Metal working – Plural diverse manufacturing apparatus including means for... – Binding or covering and cutting
Reexamination Certificate
2001-07-12
2003-06-10
Wellington, A. L. (Department: 3722)
Metal working
Plural diverse manufacturing apparatus including means for...
Binding or covering and cutting
C029S221500, C029S264000, C029S235000, C029S267000, C029S890121, C029S426500
Reexamination Certificate
active
06574843
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tools for installing and replacing tubeless tire valve stems, and more particularly to a method and apparatus for installing and replacing tubeless tire valve stems without requiring removal or separation of the tire from the wheel rim.
2. Preliminary Discussion
Tubeless or pneumatic tires were first introduced in 1947 by B.F. Goodrich, Inc. Such tubeless tires have an inner rubber liner rather than a separate inner tube, and incorporate a rim bead, a stiffened molded edge section, usually formed by high tensile steel wire hoops embedded in the two inner edges of the tire. The bead conforms to and fit against the rim seat or inner ledge portion of a vehicle's wheel rim to hold the tire to the rim. Upon inflation, an airtight seal between the rim seat and the tire bead is created. Provided there is no defect in the rim or tire, once the tire is properly inflated on the rim with a tight uniform seal between rim seat and the tire bead, there is no way for air to be forced into or out of the wheel, except through an inflation valve.
Since there is no inner tube, the inflation valve stem is usually secured in an annular opening provided through the rim for the valve. Conventional tubeless tire valve stems are comprised of an elastic rubber body or casing, which casing houses a valve core, typically comprised of a spring biased valve mechanism. The rubber casing typically includes an upper portion surrounding the protruding metal threaded end of the valve core, which portion can pass readily through the rim opening and may be slightly downwardly and outwardly tapered. The upper portion merges toward its lower end opposite the threaded end with a conical portion of rapidly increasing diameter, the conical portion being adjacent to or accommodating at its lower end an annular bead with a diameter slightly larger than the diameter of the rim opening. Below the annular bead is a substantially annular flat-bottomed groove sized to cooperate with and sealingly interfit with the rim opening. Finally, such annular flat-bottomed groove portion merges at its lower end into an enlarged annular flange or bulbous head having a substantially larger diameter than the rim opening.
Ordinarily, valve stems are installed from the inner side of the rim by pulling the valve, threaded end first, through the rim opening using a suitable pulling tool until the bulbous head of the valve stem is seated against the inner, or tire, side of the rim and the flat-bottomed annular groove is seated or secured in the rim opening. The inherent elasticity of the rubber body seats or anchors the valve in the rim opening, and in addition, since in most valve stems the valve is not bonded tightly or directly to the enlarged head or base, such head will resist dislodgment by the high pressure within the tire since it can mushroom outwardly along the inner side of the rim.
The valve stems just described are commonly used because they are relatively inexpensive, easy to install, light, and wear well. However, eventually they may become deformed, bent, or cracked, or the rubber casing will begin to lose its elasticity and leak. Tire valve stems on trucks, farm equipment or other construction-type vehicles may also experience more severe damage at a higher rate than a typical valve stem on a passenger vehicle. Since the bulbous head portion cannot be easily forced through the rim opening from the outer side of the rim without damaging the rubber casing, in most cases, when it is required to remove or replace an inflating valve stem, the tire must be unseated or dislodged from the rim in order to gain access to the inside or tire side of the rim, thereby breaking the airtight seal between the bead seat and bead. Since special equipment is usually required to correctly seal a tubeless tire to a rim, and every time the seal is broken there is an increased likelihood of later leaks, the removal of the tire from the rim can result in prolonged downtime and significantly delay or hinder use of the vehicle. Thus, there is a need for an improved tool wherein a cracked, bent, or otherwise damaged valve stem can be replaced “in the field” without requiring that the tire be removed from the rim and wherein the valve stem could be inserted into the rim opening of a tubeless tire from the outer side of the rim and tire, rather than from the inner side.
3. Description of Related Art
Numerous tools and methods for repairing damaged valve stems without requiring that the tire be unseated from the rim are known. For example, U.S. Pat. No. 2,652,858 issued to R. V. Snyder entitled “Repair Unit for Tire Valve Stems,” teaches a method wherein the damaged portion of the stem is cut away or removed and a repair unit is clamped over the undamaged or remaining portion of the stem. In U.S. Pat. No. 3,863,697 issued to R. C. Brown, entitled “Instant Valve Insert,” the entire stem except for the old valve plug is broken off and a new valve having an anchoring means is slipped through and secured to such plug. While such solutions are useful in an emergency, they only provide temporary relief, and still require that eventually a new stem be inserted from the inner side of the tire in the usual manner.
U.S. Pat. No. 3,255,520 issued to J. A. Jerdon, entitled “Automobile Tire Stem Removing and/or Inserting Tool,” discloses a lever having a pivot, wherein the end of a valve stem is screwed to a threaded rod attached on the end of the lever, and wherein the lever is used to forcibly pull a valve out of the rim opening. Although such device is apparently useful in removing valve stems, it would be difficult if not impossible to use such device to push a stem through the rim opening without tearing or damaging the rubber casing covering the stem, which casing is not compressed prior to insertion.
Other known valve stem installing tools include various means for forcing a stem down an elongated and sharply tapered nozzle, such as U.S. Pat. No. 3,750,258 issued to J. J. Sampo, entitled “Insertion Tool for Tire Valve Stems,” and U.S. Pat. No. 4,765,048 issued to B. M. Hokanson, entitled “Valve Stem Inserter.” Such tools force the stems through long tapered nozzles having an inner diameter on the far end that is less than the diameter of a rim opening using a pusher rod or other pushing tool, thereby gradually compressing the bulbous flange of the stem such that it may be inserted into the rim opening from the outside. Although such tools employ a lubrication means, they are generally difficult to operate since a very large amount of force is required to compress the flange and gradually push the stems down the tapered nozzles. Other similar devices employ some additional means to facilitate forcing of the stems down a tapered nozzle. For example, U.S. Pat. No. 3,387,354 issued to H. J. Mossberg, entitled “Valve Inserting Device,” employs a pusher rod attached to a notched trigger handle. U.S. Pat. No. 4,807,343 issued to T. P. Wadsworth, entitled “Tubeless Tire Valve Stem Inserter,” also employs a trigger mechanism, attached to a pusher rod using grips to force the rod forward. Finally, U.S. Pat. No. 5,097,580 issued to A. J. Story, entitled “Apparatus for Installing and Removing Valve Stems,” discloses a valve insertion and removal tool having a tapered elongate tubular body, with the top end fitted to an air piston assembly. Although such a device would make it easier to force the stem down a tapered tube, it is only useful in a garage or other area where a suitable source of power for the operating piston is available.
While valve assemblies for tubeless tires that can be installed from the outer side of the rim are also known, such as disclosed in U.S. Pat. No. 5,211,782 issued to D. Thelen, entitled “Valve Assembly for Tubeless Tire,” such alternative valve structures are more expensive and generally are less preferred than standard tubeless tire valves. Thus, despite the continued progression of the prior art, there is still a need for an inexpensive tool that can be used
Cadugan Erica E
Wellington A. L.
Wilkinson, Esq. Charles A.
Wilkinson. Esq. Clinton H.
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