Abstract: Provided is a pneumatic tire with which measurement of the strength of a magnetic field, which changes with wear, can be carried out regularly with stability and sufficient detection sensitivity so that the wear state of the tire can be ascertained regularly with accuracy. In this pneumatic tire, in a tread part where a pattern of protrusions and recessed grooves has been formed, a recess of a prescribed shape is formed in one or more of the protrusions so as to extend radially inward from the ground contact surface. A soft magnetic body formed by dispersing a granular soft magnetic material in a polymer material is embedded in the recess. A magnet formed using a hard magnetic material is provided radially inward from the soft magnetic body. A magnetic circuit formed by the soft magnetic body and magnet forms a magnetic field having a prescribed strength in the thickness direction of the protrusion.

Abstract: A tire can include a first magnetic body disposed at a predetermined position in a tread portion, a magnetic sensor disposed radially inward of the first magnetic body, and a second magnetic body disposed closer to the magnetic sensor than the first magnetic body is. At a position where the magnetic sensor is disposed, a direction of a magnetic force line emitted by the first magnetic body and a direction of a magnetic force line emitted by the second magnetic body can be different from each other.

Abstract: A method of manufacturing a pneumatic tire provided with a magnetic portion containing powder particles of hard magnetic material in the tread portion which comprises a drilling step of drilling a hole in an unvulcanized tread portion forming member; a magnetic piece embedding step of embedding a magnetic piece containing the powder particles of hard magnetic material in the hole as the magnetic portion; a green tire molding step of molding a green tire using the tread portion forming member in which the magnetic piece is embedded; and a vulcanizing step of vulcanizing the green tire, and this method makes it possible to finish the tire in a designed shape without causing occurrence of abnormal unevenness on the surface, even when a magnetic piece for detecting a worn state of the tire is embedded.

Abstract: A pneumatic tire comprising a magnetic body provided in a tread portion, a magnetic sensor for detecting a magnetic flux density of a magnetic field formed by the magnetic body disposed at a radially inward position corresponding to the magnetic body, wherein a magnetic body is formed by dispersing powdery particles of a hard magnetic material in a polymeric material and is magnetized in one direction and is provided in the tread portion so that the magnetization direction and the tire radial direction coincide with each other; a method of tire wear measuring for measuring a wear state in the pneumatic tire; a tire wear measuring system for measuring a wear state in the pneumatic tire; and a sensor module installable inside the pneumatic tire.

Abstract: A golf club head in which a frequency F (fix) indicating a primary minimum value of a frequency transfer function of a head obtained by firmly fixing the head to a vibrator and measured in accordance with an vibrator method is between 600 and 1200 (Hz), and a frequency F (free) indicating a primary minimum value of a frequency transfer function of the head obtained by making the head in a free state and measured in accordance with an impact hammer method is between 2500 and 4000 (Hz).

Abstract: Pillow 1 according to the present invention includes a main body 3 having a concave portion 7 in the central part, and a cold insulator 5 mounted in the concave portion 7. This concave portion 7 is open in the central part of the main body side wall 8 on the side where the human nape is to be situated. The cold insulator 5 has a film for inclusion 11, and a gel material 9 which is internally included in the film for inclusion 11 and which includes a crosslinked polymer that is not in a swelled state with a medium. It is preferred that the gel material 9 includes an unfoamed polyurethane resin, and has an Asker F hardness of 10 or greater and 50 or less. Also, depth of the opening of the concave portion 7 that is open at the main body side wall 8 is preferably equal to or greater than one third of the height of this main body side wall 8. This pillow 1 is constituted so that the head region can be held with a shape fitting the shape of the neck and head, therefore, any strain is not imposed to the body.

Abstract: A pillow (1) according to present invention comprises a body (3) including a concave portion (7) in a central part and a cold insulator (5) incorporated in the concave portion (7). The cold insulator (5) has a gel material enclosed in a bag member which is formed by an enclosing film. It is preferable that the body (3) should be formed of a rubber or a synthetic resin material and should have a flexibility and a restoring property for a deformation. It is more preferable that the gel material should be a hydrogel or a lipogel. Furthermore, a plurality of dents (9) is provided on the surfaces of the body (3) and the cold insulator (5). The pillow can hold and cool a head in such a shape as to conform to the shapes of a neck and a head, thereby casting no burden on a human body. A cooling function lasts long by the cold insulator (5) incorporated in the body (3). Plural kinds of cold insulators (5) to be incorporated can be retained and replaced, and can be regulated depending on a user and a situation.

Abstract: A golf club comprises a club shaft and a club head attached to the end of the club shaft, the club head volume is not less than 280 cc, the club head comprises a face portion which has, at least partially, a Young's modulus E of from 30 to 110 GPa, and the club shaft has a kick point index of not less than 50, wherein kick point index={inverse flexure/(inverse flexure+normal flexure)}×100.

Abstract: A golf club head in which a frequency F (fix) indicating a primary minimum value of a frequency transfer function of a head obtained by firmly fixing the head to a vibrator and measured in accordance with an vibrator method is between 600 and 1200 (Hz), and a frequency F (free) indicating a primary minimum value of a frequency transfer function of the head obtained by making the head in a free state and measured in accordance with an impact hammer method is between 2500 and 4000 (Hz).

Abstract: A golf club head comprises a face portion defining a clubface for striking a golf ball; the face portion provided in the clubface with a high-resilience part made of a metal material having a Young's modulus E of not less than 29 (GPa) but not more than 107 (GPa); and in a measuring state of the club head which is defined as being placed on a horizontal plane such that a clubshaft center line inclines at its lie angle within a vertical plane and the clubface inclines at its face angle with respect to the vertical plane, a moment of inertia of the club head around a horizontal axis passing a gravity point of the club head in parallel with the vertical plane, being not less than 1600 (g·sq.cm) but not more than 4000 (g·sq.cm).