MXPA98001767A - Injection molding of a component of lla - Google Patents

Abstract

The present invention relates to an apparatus for injection molding an elongated component of an elastomeric material, comprising: (a) a mold assembly having a cold plate and a heated mold mounted on the cold plate; injection to heat, mix and inject the elastomeric material into the mold assembly, (c) a plurality of slides in the cold plate, to communicate the material from the injection apparatus with the heated mold, (d) a generally elongated collector, defined by heated opposing surfaces of the mold connected to the slides in the cold plate; (e) an elongated mold cavity, adjacent to the elongated manifold, defined by the opposite heated surfaces of the mold; (f) a shoulder area between the elongate manifold and the elongated mold cavity, defined by the opposing surfaces of the heated mold, and having a narrow elongated opening that is provided for heating and cutting the material as measured. to which is injected to the elongated mold cavity, to increase the temperature and decrease the healing time of the elastomeric material

Description

INJECTION MOLDING OF A RIM COMPONENT BACKGROUND OF THE INVENTION Car and truck tire manufacturers require the pre-assembly of certain tire components, assembling the components in a tire building machine and vulcanizing the rim components assembled in a tire press. Two of the components, which are obtained before assembly in the tire building machine, are the apex assembly of the rim flange and the tread of the rim. These components, which have been made of unvulcanized rubber, are relatively thick and the extra time required to cure the rubber in them has increased the time required to cure the tire in the press of the same. Likewise, the uncured apex tab assembly may be distorted during the construction of the rim or during transport of the rim to the vulcanizer thereof. The unvulcanized tread is also subject to distortion during assembly and vulcanization. It has been found that the uniformity of the cured rim can be improved and the healing time in the rim press can be reduced by constructing a rim with previously vulcanized eyelash apex assemblies and / or a previously vulcanized tread.

SUMMARY OF THE INVENTION In accordance with this invention, the rim components, such as the apex assemblies of the flange and the treads of the rim, are injection molded, providing semi-vulcanized rim components molded to dimensions precise and that do not require an additional time of healing in the press of the rim. This is achieved by injecting an elastomeric material, such as rubber, into the molds, which have the component configuration on the finished rim. The time required to cure the rubber injected into the injection molding apparatus is reduced by increasing the temperature of the elastomeric material as it is injected through a narrow gate opening into the mold cavity. The temperatures of the elastomeric material before reaching the mold are controlled by heating and cooling the passages leading to a collector, generally circular, adjacent to the gate. By injecting the elastomeric material into a manifold, surrounded by the mold cavity, the weld lines in the molded components can be avoided, by positioning the manifold so that some portions are closer to the mold cavity than others, whereby the Pressure in the mold cavity is the same at all points along the edge of this cavity. The tab of the apex assembly may be supported by sheet elements on the surface of the mold, which form slits in the assembly, which are filled during the vulcanization of the rim. The apex assembly of the flange can be removed from the mold with an unloaded ring, communicating a vacuum to this ring to retain the apex assembly of the flange during removal. According to one aspect of the invention, a method for injection molding a circular rim component is provided, which comprises: (a) heating and mixing an elastomeric material; (b) injecting the elastomeric material into a plurality of runners in a cold block of a mold assembly; (c) controlling the temperature of the elastomeric material in the corridors in the cold block; (d) communicating the elastomeric material from the corridors to a collector, generally circular, in a heated mold, having corresponding opposite surfaces; (e) communicating the elastomeric material from the circular collector, through a shoulder area, to a mold cavity and subjecting the material to cutting and contacting the surface of the heated mold, in order to increase the temperature of the material from 116 to 166SC, more or less lisc, to accelerate the healing of the material; (f) cure the elastsmeric material for a certain period of time; (g) open the mold; and (h) removing the tire component from the mold.

According to another aspect of the invention, an apparatus for the injection molding of a circular rim component of elastomeric material is provided, this apparatus comprises: (a) a mold assembly, having a cold block and a heated mold, mounted on the cold block; (b) an injection apparatus, for heating, mixing and injecting the elastomeric material into the mold assembly; (c) a plurality of runners in the cold block, for communication of the material from the injection apparatus to the mold; (d) a collector, generally circular, defined by the opposite faces of the mold, connected to the runners in the mold; (e) a mold cavity, radially outwardly of the manifold, defined by the opposite faces of the mold and (f) a shoulder area, between the manifold and the mold cavity, defined by the opposite surfaces of the mold and having a narrow opening that supplies the heating and cutting of the material, as it is injected into the mold cavity, to increase the temperature and decrease the curing time of the material.

