The instant invention concerns a proceeding and an arrangement in connection with a winch for a sheet or a halyard on a sailing boat. This is, besides for sheeting-in, constructed to also allow veering-out of sheet or halyard rope arranged thereon by means of means that normally otherwise are intended for sheeting-in, more precisely a crank possibly having an appurtenant transmission integrated in the winch or the corresponding motor drive and appurtenant transmission, for driving of a drum belonging to the winch and a self-tailing unit arranged at the upper end of the same. The last-mentioned one has upper and lower rope guide rings as well as means in the form of an expedient arm for directing the rope into and out of the self-tailing unit in a controlled way. The invention embraces suspension and spring-mounting means for at least one of the rope guide rings that are arranged in such a way that this/these obtain(s) a mutually static and dynamic motion pattern. This pattern is such that, in connection with forcing apart the rope guide rings somewhere along the periphery thereof, for instance, by the arrangement of a rope between the same, the corresponding opposite portions of the rope guide rings automatically approach each other, for clamping of the rope arranged therebetween.