Abstract:
A pneumatic tire having a block type tread pattern improved in stone trapping, which comprises a tread portion being provided with a mesh of grooves to define a plurality of blocks consisting of shoulder blocks adjacent to the tread edges and central blocks other than the shoulder blocks, each of the central blocks being surrounded by at least one projection standing out from the groove bottom leaving spaces from the groove walls, the projection comprising alternate wide main portions and narrow coupler portions, the height of the wide main portions being 10 to 25% of the groove depth, the height of the narrow coupler portions being 5 to 10% of the groove depth, the length of each of the wide main portions being 3 to 10 mm, the length of each of the narrow coupler portions being 2 to 8 mm, the width of the narrow coupler portions being 0.5 to 2 mm, and the main portions comprises first main portions and second main portions, the first main portions being disposed between junctions of the grooves and being relatively taller than said second main portions.
Abstract:
A tire for heavy load with a aspect ratio of 80% or less has five ribs which are a center rib extending on a tire equator, a pair of outer ribs extending along a tread edge and a pair of intermediate ribs each extending between the center rib and the outer ribs. An outer end line of the intermediate rib extends in the circumferential direction in zigzags. In a state of 5% internal pressure, a distance (X) from the tire equator line to a center line (Q) of the zigzagged outer end line is in a range of 0.25 to 0.275 times the tread width (WT). A tread radius of curvature R under the state of 5% internal pressure and a difference (Y=y2-y1) satisfy the following equation (1):-0.001R+0.4 mm.ltoreq.Y.ltoreq.-0.00357R+2.4 mm (1)wherein the difference (Y=y2-y1) being the difference between an inflation amount (y1) at the tire equator from the state of 5% internal pressure to a state of the standard internal pressure and an inflation amount (y2) at the center line (Q) of zigzagged outer end line of the intermediate rib from the state of 5% internal pressure to a state of the standard internal pressure.
Abstract:
The present invention provides a rodless cylinder capable of displacing a piston without its operation stoppage in particular even when a large load or force is applied, smoothly reciprocating a sliding table and forming its entire structure in a compact manner. The rodless cylinder according to the present invention has a cylinder body and an L-shaped sliding table. A rail-shaped member fitted on a linear guide member of the sliding table is mounted on the upper surface of the cylinder body, which is held against the sliding table, so as to extend along the longitudinal direction of the cylinder body. A plurality of ball bearings are linearly disposed inside the linear guide member held in engagement with the rail-shaped member so as to extend along the longitudinal direction of the linear guide member.
Abstract:
A heavy duty radial tire is provided between the tread edge and the maximum tire width point with a profile which is formed by adding at least a protrusion to a basic profile, the basic profile consisting of an upper line and a lower line, the upper line extending radially inwardly from the tread edge and curved concavely so as to have a center of curvature outside the tire, the lower line extending radially outwardly from the maximum tire width point and curved convexly so as to have a center of curvature inside the tire, the upper line and lower line intersecting each other so as to form an inflection point, the radial height of the inflection point from the bead base line being in the range of from 0.82 to 0.88 times a groove bottom line height, the groove bottom line height being the radial height between the bead base line and a groove bottom line drawn parallel with the tread surface at the depth of the main grooves measured at axial ends of the groove bottom line, and the protrusion having an apex positioned such that the axial distance measured axially outwardly from the inflection point to the apex is in the range of from 4 to 8 mm, and the radial distance measured between the inflection point and the apex is in the range of from 0 to 5 mm, whereby the resistance to carcass damage can be improved if the carcass is minimized.
Abstract:
A heavy duty pneumatic tire comprises a pair of bead portions with a bead toe, a bead core disposed in each bead portion, a carcass comprising at least one ply of cords extending between the bead portions and turned up around the bead cores, an inner liner made of an airtight rubber compound disposed inside the carcass along the inner surface of the tire, the inner liner extending from one of the bead portion to the other and terminating before the bead toe, a chafer made of a hard rubber compound disposed in each bead portion along the bead base, the chafer extending axially inwardly to the bead toe, and an adhesiveness improvement rubber layer disposed between inner liner and chafer.
Abstract:
A heavy duty tire having an improved tread wear resistance, which comprises a tread portion provided on each side of the tire equator with a wide circumferential groove and a narrow circumferential groove. The wide circumferential groove is spaced apart from the tire equator by an axial distance of 15 to 25% of the tread width. The narrow circumferential groove is disposed on the axially inside of the wide circumferential groove and spaced apart from the axially inner groove edge of the wide circumferential groove by an axial distance of 0.02 to 0.05 times the tread width. The depth of the wide circumferential groove is in the range of 0.05 to 0.08 times the tread width. The depth of the narrow circumferential groove is in the range of 0.7 to 1.0 times the depth of the wide circumferential groove. The groove width of the narrow circumferential groove is in the range of 1.5 to 2.5 mm.