Abstract: The belt tentioner includes a solid damping device between the pivotal member and the fixed member, and the amount of deformation of the solid damping device and that of a spring are adapted to be set independently of each other.This permits the vibration damping operation by the solid damping device and the tensioning operation by the spring to be performed under the respective optimum conditions.

Abstract: A material for forming a hollow-molded body, which comprises a polyamide comprising hexamethylene isophthalamide units as the main recurring units. A hollow-molded body having an excellent gas barrier property can be obtained by using this polyamide molding material alone or in combination with polyethylene terephthalate.

Abstract: A glass fiber-reinforced thermoplastic polyester composition composed of(A) 100 parts by weight of a polyethylene terephthalate resin having an intrinsic viscosity, measured at 35.degree. C. in ortho-chlorophenol, of from 0.4 to 0.9 and comprising at least 80 mole %, based on the total acid component, of terephthalic acid or an ester-forming derivative thereof and at least 80 mole %, based on the total polyol component, of ethylene glycol or an ester-forming derivative thereof.(B) 5 to 200 parts by weight of glass fibers having an average length of at least 0.2 mm,(C) 0.05 to 3 parts by weight of a partially esterified montan wax acid having a neutralization value (NV) and a saponification value (SV) which are in the following relation50.ltoreq.NV.ltoreq.110 (1)100.ltoreq.SV.ltoreq.180 (2)10.ltoreq.(SV-NV).ltoreq.100 (3)and(D) at least one component selected from the group consisting of(D.sub.1) 0.01 to 3 parts by weight of a sodium or potassium salt of a monocarboxylic acid having 2 to 28 carbon atoms and(D.

Abstract: A polyethylene terephthalate resin composition capable of providing a molded article of a high crystallinity and an excellent dimensional stability and thermal resistance consists essentially of a polyethylene terephthalate resin having an intrinsic viscosity of 0.35 to 0.9 and, per 100 parts by weight of the polyethylene terephthalate resin, 5 to 200 parts by weight of an inorganic filler, 0.01 to 20 parts by weight of dimethyl or diethyl terephthalate and 0.01 to 5 parts by weight of a salt of a carboxylic acid with a metal of Group I or II in the periodic table or 0.1 to 10 parts by weight of an ionic copolymer of an .alpha.-olefin with a salt of an .alpha.,.beta.-unsaturated carboxylic acid and containing an ion of a metal of Group I or II in the periodic table.