BRIEF DESCRIPTION OF THE DRAWINGS To familiarize persons skilled in the art most closely related to the present invention, certain preferred embodiments, which illustrate the best modes now considered for practicing the invention, are described herein by and with reference to the attached drawings, which are part of the specification. The modalities shown and described herein are illustrative and as they will become apparent to those skilled in the art, they can be modified in numerous ways within the spirit and scope of the invention, as defined in the claims thereof. In the attached drawings: Figure 1 is a fentary sectional view, with parts in section and separated from a cold block and the mold of the single apex assembly embodying the invention; Figure 2 is a fentary plan view of the lower half of the mold shown in Figure 1; Figure 3 is a fentary, enlarged schematic view of the mold shown in Figure 1, illustrating the sheets for supporting and attaching the flange; Figure 4 is an enlarged sectional view, similar to Figure 1, showing the manifold, the protrusion and injection passage in the mold cavity; Figure 5 is a fentary plan view, similar to Figure 2, showing a modified manifold and shoulder, for the lower mold half, to provide an equal drop in pressure from the mold inlets to the mold cavity. mold; Figure 6 is a schematic elevation in section of an injection molding apparatus, screw type, for a tread pattern of the rim in the mixing position of the extruder barrel; Figure 7 is a view similar to Figure 6, showing the apparatus with the extruder barrel in the loading position; Figure 8 is a plan view of the distribution plate and cold plate, illustrating the cold runner system, taken along line 8-8 in Figure 6; Figure 9 is a fentary cross section of the nozzle, cold plate assembly, and mold sprue plate, of the apparatus shown in Figures 7 and 8, taken along the plane of line 9-9 in Figure 8. , which shows one of the tubes with the cooling passages; Figure 10 is an end view of the tube, taken along line 11-11 in Figure 9, with parts in section and separated; Figure 11 is an enlarged sectional view, similar to Figure 4, showing the boss of the manifold and the narrow opening in the injection gate for the tread mold, shown in Figure 9; Figure 12 is a fentary sectional view of a plurality of stacked mold plates for the simultaneous injection of a plurality of flange apex assemblies, using the injection molding apparatus of Figures 6 and 7; Figure 13 is a plan view of the bottom mold plate of the assembly shown in Figure 12, illustrating the collector and the shoulder;Figure 14 is a schematic sectional view showing a discharger for the flange apex assembly. Referring to Figures 1, 2, 3 and 4, there is shown a mold assembly 10, having a heated lower half of mold 12, and an upper heated mold half 14, which supply a mold cavity 16 for the injection molding of a circular rim component, such as a flange apex assembly 18. The mold assembly 10 is mounted on a sprue plate, which is attached to a cold block 22, which has cooling passages 24. The cold block 22 can be mounted on an input block (not shown) for coupling with an injection molding apparatus and communicates with an elastomer under pressure to a distribution block 28, through an inlet passage 30. Runners 32, extending radially, circumferentially spaced apart, communicate the elastomer under pressure from the distribution block 28 to the nozzles 34 in engagement with the metal sprues 36, circumferentially spaced on the sprue plate 20. The number of runners 32 can vary and, in this modality, there are six runners. The passages 38 in the upper mold half 14 are connected to the metal sprues 36 and communicate the elastomer under pressure in the lower mold half 12. An enlarged cross-section of the manifold 40 is shown in Figure 4. Between the manifold 40 and the mold cavity 16, a circular shoulder area 42 is provided in the lower mold half 12, which defines an injection passage 44 with the opposite faces of the upper mold half 14. The injection passage 44 extends radially outwardly in the mold cavity 16. A raised circular rib 46 is placed over the shoulder area 42 for further restriction of the flow of the elastomer through passage 44 and thus increases the temperature of the material due to exposure to the surfaces. heated from the upper mold half 14 and the lower mold half 12 and due to the shearing force of the material. This can increase the material temperature from 115 to 1652C ± 112C). The increased temperature increases the cure rate of the elastomer, which reduces the healing time of the apex assembly 18 of the flange, necessary to stay in the mold assembly 10. The elastomeric material is preferably cured for a predetermined amount of time by passing the blowing point of the material upon removal from the mold component. On the scale of the rheometer, this is around T-25.

