Abstract: An link of a caterpillar which is allowed to maintain stabilized durability for a long period.

Abstract: In a travelling crawler belt in which a pair of left and right links are connected by pins respectively press-fitted into the corresponding links, a fixing end surface of the pin or the links is continuously and locally pressed and deformed in an axial direction of the pin from the fixing end surface, along an inner or outer peripheral portion of an opening of a pin-press-fit hole. Then, a part of the opening peripheral portion of the end of the pin or the link is enlarged or reduced in diameter, so that the diametrically increased or reduced portion is retained and fixed to a mating retaining space. With this fixing method, it is possible to easily and strongly couple the links and the pin, and to obtain a fixing structure of the links and the pin for a crawler belt capable of sufficiently securing a holding force of the pin in the axial direction.

Abstract: In the bicycle hanger structure of the invention, a slope such as taper surface or spherical surface formed at one end side of a sleeve of a crankshaft unit is adjusted to a corresponding slope of a hanger, and the other end side is screwed and fixed in the corresponding hanger, so as to be screwed to the hanger only at one side. As a result, effects of deformation of female threads due to thermal deformation of right and left lugs of the hanger do not act on the rotation condition of the crankshaft, and one or both of processing of female threads on the right and left lugs of the hanger may be omitted, and screwing is required only in one position for mounting the crankshaft and the assembling of crankshaft is easy and working efficiency is enhanced, thereby obtaining a bicycle hanger structure not spoiling the rotation condition of the crankshaft.

Abstract: A seal for a joint subjected to oscillatory motion having a W-shaped seal ring in an unloading condition which encompasses a load ring. The W-shaped seal ring comprises a driving flange, a sealing flange and a bight portion interconnecting the two flanges. The load ring is adapted to be fitted in the seal ring to force the driving flange into an interference fit with the counterbore walls so as to cause the driving torque to be applied through the seal ring. The thickness of the driving flange and the bight portion is made substantially same so as to ensure enough rigidity in the radial direction while allowing the seal ring to deform readily in the axial direction.