Abstract:
A repair device can repair a puncture in a normally pressurized vehicle tire. The device has a dispenser with dual barrels containing a pair of separate constituents adapted to form a cement that can adhere to the vehicle tire. A static mixer can be mounted on the dispenser for receiving and mixing the pair of constituents to form the cement. An injection tube mounted on the static mixer is sized to fit into the puncture. A pair of piston heads slidably fitted in the dual barrels can push the pair of constituents through the static mixer to form the cement for injection from outside the tire, through the injection tube, and into the puncture to reach inside the tire. After removing the injection tube, the cement that was injected is allowed to set at least partially before using the tire.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to apparatus and methods for repairing tire, and in particular, to repairs performed with a cement.  
           [0003]    2. Description of Related Art  
           [0004]    Repairing flats in tubeless pneumatic tires is usually done in one of two ways. In the one method, the tire is first taken off the rim. The inside surface of the tire is then ground smooth to enable a rubber repair patch to make good contact with the tire&#39;s inside surface. Rubber cement is then applied to the area surrounding the puncture and allowed to dry. Thereafter, a specially coated and treated rubber patch is applied and a special tool presses the patch in place, ensuring good contact between opposing surfaces. This method is time-consuming, requires unmounting of the tire, requires technical skills, and the grinding process damages and weakens the tire due to the removal of some support elements. Also, this method fails when the contact between the tire and the patch is inadequate or when the puncture hole is too big.  
           [0005]    In the second conventional method, a round rasp is forced through the puncture in the tire in order to enlarge the original hole. A plug is then mounted on a needle hook and is coated with cement before being forced through the enlarged hole. U.S. Pat. No. 5,536,346 gives an example of a tool for inserting a plug into a puncture of a tire. In general, enlarging the puncture in this type of method will weaken and damage the tire. Consequently, the tire is likely to start leaking soon after, requiring a repeat of the repair with additional damage to the tire.  
           [0006]    In U.S. Pat. No. 4,279,343 a threaded plug has two cavities filled with a sealant material. The plug is pressed into a tire puncture and threaded into place. Threading wrings the sealant out of the chambers to seal the plug in place. However, few punctures will be suitable for threading, unless the puncture is enlarged, which will again weaken the tire structure.  
           [0007]    In FIG. 3 of U.S. Pat. No. 3,190,338 the region of a tire in need of repair is cut out (skived) and clamped on either side. A fluid inlet 34 is used to inject a repair compound into the repair site. The injected material fills the skived region and forms an internal plug. The injected compound is formed by mixing constituents just prior to injection. This apparatus can only function when the damaged area is skived to form a large cavity that is accessible by inlet 34.  
           [0008]    In U.S. Pat. No. 4,093,481 a tire is repaired by first filling a damaged area with unvulcanized bonding rubber before covering the area with a flexible cover 3 a . Thereafter, a needle pierces the cover  3   a  to create a vacuum. The needle is not directly inserted into the puncture in the tire. This method is designed to fill a relatively large damaged area and does not teach an effective method for repairing a simple puncture.  
           [0009]    In U.S. Pat. No. 4,453,992 a tire is formed with an internal pocket for holding a lubricant. This lubricant will be released from the pocket should the tire deflate, in order to prevent rubber from rubbing on rubber. The lubricant is loaded into the pocket with a syringe that is injected from the inside of the tire. This arrangement requires a relatively complicated tire, which by itself may increase the possibility of tire failure. See also, U.S. Pat. No. 5,070,917 (system for pumping a tire leak sealant into a tire through the valve stem).  
           [0010]    It is well known to employ a gun that can inject two-part compounds for various purposes: U.S. Pat. No. 3,439,839 (applying a strip of sealant for installing glass plate in an automobile); U.S. Pat. No. 5,386,928 (materials used in the construction industry or as dental materials); U.S. Pat. No. 5,242,082 (sealing cracks in masonry and around window frames); and U.S. Pat. No. 5,443,181 (material “used in buildings, motor vehicles, ships, aircraft, machines and numerous other apparatus”). For other type of guns for injecting two-part compounds, see U.S. Pat. Nos. 4,986,443; 5,104,005; 5,535,922; and 5,566,860. See also U.S. Pat. No. 4,453,651 (injecting mastic). None of these guns are described as useful for injecting compounds into a tire puncture.  
           [0011]    Accordingly, there is a need for a simple and effective method and apparatus for making a long-lasting, high-quality repair.  