Referring to Figures 2 and 3, the support sheets 48, circumferentially spaced, are mounted on the half 12 of the lower mold and the half 14 of the upper mold, on the internal surface radially of the mold cavity 16 to support a beam of tabs 50, when the assembly 10 of the mold is closed. The sheets 48 support the bundle of flanges 50 in the position spaced from the surface of the cavity 16 of the mold, so that when the elastomer is injected into the mold cavity, the internal diameter 52 of the bundle of tabs is uniformly coated. A flap, normally used to separate the eyelash wires from the layered wires in a tire, may also not be required. The rounded inner contour of the eyelash bundle 50 also allows the layer wires to move uniformly during configuration. In addition, the support sheets 48 place the eyelash bundle 50 in position, so that injection against the face of the internal diameter of the flange will place this flange in tension, preventing twisting of the wires in the eyelash bundle. As shown in Figure 2, each of the support sheets 48 is positioned at an angle α of 45 degrees to the radius R of the mold assembly 10. In this position of the blades 48, the resulting grooves in the flange apex assembly 18 extend in a direction different from the direction of the layer cords wrapped around the flange apex assembly 18 on the rim constructed with this assembly, so the laces of the layers will not be pulled into the slots. The support sheets 48 are also tapered to facilitate removal of the flange apex assembly 18 from the lower mold half and the upper mold half 14 upon opening the mold assembly 10. Referring to Figure 5, a modified lower mold half 54, having a modified manifold 56, is shown. Where the parts are the same as in set 18, shown in Figures 1, 2, 3 and 4, they will be identified with the same number and a premium mark. The inlets 58 of the runner are in circumferentially spaced positions, corresponding to the positions of the nozzles 34 shown in Figure 1. Each of the inlets 58 is at the same radial distance from the edge of the mold cavity 16 '. The manifold 56 is inclined from a circular configuration, shown by the line C to the radially outward positions, P, between the inlets 58. The location of the collector positions P is halfway between the inlets 58 and closer to the mold cavity 16 'by a distance sufficient to supply an elastomeric pressure to the mold cavity 16', which is substantially equal to the pressure at the edge of the mold cavity in the T positions, which are radially outward from the inlets 58. Between the inlets 58 and the positions P, the collector positions Q, R and S are also closer to the mold cavity 16 'than the inlets 58 for distances to supply a substantially equal elastomeric pressure at the edge of the cavity of mold 16 '. The radial locations in the collector positions Q, R and S can be calculated by determining the pressure drop per centimeter of the elastomeric material passing through the collector 56 and the pressure drop per centimeter of the material passing through the injection passage. 44 *. The pressure drop in "T" can be determined by multiplying the distance U between the inlets 58 of the runner and the edge of the cavity 16 'by the pressure drop per centimeter in the injection passages 44'. This same pressure is then provided in positions corresponding to Q, R and S locating the collector 56 in a radial position relative to the cavity 16 ', so that the sum of the pressure drop in the collector 56 and the pressure drop in the injection passageway 44 'is equal to the pressure drop in the position T. Therefore, locating the collector 56, as indicated by the injection pressure in all positions around the cavity 16', will be substantially the same. same and welding lines in the injected rim component, such as in the apex assembly 18 of the flange will be substantially eliminated With reference to Figures 6 and 7, a manifold injection molding apparatus 65 is shown, for molding by injection a rim component of an elastomeric material, such as a rubber tread, in the mixing position (Figure 6 ^ and the injection position (Figure 7). to have a mold plate 70 in motion, mounted on a movable piston plate 72, connected to a mold cylinder 74 for holding the mold 68 between the mold plate 70 and a fixed press plate 76. The mold 68 segmented of the tread includes a core 78, a bead block 80, a plurality of radially movable mold segments 82, a sprue plate 84, a cold plate 86 and a distribution block 88. A nozzle cylinder 90 is mounted on the fixed press plate 76 and has an extruder cylinder 92, slidably movable in the cylinder, between the mixing position, shown in Figure 6 and the injection position, shown in Figure 7. The extruder cylinder 92 is part of a extruder 94 having an extruder screw 98. This extruder 94 is mounted on double-acting cylinders 100, which contain pistons (not shown) connected to piston rods 102., attached to the fixed press plate 76, whereby the extruder 94 and the extruder cylinder 92 can be moved towards and away from the mold 68 of the tread. As shown more clearly in Figure 9, the doors 103, spaced circumferentially in the distribution block 88, extend from the centrally located cavity 124 to the tubes 125, which have channels 104 in communication with the mold nozzles 106. spring loaded, abutting the sprue plate surface 107 of metal and surrounding openings 108 which are in communication with the