Patent Application
20080196812
1. Field of the Invention
The present invention relates generally to tire beads that are used in pneumatic tires (see DEFINITIONS section), and more particularly to a tire bead geometry and manufacturing process useful in certain tire manufacturing processes.
2. Description of the Related Art
Conventional pneumatic tires include a tire body (see DEFINITIONS section), which may include, for example, a tread, a belt structure, and a carcass. The carcass generally includes at least one ply of fabric cords coated with an elastomer. Conventional tires also include tire beads, which are typically made of metal wire, or metal wire coated with a coating, such as uncured rubber. The tire beads are embedded in the tire body. These tire beads are ring shaped and run around the tire in the angular direction. There is generally one tire bead embedded in the vicinity of each cross-sectional end (see DEFINITIONS section) of the tire. The tire beads help secure the tire into a wheel assembly by engaging the rim of a wheel.
One common type of tire bead is called the single wire tire bead. With a single wire tire bead, a single wire, or coated wire, is wound through a plurality of turns in the angular direction to form the ring shape.
Besides single wire beads, ribbon, or weftless, type beads are also conventional. Ribbon type beads are built by turning a ribbon that has a row of discrete wires embedded in it into a ring shape. There are other types of beads, too. For purposes of this document, single wire tire beads are generally preferred, but other bead types may also be possible to use in some of the inventive embodiments discussed herein.
Tire beads are typically combined with an extension strip (also sometimes called an apex or filler) to: (i) physically reinforce the tire bead; (ii) reduce stresses on the tire body in the vicinity of the tire bead; and/or to help secure it within its embedded location in the tire body. The extension strip may be made of, for example, hard rubber). In conventional methods of assembling a tire, the tire bead and extension strip are conventionally connected to each other first (for example, by stitching) to form a bead subassembly. After this, the tire body and bead subassembly are brought together, and then the tire body is wrapped around the bead subassembly to embed it within the tire body and make the tire.
U.S. Pat. No. 4,922,985 (“Gasowski”) discloses, at
U.S. Pat. No. 5,058,649 (“Hoang”) discloses a tire including: (i) bead core 11; (ii) clamping member 18; (iii) stiffening members 19, 20; and (iv) tire body 12, 13, 14, 15, 16, 17. As shown in
An example of a conventional tire including a tire bead and an extension (or apex) is disclosed in U.S. Pat. No. 5,253,692 (“Stephens”). As shown at
US patent application 2003/0106627 (“Tonezzer”) discloses a tire that includes: (i) bead core 110; (ii) bead filler 111; and (iii) tire body (components shown if
US patent application 2005/0161141 (“Nakagawa”) discloses a tire that includes: (i) tire body portion 6; (ii) bead core 5; and (iii) bead apex 8. As shown in
US patent application 2006/0108053 (“Hart”) discloses a method and apparatus for applying an apex at a workstation of a pneumatic tire building machine. In the Hart method, one or more bead area components have been built into an in-process carcass on a tire building drum of the tire building machine. Hart does not disclose that its bead core is built on a tire building drum.
US patent application 2007/0113954 (“Downing”) discloses a method of producing a tire. Downing discloses: “
Various other tire bead assembly methods and/or tire bead geometries are disclosed in the following: (i) U.S. Pat. No. 6,228,198 (“Powell”); (ii) U.S. Pat. No. 6,363,988 (“Yasufuku”); (iii) U.S. Pat. No. 6,413,342 (“Yun”); (iv) U.S. Pat. No. 6,524,416 (“Kubinski”); (v) US patent application 2003/0029573 (“Franke”); and (vi) US patent application 2007/0256790 (“Nijhuis”).
The published article “VMI and Marangoni to offer flexible tyre building system” in the European Rubber Journal (Vol. 187, No. 2: March/April 2005; by David Shaw, ERJ staff, herein “the First ERJ Article”) describes a recently developed tire manufacturing assembly process (herein “the ERJ process”). The ERJ process utilizes cells in which the tire building process is highly automated. In the ERJ process, tire beads and extensions are preassembled to form tire bead assemblies, and these pre-assembled tire bead assemblies are then fed into the tire building process. The tire beads utilized in the ERJ process are conventional tire beads, single wire or weftless. Because pre-assembled tire bead assemblies must be used in the ERJ process, this requires: (i) additional tire bead assembly machinery; (ii) additional tire bead assembly time; (iii) additional tire bead assembly expense; and/or (iv) increased process complexity.
The article “VMI's ultra-flexible tyre-making machine comes to life” in the European Rubber Journal (Vol. 188, No. 6: Global Tyre report 2006; herein “the Second ERJ Article”) describes a tire manufacturing system.
Description Of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications (for example, published patents) are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section, they are all hereby incorporated by reference into this document in their respective entirety(ies).
