Abstract: The method of and device for controlling the roll exchanging operation in an unrolling device includes the provision of a set of control numbers computed from the counted number of revolutions of the old roll and from the length of the withdrawn web prior to the initiation of the roll exchanging operation; the control numbers are computed from two intervals of the measured web length, from corresponding intervals of the counted number of revolutions, from the thickness of the web, from the feeding speed of the web, from the time constents of the control elements of the roll exchanging device, from the length of the adhesive leading edge of the new roll, from the desired length of the residual trailing end portion of the old web and from the diameter of the supporting central reel; computed control numbers are stored and compared in a comparator with the actual number of revolutions of the old roll whereby the coincidence of the actual number with the stored number generates in a control unit a control signal

Abstract: Arrangement for washing transparent parts of vehicles, particularly windshields and lightlamp lens shields of motor vehicles. The arrangement includes a solid liquid conducting member and a bore-like liquid supplying channel extending therethrough between an inlet port and an outlet port. A liquid conduit communicating with a liquid container has a terminal portion distant from the container and provided with a connecting piece press-fit or with prestress inserted in the inlet port. A nozzle body is associated with the outlet port and has a discharge aperture aimed at the transparent part to be washed. A selectively actuable liquid releasing means is operable to release liquid to travel from the container under pressure at the driver's command to the nozzle body.