[0001] This application claims priority to, and the benefit of, U.S. provisional patent application no. 62/272,485, filed December 29, 2015 with the U.S. Patent Office, which is herein incorporated by reference.

BACKGROUND

[0002] This invention relates generally to a valve stem for a pneumatic tire. Particularly, to a valve stem capable of filtering the air released from within the tire through the valve core. More particularly, to prevent particulate material contained within the tire from entering the valve core seat assembly and the atmosphere. Particulate material may comprise any particulate, such as, for example, a pulverulent material (that is, a powder or dust) or debris.

[0003] It is not uncommon for a tire to contain other particulate matter, such as dust, dirt, or other debris, and as a consequence of use whereby particles of rubber become dislodged from the interior bead of the tire and freely move about the interior of the tire when the tire is in use. Over time, a large number of such particles may be found in any tire. It is not uncommon for these particles to enter into the tire valve core and prevent the valve from fully closing resulting in an air leak. This is especially likely to occur when air is released from the tire as the flow of air exiting the valve naturally draws the particles into the valve core.

[0004] It is also becoming increasingly popular to purposely introduce particulate material into a tire to affect the tire characteristics, such as improving tire and/or wheel balance or force variations and reducing vibrations during tire operation. For example, a powder of specific composition may be disposed within the tire pressurization cavity to dynamically "balance" the tire and to reduce radial and lateral force variations found within a tire under varying load conditions. This method is taught and described U.S. Pat. No. 5,073,217, for example. The particulate material is sold by International Marketing, Inc. under the trademark "EQUAL®."

[0005] Use of particulate materials, however, may become arranged within the tire valve core (which is more generally referred to as a gas valve), which controls the input and output of gas through a valve stem of the tire/wheel assembly. In such instances, the arrangement of particulate material within the tire valve core can hinder its operation, and therefore, can cause loss of air through the tire valve core.

[0006] Therefore, it is desirable to prevent the influx of particulate material into the valve core to maintain proper operation of the valve core. More generally, it is also desirable to prevent the particulate material from escaping the tire.

SUMMARY OF THE INVENTION

[0007] This present invention is therefore directed to a tire valve specifically designed to allow the relatively unimpeded flow of compressed air into a tire while at the same time being capable of preventing any particulate or pulverulent matter contained within a tire from entering the tire valve core as is especially likely to occur when compressed air contained within the tire is vented through the valve core. The invention comprises an elongated valve body having a first end, a second end, and including a passageway formed therein, said passageway extending from said first end of said valve body to said second end of said valve body and said passageway defining an inlet port at said first end of said valve body for communication with a source of compressed air, and defining an outlet port at said second end of said valve body for communication with the interior of a tire; valve means disposed within said passageway for selectively blocking the flow of air through said passageway; a filter element capable of forming a barrier at said second end of said valve body overtop said passageway to substantially preclude the passage of particulate matter; and, means for preventing said filter element from separating from said second end of said valve body. The valve may be sized and configured for use with automobiles or light trucks, or it may be sized and configured for use with heavy duty trucks.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is an elevation view showing the valve of the present invention as it may be installed in a wheel rim (the rim shown in ghost lines);

[0009] FIG. 2 is an elongated elevational longitudinal cross-section of the present invention;

[0010] FIG. 3 is a plan view as it may be taken at line 3-3 of FIG. 2; [0011] FIG. 4 is exploded perspective view of the present invention; and [0012] FIG. 5 is a perspective view of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference will now be made in detail to an exemplary embodiment of the present invention in the accompanying drawings. Referring to FIG. 1, the invention is shown generally at 10 and comprises an elongated valve body 20 having a first end 30 and a second end 40. First end 30 may contain external threads 50 to allow for the attachment of a protective cap or to allow for the attachment of a mating pneumatic fitting. Additional external threads 60 may be provided along the valve body to allow for attachment of valve body to wheel rim 70 using a nut (not shown). Second end 40 preferably contains an annular seal 80 to provide for a gas-tight (an airtight) seal between second end 40 of valve body 20 and wheel rim 70. Many shapes and sizes and varieties of valve bodies are known in the art and the present invention is not meant to be limited to a particular valve body or any particular method of attachment with wheal rim 70. In particular, those skilled in the art will recognize that the disclosure and figures may apply equally to a valve sized and configured for use with automobile and light truck tires, as well as valve sized and configured for use with tires and wheels of heavy duty over-the-road and off-road trucks.

