WO1981003146A1

WO1981003146A1 - Method for forming a tube article on a core

Info

Publication number: WO1981003146A1
Application number: PCT/US1980/000492
Authority: WO
Inventors: R Satzler
Original assignee: Caterpillar Tractor Co; R Satzler
Priority date: 1980-04-28
Filing date: 1980-04-28
Publication date: 1981-11-12
Also published as: JPS57500502A

Abstract

A method for forming an elastomeric tube on a core (20) wherein a core (20) is loaded into a vacuum chamber (14, 114) in a vacuum container (10, 110); an elastomeric sheet (36) is placed thereover and sealed around the edge of said container; the core (20) is pressed into the sheet (36) an a vacuum is created in the vacuum chamber (14, 114); the sheet (36) is stitched to the core (20); excess elastomeric material is trimmed away and removed; and the core (20) is turned over with the above steps repeated to form the other side of the tube. The container in which the core (20) is placed may be either moved in a closed path between the tools which perform the steps or it may be stationary with the tools moved to it.

Description

Method for Forming a Tube Article on a Core

Technical Field

This invention relates to a method for applying sheets of elastomeric material to a core, and more particularly, to such a method either for moving a core from tool station-to-tool station for applying the sheet or for moving the tools to a fixed core location.

Background Art The C E. Grawey U. S. Patent No. 3,606,921, issued September 21, 1971, entitled "Belted Oval Pneumatic Tube-Tire" (assigned to the assignee of this application), discloses a novel pneumatic tube tire. Such a tire is generally constructed by wrapping a continuous tape of elastomeric material about a core of a disintegratable material to form a tube member. After sufficient thickness of elastomeric material is built up on the core, a winding of inextensible filament is wound about the tube member whereupon further layers of elastomeric material is applied to form the final tube tire as illustrated therein. At the appropriate time, the core is disintegrated and removed from within the tube tire.

Of particular importance in the manufacture of such a tire as disclosed in said patent is the proper formation of the oval, toroidal tube member on the disintegratable core, in preparation for the wrapping of the filament material thereabout. The method and the apparatus for practicing such manufacture should be as simple and effective as possible, especially considering that the core which is used may be extremely heavy and large.

It will be understood that as an improvement over the method of wrapping a continuous tape onto a core, an annular strip or sheet of elastomeric material was applied to each side of the core with each strip on one side overlapping with the strip on the other side. One or more complete layers of the strips of elastomeric material are applied to the core to form a tube member. Apparatus for applying the strips or sheets of elastomeric material is shown in the U. S. Patents 4,044,085, issued August 23, 1977, entitled "Method for Forming a Tube Article on a Core", and 4,053,272 issued October 11, 1977, entitled "Apparatus and Method for Forming a Tube Article on a Core", to C. E. Grawey and assigned to the common assignee of the present application. While it is clear that such strips or sheets of elastomeric material forming the side wall portions of the toroidal tube member can also be applied by hand, it will be understood that such hand application is a relatively time-consuming operation, and must be done with extreme care and with special tools.

The above-mentioned U. S. Patents No. 4,044,085 and No. 4,053,272, disclose apparatus for vacuum forming of a toroidal tube member. Since only one layer or one sheet of material is applied on one side per cycle, the application of one sheet at a time must be repeated several times to form a multilayered tube member. It has been necessary to use many different types of material handling equipment to initially load the core in the apparatus for performing the first application of a sheet. The material handling equipment must then be used to turn the core for a second and subsequent applications. Finally, the core with the several layers of elastomeric material is removed from the apparatus, ready for subsequent processing. This has resulted in a relatively slow and inefficient use of the tools, with an attendant slow rate of manufacture of the tires.

The present invention is directed to overcoming one or more of the problems as set forth above.

Disclosure of Invention

One aspect of the present invention is a simplified method of forming a tire or tube carcass around a core, the steps of which are to load a core into a vacuum chamber, place an elastomeric sheet over that chamber, seal the sheet around the edge of the chamber, press the core into the sheet and evacuate the chamber, stitch the sheet to the core to partially cover the core, trim away excess portions of the sheet, remove the excess elastomeric material, turn over the partially wrapped core, and repeat the above steps as necessary to form the desired number of layers. of elastomeric material on the core.