manifold 109, generally circular, in the metal sprue plate 84. As shown in Figure 11, the manifold 109 is in communication with a mold cavity 110 through an injection passage 112, between the shoulder areas 114 and the core 78 of the mold. A circular rib 116 may be provided in the shoulder area 114 to further restrict the flow of the elastomeric material through the passageway 112. Reference is made to Figures 6 and 7, a feed opening 118 is provided in the extruder barrel 92 for feeding the elastomeric material into the cylinder and a motor 120 is connected to the screw 98 to rotate the screw and mix the material. As mixed, the material is communicated by the screw 98 to a cavity 124 centrally positioned in the distribution block 88, as shown in Figure 6. At the same time, the extruder 94 can be moved away from the fixed plate 76. Press with the injection cylinders 100 to the position shown in Figure 6. Then, the hydraulic fluid communicates to the injection cylinders 100, causing them to move to the position shown in Figure 7 and communicate the elastomeric material from the cavity 124 to the mold cavity 110. In figures 8, 9 and 10, the distribution block 88, the cold plate assembly 86, the sprue plate 84 and the tread mold are shown, as well as that an enlarged view of one of the tubes 125 for the channels 104. Figures 9 and 10 also illustrate the configuration of the cooling passages 126, generally spiral, arranged adjacent to the tubes 125. The passages 126 carry a refrigerant and extend from an inlet 127 in a first position 128, upstream from the manifold 108 to a second position 130, further upstream of the manifold, back to a third position 132, adjacent to the manifold and then back to the first position, where the coolant is led away by an outlet 129. In this way, the elastomeric material is injected through the channels 104 first cooled into the second position 130, where it enters the channels with the coolant at the lowest temperature. low and then as the material passes through the channels continues cooling with the coolant, which is hotter and does not cause a drop in the temperature of the material, which would adversely affect the healing of the elastomeric material, after entering the cavity of the mold. In other words, scorching of the material is avoided without causing an inconvenient drop in the temperature of the elastomer. As shown in Figures 9 and 10, the annals 104 and the cooling passages 126 are each enclosed in one of the tubes 125, having a spherical end 136, for the sealed coupling with a female bushing 138 in a distribution block 140. Each tube 125 may have a flange 142 with screws 144 extending through the flange and threaded into the cold plate 86 to push the spherical end 136 into the female bushing 138 and thus provide a seal. The flange 142 can also be screwed to the cold plate 86 by screws 145 to retain the tube 125 in sealed engagement. As shown in Figure 9, a pin 147 on the bottom side of the rim 141, is in sliding engagement with a groove 149 in the cold plate 86, to provide alignment.

The refrigerant circulated in the cooling passages 126 can be controlled by a separate cooling system, which includes a separate pump and thermostat, to supply the most desirable coolant temperature and flow the elastomer passing through the channels 104. Likewise, separate cooling systems can be provided to control the cooling passages 180 in the distribution block 140 and the cooling passages 24 in the cold plate, so that the temperature of the injected elastomer can be controlled in different locations to supply high temperatures without scorched, for the fast flow of the elastomer. Referring to Figure 12, a stacked mold 150 is shown, which has a distribution plate 151, which can be mounted on a fixed press plate 76 of an injection molding apparatus, such as the apparatus 65. , shown in Figures 6 and 7. The mold 150 has a cylindrical core 152, generally tapered, for supporting a bottom mold plate 153, a top mold plate 154 and an intermediate mold plate 155. Runners 156, circumferentially spaced, extend from a nozzle chamber 157 to the inlet passages 158 in the core 152, which are in alignment with the runner inlets 160 in the mold plates 153, 154 and 155. As shown in FIG. Figure 11, the corridor entries 160 are connected to the manifold 162, which is connected to a mold cavity 164 by an injection passage 166, defined by a shoulder area 168 on the respective mold plates 153, 154 and 155, spaced from a corresponding surface 169. As shown in Figures 12 and 13, the bottom mold plate 153 is secured to the distribution plate 151, while the intermediate mold plates 155 and the upper mold plate 154 can be raised and displaced from the core 146 for the removal of a molded rim component, such as the flange apex assembly 170 from the mold cavity 164. The number of molded rim components that are molded together can be changed by increasing or decreasing the thickness of the bottom mold plate 153 and adding or decreasing the number of intermediate mold plates 155. Referring to Figure 14, the upper mold plate 154 is shown after opening the stacked mold 150, which shows the flange apex assembly 170 after injection and still retained in the mold cavity 164. A ring 172 discharger it can be moved in an abutting position with the flange apex assembly 170 and may have sealing rings 174 at the edges for engagement with the surface of the assembly 170. A