Seals and joints incorporating seals

摘要

A window assembly 10, for example for a containment box, comprises a rigid plate 11 having an aperture having peripheral edge 11a embraced by a resilient seal 18. When unstressed the seal has flat faces 40a, 42a which in use engage flat face 50 of transparent sheet 16 and a tapered slot 29 for receiving the edge 11a. Tongue 40 has flat surface 40b for engaging the surface 13 of plate 11 and surface 41a of inclined tongue 41 for engaging the opposite surface 51 to provide a firm seal.