Previous methods for forming a tube article on a core by shaping elastomeric material onto one half of a toroidal core have been relatively slow and inefficient requiring frequent handling of the core using generally available material handling equipment. With the present method, the core is loaded in a chamber which can easily carry the core between a plurality of tool stations where, at each station, an. operation is performed on the core, thereby resulting in a more efficient use of the tools and a faster rate of manufacture of the tires. in an alternative method, the core is loaded in a chamber surrounded by various tools, with each tool advancing into position to perform a desired function on the core before it is retracted and the next tool advances to perform its function until the core is wrapped with the desired number of layers of elastomeric material. A third method incorporates both moving the core from one tool station to the next, and moving a tool to the core as the core is held in one location until a completely wrapped core is produced.

Brief Description of Drawings

Fig. 1 is a top view showing the layout of an apparatus employing one of the preferred embodiments of the invention;

Fig. 2 is a schematic view indicating the steps of the embodiment shown in Fig. 1;

Fig. 3 is a cross-sectional side view of the vacuum chamber as used in the apparatus of Fig. 1 and as in position prior to forming the sheet on a core; Fig. 4 is a view similar to Fig. 3 but showing the elastomeric sheet as applied to a core and prior to severing; and Fig. 5 is a schematic view of a second preferred embodiment of the invention wherein a vacuum chamber- remains stationary.

Best Mode for Carrying Out the invention The inventive steps and apparatus for use in carrying out one preferred method of forming a tube article on a core are shown in the figures. The basic component of the apparatus is a vacuum container 10, shown in Figs. 3 and 4 , which has a rectangular or cylindrical shape with an outwardly extending lip or rim 11 and has a center member 12 topped by a circular support platform 13. The walls of the container 10 and the center member 12 form an annular vacuum chamber 14 in which is located a vertically movable annular support member 16. Figs. 1 and 2 show a four-station machine having a closed path for movement of the vacuum container 10 with the various steps of the method carried out at succeeding stations.

To begin the tire forming process, an empty vacuum container 10 is brought to a first or initial station 18 where a load, unload and turn over apparatus or tool 21 is located, see Figs. 1 and 2. A toroidal core body 20 (Figs. 3 and 4), is delivered either by conveyor, dolly, or the like, (not shown) to a delivery station 19, which station 19 is within reach of a pivoted robot 27 of the tool 21. The robot 27 includes an overhead boom 22 rotatable around a base 24, as shown in Fig. 1, and has a core-engaging mechanism 25 that grasps the core 20 without scuffing the surface. The robot 27 lifts the core whereupon the core is automatically centered and moves the core either to any one of several horizontally spaced locations, or turns the core top-to-bottom. Specifically, the robot 27 grasps a core that is either at the delivery station 19 or is in the vacuum container 10 at the first or initial station 18, and lifts the core 20 whereupon the core will be centered automatically with respect to a geometric center of the core-engaging mechanism 25. The robot 27 will move the core 20, if it was initially in the delivery station 19, to a vacuum container 10 positioned at the first or initial station 18 or, if it was initially in the vacuum container 10, to turn the core 20 over and reposition it in the vacuum chamber 14 with the previous bottom sideof the core now .facing up. If the core 20 was in the vacuum container 10 and had received all of the applications of elastomeric material required, the robot 27 will lift the core 20 from the vacuum container 10 and swing it to an exit station 23 where it will be moved either to storage or to subsequent processing.

