Abstract: A conductive roller comprising a toner-transporting portion, made of a vulcanized rubber composition, which is disposed at least on an outermost layer thereof. The vulcanized rubber composition contains a rubber component (A) mixed with a weakly conductive carbon black (B) having a large particle diameter not less than 80 nm nor more than 500 nm, a highly conductive carbon black (C) having a small particle diameter not less than 18 nm nor more than 80 nm, and an inorganic filler (D) consisting of not less than one kind of a metal oxide selected from among a group of titanium oxide, alumina, and silica. The total of a mixing amount of the weakly conductive carbon black (B), that of the highly conductive carbon black (C), and that of the inorganic filler (D) for 100 parts by mass of the rubber component (A) is not less than 15 parts by mass nor more than 60 parts by mass.

Abstract: A heavy duty pneumatic tire having improved resistance to uneven tread wear includes a tread portion provided with an axially outer longitudinal main groove and an axially inner longitudinal narrow groove, each extending circumferentially about the tire to define a narrow rib therebetween, the axially inner edge of the narrow rib being chamfered by a slope. In the tire meridian section, the slope is straight or concave. The axial width of the axially inner longitudinal narrow groove is in the range of from 0.5 to 2.5 mm. The axial width (W3) of the slope measured between the upper and lower edges thereof is in the range of from 0.3 to 0.8 times the axial width (W2) of the narrow rib, and the radial height (H2) of the slope measured between the upper and lower edges is in the range of from 0.3 to 0.8 times the depth (H1) of the axially inner longitudinal narrow groove.

Abstract: A tire pressure drop detecting method, which executes a pneumatic pressure drop judging processing for autocruise traveling when the vehicle is in a state of autocruise traveling. It is judged based on a front/rear acceleration of the vehicle whether the vehicle is in a state of autocruise traveling or not. Furthermore, the pneumatic pressure drop judging processing for autocruise traveling is performed by using a judging threshold value which is set to become smaller as the speed of the vehicle becomes larger.