Abstract: The sizing agent of the invention contains a rosin substance, a dispersant and water in which an amphoteric, anionic or cationic copolymer is used as the dispersant, the copolymer being prepared by copolymerizing (A) a vinyl carboxylate as an essential monomer and (B) an anionic unsaturated monomer and/or (C) a cationic unsaturated monomer.

Abstract: A planetary-roller transmission for transmitting power from one rotating shaft to another by means of a plurality of planet rollers pivotally supported, in contact with the outer periphery of a sun roller fixedly mounted on one rotating shaft and also with the inner periphery of an internal contact ring secured to a stationary member and made unmovable circumferentially of the rotating shaft, by a carrier connected to the other rotating shaft, characterized in that either the internal contact ring or the sun roller or both are in the form of an elastic element or elements adapted to receive, on one side thereof, a compressive force axially of the rotating shafts to change the radius of the element surface in pressure contact with the mating rollers, and a presser device is provided which applies the compressive force to one side of each elastic element and brings the element into or out of engagement with the mating rollers by increasing or decreasing the compressive force.