PLUG PATCH FOR RADIAL TIRES

Abstract: A plug patch (10, 50) for repair of an injury in a radial tire (14) including an elongated patch member (11, 51) fixed to an elongated plug (12, 52) projecting eccentrically from the patch member (11, 51) to provide a substantially elongated end portion (38, 59) adapted to lie flush and be adhesively secured to, the inner tire surface (20), over the tread area (15), the shoulder flex area (16) and a substantial portion of the sidewall (18) of a radial tire (14) when the plug (12, 52) is seated within a hole (40) cut through the injury in the tread area (15) of the tire (14). The patch member (11, 51) is preferably built up of plies (25-28; 55-58) of different lengths, each ply containing parallel tire reinforcing cords (29-32; 61-64), the cords (29, 30; 62, 64) in the longer plies (25, 26; 56, 58) extending longitudinally of the patch member (11, 51), while the cords (31, 32; 63) in some of the shorter plies (27, 28; 57) extend transversely of the patch member (11, 51), to reinforce the tread (15) areas surrounding the plug (12, 52) and to permit the longer plies (25, 26; 56, 58) to extend over the shoulder flex area (16) and the adjacent sidewall (18).

Description: PLUG PATCH FOR RADIAL TIRES Technical Field This invention relates to tire repair patches, and more particularly to a plug patch for a radial tire. Background Art It is currently the custom in repairing an injury to the tread of a radial tire having a puncture larger than 3/8" in diameter, to send the entire tire to a fully equipped repair plant. At the repair plant, a smooth hole is cut with an appropriate cutting tool through the tread containing the injury. An uncured rubber plug of a diameter slightly greater than the pre- cut hole is inserted into the hole and the uncured rubber of the plug is heated until the plug sets within the hole. Then a separate flat laminated patch having multi¬ ple plies containing tire re-inforcing cords is laid over the plug and secured to the inner surface of the tire by a chemically activated adhesive. The patch may be large enough to extend over the shoulder flex area and up the side wall of the tire. The tire repair process requires a substantial amount of time, in addition to the time consumed by transporting the tire to and from the repair plant. Injuries in radial tires having diameters less than 3/8" can be patched in the field by small repair patch kits, however, these small patches are only large enough to cover the inner surface of the tread area surrounding the injury and do not extend to the shoulder areas of the tire, In cases where a conventional combination plug patch is utilized to repair a relatively large injury, 3/8" or greater in diameter, the patch covers only the inner sur¬ face of the tire in the tread area and extends only to the shoulder flex area. The end portion of the patch ad- jacent the flex area soon becomes loose because of the vigorous flexure of the shoulder area of the tire during its normal operation on a vehicle. Combination plug patches in which the patch member is built up of layers of plies of tire reinforcing cords, are known in the art, but are principally used in the re¬ pair of tire injuries of bias ply tires, and only cover the inner surface of the tread area of the tire. These plug patches are constructed so that the patch itself is fixed concentrically- or symmetrically about the longi¬ tudinal axis of the plug. Such patch members are usually either circular or square in shape. Conventional combination plug-patches of symmetri¬ cal structure, principally for use in the repair of bias ply tires are as follows: PRODUCT COMPANY NAME "COMBI-METHOD PLUG PATCHES REMACO, a division of: Stahlgruber, Munich, Germany "UNI-SEAL" Technical Rubber Company Johnstown, Ohio "TEE UNIT" Tru Flex Rubber Products Los Angeles, California "PANG-SEAL" Pang, French Division of Tru Flex Rubber Products "PATCH RUBBER CO. PATCH Patch Rubber Company PATCH PLUG Roanoke Rapids, North Carolina, Division of Myers Industries, Akron, Ohio Disclosure of the Invention It is therefore an object of this invention to pro¬ vide a combination plug and patch, particularly adapted to repair injuries in the tread area of a radial tire in the field, without the necessity of sending the tire to a repair plant. Another object of this invention is to provide a plug patch particularly adapted for a radial tire, in which the patch member is made up of a plurality of plies of unequal lengths, each ply consisting of tire reinforcing cords, and a longitudinal plug fixed to and projecting eccentrically from the inner adhesive surface of the patch member and adapted to extend through a hole cut through the injury in the tread area of a radial tire. The patch member is characterized by having one end portion projecting from the center axis of the plug substantially farther than the other end portion or the side portions project from the center axis of the plug. The longer end portion of