公开(公告)号：JPS5996004A

公开(公告)日：1984-06-02

申请号：JP20540382

申请日：1982-11-25

Applicant: BRIDGESTONE CORP

Inventor： KURODA MASAHIRO

IPC: B60C11/16

Abstract: PURPOSE:To restrain spikes from excessively projecting, by forming damping holes which are stepped bottom holes, in each spike driving hole formed in a tread section so that each spike is sunk into the spike driving hole by deforming the damping holes in accordance the degree of tread abrasion. CONSTITUTION:In each driving hole 6 opened to the tread section 4 of a tire, for driving thereinto a spike S, S', there is provided damping holes 7 which are stepped bottom holes opened face to face with the bottom 8 of the spike S, S'. Further, the depth of the driving hole 7 including the damping holes 7 is more than 115% of the length of the spike S, S'. Further, the sum of the maximum cross-sectional areas of the damping holes 7 in each driving hole 6 is set in a range of 1-16% of the maximum cross-sectional area of the spike S, S'. With this arrangement, reaction force by tread rubber with respect to the sinking of the spike S, S' is reduced and controlled by deformation of the damping holes 7. Accordingly, the sinking is continued even after initial abrasion of the tread section 4 so that the spike S, S' may be restrained from excessively projecting.

公开(公告)号：JPH01317807A

公开(公告)日：1989-12-22

申请号：JP2867889

申请日：1989-02-09

Applicant: BRIDGESTONE CORP

Inventor： NAKAYAMA SHOHACHIRO ,  IWATA TOYOMI ,  KURODA MASAHIRO ,  GOTO NAOYUKI ,  UEDA HIROSHI ,  ISHII MICHIO

IPC: B60C11/02 ,  B29D30/06 ,  B29D30/56 ,  B60C11/00 ,  B60C11/03 ,  B60C11/04

Abstract: PURPOSE:To prevent the breakaway of a tread caused by the existence of a rear groove so as to improve the durability by disposing the groove bottom of the rear groove at the level higher than that of the groove bottom of a surface groove as well as having the rear groove communicated to the air. CONSTITUTION:In a retreaded tire 11 used for a truck, etc., a precured tread 12 is adhered to the crown part 13a of a base tire 13 made of a used-up tread buff-processed by means of a sheet-formed cushion gum 15. In the precured tread 12, a surface groove 16 is formed in a ground plane part 12b and a rear groove 18 in a rear part 12d respectively. The depth D18 of the rear groove 18 is set higher than the depth to reach the depth D16 of the groove bottom 16a of the surface groove 16. A vent hole 20 and a sipe 21 are formed respectively as passages and the groove bottom 18c of the rear groove 18 is communicated to the outside air. The tread 12 is thus prevented from the breakaway caused by the thermal expansion of gas inside the rear groove 18.

公开(公告)号：JPS5996005A

公开(公告)日：1984-06-02

申请号：JP20540482

申请日：1982-11-25

Applicant: BRIDGESTONE CORP

Inventor： KURODA MASAHIRO

IPC: B60C11/16

Abstract: PURPOSE:To aim at enhancing the performance of a tire and preventing roads from being damaged, by forming cuts around spike driving holes in a several number formed in a tread section to locally relax the rigidity of the tread section so that the spikes are inclined only when force due to slip is brought about. CONSTITUTION:In a tire formed with a several number of driving holes 3 for planting spikes 2 on the tread section T of the tire, a plurality of cuts 4 are formed in the tread section T around the driving holes 3 to locally relax the rigidity of the tread section T. In this arrangement, the cuts 4 are arranged so that they are independent from each other and each driving hole 3, for example, intervanes between them in the fore-and-aft direction of the tread section T. Further, the shape of the cuts 4 is circular. Further more, the depth (h) of the cuts 4 is preferably in a range 25-50% of the depth H of the driving holes 5. Further, in the case of that the cuts 4 are arrayed annularly, the included angle (d) of each cut 4 is preferably less than 75 deg.., measuring from the center of the spike 2.

公开(公告)号：JPH02234804A

公开(公告)日：1990-09-18

申请号：JP5680089

申请日：1989-03-09

Applicant: BRIDGESTONE CORP

Inventor： TOGASHI MINORU ,  TAKANAMI TAKESHI ,  KURODA MASAHIRO

IPC: B60C9/06 ,  B60C3/04 ,  B60C15/00 ,  B60C19/00

Abstract: PURPOSE:To enhance the durability of a bead without increasing the weight by forming a representative ply of a laminate from a specific crown shape curve and a specific side shape curve. CONSTITUTION:In a certain representative ply 20a, the dia. is represented by D, the cord angle on tire equator by A, the dia. of a rim point by B, its width by C, and the natural equilibrium shape curve determined from them by E, and further the natural equilibrium shape curve determined from a certain dia. within the range expressed as D+3(D-B)/100

公开(公告)号：JPH0210721B2

公开(公告)日：1990-03-09

申请号：JP5116981

申请日：1981-04-07

Applicant: BRIDGESTONE CORP

Inventor： KURODA MASAHIRO

IPC: B60C11/11 ,  B60C11/117 ,  B60C11/12

公开(公告)号：JPS58183301A

公开(公告)日：1983-10-26

申请号：JP6398182

申请日：1982-04-19

Applicant: Bridgestone Corp

Inventor： KURODA MASAHIRO

IPC: B60C11/16

CPC classification number: B60C11/16

Abstract: PURPOSE:To prevent a road surface from damaging by maintaining appropriately a protrusion quantity of a spike irrespective of progress of wear of a tire tread, by providing a drive hole of the spike provided with a stepped and bottomed hole to be opened facing toward a bottom flange of the spike in the tread. CONSTITUTION:A stepped and bottomed holes 7 to be opened facing toward a bottom flange 2 of spikes S and S' are provided in drive holes of spikes provided in a tread 4 of a tire. Deterrent action for sinking through a casing part 5 is alleviated due to the existence of the stepped and bottomed holes 7 and moreover the allowance for elastic deformation and restoration under a load acting upon spikes 3 are improved. Thereby, the damage to a road surface irrespective of wear of the tread can be prevented from occurring.

Abstract translation: 目的：通过设置具有阶梯状和有底孔的尖端的驱动孔，通过设置朝向底部打开的阶梯状和有底孔的方式，通过适当地保持尖峰的突出量来防止路面的破坏，而不管轮胎胎面的磨损的进展 胎面上穗的法兰。 构成：设置在轮胎的胎面4中的尖钉的驱动孔中，设置有朝向鞋钉S和S'的底部凸缘2朝向打开的阶梯状和有底孔7。 由于存在阶梯式和有底孔7，因此通过壳体部分5下沉的阻力作用得到缓解，此外在作用在钉3上的载荷下的弹性变形和恢复的允许被改善。 由此，可以防止不考虑胎面的磨损对路面的破坏。