GREEN TIRE STORAGE DEVICE WITH INFLATABLE BLADDERS

Abstract: A green tire holding device (10) including a frame (12), a rod (14) extending horizontally from the frame (12), and a bladder (16) mounted on the rod (14). The bladder (16) is inflatable to an inflated shape so that it contacts a substantial portion of an inner circumference of a green tire (T) to support the green tire during a pre-curing wait cycle. The green tire holding device (10) can comprise a plurality of rods (14), a plurality of bladders (16), and/or a plurality of bladders (16) on each rod (14). The bladders (16) can be inflated at substantially the same time and/or certain bladders (16) can be deflated independently of other bladders (16). In a tire manufacturing method, the loaded green tire storage device (10) is transported to a doping/curing area with the bladders (16) deflated. At the doping/curing area, the tires (T) are removed from the rods (14), doped, and re-hung on the rods (14). The bladders (16) are then inflated so that the tires (T) are stored on inflated bladders during the pre-curing wait cycle.

Description: GREEN TIRE STORAGE DEVICE WITH INFLATABLE BLADDERS FIELD OF THE INVENTION This invention relates generally to a device for storing green tires during a pre-curing wait cycle. BACKGROUND OF THE INVENTION In the manufacture of a tire, its various components, including reinforcing components embedded in a matrix of unvulcanized rubber or other unvulcanized rubberlike material, are assembled on a building form. The tire at this stage of the manufacturing process is commonly called a green tire. After being built, a green tire is transported to a doping/curing area whereat it is doped. Thereafter, the green tire is subjected to a shaping and vulcanizing press and shaped into its final form. There is almost always a waiting period between the doping of the green tire and its subsequent curing. This time period can be referred to as the pre-curing wait cycle and can extend anywhere from a few hours to several days. During the pre-curing wait cycle, a green tire is usually stored on a holding device. Of particular relevance to the present invention is a green tire holding device having a plurality of horizontal arms (e.g., eight) each on which a number of green tires (e.g., three) are hung. The horizontal arms can have a cross-sectional shape compatible with this hanging. For example, the arm can have a half-moon shape to form a sling for the green tires. In its vertical hanging position, a green tire has a tendency to sag or droop under its own weight, due to gravitational forces on the unsupported portions of the green tire, and become distorted. Specifically, because only an upper portion of the green tire rests on the horizontal arm, this portion is constantly subjected to the gravitational pull of the lower portions of the green tire. SUMMARY OF THE INVENTION The present invention provides a green tire storage device that counters the constant gravitational forces for a green tire during the pre-curing wait cycle for that tire. More particularly, the present invention provides a green tire holding device comprising a frame, a rod extending horizontally from the frame, and a bladder mounted on the rod. The bladder is inflatable from a deflated shape to an inflated shape so that it can contact a substantial portion of an inner circumference of the green tire to support the green tire during a pre-curing wait cycle. Preferably, the inflated size of the bladder can be varied so that the green tire storage device can accommodate green tires of different sizes without any structural modifications. The green tire holding device can comprise a plurality of rods, a plurality of bladders, and/or a plurality of bladders on each rod. The frame can include an inlet connection valve and a conduit system can connect the inlet connection valve to each of the bladders. The conduit system can be such that a plurality of the bladders are inflated at substantially the same time. Additionally or alternatively, the conduit system can be such that certain bladders can be deflated independently of other bladders. For example, if the green tire holding devices includes a plurality of rods, and each rod includes a plurality of bladders, an outlet valve could be provided for deflating the bladders mounted on one rod independent of the bladders mounted on the other rods. In a method of making a tire according to the present invention, a green tire is made and then placed on the rod of the holding device with the bladder being in a deflated condition. The bladder is inflated during the pre-curing wait cycle. When the time arrives to cure the green tire, the bladder is deflated, the green tire is removed from the rod, and the tire is cured. The green tire holding device can be transported to another location after the tire is placed thereon. If this transportation is to a doping/curing area, the tire(s) can be removed, doped, and then returned to the rod prior to inflating the bladder(s). The present invention provides these and other features hereinafter fully described and particularly pointed out in the claims. The following description and drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention can be employed. DRAWINGS Figure 1 is a perspective view of a green tire storage device according to the present invention, the device including a series of horizontal arms with inflatable bladders. Figure 2 is a front view of a green tire as initially placed on a rod of the storage device, the bladder being in a deflated condition. Figure 3 is a front view of the green tire on the rod once the bladder has been inflated. Figure 4 is a sectional view of one of the rods of the green tire storage device. Figures 5A - 5H are schematic drawings of a method of