Cellular tire liner and air chamber system for pneumatic tires

A cellular tire liner and air chamber system for pneumatic tires comprising a cellular tire liner interposed between the interior surface of a tire and an air chamber with an annular interface that extends from the air chamber to the interior surface of the tire, in the tread area of the tire and disconnects the sidewall portions of the tire liner from each other.

BACKGROUND OF THE INVENTION

The present invention is in the field of “flat-proofing” pneumatic tires. The present invention is an improved Cellular Tire Liner and Air Chamber System for pneumatic tires that can be utilized with existing one-piece drop center wheels. And is primarily for use in high aspect ratio pneumatic tires. The aspect ratio is the sidewall height of a tire, divided by its maximum section width, Aspect ratios are commonly referred to in percentages of sidewall height relative to tire width

A cellular tire liner lines the interior surface of a pneumatic tire with a given thickness, providing a void in the center of the tire for a subsequently pressurized air chamber. Because the tire liner does not completely fill the interior of the tire, a tire equipped with a “liner” can be mounted onto existing one-piece, Original Equipment Manufactured (O.E.M.) wheels. As almost all tire punctures encountered during driving penetrate the tire maybe a couple of inches, the Cellular Tire Liner and Air Chamber System of the present invention will make a tire blow-out proof and flat-proof. Because the entire volume of compressed air inside the tire can never be lost due to a puncture, or if a portion of the tire fails. And in the event a puncture does penetrate all the way through the liner and depressurizes the air chamber, the liner itself provides sufficient load-bearing capability to allow the vehicle to be driven to a safe location to change the tire. Depressurizing the air chamber is the equivalent of releasing that same volume of compressed air out of a regular tire. The tire would be “low”, but it still could be driven to a safe location.

High tire deflections cannot result in an extreme tension load being placed on a tire liner. A tire liner for a high aspect ratio tire should be under a compression load only.

BRIEF SUMMARY OF THE INVENTION

The object of the present invention is to provide a functional means of eliminating pneumatic tire blow-outs and flats for high aspect ratio tires/high deflection applications, that can be utilized with existing one-piece drop center wheels. The present invention Cellular Tire Liner and Air Chamber System provides an annular interface which disconnects the sidewall portions of the Cellular Tire Liner from each other. Thereby eliminating a key detrimental tension load during high tire deflections.

REFERENCE NUMERALS IN THE DRAWINGS

15—Pneumatic Tire with Large Sidewalls20—Interior Surface of the Pneumatic Tire25—Inner Tube30—One-Piece Drop Center Wheel40—An Exterior Surface of the Present Invention Tire Liner that is Parallel to the Rotational Axis of the Tire50—View that Looks Perpendicular at the Air Chamber Surface and the Surface that Contacts Adjacent Liner Segments50—Air Chamber65—Tire Tread70—Pneumatic Tire Sidewall Deflecting Under A Load85—Annular Interface95—Rotational Axis of the Tire200—Cellular Tire Liner of the Present Invention

DETAILED DESCRIPTION OF THE INVENTION

The Cellular Tire Liner of the present invention is a cellular structure comprised of a multiplicity of elastomeric cells. The construction of “elastomeric cellular structures” for use in the interior of pneumatic tires is well known in the art. The Tire Liner of the present invention can be made by any of the methods known in the art. The preferred elastomeric cellular structure to be used for the Tire Liner of the present invention, is described in Applicant's U.S. Pat. Nos. 5,031,679 and 5,080,737. The composite cellular structure described therein, provides a lightweight structure that fulfills the requirements for use in pneumatic tires. Specifically, the preferred elastomeric cellular structure comprises a multiplicity of preconstructed cells comprising enclosed hollow cavities. Prior to being incorporated into the cellular tire liner, each of the preconstructed cells is a complete, individual structure. Each of the preconstructed cells comprises an external surface and an internal surface, defining one complete cell wall therebetween of a given thickness, completely enclosing a single hollow center of a given volume. The cell walls are composed of an elastomeric material, and the hollow center of the preconstructed cells contain a gas under pressure above atmospheric. The multiplicity of preconstructed, individual cells have surface portions of the external cell wall surfaces which are engaged with external cell wall surface portions of adjacent cells in a state whereby substantially all of the total external cell wall surface of all cells is in engagement with surrounding portions of external cell wall surfaces of the surrounding cells. The multiplicity of preconstructed, individual cells are permantly connected together at the engaged external surface portions in the engaged state to collectively provide the cellular tire liner, whereby the cells of the cellular tire liner remain in the connected and the engaged state.

InFIG. 1there is shown an isometric view of one (1) Cellular Tire Liner200of the present invention and view45that looks square to the indicated surface. The Liner200shown inFIG. 1, is in a 90 degree segment configuration. In a 90 degree segment configuration, it will take eight (8) 90 degree liner segments200to completely line the inside of a tire. If the Tire Liner of the present invention is molded in 45 degree segments, it will take sixteen (16) to line the inside of a tire. If the Tire Liner of the present invention is molded in 180 degree segments, it will take four (4) to line the inside of a tire. If the Tire Liner of the present invention is molded in 360 degree segments, it will take two (2) to line the inside of a tire. The Cellular Tire Liner of the present invention can be molded in any “degree” configuration desired.