the patch member lies flush against the inner surface of the radial tire, extending over the tread area, the shoulder flex area and a sub- stantial portion of the sidewall, when the plug is seat¬ ed in its operative position in the pre-cut hole within the tread area. The long offset end portion of the patch member permits the patch to bridge the high flex¬ ure shoulder area, so that the patch will be securely bonded to the inner surface of the tire, even during extreme flexure of the shoulder area during road use. Preferably, the plies constituting the patch member of the plug patch include at least one ply hav¬ ing long radial tire reinforcing cords extending per- pendicularly to the cords in the other plies, so that the long radial cords in the plies extend over the shoulder area and the side walls, parallel to the rad¬ ial body cords within the tire. The shorter transverse plies, which do not extend across the shoulder area, provide additional reinforcement and anchoring of the radial body cords in the tread area adjacent the in¬ jury. The shorter end of the elongated patch member preferably terminates in the tread area short of the opposite shoulder so that the patch member experiences the flexure of only one of the tire shoulders. Brief Description of Drawings FIG. 1 is a top plan view of one embodiment of a plug patch made in accordance with this invention, with portions of the outer rubber layer and the plies broken awa ; FIG. 2 is an enlarged section taken along the line 2-2 of FIG. 1; FIG. 3 is a side elevational view of a plug patch made in accordance with this invention secured in oper- ative position on the inner surface of a radial tire, shown in cross-section and FIG. 4 is a top plan view, similar to FIG. 1, of a modified embodiment of a plug patch. Best Mode for Carrying Out the Invention Referring now to the drawings in more detail, FIGS. 1-3 disclose a combination lug patch 10 ' made in accordance with this invention including an integral elongated rectangular patch member 11 and an elongated plug 12. In FIG. 3, the plug patch 10 is disclosed secured in operative position within a radial tire 14, having a crown or tread area 15, opposite flex shoulder areas 16 and 17, opposed sidewalls 18 and 19, and an inner tire surface 20. The tread area 15 includes a plurality of circumferential belts 21 of reinforcing cords, con¬ stituting a breaker strip. Inwardly of the belts 21 are the radial body plies, including the radial steel cords 22 in a conventional steel-belted radial tire 14. The ends of the radial body cords 22 are hooked about the circumferential bead reinforcing wires 23 in the corresponding beads 24. The patch member 11 is built up from a plurality of substantially rectangular plies, such as the outer ply 25, two intermediate plies 26 and 27 and an inner ply 28, each of progressively smaller sizes. Each of the plies 25-28 is made from a plurality of parallel tire reinforcing cords of any desired material, such as Nylon or rayon. The longer rectangular plies 25 and 26 have their long reinforcing cords 29 and 30 extending longitudinally of the patch member 11, while the short¬ er intermediate ply 27 and inner ply 28 have their re¬ spective reinforcing cords 31 and 32 extending trans- versley of the longitudinal axis of the patch member 11 and perpendicular to the cords 29 and 30 of the plies 25 and 26, as best disclosed in FIG. 1. The cords 29- 32 of each of the plies 25-28, respectively, are coat¬ ed with uncured rubber. The plies 25-28 are sandwiched between a top or inner, uncured rubber cover sheet 33 and a bottom or outer cover sheet 14 of uncured rubber, The bottom or outer surface 35 of the bottom cover sheet 34 is uncurable by heat, but is adapted to be cured by chemical cement activation when installed in the tire 14. The assembled plies 25-28 and cover sheets 33 and 34 are cured together in a special press having a cavity in which the uncured plug 12_ > of conventional shape, is also fixed to the outer surface 35 by heat curing, to project substantially normal to the plane of the outer patch surface 35. The longitudinal central axis 36 of the projecting plug 12 is located eccentrically of the lengthwise dimension, or longitudinal axis, of the patch member 11, so that one end portion 38 of the patch mem- ber 11 is longer than the opposite end portion 39, rela¬ tive to the plug 12. As shown in FIG. 1, the longer end portion 38 of the patch member 11 includes the extended longitudinal portions of the plies 25 and 26, as well as the cover sheets 33 and 34. The length of the long end portion 38 relative to the plug 12 is such that when the plug 12 is inserted through the hole 40 cut within the tread por¬ tion 15 over the injured portion of the tire 14, the long end portion 38 extends over the closest shoulder flex area 16 and over a substantial portion of the ad¬ jacent sidewall 18, toward the closest bead 24, and in flush engagement with the inner surface 20 of the radial tire 14, as best