Some embodiments of the present invention provides a single wire tire bead that includes a reinforcing top section and a stable base section. The tire bead comprises a base section with several rows and columns of aligned wire passes, and a top section that is triangularly shaped, either in the form of a right hand triangle with the wire passes being vertically aligned with the wire passes in the base section, or a non-right hand triangle (e.g., equilateral, isosceles, scalene, etc.) where the top section is built by stepping the outer-most wire passes inwardly relative to the base section by about half the wire diameter. A servo or similar control system is utilized in conjunction with the pay-on head during the manufacturing process to dictate the cross sectional profile of the bead.
Some embodiments of the present invention is directed to a tire with a tire bead having a cross sectional profile including a relatively wide base section and a top section that is tapered on at least one side, with the tire bead being embedded directly (see DEFINITIONS section) in the tire body without the use of an extension. Preferably, these embodiments are single wire tire beads. Preferably, these embodiments have orthogonal wire center geometries. Preferably, these embodiments have a top section with one tapered side and one untapered side.
Some embodiments of the present invention is directed to a tire with a tire bead having a cross sectional profile including a relatively wide base section and a top section with one tapered side and one untapered side, with the tire bead being embedded in the tire body along with an extension. Preferably, these embodiments are single wire tire beads. Preferably, these embodiments have orthogonal wire center geometries. Preferably, the extension of these embodiments is relatively tall.
A method of building a tire where the tire bead and extension are assembled into the tire body at the tire building drum of the tire assembly machine (for example, a tire carcass drum of a tire building cell), and the tire bead and extension are not pre-assembled prior to being introduced onto or into the tire body.
Various embodiments of the present invention may exhibit one or more of the following objects, features and/or advantages:
(1) to provide a tire bead assembly having a profile that may be utilized in a tire building cell;
(2) to provide a tire bead building process that may be retrofit into existing tire building production processes;
(3) to provide a single wire bead profile that provides adequate support to the tire without having to use fillers or an apex;
(4) a tire bead assembly geometry and process that does not trap air within the tire body in the vicinity of the tire bead;
(5) to provide a tire bead assembly and associated manufacturing process with decreased machinery cost, reduced tire building time, reduced expense and/or reduced complexity; and/or
(6) to provide a tire without an extension (also sometimes referred to as an apex or filler or bead filler), and to associated materials cost and/or manufacturing cost and/or time savings.
According to one aspect of the present invention, a tire includes a tire body and at least tire bead. The tire bead is embedded directly (see DEFINITIONS section) in the tire body. The tire bead has a cross sectional profile including a base section and a top section. The top section includes at least one tapered side.
According to a further aspect of the present invention, a tire includes a tire body, at least tire bead, and an extension. The tire bead is embedded in the tire body. The tire bead has a cross sectional profile including a base section and a top section. The top section includes one tapered side and one untapered side. The extension has a bead interface surface. The extension is embedded in said tire body. The extension is oriented so that the bead interface surface is facing the tapered side of the tire bead.
According to a further aspect of the present invention, a method of building a tire includes steps identified as follows. One step is providing a tire building drum. Another step is placing starting stock for at least a portion of a tire body on the tire building drum. Another step, performed after the placing step, is feeding a tire bead onto the tire building drum. Another step is turning up a portion of said starting stock so that said tire bead is embedded in said tire body.
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
Referring now to the drawings, in which like reference numerals refer to like parts throughout,
The controller for pay-on head 22 is programmed to build the bead profile as a single wire tire bead in the desired geometry. With respect to some preferred embodiments of the present invention, the pay-on head is programmed to build the tire bead's cross sectional profile, as illustrated in
The top section tapers inwardly, having fewer wires across in each successive row in the upwards direction. It is noted that the use of “top” and “upwards” here merely refers to the tire bead orientation shown in
In
As explained above, tire bead 15 has an orthogonal wire center geometry such that each wire turn in a row is balanced on top of its corresponding wire turn in the row beneath it, creating: (i) a true orthogonal matrix (in both base section 26 and top section 28); and (ii) a true rectangular shape in base section 26). This can be done in a repeatable and reliable way. The technical challenge of an orthogonal wire center geometry is simply to be able to wind the bead while balancing one round wire on top of another. This can be accomplished by reducing the back tension on the wire as it is wound onto the bead former, so that the back tension does not pull the wire off the top of the wire in the layer below. Also, the pay-on-head (that's the part that steers the wire to change its position upon each revolution of the former) should be designed so that the wire movement is controlled with servo drive systems in both height and side ways movement. This process can be used to make wire beads having the cross sectional profiles of the present invention and also having orthogonal wire center geometries (in their base and/or top sections).
In the preferred embodiments of
In tire bead 15′, there are one fewer wire passes on the inner (left-side direction in orientation of
Tire bead 15″ of
In tire manufacturing assembly 10 shown in
The geometry illustrated by
With respect to advantage (i), in some tire applications the tapered tire bead, whether a double sided taper or a single sided taper, can eliminate the need for a separate extension piece. For example, some tires for passenger vehicles have a construction and performance requirements such that no extension would be needed because the tapered top section of the tire bead is sufficient to provide the tire-related functionality that an extension is otherwise required to provide. Also, when the extension is eliminated, and the tire bead is a single wire tire bead, then only one winder will be required to make it, which reduces manufacturing time, manufacturing costs and/or complexity relative to tire beads made up of multiple wires.
