Patents by Inventor Philip C. Lessard

Philip C. Lessard 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).

  • Pressure controlled cryopump regeneration method and system
    Patent number: 5517823
    Abstract: In a subatmospheric regeneration process, a relief valve and a roughing valve are coupled in parallel to a common roughing pump. During regeneration, the cryopump is warmed to release gases from cryopump stages. The relief valve opens at a first cryopump pressure level less than a predetermined maximum pressure. The maximum pressure is subatmospheric. The relief valve closes when the cryopump pressure drops below a second cryopump pressure level. Pressure in a line between the relief valve and the roughing pump is monitored to control the opening of the roughing valve to the roughing pump.
    Type: Grant
    Filed: January 18, 1995
    Date of Patent: May 21, 1996
    Assignee: Helix Technology Corporation
    Inventors: Bruce R. Andeen, Gerald J. Fortier, Allen J. Bartlett, Michael J. Eacobacci, Philip C. Lessard