US Patent 7478981 Concealed glandular seal

Disclosed herein is a contamination protection apparatus that includes a concealed linear glandular seal for providing continuous protection along an entire length of a movable table of a precision apparatus such as testing and metrology machines, laser machines, biomedical equipment, and precision fabricating machines. The disclosed glandular seal is formed on an inner structure of the protective apparatus, which includes a plurality of mechanical translation stages positioned in the inner structure and two normally closed linear parts of the glandular seal attached to respective mechanical translation stages. The linear parts interfere with each other and are opened by movement of a mechanical translation stage saddle.