plurality of apertures 176 circumferentially spaced in the annulus 172, disposed between sealing rings 174, are in communication with a vacuum source through the passages 178. In operation, a vacuum is communicated to the passages 178 to pull the flange apex assembly 170 out of the mold cavity 164, against the ring 172 download, without distorting the whole. The discharge ring 172 is then movable to a spaced position of the upper mold plate 154, where the assembly can be stored or used to build a rim. This same discharge ring 172 can be used in conjunction with the intermediate mold plates 155 of the embodiment shown in Figure 12., or with the upper mold half 14 of the embodiment shown in Figure 1. In this way, this rim component, which is partially vulcanized, can be removed from the mold and handled without distortion, which is important for manufacturing of high precision rims. The invention has been described with reference to a preferred embodiment. Obviously, modifications and alterations to others of the reading and understanding of this specification will be evident. It is intended to include all these modifications and alterations as they fall within the scope of the appended claims or their equivalents.

Claims (32)

1. CLAIMS 1. A method for injection molding a circular rim component, this method comprises: (a) heating and mixing an elastomeric material; (b) injecting the elastomeric material into a plurality of runners in a cold plate of a mold assembly; (c) controlling the temperature of the elastomeric material in the runners in the cold plate; (d) communicating the elastomeric material from the corridors to a collector, generally circular, in a heated mold, having corresponding opposite surfaces; (e) communicating the elastomeric material from the circular collector, through a shoulder area, to a mold cavity and subjecting the material to cutting and contacting the surface of the heated mold, in order to increase the temperature of the material from 116 to 166sc, more or less lisc, to accelerate the healing of the material; (f) cure the elastomeric material for a certain period of time; (g) open the mold; and (h) removing the tire component from the mold.
2. 2. The method of claim 1, wherein the rim component is a tread of the rim and the cooling of the cold plate includes supplying the flow of a coolant in passages in the cold plate, adjacent to each of the runners, characterized in that the flow is directed from a first position, downstream of the collector, to a second more downstream of the collector, back to a third position adjacent to the collector and then to a position adjacent to the first position. The method of claim 1, further characterized in that the rim component is a flange and apex assembly, and this flange is placed in the mold cavity and can be engaged with the sheets extending outwardly from a surface radially. internal of the cavity, to support the flange during the injection of the elastomeric material into the cavity. The method of claim 3, further characterized in that the shoulder area is in communication with the mold cavity in radially inward positions, around the mold cavity, to position the flange in tension and to coat an internal side radially of the flange with the elastomeric material in the injection of this elastomeric material into the cavity. 5. The method of claim 1, further characterized in that the rim component is cured for a predetermined period of time, past the point of blowing of the material, before removing the component from the mold. The method of claim 3, further characterized in that the sheets are positioned so that the resulting grooves in the flange apex assembly = < = > extends in a direction other than the direction of the laces of the layer wound around this flange apex assembly on a rim constructed with the assembly, so that the cords are not pulled into the slots. The method of claim 1, further characterized in that the elastomeric material is communicated to the manifold at a plurality of equally spaced corridor inlet positions and then communicated through the collector section and a corresponding section of the ledge area, having a configuration whereby the sum of the pressure drop in the collector section and the pressure drop in the corresponding section of the shoulder area, from the runner inlets to the mold cavity, is substantially the same in all positions circumferentially of the mold cavity. The method of claim 1, further characterized in that the section of the manifold is bent from a circular position towards the mold cavity, whereby the elastomeric material undergoes a lower pressure drop in the shoulder area, as circumferentially communicated in distance from the entry positions. 