         SUMMARY OF THE INVENTION  
         [0012]    In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a method for repairing a puncture in a normally pressurized vehicle tire with cement and an injection tube. The method includes the step of inserting the injection tube from outside the tire into the puncture. Another step is pushing the cement through the injection tube and the puncture to reach inside the tire. The method includes the step of removing the injection tube, and allowing the cement that was injected to set at least partially before using the tire  
           [0013]    In accordance with another aspect of the invention there is provided, a repair device for repairing a puncture in a normally pressurized vehicle tire. The device has a dispenser containing a cement adapted to adhere to the vehicle tire. Also included is an injection tube adapted to be mounted on the dispenser and sized to fit into the puncture without reaching inside the vehicle tire. The device also has a plunger slidably fitted in the dispenser for pushing the cement through the injection tube and through the puncture  
           [0014]    In accordance with yet another aspect of the invention there is provided, a repair device for repairing a puncture in a normally pressurized vehicle tire. The device has a dispenser with dual barrels containing a pair of separate constituents adapted to form a cement that can adhere to the vehicle tire. Also included is a static mixer adapted to be mounted on the dispenser for receiving and mixing the pair of constituents to form the cement. The device also includes an injection tube mounted on the static mixer and sized to fit into the puncture. Also included is a pair of piston heads slidably fitted in the dual barrel for pushing the pair of constituents through the static mixer to form the cement for injection through the injection tube and into the puncture.  
           [0015]    By employing apparatus and methods of the foregoing type, an improved tire repair will be achieved. In a preferred embodiment, a syringe-like device has two barrels filled with separate constituents. These constituents can be pressed out of the barrel to flow through a static mixer and form a cement. This cement is then pushed through an injection tube, which is inserted into a tire puncture from the outside, preferably, to a depth that reaches into but not through the tire.  
           [0016]    The cement pushed through the injection tube flows through the tire puncture and eventually to the inside of the tire to form a flared head. As the injection tube is then withdrawn, the cement is still pushed through the tube in order to fill any voids in the regions just vacated by the injection tube.  
           [0017]    In some embodiments the cement is pushed by a manually operated plunger. In some cases the device can be sized to dispense cement for a single puncture, and will thereafter be disposed in its entirety. In other embodiments the device can repeatedly dispense cement into successive punctures, in which case just the static mixer and the injection tube are disposable. After disposal of the mixer and injection tube, a cap can be placed over the dispensing end of the barrels that contain the cement-forming constituents.  
           [0018]    For repair centers, larger barrels containing the two cement-forming constituents can be mounted on a handle having a trigger-operated ratchet mechanism for deploying a pair of plungers in order to dispense the cement. This mechanism can be used to rapidly inject cement into successive punctures. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:  
         [0020]    [0020]FIG. 1 is a side view of a dispenser, partly in section, in accordance with principles of the present invention;  
         [0021]    [0021]FIG. 2 is a longitudinal sectional view of a portion of the dispenser of FIG. 1;  
         [0022]    [0022]FIG. 3 is an exploded, perspective view of the distal end of the dispenser of FIG. 1, showing a cap used to cover the barrel when the static mixer and injection tube are not installed;  
         [0023]    [0023]FIG. 4 is a perspective view showing the dispenser of FIG. 1 being used to perform a method in accordance with principles of the present invention;  
         [0024]    FIGS.  5 A- 5 B show successive steps for the method of FIG. 4;  
         [0025]    [0025]FIG. 6 is a detailed perspective view of a portion of an injection tube that is an alternative to that shown in FIG. 1;  
         [0026]    [0026]FIG. 7 is a side elevational view, partly in section, of a handle that can be used to dispense cement from a barrel similar to that shown in FIG. 1; and  
         [0027]    [0027]FIG. 8 is an end view of the face of the receptacle of the handle of FIG. 7, which is adapted to hold a barrel similar to that shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    Referring to FIGS.  1 - 3 , the illustrated dispenser is shown with dual barrels  10  and  12 , which are molded, hollow plastic cylinders connected together by integral flange  14  at their proximal ends (in this view, the left end). The barrels  10  and  12  are about 3.0 inches (7.6 cm) long and have an inside diameter of about 0.44 inch (1.14 cm), although different dimensions may be employed depending upon the desired capacity of the barrels. Fitted into the barrels&#39; open proximal ends is a plunger in the form of a parallel pair of closed plastic cylinders  16  and  18 , which are joined together at their proximal ends by an integral flange  20 . While the foregoing components are made of plastic, in other embodiments they may be made of metal, ceramic, or other suitable materials.  
