Abstract: A rubber composition, including ?,?-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (A) having number average molecular weight of 50,000 to 150,000, ?,?-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (B) having number average molecular weight of 1,000 to 20,000, ethylene-?-olefin copolymer rubber (C), and a graft copolymer (D); wherein said graft copolymer (D) is obtained by performing graft copolymerization on a mixture of an aromatic vinyl compound and an ?,?-ethylenically unsaturated nitrile monomer with an ethylene-propylene-unconjugated copolymer, and a content of structure units of said ethylene-propylene-unconjugated copolymer is 20 to 70 wt %; a ratio of the graft copolymer (D) with respect to 100 parts by weight in total of said rubber (A), rubber (B) and rubber (C) is 1 to 30 parts by weight; and a composition ratio of the rubber (A), rubber (B) and rubber (C) is rubber (A): 20 to 79 wt %, rubber (B): 1 to 30 wt %, and rubber (C): 20 to 50 wt %, is subjected

Abstract: A rubber composition includes ?,?-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (A), ?,?-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (B), ethylene-?-olefin copolymer rubber (C), and a graft copolymer (D). The graft copolymer (D) is obtained by performing graft copolymerization on a mixture of an aromatic vinyl compound and an ?,?-ethylenically unsaturated nitrite monomer with an ethylene-propylene-unconjugated copolymer. A content of structure units of the ethylene-propylene-unconjugated copolymer is 20 to 70 wt %, a ratio of the graft copolymer (D) with respect to 100 parts by weight in total of said rubber (A), rubber (B) and rubber (C) is 1 to 30 parts by weight. A composition ratio of the rubber (A), rubber (B) and rubber (C) is rubber (A): 20 to 79 wt %, rubber (B): 1 to 30 wt %, and rubber (C): 20 to 50 wt %.

Abstract: A rubber composition, including &agr;,&bgr;-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (A) having number average molecular weight of 50,000 to 150,000, &agr;,&bgr;-ethylenically unsaturated nitrile-conjugated diene copolymer rubber (B) having number average molecular weight of 1,000 to 20,000, ethylene-&agr;-olefin copolymer rubber (C), and a graft copolymer (D); wherein said graft copolymer (D) is obtained by performing graft copolymerization on a mixture of an aromatic vinyl compound and an &agr;,&bgr;-ethylenically unsaturated nitrile monomer with an ethylene-propylene-unconjugated copolymer, and a content of structure units of said ethylene-propylene-unconjugated copolymer is 20 to 70 wt % ; a ratio of the graft copolymer (D) with respect to 100 parts by weight in total of said rubber (A), rubber (B) and rubber (C) is 1 to 30 parts by weight; and a composition ratio of the rubber (A), rubber (B) and rubber (C) is rubber (A): 20 to 79 wt %, rubber (B) 1 to 30 wt %, and rubber (C):

Abstract: A tester for measuring a durability of a knitted yarn portion in which at least two sets of yarns, including a set of first yarns and a set of second yarns, are intersected, the tester includes: a first holding unit holding ends of the two sets of yarns at first positions that are relative to the knitted yarn portion; a second holding unit holding opposite ends of the two sets of yarns at second positions that are relative to the knitted yarn portion; and a position adjusting unit, connected to the first holding unit and the second holding unit, allowing at least one of the first positions and the second positions, relative to the knitted yarn portion, to be moved to other positions, thus varying an intersecting angle of the yarns of the knitted yarn portion.

Abstract: A reinforced hose includes an inner tubular rubber layer, a cover layer made of rubber, and at least two reinforcing thread layers, including an upper thread layer and a lower thread layer, disposed between the inner tubular rubber layer and the cover layer. At least the lower thread layer includes a polyester thread having the following physical properties: a tensile strength of 8 grams or more per a unit denier, an elongation of 10.+-.1.5%, and a loaded elongation of 2.7.+-.1.0% per a unit denier under 3-gram load. With this construction, the reinforced hose satisfies the fatigue resistance and volume expansion requirements simultaneously.

Abstract: A reinforced rubber hose having a layer of ethylene-propylene rubber outside or inside a fiber-reinforcing layer. The two layers are firmly bonded to each other by an extruded adhesive layer of butyl rubber which exhibits a high bond strength after vulcanization. This obviates the necessity of treating (usually by dipping) the fibrous reinforcement with an adhesive before its braiding or knitting.

Abstract: A method and apparatus for controlling the die-retaining force of an extruder is disclosed. In the operation of an extruder adapted to retain a die with a container actuated by a container cylinder and effect extrusion of a billet readied for use in the container by forcing the billet through the die, to keep the die-retaining force of the extruder constant, the control of the die-retaining force of the extruder is carried out by causing the container cylinder to impart to the container a force directed away from the die so as to be sequentially decreased during the first half period of the extrusion and causing the container cylinder to impart to the container a force directed toward the die so as to be sequentially increased during the last half period of the extrusion.

Abstract: Disclosed is a hose unit including harnesses which can be easily attached to and detached from the other portion of the unit at the time of fastening thereof to the body of a motor vehicle or the like and which hardly undergoes stress even at the time of vibration or torsion of the hose of the unit. The hose unit includes the hose to which respective end metal members are secured. Holders are removably fastened to these members. One harness extends along the hose and is fastened to the holders and another harness is connected to the former through the holders and extends therefrom. Also disclosed is a special hose clamp.

Abstract: In a burner assembly connected with a combustion chamber at a fuel inlet of said combustion chamber, the improvement of which comprising a fuel duct which is connected at its one end to said fuel inlet and contains therein a fuel injection nozzle, ignition rod and air-fuel mixture diffuser, a blower means which has an outlet for blowing an air through said outlet of the blower means and said fuel duct into said combustion chamber, and a conduit member coupled to said inlet of the blower means, whereby pneumatic oscillation plane progressive waves are converted into plane stationary waves to thereby reduce progressive energy of said pneumatic oscillation plane progressive waves.