Schott Glas

Heinz-G Bordt

Georg Sparschuh

Funnels of picture tubes are typically produced by pressing a molten gob of glass in a mold using a pressing die and by using a ring resting on the mold and resiliently secured to the die, for molding a flat funnel upper edge. At the same time, through corresponding recesses in the mold, bearing faces, so-called pads for connecting the funnel adjustably to the picture screen, are molded onto the outer collar of the funnel. In order to attain an encompassing upper edge of constant width by recessing of the pads without an encompassing mold seam on the finished funnel, the mold is provided in the region of the pads with recesses, in which movable, flat molded parts that are flush with the upper edge of the mold can be placed, the thickness of the molded parts being determined in accordance with the extent of recessing of the pads and their radial length being determined such that they produce protrude into the mold cavity in accordance with the recessed upper edge of the pads to be molded on, and are arranged such that they can be moved out of the mold cavity after the funnel has been molded.

Growing community of inventors

Bischofsheim, Germany

Heinz-G Bordt