AU2007203377B2

AU2007203377B2 - Pneumatic tire with reinforced bead part

Info

Publication number: AU2007203377B2
Application number: AU2007203377A
Authority: AU
Inventors: Doh-Zong Chung; Myung-Jin Lee; Bok-Soo Park
Original assignee: Kumho Tire Co Inc
Current assignee: Kumho Tire Co Inc
Priority date: 2001-03-20
Filing date: 2007-07-20
Publication date: 2010-05-13
Anticipated expiration: 2021-08-31
Also published as: AU2007203377A1

Description

PNEUMATIC TIRE WITH REINFORCED BEAD PART Technical field The present invention relates to a pneumatic tire with a rubber lump applied to the 5 bead part, and more particularly, to a pneumatic tire wherein bead part is reinforced by using a rubber lump, and carcass ply or a reinforcing structure which encloses the rubber lump, to minimize the movement of the bead so that the bead portion is not easily released from the rim of the tire, especially the tire installed on the rim without flange, while driving under low air pressure of tire. 10 Background art In conventional pneumatic tires, a wedge is installed at the side of the bead so that the bead portion of the tire is not released from the rim when the tire is deflated or at low air pressure. As one example of prior art, US Pat. No. 5,971,047 is illustrated in Fig. 1. As 15 shown in the figure, the upper part of carcass ply 3 winds a wedge 2 and is turned up, and then spherical bead 1 is installed wound on the carcass ply. This art requires many manufacturing steps and has many problems as described below. First, the process of installing bead and wedge is very complicated, and there is a possibility that the bead is released from the rim due to the movement of the spherical 20 bead applied when the tire is deflated. Moreover, since the hardness of the wedge 2 used is low, about 95 or lower, the wedge 2 can be deformed partially on the portion suppressed by the bead 1, and cannot perform desired role. 25 -2 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the referenced prior art forms part of the common general knowledge in Australia. 5 Summary of the invention The object of the present invention is to improve the bead portion of the pneumatic tire installed on the rim the toe of which is larger than the heel in diameter while not changing the function of the tire, and to provide a pneumatic tire which can prevent the bead portion from releasing from the rim when the tire is deflated so that car accidents can be avoided. 10 Brief description of drawings Fig. 1 is a sectional view of the bead portion of a conventional tire, Fig. 2 is a sectional view of the bead portion of a tire according to one embodiment of the present invention, Fig. 3 is a sectional view according to another embodiment of the present invention, 15 which inserts reinforcing structure in the bead portion, and Fig. 4 a sectional view illustrating various embodiments of the present invention, in which two sheets of carcass ply are installed winding in various forms. Explanation of marks in the figures 1: bead, 2: wedge 20 3,3a, 3a', 3b, 3b', 3c, 3c', 3d and 3d': carcass ply 4: flipper 5: rubber lump 6: flange 7: bead seat 8: bead portion -3 Best mode for carrying out the invention To address the object as stated above, a rubber lump is installed at the side surface of a bead, and a carcass ply winds the rubber lump in the same direction or in various shape, so 5 that the rubber lump and the carcass ply wound thereto prevent the bead portion from being released from the bead seat of the rim when the tire is deflated. The constitution of the pneumatic tire having reinforced bead part of the present invention will be described in detail with reference to the accompanying drawings. Fig. 2 is a cross-sectional view of a tire according to one embodiment of the present 10 invention, wherein a wedge-shaped rubber lump 5 having shore harness of 95-100 is installed at the bottom of the bead in square shape in order to decrease movement of the bead 1 in the bead portion 8 mounted to the bead seat 7 of the rim, and a carcass ply 3 winds from the upper end to the lower end of the bead, and then from the upper surface to the side surface and to the bottom surface of said rubber lump 5. It is much more effective for the carcass ply 3 to wind 15 in above order than it winds in the order of bottom surface, the side surface and upper surface. Now the process of manufacturing the bead part 8 in which the carcass ply 3 winds the rubber lump 5 will be described. The carcass ply can be manufactured easily in the following manner: the rubber lump 5 winds at an arbitrary point of the moulding drum, and one sheet of carcass ply 3 winds 20 thereto, and the rubber lump 5 is turned down at both ends of the carcass ply 3 to wind the bead. Accordingly, when the tire is deflated under-inflated while driving, the carcass ply 3 is pulled toward the side of the tire, and this force makes the carcass ply 3 push the bead 1 against the rubber lump 5. Then the rubber lump 5 is pushed to the rim and the bead 1 does 25 not push rubber lump 5 any more. Therefore, the bead part 8 is not easily released -4 from the rim because the bead part 8 is prevented from being released from the bead seat 7. Fig. 3 represents the pneumatic tire in which a flipper 4 is applied as a reinforcing structure. By using the reinforcing structure, the problem of prior art tire that the bead part of 5 tire is moved to the wall area and released from the bead seat 7 when the tire is deflated or is under-inflated while driving can be overcame. As illustrated in Fig. 3, the flipper 4 overlaps the carcass ply 3 under the rubber lump 5, and expands along the side surface and upper surface of the rubber lump 5, and passes under the bead 1, and finally reaches above the bead I so that the bead 1 and the carcass ply 3 are not be deviated from the bead seat 7 area. 10 The figures (a), (b), (c) and (d) of FIG. 4 are cross-sectional views of the bead part of tire illustrating other embodiments of the present invention, wherein two sheets of carcass ply wind in various form in each bead part. While one sheet of carcass ply is applied in the bead part of FIG. 2 and FIG. 3 respectively, two sheets of carcass ply are applied in the embodiments of Fig. 4; (a) two 15 carcass plies 3a, 3a'wind to upper and lower part of the rubber lump 5, (b) two carcass plies 3b, 3b'wind to upper and lower part of the rubber lump 5 and meet and overlap at the side of the rubber lump, (c) two carcass plies 3c, 3c'wind the rubber lump 5 overlapping on the upper surface of the rubber lump 5, one carcass ply winding to the middle of the side surface of the rubber lump 5 and the other carcass ply overlapping said carcass ply and winding side surface 20 of the rubber lump 5 completely, (d) two carcass plies 3d, 3d'wind the rubber lump 5, one carcass ply winding via lower surface of the rubber lump 5 to the middle of the side surface of the rubber lump 5 and the other carcass ply overlapping said carcass ply and winding the rubber lump 5 completely.