9. A method for injection molding a circular component of an elastomeric material, this method comprises: (a) heating and mixing an elastomeric material; (b) injecting the elastomeric material into a plurality of runners in a cold plate of a mold assembly; (c) controlling the temperature of the elastomeric material in the runners in the cold plate; (d) communicating the elastomeric material from the corridors to a collector, generally circular, in a heated mold, having corresponding opposite surfaces; (e) communicating the elastomeric material from the circular collector, through a shoulder area, to a mold cavity and subjecting the material to cutting and contacting the surface of the heated mold, in order to increase the temperature of the material, to accelerate the healing of the material; (f) cure the elastomeric material for a certain period of time; (g) open the mold; and (h) removing the tire component from the mold. The method of claim 9, further characterized in that the circular component is cured for a predetermined period of time by passing the blowing point of the elastomeric material, before removing the component from the mold. The method of claim 9, further characterized in that the elastomeric material is communicated to the manifold at a plurality of equally spaced corridor inlet positions, and then communicated through a manifold section and a corresponding section of the manifold area. I emphasize that it has a configuration whereby the sum of the pressure drop in the collector sections and the pressure drop in the corresponding sections of the shoulder area from the runner inlets to the mold cavity is substantially the same in all the positions circumferentially of the mold cavity. 12. A method for injection molding an elastomeric material component, this method comprises: (a) heating and mixing an elastomeric material; (b) injecting the elastomeric material into a plurality of runners in a cold plate of a mold assembly; (c) controlling the temperature of the elastomeric material in the runners in the cold plate; (d) communicating the elastomeric material from the corridors to a collector, generally circular, in a heated mold, having corresponding opposite surfaces; (e) communicating the elastomeric material from the circular collector, through a shoulder area, to a mold cavity and subjecting the material to cutting and contacting the surface of the heated mold, in order to increase the temperature of the material, to accelerate the healing of the material; (f) cure the elastomeric material for a certain period of time; (g) open the mold; and (h) removing the tire component from the mold. The method of claim 12, further characterized in that the elastomeric material is communicated to the manifold at a plurality of equally spaced inlet corridor positions, and then communicated through a manifold section and a corresponding section of the manifold area. I emphasize, that it has a configuration whereby the sum of the pressure drop in the collector section and the pressure drop in the section of the shoulder area, from the entrances of the runner to the mold cavity, is substantially equal in all positions along the length of the elongated cavity. 14. Apparatus for the injection molding of a component of elastomeric material, this apparatus comprises: (a) a mold assembly, having a cold plate and a heated mold, mounted on the cold plate (b) an injection apparatus, for heating, mixing and injecting the elastomeric material into the mold assembly; (c) a plurality of runners in the cold plate, for communication of the material from the injection apparatus to the mold; (d) a collector, generally circular, defined by the opposite faces of the mold, connected to the runners in the mold; (e) an elongated mold cavity, adjacent the elongate manifold, defined by the opposite faces of the mold and characterized by: (f) a shoulder area, between the manifold and the mold cavity, defined by the opposite surfaces of the mold and having a narrow opening that supplies the heating and cutting of the material, as it is injected into the mold cavity, to increase the temperature and decrease the healing time of the elastomeric material. Apparatus, according to claim 14, in which the collector, generally elongate, is connected to the pins in the spaced corridor inlet positions, along the collector, further characterized in that the collector and the shoulder area have a configuration whereby the sum of the pressure drop in one section of the manifold and the pressure drop in the corresponding section of the shoulder area is substantially equal in all positions along the elongated mold cavity. 16. Apparatus, according to claim 15, further characterized in that the manifold is curved towards the mold cavity, between the entry positions of the runner, whereby the elastomeric material undergoes a smaller pressure drop in the shoulder area, as communicates circumferentially away from the entrance positions of the corridor. Apparatus, according to claim 14, further characterized in that the elongate component is a circular rim component and the manifold is circular, with the mold cavity positioned radially oudly of the manifold. 18. Apparatus, according to claim 17, wherein the rim component is a tread of the rim and the cold plate includes cooling passages, disposed adjacent to the runners, further characterized in that at least one of the passages is extends dOC = from a first position, upstream of the collector, to a second position, more upstream from the collector, back to a third position, adjacent to the collector and then to a position adjacent to the first position. The apparatus of claim 17, wherein the rim component is a flange and apex assembly, characterized in that the mold cavity has a plurality of spaced blades, embedded in the radially internal surface of the mold, to support the flange of the mold. assembly during the injection of the elastomeric material into the mold cavity. Apparatus, according to claim 19, further characterized in that the blades are inclined in a direction different from the direction of the cords of the layers wound around the flange apex assembly on a rim constructed with this assembly. 