InFIG. 2there is shown view45and two (2) of the Liner segments200shown inFIG. 1, positioned approximately as they would be oriented to each other in a tire, but spaced apart to show they are two independent structures. And that two (2) are required to line the cross section that is parallel with the rotational axis of a tire.

A cross sectional view of a tire lined with the present invention Tire Liner is shown inFIG. 3.FIG. 3is a cross sectional view that is on and parallel to the rotational axis of the tire. InFIG. 3there is shown high aspect ratio/large sidewall tire15, interior surface20, tire tread65, four (4) of the Tire Liners200shown inFIG. 1, air chamber50unpressurized, annular interface85and rotational axis95. Tire15has an aspect ratio of approximately 80% (the sidewall height is 80% of the maximum section width). Tire Liner200of the present invention, provides for air chamber50by creating a void in the interior of tire15. Air chamber50as shown inFIG. 3, is not sealed or pressurized. Air chamber50is subsequently sealed by an inner tube or any other suitable means and pressurized with air or any other suitable gas to a desired pressure. Tire Liner200“lines” the interior of tire15by being interposed between interior surface20and air chamber50. Each of Tire Liners200, provides a part of air chamber50. The eight (8) Tire Liners200required to completely line tire15, collectively form air chamber50.

FIG. 4is a cross sectional view of the tire and present invention Tire Liner ofFIG. 3, that is perpendicular to the rotational axis of the tire. InFIG. 4there is shown high aspect ratio/large sidewall tire15, tire tread65, four (4) of the Tire Liners200shown inFIG. 1, view45, rotational axis95and annular interface85. Annular interface85is established when a multiplicity of Tire Liners of the present invention are installed in and line the interior of a pneumatic tire. InFIG. 4, annular interface85can clearly be seen in its entirety. Annular interface85is the ring-shaped surface that forms a common boundary between Tire Liners200in tire15. This common boundary between Tire Liners200(annular interface85), is clearly seen inFIG. 3. Annular interface85extends from air chamber50to interior surface20in tread area65of tire15.FIG. 3shows that annular interface85provides a two-piece cross section which disconnects the sidewall portions of the present invention Tire Liner from each other. Because the sidewalls of a pneumatic tire move in opposite directions during load deflection, the annular interface feature of the present invention eliminates extreme tension loads during high tire deflections because the sidewall portions are not connected together.

This sidewall movement in opposite directions is illustrated inFIG. 6.FIG. 6shows the sidewall movement of a pneumatic tire deflecting under a load70. The sidewall portions of the present invention Tire Liner can “move” in the required opposite directions, independent of each other during high tire deflections, because they are not connected together. This eliminates the tension load of the prior art tire liners because their sidewall portions are connected together in one continuous structure.

FIG. 5is a partial cross sectional view of the tire and present invention Tire Liner ofFIG. 3mounted onto a wheel with the Air Chamber sealed and pressurized. InFIG. 5there is shown one-piece drop center wheel30, high aspect ratio/large sidewall tire15, interior surface20, tire tread65, air chamber50pressurized, inner tube25, annular interface85, Tire Liners of the present invention200and exterior surface that is parallel40. Tire15is mounted onto one-piece drop center wheel30with the Tire Liners of the present invention200lining the interior of tire15. Tire Liners200are interposed between interior surface20and air chamber50. InFIG. 5, air chamber50has been sealed by means of inner tube25and air chamber50is also pressurized. The air pressure force in air chamber50presses Tire Liners200against interior surface20of tire15. This constant pressure from pressurized air chamber50stops Tire Liners200from rubbing against interior surface20and therefore stops the heat that would be generated by this friction, when tire15is put to use. Pressurized air chamber50also provides part of the total load-bearing capability of tire15, because Liners200and pressurized Air Chamber50function together as a System that establishes the entire load-bearing capability of the tire.

If an “inner tube” is the means chosen to seal air chamber50, some steps can be taken to insure that it will not protrude into the area that is annular interface85during high load deflections. This may be necessary because the sidewall portions of the present invention Tire Liner can “move” independently in opposite directions during high load deflections. A degree of interference could be molded into Tire Liners200in the area that will be annular interface85. This interference will compress together the surfaces that comprise annular interface85when Tire Liners200are installed in a tire. The amount of compression that may be required, depending on the specific aspect ratio of a tire, could be approximately ¼ to ⅜ of an inch. Alternatively, a “lip” could be molded on the exterior surface of Tire Liners200at the junction where annular interface85and air chamber50meet. Still further, a “lip” and “compression” could possibly be used together. A special inner tube could also be used with a “lip” and/or “compression” or alone. A special inner tube would incorporate means of stopping protrusion into annular interface85during high tire/load deflections. This “special inner tube” could incorporate fiber reinforcement, Kevlar® for example, to stop protrusion into annular interface85during high tire deflections.