using the green tire storage device in a tire manufacturing process according to the present invention. DETAILED DESCRIPTION Referring now to the drawings, and initially to Figure 1 , a green tire storage device 10 according to the present invention is shown. The storage device 10 includes a frame 12, rods 14 extending horizontally from the frame 12, and bladders 16 on the rods 14. The green tire storage device 10 is used to store green tires while they are waiting to be cured, that is during a pre-curing wait cycle. Referring now to Figures 2 and 3, a green tire T is shown hung on the rod 14 of the green tire storage device 10. In Figure 2, the bladder 16 is deflated and only an upper portion of the green tire T is supported by the rod/bladder whereby this portion is constantly subjected to the gravitational pull of the lower portions of the green tire T. In Figure 3, the bladder 16 is inflated so that it expands to the shape of the central opening of the green tire T, thereby substantially supporting the circumferential edge of the green tire defining this opening. This increased support of the green tire T minimizes its tendency to sag or droop under its own weight and become distorted The bladders 16 can be made of a reinforced fabric and have a construction similar to that of an inner tube for a passenger tire. Preferably, the bladders 16 are such that they can be inflated to different pressures and will take on different shapes/sizes. In this manner, the green tire storage device 10 can accommodate different sized tires without structural modifications by simply changing the inflation pressure. Referring now back to Figure 1 , the illustrated frame 12 includes a bottom support 20 and wheels (or castors) 24 attached to the support's corners for convenient transfer of the storage device 10 from one location to another. Four vertical frame posts 26 extend upwardly from the bottom support 20 and a cross rod 28 extends across the top of the posts 26. A fluid supply inlet connection valve 30 is located on the cross bar 28. A conduit system connects the inlet connection valve 30 to the bladders 16. For example, the rods 14, the vertical frame posts 26, and the top cross rod 28 could be hollow so that conduit could be installed therein. A top conduit line (not visible in the drawings) could run through the top cross rod 28, four conduit lines (not visible in the drawings) could extend downwardly therefrom through each the vertical frame posts 26, and two horizontal conduit lines 40 (not visible in Figure 1 but shown in Figure 4) could extend outwardly from each of the vertical lines through the rods 14. The horizontal conduit line 40 includes passageways 42 into each of the bladders 16. When the green tire storage device 10 is hooked up to a source of pressurized fluid (e.g., compressed air), the fluid would flow through the inlet connection valve 30, through the top conduit line (in the top cross bar 28), into the four vertical conduit lines (in the vertical posts 26), into each of the eight horizontal conduit lines 40 (in the rods 14), through the passageways 42 and into each of the bladders 16. In this example, the bladders 16 would be inflated at substantially the same time (ignoring flow differentials due to varying distances from the inlet valve 30). Sequential or other inflation patterns could be accomplished, if necessary or desired, by incorporation of a manifold or other type of flow distribution device. As shown in Figure 4, the conduit line 40 in the rod 14 can have a check valve 44 at its proximate end to ensure that the pressurized fluid does not escape therefrom back into the vertical conduit line in the corresponding vertical post 24. The conduit line 40 can also have a valve 46 at its distal end, which can be activated outside the rod 14, for releasing fluid from the conduit line 40 to deflate the bladders 16. In this manner, the bladders 16 on each rod 14 can be deflated independently of the bladders on other rods thereby allowing each set of three tires T to remain on the inflated bladders until just prior to curing. In a method of making a tire according to the present invention, a green tire T is made and placed on the green tire storage device 10 while the bladders 16 are deflated. (Figure 5A.) The device 10, with the tire T placed thereon, is then transported to a doping/curing area. (Figure 5B.) The tires T are removed from the rods 14 (with the bladders 16 still deflated) and the doping process is performed. (Figure 5C.) The doped tires T are returned to the rods (with the bladders 16 still deflated). (Figure 5D.) A pressurized air supply is then connected to the inlet 30 (Figure 5E) and the bladders 16 are inflated (Figure 5F). The bladders 16 are left in the inflated condition during the pre-curing wait cycle. When curing time arrives, the bladders 16 on one rod 14 are deflated. (Figure 5G). The tires T are then removed from this particular rod 14 for curing. (Figure 5H). This deflation/removal process is repeated for each rod 14 at the appropriate time. Rod-by-rod deflation of the bladders 16 is believed to be sufficient for most tire making methods. However, a green tire storage device allowing individual bladders to be deflated independently of each other might be more acceptable in some tire making methods. Also, a green tire storage device allowing substantially simultaneous deflation of all of the bladders can be adequate in other tire making methods. These alternate deflation patterns are certainly possible with and contemplated by the present invention. Although the invention has been shown and described with respect to a certain embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such alterations and modifications and moreover is limited only by the scope of the following claims.