disclosed in FIG. 3. In order to install the plug patch 10, a cutting tool is cused to cut or skive out a hole 40 through and encompassing the injured portion of the tread area 15. The inner surface 20 is buffed with an abrasive tool to provide a clean surface to which the patch member 11 may be adhesively secured. * The inner tire surface 20 is coated with an adhesive cement, which will activate the uncured surface 35 and bond to the inner tire surface 20. A plug patch 10 is then selected, in which the diameter of the plug 12 is slightly greater than the di¬ ameter of the hole 40. The plug patch 10 is then placed within the tire 14 and the plug 12 inserted through the hole 40, with the long end portion 38 directed toward the closest bead 23, so that the long reinforcing cords 29 and 30 are parallel, or in alignment with, the radial body ply cords 22. The plug 12 is then pulled through the hole 40 un- til the inner patch surface 35 is firmly seated against :• the inner tire surface- 20 so-that the * chemical cement- can- activate the opposing surfaces and cause them to adhere firmly to each other. The portion of the plug 42 (dis closed in phantom in FIG. 3) is cut along the outer sur- face of the tread and removed, in a conventional manner. As disclosed in FIG. 3, the long portion 38 of the patch member 11 is secured in flush engagement with the inner tire surface 20, and extends from the plug 12 along the short inner tread surface, across the shoulder flex area 16 and substantially along the sidewall 18, to firmly reinforce these areas, and particularly the high flexure shoulder area 16. The short end portion 39 of the patch member 11 terminates on the inner surface 20 of the tread area 15, on the opposite side of the plug 12 from the longer portion 38, but does not extend to the shoulder flex area 17. Also, as best disclosed in FIG. 3, the patch member 11 is built up around the plug 12 and the hole 40 to ex¬ tend generally in the same amount radially from the hole 40 in all directions, to reinforce the area of the tire immediately surrounding the injury or hole 40. The plug patch 10, made in accordance with this invention, anchors the shorter portions of the radial body cords 22 cut by the tread injury, by virtue of the extended long portion 38 of the patch member 11. When the shorter portions of the cut radial body cords ad¬ jacent an injury in the crown or tread 15, are not properly reinforced, the shorter radial body cords 22 tend to bulge outwardly with the sidewall 18. In FIG. 4, a modified plug patch 50 is disclosed having a patch member 51 and a plug 52 of generally the same construction as the plug patch Ϊ0, except that the plies 55-58 are of different shapes and sizes from the plies 25-28, and the reinforcing cords in some of the plies extend in different directions. In the patch member 51, the outer or bottom ply 55 and the upper in¬ termediate ply 57 are generally square and short, and confined to the area surrounding the plug 52. On the other hand, the lower intermediate piy 56 and the ' upper or inner ply 58 constitute the long plies having the ex- tended portions eccentrically extending from the plug 52 to form the long end portion 59 and the short end por¬ tion 60. The respective ply directions are shown by the respective arrows 61, 62, 63 and 64. In the configura- tion of the patch member 51,. only the upper intermediate patch 57 has transversely extending reinforcing cords, as indicated by the transverse arrow 63, while all the remaining plies 55, 56, and 58 have- their cords extend¬ ing in a longitudinal direction as indicated by the arrows 61, 62, and 64 respectively. . The plies 55-58 are covered by the inner or top rubber cover sheet 65 and the bottom or outer cover sheet 66 . It will also be noted in FIG. 4 that the general outline of the patch member 51 is a cruciform, with the narrower long end portion 59 being adapted to extend along the shoulder flex area 16 and the sidewall 18, in the same manner as the long end portion 38 disclosed in FIG. 3. Industrial Applicability It will therefore be apparent that plug patches 10 and 50 have been designed in which patch members 11 and 51 are fixed eccentrically to elongated projecting plugs 12 and 52 to form long end portions 38 and 59, respectively, adapted to extend along the short inner tire surface of the tread area, and also along the high flexure shoulder area 16 and a substantial part of the adjacent sidewall 18. The patches 10 and 50 are manufactured as a compos¬ ite unit which may be easily used and installed in the field to repair in injury in the tread area 15 of a ra- dial tire 14, with only an appropriate cutting tool, not shown, for cutting the hole 40 around the injury in . the tread area 15. These plug patches 10, and 50, may be utilized " for repairing injuries in the tread areas 15 where the injuries are large, such as injuries having 3/8" to 1" diameter punctures, which previously could be repaired only at a tire repair plant.

