a tire building drum for receiving at least one ply of tire material having an edge overhanging an axial end of the drum, a bladder turn-up mechanism extending axially outwardly from the drum, an annular array of radially contractible ply-down fingers movable axially to and from a position encircling the overhanging ply edge, and an axially movable ring device operative first to effect radial contraction of the ply-down fingers to turn the ply edge down over the end of the drum, then to set a tire bead against the turned down ply edge at the end of the drum, and then to push the bladder of the turn-up mechanism when inflated to cause the ply edge to be progressively wrapped around the bead and then over the drum.

Abstract: A mould particularly as used in the manufacture of a product from elastomeric material which is required to be heated.Preferably the heating is carried out by means of an electric current which may be induced electromagnetically.The product may be a tire.

Abstract: A rod gland (28) has axially extending inlet and outlet grooves (64,66) at circumferentially spaced positions on a cylindrical outer surface (34) and is provided with an annular seal (60) for preventing leaks between the grooves (64,66). The annular seal (60) is positioned in a groove (59) between an adapter hub (36) and a lower clamping ring hub (38) surrounding and in sliding engagement with the cylindrical outer surface (34) of the rod gland (28) so that at the inlet and outlet grooves (64,66) the sealing is on three sides of the annular seal (60) and between the grooves (64,66) the sealing is on four sides of the annular seal (60).

Abstract: A green tire vulcanizing press including a lower die having a heat source, an upper die capable of being opened and closed relative to the lower die and having a heat source, a shaping bladder received in a bladder well disposed in a central part of the lower die, and a hot pressure medium supplied into the bladder, the bladder well is made movable vertically and an upper clamp ring for the shaping bladder is held stationary while a lower clamp ring is provided vertically movably, whereby the shaping for a green tire as well as the separation of the bladder from the tire and removal of the tire after the vulcanizing press work are performed through vertical movements of the lower clamp ring and the bladder well under a fixed state of the upper clamp ring.

Abstract: A tube assembly for use in a process of vulcanizing a pre-cured tread onto a tire casing is disclosed. The tube assembly includes an elastomeric tubular wall having an inner periphery with a protective non-woven fabric layer covering a major portion thereof. The fabric layer includes a plurality of polyester cords extending in parallel relation in a single ply elastomeric matrix. Longitudinal edges of the fabric are covered by thin strips of elastomer bonded to the fabric layer and the tube wall. Superimposed fabric reinforcing swatches are bonded to the fabric layer around the valve stem. The tube assembly is resistant to being damaged prematurely by the rim which supports the tire casing in the tread vulcanization process.

Abstract: A method employing tool (10) for taking an impression of an area of the internal bore of a tubular member (16) or a joint between two such members comprising means for directing a casting compound between two flexible membranes (20, 22) which are then forced outwardly so that the outer membrane (22) engages the area to be inspected within a bore where the compound forms a resilient mold (cast). When the force against the membranes and mold is removed, the membranes and mold collapse allowing the mold and tool (10) to be retrieved out the bore.

Abstract: A tire manufacturing process of the type which employs a reusable rubber or the like curing bag or bladder. The process includes deflating, between curing cycles of the tire manufacturing process, the curing bag or bladder; preventing oxygen bearing medium entering the curing bag or bladder; and supplying a non-reactive medium upstream of the curing bag or bladder to maintain the bag or bladder in its unstretched state until the bag or bladder is next inflated.

Abstract: A tire press, loader and method employs a stationary bottom mold section and a vertically movable top mold section which moves upwardly to open the press clearing the area therebetween for discharge of the cured tire and loading of the green or uncured tire. The press loads the green tire initially into the top mold section centering and holding the top bead of the green tire on the bead ring of the top mold section. To position the uncured tire for such top loading there is provided a loader which engages the uncured tire at the lower shoulder of the tread area. The loader includes pivotally movable chuck sector assemblies, each mounted on a ring. The ring can readily be centered with respect to the axis of the mold sections and each assembly can be moved concurrently uniformly radially of the ring to accommodate tires of different sizes.

Abstract: A vulcanization method and press in which at time-spaced intervals of 1 to 40 seconds, temperature measurements representing increments of heat supplied to the vulcanizable body are taken of a medium used for vulcanization. A summation of the measurements continuously during the vulcanization process represents the heat supplied to the body and when the summed heat quantity equals the total heat quantity previously determined to be necessary for complete vulcanization, the process is terminated.

Abstract: Injection molding a tread on an annular tire casing (44) positioned in a mold (10') by introducing a fluid molding compound (76',78') at high pressures and high temperatures into a tread molding space (105) through runner passages (114) extending from an edge (116) to a centerplane (20'--20') of the mold (10') and having gates (118) opening into the tread molding space (105). Alternatively the runner passages (56,58) may be defined by annular runner surfaces (60,62,64,66) in communication with the tread molding space (48) through annular gates (52,54). The fluid molding compound (76,78) may be ejected from annular transfer recesses (68,70) in the mold (10) by squeeze rings (84,86) movable into the transfer recesses (68,70) to introduce the fluid molding compound (76,78) into the runner passages (56,58).