Claims: CLAIMS 1. A green tire holding device (10) comprising a frame (12), a rod (14) extending horizontally from the frame (12), and a bladder (16) mounted on the rod (14), the bladder (16) being inflatable from a deflated shape to an inflated 5 shape so that it can contact a substantial portion of an inner circumference of a green tire (T) to support the green tire during a pre-curing wait cycle. 2. A green tire holding device (10) as set forth in the preceding claim, comprising a plurality of bladders (16). 3. A green tire holding device (10) as set forth in the preceding claim, o wherein the plurality of the bladders (16) are inflated at substantially the same time. 4. A green tire holding device (10) as set forth in either of the two preceding claims, wherein certain bladders (16) are deflated independently of other bladders (16). 5 5. A green tire holding device (10) as set forth in the preceding claim, comprising a plurality of rods (14) and wherein each rod (14) includes a plurality of bladders (16) and means (46) for deflating the bladders (16) mounted on this rod (14) independent of bladders (16) mounted on other rods (14). 6. A green tire holding device (10) as set forth in any of the preceding o claims, wherein an inflated size of the bladder (16) can be varied to accommodate green tires (T) of different sizes. 7. A method of making a tire, comprising the steps of: making a green tire (T); placing the green tire on the rod of the green tire holding device (10) of any of the preceding claims with the bladder (16) in a deflated condition; inflating the bladder (16) to an inflated shape; storing the tire (T) on the inflated bladder during the pre-curing wait cycle; deflating the bladder (16); removing the tire (T) from the rod (14); and curing the tire (T). 8. A method of making a tire, comprising the steps of: making a green tire (T); hanging the green tire (T) on a green tire holding device (10) having a rod (14) with an inflatable bladder (16) mounted thereon, the bladder (16) being in a deflated condition; inflating the bladder (16) to an inflated shape so that it can contact a substantial portion of an inner circumference of a green tire (T) to support the green tire (T); storing the tire on the inflated bladder (16) during a pre-curing waiting cycle; deflating the bladder (16); removing the tire (T) from the rod (14); and curing the tire (T). 9. A method as set forth in either of the two preceding method claims, further comprising the steps of: transporting the green tire holding device (10) to a doping/curing area, removing the green tire (T) from the rod (14), doping the green tire (T), and returning the doped green tire (T) to the rod (14); wherein these transporting, removing, doping and returning steps are performed after the placing step and prior to the inflating step. 10. A method as set forth in any of the three preceding method claims, wherein said inflating step comprises inflating the bladder(s) (16) to a first inflation pressure for a first sized of green tire and inflating the bladder(s) (16) to a second different inflation pressure for a second different sized green tire.

Inventors: KIRBY JAMES M, KIRBY, JAMES, M.
Applicants: BRIDGESTONE FIRESTONE NORTH AM, BRIDGESTONE/FIRESTONE NORTH AMERICA TIRE LLC
Application year: 2001
Main classification: B29D30
IPC codes: B29C33, B29C35, B29D30, B29L30, B60B30, B62D43