Claims: Claims 1. A plug patch (10,50) for repairing an injury in a radial tire (14) having a tread area (15) a side¬ wall (18) , and a shoulder flex area (16) joining the ^ tread area (15) and the sidewall (18) , and an inner tire surface (20) , comprising: (a) an elongated patch member (11,51) having an outer patch surface (35) adapted to be adhesively secured to the inner tire s r- 0 face (20) of a radial tire (14) , and com¬ prising first (38,59) and second (39,60) end portions , (b) an elongated plug (12,52) having a longi¬ tudinal central axis (36) integral with and 5 projecting from said outer patch surface (35) , said plug (12,52) being adapted to extend snugly through a hole (40) cut through an injury in a radial tire (14) in operative position, (c) said first end portion (38,59) extending longitudinally of the patch member (11,51) far enough away from the central axis (-36) of said plug (12,52) that said first end portion (38,59) fits flush against the inner tire surface (20) of the shoulder flex area (16) and a substantial portion of the sidewall (18) of a radial tire (14) when said plug (12,52) is in said opera¬ tive position, and (d) said patch member (11,51) having a sub¬ stantial exterior surface area surround¬ ing said plug (12,52) and positioned flush against the interior tire surface (20) when said plug (12,52)is in said operative posi- tion. .2. The invention according to claim 1 in which said plug (12,52) extends through said hole (40) in the tread area (15) in said operative position, and said sedond end portion (39,60) of said patch member (11, 51) terminates on the interior surface (20) of the tread area (15) . 3. The invention according to claim 1 in which* said patch member (11,51) comprises a plurality of plies (25-28,55-58) of tire reinforcing cords (29-32,61-64). .4. The invention according to claim 3 in which said patch member (11,51) comprises at least two plies, at least one of said plies (25,26;.56,58) extending over the sidewall " (18) of the radial tire (14) when said plug (12,52) is in said operative position. 5. The invention according to claim 4 in which the reinforcing cords (29,30;62,64) in said one ply (25,26? 56,58) extending over the sidewall (18) extend longi¬ tudinally of said patch member (11,51) . 6. The invention according to claim 4 in which at least one of the plies (27,28;57) in said patch member (11,51) extend only over the tread area (15) of the radial tire (14) when said plug (12,52) extends through said hole (40) in the tread area (15) in said operative position, and the reinforcing cords (31,32; 63) in said one ply (27,28;57) extend transversely of the longitudinal axis of said patch member (11,51). 7. The invention according to claim 6 in which said patch member (11) comprises an inner ply (28) , an outer ply (25) and at least one intermediate ply (27,26) between said inner (28) and outer (25) plies, said plies being of unequal length and width, at least said outer Piy (25) extending substantially the full length of said patch member (11) so that said outer ply (25) extends over the shoulder flex area (16) and the sidewall (18) of the radial tire (14) , when said plug (12) is in said operative position. 8. The invention according to claim 7 in which each of said plies (25-28) comprises a plurality of parallel tire reinforcing cords (29-32) , the cords (29) in said outer ply (25) extending longitudinally of - said patch member (11), and the cords (31) within one (27) of said intermediate plies (26,27) extending transversely of the longitudinal axis of said patch mem- ber (11) . 9. The invention according to claim 7 further comprising two intermediate plies (26,27) . 10. The invention according to claim 9 in which two (27,28) of said plies (25-28) have opposite ends terminating within the tread area (15) of the radial tire (14) when said plug (12) is in said operative posi¬ tion. 11. The invention according to claim 1 in which said exterior patch surface (35) comprises rubber mat- erial capable of being activated by a chemical cement for adhering to the interior tire surface (20) .

Inventors: BAUMGARDNER RICHARD H, BAUMGARDNER, RICHARD, H.
Applicants: PERFECT EQUIP CORP, PERFECT EQUIPMENT CORP.
Application year: 1985
Main classification: B29H5
IPC codes: B29C73