When the vacuum container 10 arrives at the first or initial station 18, the programmed controls, not shown, will activate valves to energize the air motor or hydraulic cylinder 26 (see Figs. 3,4) to extend the rod 28 to raise the annular support member 16 to a position at the open top of the vacuum container10 so as either to receive a core 20 from the robot 27, or to locate a core 20 so that the robot 27 can grasp and lift the core 20 either for turning and repositioning on the support member 16, or for moving the core 20 to the exit station 23. Once the core 20 has been positioned on support member 16, support member 16 and core 20 are lowered by the hydraulic cylinder 26 into the annular chamber 14. As shown in Figs. 1 and 2, the vacuum container 10 is moved by a conveyor or rollers 34 to a second station 33 where movement of the vacuum container 10 is stopped and a tool or apparatus 35 for applying an elastomeric sheet 36 over the top of the vacuum chamber 14 is activated. The sheet-applying apparatus may consist of two extending arms (not shown) which pull the sheet 36 from a roll and deposits it on the lip 11 of the container 10 and on the platform 13 whereupon a cutting blade, not shown, cuts the sheet 36 from the roll when the sheet is in position. Since any method for applying the sheet 36 is acceptable, this application is not to be read in a manner to limit it to the operation of the above-described tool or apparatus. With the sheet 36 in position, the vacuum container 10 is again moved over rollers 40 to a wait station 38. From the wait station 38, the container 10 is moved over rollers 40 to a third station 41 where a vacuum forming, stitching and trimming apparatus or tool 43 is located. As shown in Fig. 3, the vacuum container 10 has the core 20 nested in the vacuum chamber 14 with the sheet 36 of elastomeric material laying across the lip 11 and platform 13 of the container 10. A stationary sealing member 42 is located at the third station 41 above the lip or rim 11 of the vacuum container 10. As shown in Fig. 3, the vacuum container 10 has tracks 37 on outboard bottom flanges which tracks roll from the elongate rollers 40 onto short rollers 39 carried by a frame of the conveyor. When the container 10 is in aligned position at the third station 41, locator pins 44 in the platform 46 of the lift mechanism 47 move into registering apertures 45 in the bottom of the container 10. The annular support member 16 is in its bottom or lowered position. Proximity switches, or the like, (not shown) will signal the programmed controls that the vacuum container 10 is in position on the platform 46 whereupon valves will be activated to charge the hydraulic cylinders 48 to raise the rods 49, platform 46 and container 10 to engage the lip 11 and sheet 36 against the sealing member 42. The annular support frame 16 is then raised by the hydraulic cylinder 26 so that the core 20 is pressed into the elastomeric sheet 36 as air is evacuated from the vacuum chamber 14, drawing the elastomeric sheet 36 around the core 20 as the core is raised to form the configuration of the sheet on a portion of the core as shown in Fig. 4. It will be noted in Fig. 4 that the container 10 is raised from the rollers 39 by the cylinders 26 and the core and support member 16 are raised from the bottom of the container 10. When so shaped, the stitch and trim steps take place with conventional methods such as those disclosed in U. S. Patent No. 4,044,085, referred to hereinabove. In essence, these steps consist of passing a machine around the annular body formed by the elastomeric sheet 36 and core 20, which machine cuts and stitches the sheet 36 to the core 20 both around the outside and around the inside of the core. The material remaining, between the. lip 11 and the sealing member 42 and the circular portion of material lying on the support platform 13 is considered to be scrap 51. When the material has been cut and stitched, the annular support member 16 is lowered to its bottom position in the vacuum chamber 14 and the central hydraulic cylinder 26 is de-energized so that the vacuum container 10 is lowered to rest on the rollers 39 and 40.

The vacuum container 10 is then moved along the path over the rollers 40 to a fourth station 55 where a scrap removal apparatus or tool 57 is located. The scrap removal apparatus or tool 57, used in removing the scrap, is conventional and includes a platen 59 carried by a boom 56 which is pivotable about a base 58. The platen 59 may include vacuum cups, or the like, to grasp the scrap portions 51 and to deposit them in one of several bins located close to the apparatus. Once the scrap has been removed, the vacuum container 10 is moved along rollers 60 and 39 toward the first station 18 at the load, unload and turn over apparatus or tool 21. At the load, unload and turn station 18, the tracks 37 of the container 10 roll from the rollers 60 onto short rollers 39 similar to those shown in Fig. 3 where, once again, locating pins 44 will move into the aligned apertures 45 in the container 10 to locate the container 10 in proper position for the raising and lowering of the support member. At this time, the support member 16 and the core 20 are raised by the hydraulic cylinder 26, whereupon the robot 27 grasps, lifts and turns the core 20 over, and replaces it on the annular support member 16 with the uncovered side now exposed on top. The core 20 is lowered into the vacuum chamber 14 and the above steps are then repeated to apply elastomeric material to the other side of the core 20. This entire process may be repeated as many times as is necessary to apply the desired number of layers of elastomeric material to the core 20. When the desired number of layers of material have been placed on the core 20, the core may be removed at the first station 18 by means of the load, unload and turn over apparatus or tool 21. The tool 21 grasps the completed core 20, that has been raised by the hydraulic cylinder 26, raises and moves it to the exit station 23. A new core 20 is picked up at the delivery station 19 and is placed on the annular support member 16 after which it is lowered into the vacuum chamber 14 and the process is repeated. Several, such as four or five, or more, vacuum containers 10 with cores 20 can be in the system and worked on at the same time. For instance, one container 10 could be in the first or initial station 18 with a second, third, fourth and fifth container 10 at the sheet-applying second station 33, at the wait station 38, at the form, stitch and trim third station 41, and at the scrap removal fourth station 55, respectively. The limit on the number of containers is determined by how many "wait" stations, such as wait station 38, are designed into the system. With the system disclosed in Fig. 1, five containers (and five cores) is a practical limit. The preprogrammed controls sense the condition of each core 20 in the system, records the number of sheets applied to each core and determines when the core 20 has attained its desired number of sheets and removes it from the system.