21. Apparatus, according to claim 20, further characterized in that the sheets are tapered to facilitate the removal of the flange and apex assembly from the mold assembly. 22. Apparatus for the injection molding of an elongated component of an elastomeric material, this apparatus comprises: (a) a mold assembly, having a cold plate and a heated mold, mounted on the cold plate (b) a injection apparatus, for heating, mixing and injecting the elastomeric material into the mold assembly; (c) a plurality of runners in the cold plate, for communication of the material from the injection apparatus to the mold; (d) characterized by a manifold, generally elongated, defined by the opposite faces of the mold, connected to the runners in the mold; (e) an elongated mold cavity, adjacent the elongated manifold, defined by the opposite faces of the mold and (f) a shoulder area, between the manifold and the mold cavity, defined by the opposing surfaces of the mold. 23. Apparatus for the simultaneous injection molding of a plurality of circular rim components of elastomeric material, characterized by: a mold assembly, with a cylindrical core; a bottom cylindrical mold plate, mounted on the cylindrical core; a plurality of intermediate cold plates, mounted on the bottom mold plate; an upper mold plate, mounted on the upper part of the intermediate mold plates; the mold assembly is connected to an injection apparatus for heating, mixing and injecting the elastomeric material into the mold cavities defined by the opposite faces of the upper part, intermediate and bottom mold plates, a plurality of runner inlets in the mold plates, in communication with the circular manifolds, defined by the opposite faces of the upper mold plate, this bottom mold plate and the intermediate mold plates and the shoulder areas between the manifold and the mold cavities they are defined by the opposite faces of the upper mold plate, the bottom mold plate and the intermediate mold plates. 24. The apparatus of claim 23, further characterized in that the upper mold plate and the intermediate mold plates can be moved away from the bottom mold plate to discharge the circular rim components from the mold assembly. The apparatus of claim 17, wherein the mold can be separated into at least two mold plates, so that the circular rim component adheres to one of the mold plates during the opening, further characterized by a ring discharge, which has a movable retaining surface in abutting position with one of the rim component, sealing rings on the edges of the retaining surface, and vacuum elements in communication with the retaining surface, to retain one of the the rim components on the discharge ring and elements for moving the discharge ring with one of the rim components to a discharge position, spaced from the mold assembly. 26. Apparatus for the injection molding of a circular component of an elastomeric material from a source of material under pressure, positioned radially inside the component, this apparatus comprises: (a) a mold assembly, having a cold plate and a heated mold, with a circular mold cavity, mounted on the cold plate (b) a centrally located distribution block, having a cavity, centrally positioned, for direct communication with the circular mold cavity; (c) a plurality of tubular members, circumferentially spaced, extending between the distribution block and the mold and having channels in communication with the centrally placed cavity; characterized in that (d) the mold assembly has a plurality of corridors, in communication with the channels, and a circular collector within the mold; and (e) a shoulder area, between the manifold and the mold cavity, defined by the opposite faces of the mold for communication of the elastomeric material from the manifold to the mold cavity. The apparatus of claim 26, further characterized in that the source of the material under pressure is an extruder cylinder and the screw assembly with the screw can be moved in and out of the centrally placed cavity, to fill and empty the cavity, and the pressure element to move the screw assembly. 28. The apparatus of claim 27, further characterized in that the pressure element comprises a hollow cylinder and the piston assembly is in communication with a source of fluid under pressure. 29. The apparatus of claim 26, further characterized in that each tubular element has a spherical end, for seating within a bushing in the distribution block, and the screw element for retaining the tubular elements against the distribution block. 30. The apparatus of claim 29, further characterized in that the circular component is a rim component and the shoulder area has a circular rib, for further restriction of the flow of the elastomeric material through the shoulder area passage, increase the temperature and decrease the healing time of the elastomeric material injected into the circular mold cavity. The apparatus of claim 26, further characterized in that the tubular elements include cooling passages and at least one of the passages extends from a first position, upstream of the collector, to a second more upstream position of the collector, again to a third position, adjacent to the collector and then a position adjacent to the first position. 32. Apparatus and method, substantially as described herein or as shown in the accompanying drawings.