Method and apparatus for sealing an annular gap between two sealing surfaces, especially for extruders

摘要

A ring shaped slot between two machine parts, esp. on extruders, is sealed by a ring which contacts both surfaces. The ring (7) is made of elastic but very strong material and protrudes over the sealing surface (8,9). A force (10) is applied at the protrusion so that the ring bows, giving a ring shaped contact on both surfaces. Also claimed is a similar arrangement where the ring is initially bowed or conical and is straightened by the applied force to give a similar seal.