A second preferred embodiment of the invention is shown schematically in Fig. 5, where a vacuum container 110 is affixed to a vertically movable platform with actuators, similar to actuators 48,49 for raising and lowering the vacuum container 110 against a sealing member 42 in the manner of Figs. 3 and 4 for sealing the container 110 and sheet of elastomeric material 36 against the sealing member 42. An actuator, similar to actuator 26,28 of Figs. 3,4, is provided for raising and lowering an annular support member 16 upon which a core 20 is positioned. In this embodiment, the apparatus or tools are mounted at stations around the vacuum container 110 with each apparatus or tool being activated to move into position to perform the desired step.

Specifically, a first station 118 has a load, unload and turn apparatus or tool 121 which is located to grasp a core 20 from a delivery station 119 and to lift, center and swing said core 20 into alignment with, and to lower it into position on, the support member 16 in the vacuum container 110. The tool 121 retracts and the core 20 is lowered into the container 110 by. the programmed controls activating the actuator 26. The second station 133 has a sheet-applying apparatus or tool 135 which swings over the vacuum container 110 and applies a sheet of elastomeric material 36 over the lip 111, center platform 113 and open vacuum chamber 114. The tool 135 retracts and the container 110 is raised to seal the sheet of material 36 between the lip 111 and a sealing member 42.

A third station 141 has a form, stitch and trim apparatus or tool 143 which extends over the container 110. The preprogrammed controls raise the core 20 in the vacuum chamber 114 as a vacuum is drawn in the chamber 114. The elastomeric material is cut around the periphery of the core whereupon the cut edge of the material is stitched to the core 20. The unused portion of the sheet 36 rests on the lip 111 and on the platform 113. The core 20 retracts into the chamber 114 as the form, stitch and trim apparatus or tool 143 retracts out of alignment with the container 110.

A fourth station 155 has a scrap removal apparatus or tool 157 which moves over the container 110, lowers, engages the scrap, raises, and moves to a position over an appropriate bin where the scrap is dropped. The tool 157 then returns to a rest position. The load, unload and turn apparatus or tool 121 now advances as the core 20 is raised in the container 110. The tool 121 engages the core 20 and turns it over and replaces it on the support member 16 whereupon the sequence of steps is repeated until the desired number of layers of elastomeric material is deposited on the- core. When the laying of the number of layers is completed, the load, unload and turn apparatus or tool 121 will grasp and remove the core 20 from the container 110 and will deposit it at the exit station 123. The programmed controls will be activated by proximity switches, and the like, which will then signal the various functions to start or to stop.

Although it is not shown, it is contemplated that various combinations of features of the two preferred embodiments may be used advantageously without departing from the spirit of the invention. For instance, using the basic layout of Fig. 1, it is possible that at the second station 33, the sheet-applying tool 35 can swing in from one direction to apply the sheet of material to the container 10 and after retracting, a form, stitch and trim apparatus or tool 43 could swing in and perform its functions all at the second station 33. Likewise, at the third station 41, not only could the form, stitch and trim tool 43 cut and trim the sheet, but also the scrap removal tool 57 could follow the retraction of the form, stitch and trim tool 43 to move into position to remove 'the scrap from the lip 11 and platform 13 at the same station. Various combinations of features of the embodiments can, therefore, be combined within the scope of the invention.

industrial Applicability

With the closed path method described above with respect to Figs. 1 and 2, several different tire carcasses may be formed at one time, ensuring maximum utilization of the various tools. It is desirable to keep one station open at all times to avoid jamming up of the various containers 10 when they are moved between stations. By forming the vacuum seal as described, the method is simplified and may be performed much more quickly. The alternative method disclosed in Fig. 5 using the steps of this invention is to locate the vertically movable vacuum container at one position and to move the various tools into operative position over the container 110. With this modified method, however, only one tool at a time would be used, decreasing efficiency if each tool is used only on one core. However, if each tool operates on two or more cores in containers located about each tool, then the savings from not having to move the vacuum contairϊers from station-to-station becomes the greatest. A method employing parts of each of the two above referred to methods is contemplated and affords a high degree of flexibility in laying out and implementing a tube manufacturing operation. Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims

Claims 1. A method of forming a tire carcass around a core (20), the steps comprising: loading a core (20) into a vacuum chamber (14,114) of an open topped vacuum container (10,110); locating an elastomeric sheet (36) over the open top of said vacuum container (10,110); sealing said sheet (36) to the container rim (11,111); moving said core (20) and vacuum con tainer (10,110) relative to each other to engage said elastomeric sheet (36) with a portion of the core (20) and simultaneously evacuating air from said vacuum chamber (14,114); cutting away excess portions of the elastomeric material (36) not in contact with said core (20); stitching the portions of the elastomeric material (36) engaging with said core (20) onto the surface of the core (20); moving said core (20) and vacuum container

(10,110) relative to each other to position said core (20) with the stitched on portion of the sheet (36) in said vacuum chamber (14,114); removing the excess portions of the elastomeric sheet (36); turning said core (20) over; and repeating the above steps to apply a layer of elastomeric material to the other side of said core (20).

2. The method as claimed in claim 1 wherein the above steps are repeated to obtain the desired number of elastomeric layers on said core (20).

3. The method as claimed in claim 2 wherein said core (20) is removed from said vacuum container (10,110).

4. A method of forming a tire carcass around a core (20), the steps comprising: loading (21) a core (20) at an initial station (18) into a vacuum chamber (14) of an open topped vacuum container (10) having a raised support member (16); lowering the core (20) and support member (16) into said vacuum chamber (14) and moving said vacuum container (10) to a second station (33); locating an elastomeric sheet (36) over the open top of said vacuum container (10); moving said vacuum container (10) to a third station (41); sealing said sheet (36) to the container rim (11); moving (43) said core (20) and vacuum container (10) relative to each other to engage said elastomeric sheet (36) with a portion of the core (20) and simultaneously evacuating air from said vacuum chamber (14); cutting (43) away excess portions of the elastomeric sheet (36) not in contact with said core (20); stitching (43) the portions of the elastomeric material (36) engaging with said core (20) onto the surface of the core (20); moving (43) said core (20) and vacuum container (10) relative to each other to position said core (20) with the stitched on portion of the sheet (36) in said vacuum chamber (14); moving said core (20) and vacuum container (10) to a fourth station (55); removing (57) the excess portions of the elastomeric sheet (36); moving said core (20) and vacuum container ( 10 ) to the initial pos ition (18 ) ; turning (21) said core (20) over; and repeating the above steps to apply a layer of elastomeric material (36) to the other side of said core (20).

5. A method of forming a tire carcass around a core (20), the steps comprising: loading a- core (20) into a vacuum chamber

(114) of an open topped vacuum container (110) having a raised support member (16) using a load, unload and turn apparatus (121); moving said load, unload and turn apparatus (121) to an out-of-the-way rest position; moving a sheet-applying apparatus (135) in to position over said vacuum container (110); applying an elastomeric sheet (36) over the open top of said vacuum container (110); moving said sheet-applying apparatus (135) to an out-of-the-way position; moving a form, stitch and trim apparatus (143) into position over said vacuum container (110); sealing said sheet (36) to the container rim (111); moving said core (20) and vacuum container

(110) relative to each other to engage said elastomeric sheet (36) with a portion of the core (20) and simultaneously evacuating air from said vacuum chamber (114); cutting (143) away excess portions of the elastomeric material (36) not in contact with said core (20); stitching (143) the portions of the elastomeric sheet (36) engaging with said core (20) onto the surface of the core (20); moving said core (20) and vacuum container (110) relative to each other to position said core (20) with the stitched on portion of the sheet (36) in said vacuum chamber (114); moving said form, stitch and trim apparatus

(143) to an out-of-the-way position; moving a scrap-removing apparatus (157) into position over said vacuum container (110); removing the excess portions of the elastomeric sheet (36); moving said scrap-removing apparatus (157) to an out-of-the-way position; moving a load, unload and turn apparatus (121) into position over said vacuum container (110); turning said core (20) over with said load, unload and turn apparatus (121); and repeating the above steps to apply a layer of elastomeric material to the other side of said core (20).

