Abstract: To improve repulsion performance when a ball is hit by a racket. Grommets each include a strip-shaped portion and a cylinder portion protruding from one surface of the strip-shaped portion. The cylinder portion includes a plurality of ribs extending along an extending direction of a central axis of a cylinder main body. The plurality of ribs is constituted of first ribs protruding from an outer peripheral surface of the cylinder main body toward both sides in the extending direction of the strip-shaped portion, and second ribs protruding from the outer peripheral surface of the cylinder main body toward both sides in a direction orthogonal to the extending direction of the strip-shaped portion. Two or more of the first ribs are formed on each of the both sides in the extending direction of the strip-shaped portion, and one or more of the second ribs are formed on each of the both sides in the direction orthogonal to the extending direction of the strip-shaped portion.

Abstract: A compressor includes a suction hole provided in a cylinder. The suction hole includes a plurality of portions being different in diameter and disposed from an outer circumferential side toward an inner circumferential side of the cylinder. The plurality of portions are reduced more in diameter toward the inner circumferential side of the cylinder. A central axis of an outer circumferential side suction hole of the plurality of portions intersects a central axis of the cylinder. A central axis of an inner circumferential side suction hole of the plurality of portions is parallel to the central axis of an outermost circumferential side portion and decentered from the central axis in an opposite direction to a direction of a spring hole.

Abstract: A sealed compressor includes a centrifugal impeller above a rotor to synchronously rotate. A refrigerant rises through a rotor air hole, flows in an upper space, and flows out from a discharge pipe. The centrifugal impeller includes an oil separation plate on the rotor, and plural vanes standing on the oil separation plate, and forms inter-vane flow passages between adjacent vanes, and a vane inner flow passage that guides refrigerant from the rotor air hole to inner entrances of the inter-vane flow passages. Outer exits of the inter-vane flow passages are disposed along an entire circumference, and refrigerant increased in pressure while passing through the inter-vane flow passages flows out from the outer exits to the upper space. The oil separation plate closes a short-circuit passage through which the refrigerant directly flows from the vane inner flow passages to the discharge pipe without passing through the inter-vane flow passages.

Abstract: A compressor includes a suction hole provided in a cylinder. The suction hole includes a plurality of portions being different in diameter and disposed from an outer circumferential side toward an inner circumferential side of the cylinder. The plurality of portions are reduced more in diameter toward the inner circumferential side of the cylinder. A central axis of an outer circumferential side suction hole of the plurality of portions intersects a central axis of the cylinder. A central axis of an inner circumferential side suction hole of the plurality of portions is parallel to the central axis of an outermost circumferential side portion and decentered from the central axis in an opposite direction to a direction of a spring hole.

Abstract: A sealed compressor includes a centrifugal impeller above a rotor to synchronously rotate. A refrigerant rises through a rotor air hole, flows in an upper space, and flows out from a discharge pipe. The centrifugal impeller includes an oil separation plate on the rotor, and plural vanes standing on the oil separation plate, and forms inter-vane flow passages between adjacent vanes, and a vane inner flow passage that guides refrigerant from the rotor air hole to inner entrances of the inter-vane flow passages. Outer exits of the inter-vane flow passages are disposed along an entire circumference, and refrigerant increased in pressure while passing through the inter-vane flow passages flows out from the outer exits to the upper space. The oil separation plate closes a short-circuit passage through which the refrigerant directly flows from the vane inner flow passages to the discharge pipe without passing through the inter-vane flow passages.

Abstract: A wire for electric railways comprises a copper alloy which consists essentially, by weight percent, of 0.1 to 1.0% Cr, 0.01 to 0.3% Zr, 0.05 to 0.15% Sn, and 10 ppm or less O, and if required, further contains 0.01 to 0.1% Si, or 0.01 to 0.1% Si and 0.001 to 0.05% Mg, with the balance being Cu and inevitable impurities.

Abstract: A wire for electric railways comprises a copper alloy which consists essentially, by weight percent, of 0.1 to 1.0% Cr, 0.01 to 0.3% Zr, and 10 ppm or less O, and if required, further contains at least one element selected from the group consisting of 0.01 to 0.1% Si and 0.001 to 0.05% Mg, with the balance being Cu and inevitable impurities. The wire is manufactured by hot working a copper alloy billet having the above composition, immediately quenching the hot worked billet to prepare an element wire, cold working the element wire at least once, and subjecting the cold worked element wire to aging treatment.

Abstract: First, a steel wire is continuously dipped in molten copper or molten copper alloy so that copper or copper alloy builds up and solidifies on the peripheral surface of said steel wire, thereby obtaining an initial copper-clad steel wire. Then, the initial copper-clad steel wire is subjected to a first cycle of hot rolling by a caliber roll. The hot-rolled wire is dipped in molten copper or molten copper-alloy at least once so that copper or copper alloy builds up and solidifies thereon, thereby obtaining a final copper-clad steel wire.The final copper-clad steel wire is hot-rolled at a temperature of 750.degree. to 850.degree. C. and with a rolling ratio of 10 to 40%. Then, the hot-rolled wire is cold-rolled with a reduction of area of 20% or more.Thus, 75 to 95% of the cross sectional area of the obtained copper-clad steel trolley wire is occupied by the copper or copper alloy covering layer so that the electric conductivity of the trolley wire is as high as 80% IACS or more.