Abstract: A tire building machine and method employing a tire building drum for receiving at least one ply of tire material having an edge overhanging an axial end of the drum, a bladder turn-up mechanism extending axially outwardly from the drum, an annular array of radially contractible ply-down fingers movable axially to and from a position encircling the overhanging ply edge, and an axially movable ring device operative first to effect radial contraction of the ply-down fingers to turn the ply edge down over the end of the drum, then to set a tire bead against the turned down ply edge at the end of the drum, and then to push the bladder of the turn-up mechanism when inflated to cause the ply edge to be progressively wrapped around the bead and then over the drum.

Abstract: An improved method of loading green tires in a laterally aligned two chamber type tire curing press in which green tire loading devices for the respective chambers are provided in a movable manner at a center portion of the tire curing press. A green tire placing table is provided in a movable manner at a position in front of the center portion of the tire curing press. Positions in front of the respective chambers of the tire curing press are used as standby positions of the green tire loading devices. A position in front of the center position of the tire curing press is used as a green tire supply position onto the green tire placing table. Delivery of a green tire is effected either by moving the green tire loading device to the green tire supply position or by moving the green tire placing table to the standby position and then inverting the green tire onto gripping claws of the loading device. Green tires can be thereby successively loaded into the respective chambers of the tire curing press.

Abstract: A heat sealing apparatus for bonding plastic tubular members includes a seamless, tubular, elastic heating element encircling the plastic members. In one form, an annular inflatable bladder filled with hydraulic fluid encircles the heating element, and includes a rigid outer wall and an elastic inner wall that is bonded to the outer surface of the heating element. When the bladder is pressurized the heating element is compressed inwardly to a bonding position against the plastic members. The plastic members are then heated to a bonding temperature by the heating element resulting in a fusion bond along their interface. When the bladder is evacuated the heating element opens outwardly to be spaced from the plastic members to allow removal of the sealed members. The heating element includes a uniform dispersion of susceptor particles that will generate heat when exposed to the high frequency magnetic field of an induction heating coil. A method of heat sealing tubular plastic members is also disclosed.

Abstract: This disclosure relates to a method for preheating and preforming a green tire prior to final vulcanization of the tire. The method includes the steps of supporting the beads of a green tire between a pair of relatively cool discs to form a tightly closed space, moving the discs toward each other until the tire has a shape substantially the same as the final tire shape, supplying the space with a thermal medium, and heating the medium and the tire to a temperature substantially lower than that at which the vulcanization starts but high enough to preform the tire. A coolant is passed through the parts of the discs which engage the tire beads to prevent overheating of the beads.

Abstract: In a method for controlling a tire vulcanization of a vulcanizing apparatus, an initial green tire temperature is measured before vulcanization and a tire temperature during vulcanization is estimated on the basis of the thus measured initial tire temperature. In addition, a sum of products of vulcanizing rates derived from the thus estimated tire temperature is calculated so as to stop the tire vulcanization when the sum of products of vulcanizing rates becomes equal to a predetermined value. Therefore, the vulcanizing rate controlling can be performed in an easy and accurate manner without measuring the tire temperature during vulcanization, and thus a trace of a thermometer insertion is not remained on the vulcanized tire surface.

Abstract: An apparatus and method for cold retreading of the running surface of a vehicle tire. A rubber and cloth mold is produced utilizing a new tire male mold covered with perforated polyethylene film, uncured rubber and highly stretchable cloth enclosed in an envelope and cured by application of pressure and heat. The somewhat flexible female mold thus produced is then utilized in recapping tires by positioning it around a prepared tire carcass coated with cement, a layer of uncured rubber, and a sheet of perforated polyethylene film. The mold and tire assembly is then enclosed in an envelope, and like assemblies are placed in a chamber where curing of the rubber layer is accomplished by inflation of the tire carcass, evacuation of the envelope, pressurization of the chamber and application of heat.

Abstract: A simple economical multistage vulcanization process is disclosed for producing premium anomaly-free tires wherein the inner liner or curing bladder is supplied with dead end water and steam sequentially in several stages at high pressures which assure thorough diffusion of entrapped air. The internal steam pressure is 250 to 300 psig in stage I to effect rapid heat transfer, the internal water pressure in stage II is from 300 to 450 psig, and the internal steam pressure is 250 psig or higher in the first part of stage III. The overall cycle time for curing radial passenger car tires in "Bag-O-Matic" presses is reduced one minute or more by using internal steam pressures from 250 to 300 psig in stage I and III and reducing the steam pressure near the end of stage III to boil off the residual water.

Abstract: For folding an annular resilient band about a circumferential fold line, the band is first wrapped on a generally cylindrical, radially collapsible drum structure having a cylindrical external contour about the center axis of the drum and an annular zone radially inward of the contour with an inflatable annular first bladder positioned in such a manner as to have a folded-over axial end portion axially protruding into the aforesaid annular zone and with an inflatable annular second bladder positioned radially inwardly of the first bladder and in such a manner that the first and second bladders have axial portions overlapping each other, whereupon the first bladder is inflated to a medium expanded state so that an axial end portion of the band on the drum structure is contacted by the bladder and displaced radially outwardly and thereafter the first bladder is moved axially away from the drum structure for forming an annular gap between the first bladder and the axial end portion of the band, the second bladde

Abstract: A method for insulating a water heater with foamed insulation comprises inflating a tube in the cavity between the shell and the tank to define a boundary for the cavity into which the insulating material is injected. The device is deflated after the foamed insulation has set in the cavity. Apparatus for carrying out such method is provided.