Abstract: A motor-vehicle latent-heat storage unit is made by first positioning an elongated rectangular sheet-metal blank over a longitudinally extending slot formed in a die and then pressing an elongated anvil bar forming one of a pair of ultrasonic welding tools down against the blank over the slot to push the bar and the blank into the slot. This imparts to the blank a U-section and leaves longitudinally extending edge regions of the blank projecting out of the slot past the anvil bar. These edge regions are then folded transversely one after the other inward over the bar to form the blank into a tube with the edge regions overlapping each other. The other of the ultrasonic welding tools is subsequently pressed against the overlapped edge regions and therethrough against the anvil bar to ultrasonically weld together the overlapped edge regions along a full length of the tube. Finally the welded tube and the bar are moved longitudinally relative to each other to separate the tube from the bar.

Abstract: A motor-vehicle latent-heat unit is made by first inserting into an evacuatable chamber a subassembly comprised of a closed inner housing having upper and lower ends, a pack of medium-filled latent-heat storage cells contained in the inner housing, a side wall surrounding the inner housing and having upper and lower ends, and a floor closing the lower end of the side wall and juxtaposed with the lower inner-housing end. The upper end of the side wall is open. Then the chamber is evacuated and an upper wall or cover is fitted to the upper end of the side wall and is bonded thereto. This forms with the upper wall, floor, and side wall an outer housing in turn forming around the inner housing a closed and evacuated space. The chamber is then refilled with air around the outer housing and the housings are removed from the chamber.

Abstract: A motor-vehicle latent-heat storage unit is made by first positioning an elongated rectangular sheet-metal blank over a longitudinally extending slot formed in a die and then pressing an elongated anvil bar forming one of a pair of ultrasonic welding tools down against the blank over the slot to push the bar and the blank into the slot. This imparts to the blank a U-section and leaves longitudinally extending edge regions of the blank projecting out of the slot past the anvil bar. These edge regions are then folded transversely one after the other inward over the bar to form the blank into a tube with the edge regions overlapping each other. The other of the ultrasonic welding tools is subsequently pressed against the overlapped edge regions and therethrough against the anvil bar to ultrasonically weld together the overlapped edge regions along a full length of the tube. Finally the welded tube and the bar are moved longitudinally relative to each other to separate the tube from the bar.