Compound sliding seal unit suitable for atmosphere to vacuum applications

Abstract

The present invention is a compound sliding seal unit of markedly reduced size and height dimensions which is employed as a discrete assembly for both the passage across and the at-will height adjustment of a mounted, rotatable shaft which extends from the atmospheric environment portion into the vacuum environmental portion of an ion implanter apparatus. The extended, rotatable shaft is typically fashioned as either a rotatable hollow tube or conduit (suitable for the passage of electrical components) and/or as a rotatable support suitable for the mounting of a pivotal scanning radial arm translation system. The manner of construction and the substantially reduced height dimensions of the compound sliding seal unit permits on-demand changes of height for the mounted, rotatable shaft which extends from the atmospheric environment and extends through the compound unit into the confined and limited spatial volume of a vacuum environment within a conventional ion implantation apparatus. The compound unit also allows the user to maintain a high vacuum within the vacuum environment despite the fact that the height of the feed-through member can be raised and lowered repeatedly at will. Its compact size frees space which can be used to extend the vacuum chamber for purposes such as a deep Faraday cup for beam measurement.