Patent ID: 9558975
Date: 2017-01-31
CPC Classifications: H01L

Claim:
1. A system for transferring articles between an atmospheric pressure environment and a vacuum pressure environment, the system comprising: a vacuum enclosure including a wall separating the atmospheric pressure environment from the vacuum pressure environment; a transfer shaft extending through the wall from the atmospheric pressure environment to the vacuum pressure environment, the transfer shaft having an atmospheric transfer port in communication with the atmospheric pressure environment, a vacuum transfer port in communication with the vacuum pressure environment, and an intermediate port disposed in communication with a channel in the wall; a transfer carriage disposed within the transfer shaft, the transfer carriage having an access port for providing access to an interior of the transfer carriage, the transfer carriage being movable within the transfer shaft; a first differential pumping region formed in the wall on a first side of the channel and a second differential pumping region formed in the wall on a second side of the channel opposite the first side, each of the first and the second differential pumping regions comprising a groove configured to draw gas out of a space between the transfer carriage and the transfer shaft; and an air bearing associated with the transfer carriage, the air bearing configured to maintain a gap between the transfer carriage and the transfer shaft.