         [0029]    The distal ends of barrels  10  and  12  feed into the two outlet ports  22  formed in cylindrical hub  24 . Hub  24  is integral with platform  26  whose outer ends are fitted with overhanging, L-shaped brackets  28 .  
         [0030]    The proximal end of static mixer  30  has an oval flange  32  designed to fit under brackets  28 . Mixer  30  can be installed by bringing it against hub  24  in the orientation shown in FIG. 3. Once in place, wings  34  can be used to manually rotate mixer  30  through 90° to bring the extended portions  32 A of flange  32  under brackets  28 . Alternatively, cap  36  can be installed on hub  24  by rotating the flange  38  under brackets  28 . The flange  38  has the same outline and shape as previously mentioned flange  32 . Cap  36  is shown as a dome-like structure with reinforcing ribs integrally mounted atop flange  38 .  
         [0031]    The main body of mixer  30  is shown as a tubular housing  30 A containing a plurality of coaxial blades  40  each having a helical twist of 180°. A phase shift of 90° occurs at the transition between each of the blades  40  (that is, from preceding to succeeding blades  40 ). Accordingly, fluid flowing around either side of one of the blades  40  will be swirled 180° and then split into two different paths at the transition to the succeeding blade. In a preferred embodiment there will be twelve such blades so that the flow patterns will be divided and swirled twelve times; although a different number of blades may be employed in other embodiments. Also in this preferred embodiment, the twelve blades  40  will be molded as a single integral piece.  
         [0032]    The distal end of housing  30 A narrows down at neck  42  and is fitted with a plastic sleeve  44  whose narrow distal end is sealed around steel injection tube  46 . Tube  46  extends from sleeve  44  about ¼ inch (0.6 cm), and has an outside diameter of about 0.04 inch (1.0 mm) and an inside diameter of about 0.03 inch (0.75 mm); although these dimensions can vary depending upon the size of the puncture and the desired depth of penetration into the puncture. Preferably, the injection tube  46  penetrates about half way into the tire, up to but not past any steel belted radial. This depth of penetration is typically ¼ inch (0.6 cm) and it is therefore advantageous (but not mandatory) to limit the exposed length of the injection tube to this desired penetration depth.  
         [0033]    Plunger cylinder  18  is shown bearing against piston head  48  inside barrel  12 . It will be appreciated that a similar piston head (not shown) abuts plunger  16  inside barrel  10 . Piston head  48  is a short plastic cylinder with an annular groove containing an O-ring  50 . Thus arranged, the portions of barrels  10  and  12  on the distal (downstream) side of the piston head forms sealed chambers separately containing complementary constituents  52  that when mixed form a curable cement that acts as a sealant composition.  
         [0034]    The sealant composition for use in the present invention generally comprises two or more components that upon contact with one another polymerize together, and wherein either (a) at least one of the components alone or (b) the polymerization product or(c) both adheres to synthetic rubber as may be found in a vehicle tire. Preferably, the co-reactive components are monomers which are co-reactive with each other in the absence of an initiator. Notwithstanding the forgoing, one component may be a monomer and the other component contain an initiator for the polymerization of the first component. Either component may contain suitable carrier materials which would be well known in the art.  
         [0035]    More preferably, the composition comprises (a) a first component comprising a monomer having at least two functional groups, which functional groups are the same or if different are not reactive with each other; and (b) a second component comprising a monomer having at least two functional groups which are the same or if different are not reactive with each other. The functional groups of the monomer of component (a) are reactive with the functional groups of the monomer of component (b). Each of components (a) and (b) may be made up of mixtures of monomers as long as these limitations on the reactivity of the functional groups is adhered to.  
         [0036]    In a preferred embodiment, the monomers of the component (a) are diisocyanates, and the component (b) monomer is a di- or poly-ol, so that the polymerization product is a polyurethane. A preferable diisocyanate is alkylenedi(phenylisocyanate), most preferably is 4,4′-methylene-bis(phenylisocyanate). Component (b) may also contain a diamine, which reacts with the diisocyanate to form a polyurea compound. In a preferred embodiment, component (b) is a blend of (I) a di- or poly-ol and (II) a diamine, which upon reaction with the diisocyanate, results in generally a blend of polyurea and polyurethane with some mixed poly urea/urethane.  