Industrial applicability By using the pneumatic tire with reinforced bead part of the present invention in a tire without flange, the bead part is not easily released from the rim when the tire is deflated or under-inflated while driving, and the function of the tire is not affected 5 Therefore, the car accidents caused by released bead part can be prevented.

Claims

1. A pneumatic tire with a reinforced bead part, said bead part including: a bead having an upper side and a lower side, 5 a rubber lump having an upper surface, a side surface, and a lower surface, a carcass ply, and a flipper, wherein the rubber lump is installed below the lower side of the bead and the carcass ply is wound around the lower surface of the rubber lump, and the flipper overlaps the carcass ply on the lower surface of the rubber lump, and is wound around the side surface and 10 the upper surface of the rubber lump, the lower side of the bead, and the upper side of the bead.

2. A pneumatic tire with a reinforced bead part having a bead, said beat part including: a bead having an upper side and a lower side, 15 a rubber lump having an upper surface, a side surface and a lower surface, the rubber lump being installed below the lower side of the bead, said tire comprising two sheets of carcass ply, wherein one carcass ply is wound around an upper surface of the rubber lump, and the other carcass ply is wound around a lower surface of the rubber lump, and two carcass 20 plies meet at a side surface of the rubber lump and overlap, the overlapping plies partially wrap around the bead.

3. A pneumatic tire having a reinforced bead part according to claim 2, wherein the rubber lump has a shore hardness between 95 and 100. 25

4. A pneumatic tire with a reinforced bead part having a bead, said bead part including: a bead having an upper side and a lower side, a rubber lump having an upper surface, a side surface and a lower surface, the rubber lump being installed below the lower side of the bead, said tire comprising two sheets of carcass ply, one carcass ply being wound to the middle of a side surface of the rubber lump 30 and passing through a lower end and an upper end of the bead, and the other carcass ply being wound completely around the side surface of the rubber lump, and overlapping the one carcass ply on the side surface of the lump.

5. A pneumatic tire with a reinforced bead part according to claim 4, wherein the rubber lump has a shore hardness between 95 and 100. 7

6. A pneumatic tire with a reinforced bead part having a bead, said bead part including: a bead having an upper side and a lower side, a rubber lump having an upper surface, a side surface and a lower surface, the rubber lump being installed below the lower side of the bead, said tire comprising two sheets of 5 carcass ply, one carcass ply is wound around the middle of a side surface of the rubber lump and a lower surface of the rubber lump, and the other carcass ply overlapping the one carcass ply and is wound completely around the rubber lump.

7. A pneumatic tire having a reinforced bead part according to claim 6, wherein the rubber lump has a shore hardness between 95 and 100. 10

8. A pneumatic tire substantially as hereinbefore described with reference to figures 2 to 4(d) of the accompanying drawings.