6. In a method of forming a tube article on a core (20), the steps comprising: placing a core (20) in a vacuum chamber (14,114) in a vacuum container (10,110); placing an elastomeric sheet (36) over said container (10,110); raising (48) said container (10,110) to compress said elastomeric sheet (36) between a container rim (11,111) and a stationary sealing member (42); raising (26) said core (20) within said vacuum chamber (14,114) to press against said elastomeric sheet (36); evacuating the air from said vacuum chamber (14114) cutting (43,143) off excess portions of the sheet (36) and stitching the remaining portions of said elastomeric sheet (36) onto said core (20); lowering said core (20) into said vacuum chamber (14,114); removing (57,157) said excess portions of said elastomeric sheet (36) from the surface of said vacuum container (10,110); turning (21,121) said core (20) over; repeating the above steps to apply an elastomeric layer to the opposite side of said core (20); and repeating the above steps as is necessary to obtain the desired number of elastomeric layers.

7. The method of claim 6 wherein said vacuum container (10) with said core (20) is moved along a closed path so that at various stations

(18,33,41,55) on said path it selectively engages different tools (21,35,43,57) which perform the above operations.

8. The method of claim 6 wherein said vacuum container (110) is located at one position and said core (20) is raised and lowered at said position, and wherein tools (121,135,143,157) to perform the steps of the method are moved in andout relative to said one position of said vacuum container (110).

9. A method of forming a tire carcass around a core (20), the steps comprising: positioning a vacuum container (10) at an initial station (18); loading (21) a core (20) into said vacuum chamber (14); moving (34) said vacuum container (10) to a second station (33); locating (35) an elastomeric sheet (36) over the open top of said vacuum container (10); moving (40) said container (10) to a wait station (38); moving (40) said container (10) from the wait station (38) to a third station (41); sealing said elastomeric sheet (36) to a rim (11) of said container (10); moving (26) said core (20) and said container (10) relative to each other to press the elastomeric sheet (36) against a portion of said core (20) and evacuating air from said vacuum chamber (14); cutting (43) away those portions of the elastomeric material not pressed against the core (20); stitching (43) the pressed portions of the elastomeric material onto the core (20); moving (26) said core (20) and said stitched on portion of the sheet (36) relative to each other to return the core (20) into said vacuum chamber (14); moving (54) said container (10) to a fourth station (55); removing (57) the cutaway portions of the elastomeric sheet (36); moving (60) said container (10) back to said initial station (18); and turning (21) said core (20) over.

10. The method as claimed in claim 9 wherein the above steps are repeated to apply a layer of elastomeric material to the other side of said core (20); repeating the above steps to obtain the desired number of elastomeric layers on said core (20); and removing (21) said core from said vacuum container (10).

11. A method of forming a tire carcass around a core (20), the steps comprising: positioning a vacuum container (10) at an initial station (18) ; raising (26) an annular support member (16) to a core-receiving position in a vacuum chamber (14) in said vacuum container (10); loading (21) a core (20) into said vacuum chamber (14) on said support member (16); lowering (26) said support member (16) and core (20) into said vacuum chamber (14); moving (34) said vacuum container (10) to a second station (33); locating (35) an elastomeric sheet (36) over the open top of said vacuum container (10); moving (40) said container (10) to a third station (41); raising (48) said container (10) to compress the elastomeric sheet (36) between a rim (11) of the container (10) and a stationary member (42) located thereabove to form a seal between said sheet (36) and said rim (11); raising (26) said core (20) to press against said elastomeric sheet (36) and evacuating air from said vacuum chamber (14); cutting (43) away the portions of the elastomeric material not in engagement with the core (20) ; stitching (43) the engaged portions of the elastomeric material onto the surface of the core (20); lowering (26) said core (20) with the stitched on portion of the sheet (36) into said vacuum chamber (14); moving (54) said container (10) to a fourth station (55); removing (57) the cutaway portions of the elastomeric sheet (36); moving (60) said container (10) back to said initial station (18); raising (26) said core (20) from said vacuum chamber (14); turning (21) said core (20) over; repeating the above steps to apply a layer of elastomeric material to the other side of said core (20); repeating the above steps to obtain the desired number of elastomeric layers on said core (20); and removing (21) said raised core (20) from said suppprt member (16) and from said vacuum container (10).