         [0037]    In one preferred embodiment the monomers that can be used are commercially available from Smooth-On of Easton, Pa. under the name Ure-Bond. This product has both monomers needed for the polyurethane formation contained in separate compartments for admixture during the application process.  
         [0038]    In using the invention for the repair of synthetic rubber automotive tires, the Ure-Bond components may not be as convenient as might be desired. For example, the components would be more easily applied to a puncture without removal of the tire if the viscosity were increased. This would prevent the internal pressure from expelling the components before they had a chance to react suitably. This can be readily accomplished by reducing the solvent content of one or both components, adding a suitable viscosity enhancing agent, and other techniques well known in the art.  
         [0039]    Two methods of increasing the viscosity of the material are (i) the inclusion of a small amount of a diamine in the di- or poly-ol containing component and (ii) addition of 1-5 wt % fumed silica to the hydroxy free component (b). In varient (i), upon mixture of the diamine containing diol component with the isocyanate component, the diamine component immediately reacts with some of the 4,4′-methylene bis(phenylisocyanate) thereby rapidly increasing the viscosity. The diamines are monomeric aromatic diamines, typically selected (a) phenyl and naphthyl diamines which are unsubstituted or may be sunbstituted on the aromatic rings with one or more lower alkyl groups and (b) diamino (di(aryl) methylene) wherein the aryl groups are the same or different and selected from phenyl and naphthyl, each of which is unsubstited or substituted with one or more lower alkyl groups, the two amino groups being on any free position, but preferably one on each of the aryl groups. Preferred diamines include toluene diamine, methylene dianiline, and diethyltoluene diamine.  
         [0040]    When silica is added to increase the viscosity, it is generally used in amounts of about 1 to about 5% in the diol containing component. Fumed silica is preferable and of the fumed silicas, Cabosil 720 or Cabosil M-5 (both commercially available) are most preferred.  
         [0041]    Also, the cure time of the Ure-Bond product as marketed, while suitable for many applications, is not as short as would be most desirable. The cure time of that product is in the order of 15-30 minutes. It would be preferable to have the cure time shortened to 3-5 minutes or less. This can be readily accomplished by including suitable polymerization accelerators which are well known in the art. Suitable examples include organometallic materials such as dibutyltin dilaurate, tetrabutyl titanate and stannous octoate; amines such as tetramethylethylenediamine, triethylenediamine, or 33% triethylenediamine in propylene glycol; acids such as adipic acid, azelaic acid, stearic acid, ethylhexanoic acid, isophthalic acid, and terphthalic acid, among others.  
         [0042]    Furthermore, the Ure-Bond product results in a polyurethane which, while suitable, is more rigid than would be optimum for automotive tires, which in use, result in significant flexing of the tire walls. Increasing the flexibility of the polymer would therefore be advantageous. This is readily accomplished by inclusion of suitable plasticizers. Such plasticizers include, for example, phthalate diesters, benzoate diesters, isobutyrate diesters, or adipate diesters among others. Alternatively, the flexibility of the polymerization product can be increased by increasing the molecular weight of the oligomeric diamine in the non-isocyanate component. However, if this route is taken, the molecular weight of the diisocyanate monomer component must also be increased to match, which can be accomplished by making the diisocyante component in the from of a pre-polymer. Such techniques are well known in the art.  
         [0043]    In addition to the “formulation” type of modifications mentioned above to optimize the properties of the components (a) and/or (b) and/or the polymerization product, one can modify properties of the monomers themselves, such as by chain extension or shortening between the reactive functional groups, modify the molecule in the region between the functional groups by adding side chains which may or may not include additional functional groups which do not adversely affect the monomers, the polymer, or the polymerization reaction.  
         [0044]    A modified version of the Ure-Bond product which is particularly adapted to optimize each of these features and therefore is the most preferred version, is available from Smooth-On of Easton, Pa. under the company designation 79-88-2. In this version, the isocyanate containing component is formulated to be used in a 1:1 ratio with the diisocyanate free component. The resulting viscosity of the diisocyanate containing component is about 40-about 70 cps, preferably about 60 cps. The diisocyanante free component has a viscosity of about 5000-about 5100 cps, preferably about 5040 cps. The cured material from this reaction of these two components has a Shore A hardness of about 80-about 90, preferably about 85.  
