A tire mold comprises sector molds for forming a tread portion of a tire and mold pins provided on the sector molds for forming insertion holes in the tread portion. The insertion holes each comprise a first hole portion with a first inner diameter where a body portion of a stud pin is disposed and a second hole portion with a second inner diameter greater than the first inner diameter where a bottom flange portion of the stud pin is disposed. The mold pins each comprise a trunk portion with a first outer diameter for forming the first hole portion and a tip portion with a second outer diameter greater than the first outer diameter for forming the second hole portion.

An arrangement of studs are inserted into a tread portion of a tire. The arrangement includes a plurality of first studs protruding from an unworn tread portion for contacting a surface and a plurality of second studs embedded in the tread portion such that the second studs protrude from a worn tread portion as the tread portion wears against the surface.

A system for mounting a housing and an insert to a tire includes a housing configured to be installed in a tire, wherein the housing has a top opening. The system also includes at least one anchor connected to a side of the housing in an un-deployed configuration. The system further includes an insert configured to be inserted into the top opening of the housing. The at least one anchor projects outward into the tire when the insert is inserted into the top opening of the housing.

In a stud pin, a flange contour shape of a lower flange is an anisotropic shape in which, among imaginary rectangles circumscribing the contour shape, the smallest rectangle includes short sides and long sides having different lengths. The flange contour shape includes first recess portions on each of portions of the flange contour shape extending along the short sides, the first recess portions being curved toward a centroid of the flange contour shape, and the flange contour shape includes a second recess portion on portions of the flange contour shape extending along the long sides, the second recess portions being curved toward the centroid of the flange contour shape. A body contour shape of a body portion is a polygonal shape including vertex angles in a same number as the first and second recess portions, and the vertex angles are disposed facing the first and second recess portions.

A stud is configured to be inserted into a tread portion of a tire. The stud includes a tip end protruding from the tread portion for contacting a surface, and a base including a flanged bottom portion provided on an end opposite the tip end and extending radially outward, a stump portion provided between the bottom portion and the tip end, and a shank portion interconnecting the stump portion and the bottom portion. The base is embedded and secured in the tread portion of the tire in which the stud is installed. The bottom portion has a tear-drop shape consisting of three planar sides and one semi-cylindrical side. The stump portion has a polygonal shape consisting of three concave sides, two convex sides, and one planar side.

A studded tire includes stud pins embedded in a road contact surface of a tread portion 1; the rubber composition forming the tread portion containing at least one of natural rubber, styrene-butadiene rubber, and butadiene rubber, from 5 to 50 parts by weight of carbon black and from 5 to 70 parts by weight of silica per 100 parts by weight of the diene rubber; a nitrogen adsorption specific surface area of the carbon black being from 50 to 120 m.sup.2/g; a CTAB specific surface area of the silica being from 80 to 190 m.sup.2/g; a rubber hardness of the rubber composition being not greater than 60; and a product of a stress at the time of 400% elongation and a bottom surface area of a flange portion on a bottom side of the stud pins being not less than 400 MPa.Math.mm.sup.2 and not greater than 850 MPa.Math.mm.sup.2.

A stud pin includes a tip including an end surface that comes into contact with a road surface, a body portion that supports the tip; and a lower flange connected to the body portion at an end on an opposite side to the end surface. A profile shape of the lower flange is an anisotropic shape in which, of imaginary rectangles circumscribing the profile shape, a first smallest rectangle with the shortest side of its four sides being the shortest and/or a second smallest rectangle with the longest side of its four sides being the shortest includes short sides and long sides of different lengths. The profile shape includes four or more first protrusion portions that project in the longitudinal direction parallel with the long sides and two second protrusion portions that project in the lateral direction parallel with the short sides.

A method for installing a stud in a tyre. The method includes identifying a stud hole for the stud in the tyre; imaging the vicinity of at least the stud hole, whereby information is received about the pattern in the vicinity of the stud hole, and using the received information to determine [i] the stud type suitable for the stud suitable in the stud hole and/or [ii] the suitable stud orientation of the stud suitable in the stud hole. The method includes providing a stud and installing it in a stud hole. The stud type of the stud is the same as the suitable stud type of a stud suitable in the stud hole; and/or the stud is installed in the stud hole in such a way that the main direction of the stud is parallel with the suitable stud orientation. Further a tyre studded by the method.

A stud pin includes a tip including an end surface configured to come into contact with a road surface, a body portion configured to support the tip, and a lower flange. The flange profile shape of the lower flange is an anisotropic shape. The flange profile shape includes four or more first flange protrusion portions that project in the longitudinal direction and two second flange protrusion portions that project in the lateral direction. A tip profile shape of the tip is a shape including tip linear portions extending in a linear manner. At least one of the tip linear portions extends along a portion of the flange profile shape between two adjacent protrusion portions of the first flange protrusion portion and the second flange protrusion portion along the outer circumference of the flange profile shape.

In one aspect, a method provides a reciprocating bolt by a bolt assembly having a bolt assembly body, a cap affixed to the bolt assembly body, and a base affixed to the bolt assembly body opposite the cap. The method includes biasing a bolt carrier in the bolt assembly body in a retracted position relative to the bolt assembly, resulting in a center portion of a diaphragm disposed between the cap and the bolt assembly body being deflected toward the cap. The method also includes applying an actuation force to the bolt carrier so as to move the bolt carrier from the retracted position to an extended position relative to the bolt assembly by oppositely deflecting the center portion of the diaphragm toward the base, and discontinuing the applying of the actuation force while the bolt carrier is in the extended position.