The present invention refers to a method of continuous processinng of laminar flexible workpieces, especially in leather, shoe or clothing production, with pressing, especially hot-press gluing of the workpieces, where the workpieces are carried through at least one low-pressure zone and subsequently through at least one high-pressure zone. The invention further refers to a method of continuous processing of workpieces of the aforesaid kind with automatic depositing or stacking. Again, the object of the invention includes devices for performance of such methods.
The gluing of laminar flexible workpieces is effected, e.g. in shoe production often still by long known round plate pressing in which pairs of plates connected to a lifting press are turned in steps about a vertical axis and so come from a loading station at which one pair of plates at a time is run apart and enables the insertion of a pair of workpieces for gluing, to a pressing or heating station with hot-press gluing of the pair of workpieces and again back to the loading station.
These devices and the method performed by them are costly because the loading especially of workpieces of large area is relatively lengthy and imposes some demands for dexterity by the attendant. Working speed and in the case of difficult nature of the workpiece also the quality of work as regards freedom from wrinkles and uniform gluing therefore leave much to be desired.
Again, tests have already been made with gluing presses which exhibit a flat straight-line continuous path for the workpieces, with a conveyor belt. Here the loading station is separated spatially from the removal station and because of the heating and pressing station lying between them is relatively far removed, which makes operation more diffiult and in general makes additional personnel necessary.
Further, there is known from the West German Patent Publication No. 2,413,672 a continuous method of hot-pressing workpieces for purposes of proof printing and a corresponding drum press with a circulating conveyor belt. There the entry of the workpieces into the continuous path is effected at the peak of the drum in the region of a first roll, on account of which the workpieces come relatively rapidly under high pressure and can easily form wrinkles. For the processing of softly flexible workpieces such as in leather, shoe and clothing production, this process because of the formation of wrinkles is not very suitable. Furthermore, the continuous path for the workpieces is traversed preponderantly in a descending direction, so that the outlet point lies below the inlet point. Therefore an extensive additional section of the conveyor belt is necessary in order to bring the workpieces from the region of the feed station lying above and to be able to release them. Furthermore, to do this conveyance upwards is necessary. But this section of the conveyor device again impedes accessibility at the front of the feed station, which has the result of laborious operation.
USPTO Backgrounds
USPTO Backgrounds