         [0045]    To facilitate an understanding of the principles associated with the foregoing embodiment of FIGS.  1 - 3 , its operation will be briefly described in connection with the diagrams of FIGS. 4 and 5A- 5 E. The dispenser is normally supplied with cap  36  installed between the brackets  28  (FIG. 3). Cap  36  is removed after turning it 90° so that flange  38  clears brackets  28 . Cap  38  may contain a rotating plug (not shown) with two prongs that fit into the ports  22  of hub  24 .  
         [0046]    Next, static mixer  30  may be attached by placing flange  32  over hub  24  and rotating the mixer so that extended portions  32 A of the flange  32  will be locked under brackets  28 . In some embodiments mixer  30  will not be supplied with an injection tube and in such cases sleeve  44  may now be slipped over housing  30 A of static mixer  30  to install injection tube  46 . In other embodiments an injection tube may be sealed directly onto the distal end of the housing  30 A of the static mixer.  
         [0047]    Barrels  10  and  12  will be pre-filled with cement-forming constituents  52 , although in some embodiments, the user may have a separate supply of such constituents and may manually fill and refill the barrels  10  and  12 . In some cases, the user will separately mix these constituents and fill them into a dispenser having a single barrel, although this single barrel will be of limited utility since it must be discarded once the cement cures.  
         [0048]    [0048]FIG. 5A shows a tire T with a puncture P extending from the outside to the inside of the tire. The walls of the puncture P are shown to be uneven, but in some cases may be smooth and may have portions that are occluded. A steel belt  54  is shown embedded about midway through the thickness of the tire T, as is typically the case in steel belted radial tires.  
         [0049]    The dispenser will now be thrust from the outside, so that its injection tube  46  penetrates into puncture P of tire T (FIGS. 4 and 5B). Injection tube  46  is shown penetrating about halfway into tire T, reaching a position just to the outside of the steel belt  54 . Tube  46  may be inserted more deeply, but not so deeply as to cause cement to simply run into the inside of the tire T without beneficial effect. Tube  46  may be inserted less deeply, but not so shallowly as to cause a high back pressure that impedes injection of cement.  
         [0050]    The user will now depress flange  20  to drive plungers  16  and  18  into barrels  10  and  12 , respectively. In response, pistons  48  will be driven inwardly through the two barrels  10  and  12  to push their respective constituents  52  through ports  22  and into static mixer  30 .  
         [0051]    Inside static mixer  30  the two constituents  52  will each be divided in half (four distinct flow paths) and each half will be mixed with a half from the other complementary constituent before being swirled 180° by one of the helical blades  40 . The two flow paths around this blade  40  reach the next blade and are each divided in half again, with each half from one side of the preceding blade being mixed with a half from the opposite side of the preceding blade. These two new mixed flow paths are again swirled 180°. In the preferred embodiment the flow paths are divided and swirled twelve times, which will be adequate to thoroughly mix the two constituent components  52  to form a cement.  
         [0052]    The cement is injected from tube  46  into puncture P as shown in FIG. 5C. Specifically, cement is driven through puncture P and reaches the inside of tire T. Cement accumulates on the inside of tire T to form the flared head  56 . After this initial injection, injection tube  46  is gradually withdrawn while pressure is still applied to the plungers  16  and  18 . Consequently, additional cement fills any voids remaining in the regions of puncture P vacated by injection tube  46 , as shown in FIG. 5D. In some embodiments, the filling of the voids can be enhanced by employing an injection tube  46 ′ as shown in FIG. 6. This injection tube  46 ′ has a number of side vents  58 , which allow lateral injection of cement into such voids.  
         [0053]    Eventually, injection tube  46  is completely withdrawn and the puncture P is completely filled with cement as shown in FIG. 5E. A typical injection of cement will be about 0.33 to 0.50 cc, although this volume will vary depending upon the size of the puncture, the thickness of the tire T, the size of the flared head  56 , etc. The cement in puncture P now cures in about one to three minutes forming an elastomeric seal of polyurethane that adheres to the surfaces of tire T. Tire T can now be inflated. Flared head  56  will be pressed against the inside surface of tire T. The polyurethane used forms a good chemical bond with synthetic and non-synthetic rubber. The flared head  56  inside the tire T gives added security.  
         [0054]    The cement in puncture P is now ready for use and tire T can be driven in an ordinary fashion. The cement will be sufficiently flexible and durable to withstand the conditions existing during ordinary use. Significantly, tire T need never be removed from its supporting rim and, in fact, may be repaired while still mounted on a vehicle.  