With respect to advantage (ii), even tire applications that require an extension may be built by assembling the tire bead and the extension right on the tire carcass drum. As explained above, in the prior art tire bead assemblies having this kind of performance characteristics were typically pre-assembled by stitching an apex or other bead filler to the tire bead to form a pre-assembled tire bead assembly. This advantage (ii) is especially true of tire beads with a top section having a tapered side and an untapered side as shown in
Further with respect to advantage (ii), each time a tire size is changed on a conventional tire assembly line, where the tire bead and extension are pre-assembled with each other, it is a relatively cumbersome procedure. The bead machine, extension machine and tire assembly need to be reset in the conventional set-up. This takes time out of and adds labor in to the manufacturing process. On the other hand, if the new style beads and any rubber extension are produced directly at the tire assembly machine according to the methods of the present invention, then only the tire assembly machine need be reset. For even quicker change-over times, the bead/extension parameters can be stored in memory. Also, according to the methods of the present invention exhibiting advantage (ii), the system is part of the tire assembly machine and builds the beads only as required no excess process stock is required to be manufactured.
With respect to advantage (iii), it is good to evacuate air from the following locations before the tire body is turned up and the tire bead and/or extension are embedded in the tire body: (a) between the tire bead and extension; (b) between the tire bead and tire body; and/or (c) between the extension and tire body. The tire bead geometry of
To further explain advantage (iii), one important advantage of at least some embodiments of the present invention is that the tire bead and tire apex can be fed onto the tire carcass drum in a cell based manufacturing assembly line without trapping air when the tire body is turned up to embed the tire bead and extension (preferably a rubber extension). Advantage (iii) will now be further explained with reference to
Although many preferred embodiments of the present invention will not pre-assemble the tire bead and extension into a tire bead assembly prior to feeding these components onto a tire carcass drum, some embodiments of the present invention may still do this. Even in embodiments where the tire bead and extension are pre-assembled into a tire bead assembly, the tire bead geometries of
To repeat and/or expand on some of the points discussed above, there are usually two tire beads and two extensions in each tire. The size and shape of the extension varies from tire type to tire type with short profile representing in
The following definitions are provided to facilitate claim interpretation and claim construction:
Present invention: means at least some embodiments of the present invention; references to various feature(s) of the “present invention” throughout this document do not mean that all claimed embodiments or methods include the referenced feature(s).
First, second, third, etc. (“ordinals”): Unless otherwise noted, ordinals only serve to distinguish or identify (e.g., various members of a group); the mere use of ordinals implies neither a consecutive numerical limit nor a serial limitation.
Tire: any member flexible adapted to be fit onto a wheel assembly and contain compressed fluid (for example, compressed air); by its shape, a tire will define an angular direction, a radial direction, an axial direction and a central axis; unless otherwise noted, tires are not limited by: (i) the type of wheel assembly the tire is adapted to fit into; (ii) the type of vehicle or other device the tire may be adapted for; (iii) tire material; (iv) tire size; (v) existence of tread and/or tread type; and/or (vii) number of constituent pieces or materials.
Tire body: all parts of the tire exclusive of any bead(s) or extensions(s); tire bodies may include, but are not limited to, treads, belts and/or a carcass.
Cross section, cross sectional: unless otherwise noted herein, this refers to a cross section of a tire taken in a plane along both the axial and radial directions; generally speaking, the cross section of the tire will be substantially the same at any angular position, so the cross section will not generally specify an angular position herein; cross sectional direction shall mean the direction along the tire cross section, for example, in the Stephens patent, cross sectional direction would be the direction along the centerline of the hatched area in
Embedded directly mean a tire bead that is embedded in a tire body without an extension being embedded along with it.
To the extent that the definitions provided above are consistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall be considered supplemental in nature. To the extent that the definitions provided above are inconsistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall control. If the definitions provided above are broader than the ordinary, plain, and accustomed meanings in some aspect, then the above definitions shall be considered to broaden the claim accordingly.
To the extent that a patentee may act as its own lexicographer under applicable law, it is hereby further directed that all words appearing in the claims section, except for the above-defined words, shall take on their ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), and shall not be considered to be specially defined in this specification. In the situation where a word or term used in the claims has more than one alternative ordinary, plain and accustomed meaning, the broadest definition that is consistent with technological feasibility and not directly inconsistent with the specification shall control.
Unless otherwise explicitly provided in the claim language, steps in method steps or process claims need only be performed in the same time order as the order the steps are recited in the claim only to the extent that impossibility or extreme feasibility problems dictate that the recited step order (or portion of the recited step order) be used. This broad interpretation with respect to step order is to be used regardless of whether the alternative time ordering(s) of the claimed steps is particularly mentioned or discussed in this document.
The present application claims priority to U.S. provisional patent application No. 60/889,963, filed on Feb. 15, 2007; all of the foregoing patent-related document(s) are hereby incorporated by reference herein in their respective entirety(ies).
| Number | Date | Country | |
|---|---|---|---|
| 60889963 | Feb 2007 | US |
