Patents by Inventor Douglas F. Aitken

Douglas F. Aitken has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Cryogenic waterpump
    Patent number: 5261244
    Abstract: A cold trap includes a set of baffles cooled by the cold finger of a closed cycle refrigerator. The baffles are vertically disposed in a vertical fluid conduit with frustoconical and conical surfaces for directing liquid to a circular trough during regeneration. After the liquid is collected, it is blown from the trough through a pressure relief valve by a nitrogen purge. The trough is formed in the upper surface of a connecting flange at the lower end of the fluid conduit.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: November 16, 1993
    Assignee: Helix Technology Corporation
    Inventors: Philip A. Lessard, Douglas F. Aitken, Robert D. Bradford, Roland P. Graham, Steven A. Michaud, Karen J. Manning
  • Cryopump with differential pumping capability
    Patent number: 5211022
    Abstract: A cryopump is capable of pumping a process chamber at a process pressure and differentially pumping a second chamber such as an RGA independently at a substantially lower pressure. A member extends through the cryopump housing into a low pressure region disposed within the second stage array. The member comprises a port for accessing the low pressure region, thus providing an independent differential pumping source. No physical seal is required between the member and the main cryopump volume to maintain the pressure differential.
    Type: Grant
    Filed: May 17, 1991
    Date of Patent: May 18, 1993
    Assignee: Helix Technology Corporation
    Inventors: Allen J. Bartlett, Douglas F. Aitken