Abstract:
PROBLEM TO BE SOLVED: To provide an annular metal cord excellent in rupture strength and easy of manufacture, and to provide an endless metal belt and a method for manufacturing the annular metal cord. SOLUTION: The annular metal cord C1 is provided as follows. Six metal wires 5 are twisted into a strand 1, which is wound into a predetermined annular diameter. The start point and the end point of the strand is temporarily fixed to form an annular core 3. The strand 1 continuous from the annular core 3 is helically wound on the annular core 3 six times therearound so as to form an external layer 4 covering the external surface of the annular core 3. After that, the start point and the end point of the strand 1 are connected by a connection member 7. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a rubber-steel cord composite suitable as a reinforcing material for a tire for high speed and heavy load, especially usable as the tire for an airplane, and to provide a pneumatic radial tire for the high speed and heavy load, having improved durability by applying the composite as a rubber-reinforcing material. SOLUTION: The steel cord has a multi-twisted structure obtained by twisting N (N=2 to 8) strands 2 each obtained by twisting a plurality of wires 1, satisfies the formula: ε C ≥0.005 [wherein, ε C is defined by the formula: ε C =√(-b/2+√(b 2 /4-c))-1 (wherein b is -1+π 2 (-4R 2 +d 2 )/P 2 ; c is π 2 d 2 k(4π 2 R 2 +P 2 )/P 4 ; R is (D-d)/2; and k is tan 2 (π/2-π/N))] when d (mm) is the diameter of the strand, D (mm) is the circumcircle diameter of the cord, and P (mm) is the twisting pitch of the cord, and has an elongation at break of ≥2.5%. COPYRIGHT: (C)2008,JPO&INPIT