Device for applying a possibly coated adhesive film to a substrate

A device for applying an adhesive film to a substrate, consisting of a housing and an interchangeable cassette fitting in this housing and which comprises a supply spool, from which a backing strip provided with the adhesive film can be unrolled, an empty spool which can be driven from the supply roll through a drive device, for winding up the empty backing strip, and an application tongue, over which the backing strip coming from the supply spool is fed, wherein the housing has a through opening for the application tongue at its front end and a loading opening for introducing and removing the cassette at its opposite, rear end, wherein the cassette (4) can be slid into the housing (1) from its loading opening (3) to the through opening (2) in a straight line, wherein a compression spring (9) extending in the direction of movement of the cassette (4) is arranged in the housing (1) and is contacted by a projection (11) on the cassette, before the application tongue (7) has reached the through opening (2), and wherein a spring-loaded detent device (13, 15, 16a) with a push-button (14) is provided, acting between the cassette (4) and the housing (1), by means of which the cassette (4) pushed forward against the spring force of the compression spring (9) in the housing (1) into its working position, in which the application tongue (7) projects through the through opening (2) out of the housing (1), can be locked relative to the housing, and which can be released by actuating the push-button (14), so that the cassette (4) is automatically pushed back into its position of non-use under the action of the compression spring (9), in which position the tip (7a) of the application tongue (7) lies within the housing (1).