Abstract: In a thermo-shrinkable polyester film, the thermal shrinkage ratio in a main shrinking direction is about 20% or more after being treated in water of about 70.degree. C. for about seconds, about 35 to about 55% after treated in water of about 75.degree. C. for about 5 seconds, and about 50 to about 60% after being treated in water of about 80.degree. C. for about 5 seconds. After the film is shrunk by about 5% by treatment in water of about 75.degree. C. for about 10 seconds, the probability of the elongation at rupture of the film in the direction perpendicular to the main shrinking direction being about 20% or less, is about 10% or less. The ratio of .tau..sub.1 /.tau..sub.2 is about 0.05 to about 0.45, where .tau..sub.2 is the stress of shrinkage in a main shrinking direction of the film at about 90.degree. C., and .tau..sub.1 is the stress of shrinkage in a direction perpendicular to the main shrinking direction of the film at about 90.degree. C. The sealing strength of the film is about 1.

Abstract: Heat-shrinkable polyester films having a heat shrinkability of 30% or more, preferably 40% or more, in the direction of major shrinkage after treatment in hot water at 80.degree. C. for 30 seconds, the ratio of heat shrinkability in the direction of major shrinkage after treatment in hot water at 80.degree. C. for 5 seconds to heat shrinkability in the direction of major shrinkage after treatment in hot water at 80.degree. C. for 30 seconds being 0.8 or less, preferably 0.7 or less. The heat-shrinkable polyester films are suitable for label applications because of their particular heat-shrinkable properties such that not only do they scarcely cause longitudinal sinking when shrunk but also they have very few wrinkles, shrinkage spots and strains remaining after shrinkage.

Abstract: Improved friction pads for use with disc brake. The pad has a central main portion and a peripheral portion which are formed of different matrices having different compositions. The matrix of the central main portion contains a hard substance or substances having a specified range of hardness whereas the matrix of the peripheral portion does not contain such hard substances or contains in only a limited smaller amount than the central main portion. This prevents the brake disc from wearing due to friction with the pad and thus avoids uneven abrasion of the brake disc.

Abstract: A brake disc and a wheel having circumferentially spaced mounting seats are secured by threaded studs to a radially extending flange of a hub to form a wheel assembly in which pressure-receiving portions of the wheel assembly are provided opposite the wheel mounting seats and a recess is provided between each pressure-receiving portion and a cylindrical portion of brake disc to permit deflection of pressure-receiving portions as hub nuts are tightened on the threaded studs.