[0014] As seen in FIG. 2, a central passageway or bore 90 extends form first end 30 to second end 40 of a valve body 20. Passageway 90 defines an inlet port 100 at first end 30 of valve body, and defines an outlet port 110 at second end 40 of valve body 20. Valve means which is preferably a pneumatic valve or valve core 120 is disposed in passageway 90. Valve core 120 is threadably secured (that is, secured with threading) at or near first end 30 of passageway 90 and depends from first end 30 into passageway. Valve pin 130 is biased by means of a spring to extend into inlet port 100 to be capable of being depressed by a mating pneumatic fitting or other implement as is known in the art to open valve core 120 to allow gas (any gas, such as air or nitrogen, for example) to pass through passageway 90. It should again be noted that many such valve cores are known in the art, one such valve core being made by Schrader Automotive, Inc., Charlotte, N.C., and being commonly known in the industry as a Schrader Valve. The invention however is not meant to be limited to any particular type of valve core.

[0015] A filter means for preventing the passage of any particulate or pulverulent material contained within a tire from entering the tire valve core is shown in the exemplary embodiment in FIGS. 3-5. A filter element 140 is shown covering outlet port 110 at second end 40 of valve body 20. In particular embodiments, filter element 140 is a screen formed of a suitable material, such as any metal (which includes stainless steel and aluminum, for example), fibrous material (such as cloth or any other textile), and any polymeric material. The screen may comprise any openings suitably sized to allow gas (any gas, such as air or nitrogen, for example) to pass while also preventing substantially any particulate or pulverulent material of a desired size from passing through the filter element. In particular, the filter element or screen has a mesh sized to prevent particulate material into passageway 90 large enough to interfere with the proper operation of valve core 120 while causing little interruption in the rate of fluid flow (or more specifically, gas flow) through the valve stem passage. For example, the mesh size should preferably range from about 5 microns to 100 microns, and is more preferably about 40-50 microns. Filter element 140 should allow for the passage of air but be substantially impervious to particulate material. Furthermore, as shown in FIGS. 3-5, filter element 140 is generally circular in shape so to cover passageway 90 at outlet port 110. However, filter element 140 may include other shapes so long as it adequately covers passageway 90. Filter element may also comprise any open cell material or porous material that is able to allow the passage of gas through the filter material while also substantially preventing the passage of particulate material of a desired size.

[0016] Referring to FIGS. 4-5, filter element 140 is attached to second end 40 of valve body 20 around outlet port 110 at second end 40 of valve body 20 by retention means. As illustrated by FIGS. 4-5 retention means includes adhesives capable of adhering filter element 140 to second end 40 of valve body 20. The retention means is be capable of withstanding the pressure forces of any gas, such as compressed air, being forced into a tire through passageway 90. This not only includes the pressure associated with a pressurized gas being inserted, but also the forces associated with the velocity of the flowing pressurized gas as it is flows through the valve stem. Additionally, the retention means is capable of withstanding the pressure forces of the compressed air and any particulate or pulverulent material being forced from within the tire back through passageway 90. Furthermore, in particular embodiments, the retention means withstands heat known to be generated during specific tire use. Additionally, it is recognized that other retention means may be employed as an alternative to, or in addition to, an adhesive. For example, other retention means include other bonding compositions, weldments (via welding), fastener(s), rivet(s), tack(s), and other mechanical attachments, such as by use of threading, clamping, and mechanical interference between the a portion of the valve stem and the wheel or some other structure.

[0017] The retention means may further include a perimeter support about filter element 140. As illustrated by FIG. 4-5 a supporting member 150 (which is a perimeter support) may be provided to give rigidity at the perimeter of outlet port 110. Herein, filter element 140 is pinched between supporting member 150 and second end 40 of valve body 20. In the embodiment shown, supporting member 150 and filter element are adhered to second end 40 of valve body 20 using an attachment means comprising an adhesive.

[0018] While this invention has been described with reference to particular embodiments thereof, it shall be understood that such description is by way of illustration only and should not be construed as limiting the scope of the claimed invention. Accordingly, the scope and content of the invention are to be defined only by the terms of the following claims. Furthermore, it is understood that the features of any specific embodiment discussed herein may be combined with one or more features of any one or more embodiments otherwise discussed or contemplated herein unless otherwise stated.