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 con- tinuous tape of elastomeric material about a core of a disintegratable material to form a tube member. Afte: 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 with¬ in 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 manu— facture 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 materi¬ al 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 ϊ "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. hile it is clear that such strips or sheets of elastomeric material form¬ ing 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-con¬ suming 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

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different types of material handling equipment to in¬ itially load the core in the apparatus for performing the first application of a sheet. The material handl¬ ing equipment must then be used to turn the core for a

^• 5 second and subsequent applications. Finally, the core with the- several layers of elastomeric material is re¬ moved from the apparatus, ready for subsequent process ing. This has resulted in a relatively slow and in¬ efficient use of the tools, with an attendant slow rat

10 of manufacture of the tires.

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

Disclosure of Invention

One aspect of the present invention is a ,15 - 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

20 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 de—

25 sired 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

30 and inefficient requiring frequent handling of the

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core using generally available material handling equip¬ ment. 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 v/rapped with the desired number of layers of elastomeric material. A third method incorporates bot moving the core from one tool station to the next, and moving a tool to the core as the core is held irr 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 embodi¬ ments 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 show¬ ing the elastomeric sheet as applied to a core and prior to severing; and

Fig. 5 is a schematic view of a second pre¬ ferred 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 lo¬ cations, 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-en¬ gaging 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 con¬ tainer 10, to turn the core 20 over and reposition it __ in the vacuum chamber 14 with the previous bottom side _ _. of the core now .facing up. If the core 20 was in the vacuum container 10 and had received all of the applica¬ tions 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 ex- tend the rod 28 to raise the annular support member 16 to a position at the open top of the vacuum container ^~ -10 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 reposition— ing on the support member 16, or for moving the core 20 to the exit station 23.

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Once the core 20 has been positioned on sup¬ port member 16, support member 16 and core 20 are low¬ ered by the hydraulic cylinder •26 into the annular cham¬ ber 14. As shown in Figs. 1 and 2, the vacuum contain— er 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 con- sist 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 applica- tion- 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 con¬ tainer 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 sup¬ port member 16 is in its bottom or lowered position. Proximity switches, or the like, (not shown) will signal the programmed controls that the vacuum con- tainer 10 is in position on the platform 46 where¬ upon 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 elas_tomeric sheet 36 as air is evacuated from the vacuum chamber 14, draw¬ ing 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 dis¬ closed in ϋ. S. Patent No. 4,044,085, referred to here- inabove. In essence, these steps consist of passing a machine around the annular body formed by the elasto— meric 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 mater¬ ial remaining, between the. lip 11 and the sealing mem¬ ber 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 annu¬ lar support member 16 is lowered to its bottom posi-.- tion in the vacuum chamber 14 and the central hydraulic cylinder 26 is de-energized so that the vacuum con- tainer 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 re ov- ing 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

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core 20 are raised by the hydraulic cylinder 26, where¬ upon 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 ≤heet- 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 5-5, 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

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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 sheet ^' s and removes- it from the system.

A second preferred embodiment of the inven¬ tion is shown schematically in Fig. 5, where a vacuum container 110 is affixed to a vertically movable plat- form 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 con¬ tainer 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 HO 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 con¬ tainer 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 un¬ used 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 contain¬ er 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 pre¬ ferred embodiments may be used advantageously without departing from the spirit of the invention. For in¬ stance, using the basic layout of Fig. 1, it is poss¬ ible 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 re- tracting, 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. Vari¬ ous 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 des¬ cribed, 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 ccn- i tairϊers 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 imple¬ menting a tube manufacturing operation. Other aspects, objects and advantages of this invention can be obtained from a study of the dr wings, the disclosure and the appended claims.

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