         [0055]    Referring to FIGS. 7 and 8, a hollow handle is shown with a grip  60  integral with a cylindrical case  62 . Trigger  64  is pivotally mounted on pin  66  to swing in and out of grip  60 . Trigger  64  has an integral leaf spring  68  that bears against stud  70  and tends to drive trigger  64  outwardly, that is, to the position shown. Trigger  64  has on its upper end a knuckle  72  that pivotally supports pawl  74 . An integral leaf spring  74 A on pawl  74  tends to rotate it (clockwise in FIG. 7). The upper surface of pawl  74  has a number of ratchet teeth  74 B that engage teeth  76  of rack  78 . Pawl  74  has a pair of tines  74 C (one shown in this view) straddling either side of rack  78 . A pushbutton  79  extending through the top of case  62  can be depressed to depress tines  74 C, thereby disengaging pawl teeth  74 B from rack teeth  76 .  
         [0056]    Rack  78  is a plastic blade slidably mounted inside case  62  and extending through rear opening  80  to the outside of case  62 . Rack  78  also extends through collar  82  and can be slid to extend past collar  82  as shown in FIG. 7. The distal end of rack  78  is bifurcated into two tines  78 D supporting two circular plunger heads  78 C. Tines  78 D each have a pair of reinforcing ribs  78 B, giving this section of the rack  78  a cruciform cross-section. Rack  78  also has an upright reinforcing rib  78 A running along part of its length.  
         [0057]    Collar  82  has a hollow distal section  82 A with a slot  84  giving section  82 A a double-walled configuration. The front wall  86  of section  82 A has a slot  88 , giving wall  86  a C-shaped configuration. Accordingly, a dispenser such as that shown in FIG. 1 (perhaps slightly larger), but with the plungers  16  and  18  removed, can be installed in slot  84  by placing the flange  14  into the slot, allowing barrels  10  and  12  to extend outwardly as shown in phantom in FIG. 7.  
         [0058]    Of course, to install barrels  10  and  12 , rack  78  must be fully retracted. Such retraction can be accomplished by depressing pushbutton  79  to lower pawl teeth  74 B. Complete retraction can then be accomplished by grasping and pulling the section of rack  78  that extends through rear opening  80 . The flange  14  may then be centered inside slot  84  so that the barrels  10  and  12  will be aligned with the plunger heads  78 C.  
         [0059]    The user can then insert the injection tube associated with barrels  10  and  12  into a tire, much as shown in FIG. 4. Plungers  78  can be manually pushed until it engages the piston heads  48 , where the plungers will stop. Next, the user will depress trigger  64 , causing pawl teeth  74 B to be driven forward, to extend plunger heads  78 C through barrels  10  and  12 . When trigger  64  is released, leaf spring  68  drives the trigger outwardly and retracts pawl  74 . Teeth  74 B will now skip or ratchet over rack teeth  76  without moving rack  78 . As trigger  64  is repeatedly depressed, plunger heads  78 C will move the piston heads, such as piston heads  48  shown in FIG. 1. Consequently, barrels  10  and  12  will be operated in a manner similar to that previously described in connection with FIG. 1 in order to repair a tire as before.  
         [0060]    The foregoing embodiment is intended for a commercial service center where the handle of FIG. 7 will be used repeatedly for many tires during the course of the day. During idle times when the handle is not in use, any static mixer and injection tube associated with the handle can be discarded, and the barrels ends can be closed with a cap similar to that shown in FIG. 3.  
         [0061]    It is appreciated that various modifications may be implemented with respect to the above described, preferred embodiments. In some embodiments the injection tube may be relatively long and have insertion depth markers that are used to visually control the insertion depth, allowing the user to take into account the type of tire being repaired. Also, the static mixer can be attached to the barrels with a variety of quick-disconnect couplers; or may be permanently attached to the barrels in some embodiments. In other embodiments the user may be provided a kit having a variety of barrels, mixers, and injection tubes that may be assembled in various combinations depending upon the desired capacity, insertion depth, the properties of the cement constituents, etc. In still other embodiments the cement may be formed from a single constituent that cures by drying, by the application of heat, etc. Moreover, instead of manually ejecting cement, in some embodiments gas may be released from a pressurized container to eject the cement. Alternatively, the cement may be dispensed by squeezing a pliable container. In addition, the materials used for the various components may be made of plastics, metals, ceramics, composite materials or other materials, depending upon the desired strength, weight, temperature stability, immunity to corrosion, etc.  
         [0062]    Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.