21
John C Helmer, Giampaolo Levi: Non-centric improved pumping stage for turbomolecular pumps. Varian Associates, Bella Fishman, David J Power, October 10, 1995: US05456575 (7 worldwide citation)

The present invention refers to a pumping stage particularly designed for turbomolecular pumps, having increased compression ratio, and capable of extending the operating range of the turbomolecular pump towards high pressure. The new pumping stage comprises a casing housing, a rotor disk, and a sub ...


22
Tom A Watson: Low cost corona pre-ionizer for a laser. Cymer, David J Power, February 17, 1998: US05719896 (7 worldwide citation)

An anode and an a cathode in a gas laser, such as an excimer laser, are spaced in a first direction. A voltage difference between these members produces an electrical discharge which ionizes gasses in the laser to react chemically and produce coherent radiation. First and second tubes made from a di ...


23
Bertram G James: Cooled reentrant TWT ladder circuit having axially raised cooling bars. Varian Associates, Francis H Lewis, Gerald M Fisher, David J Power, November 8, 1994: US05363016 (3 worldwide citation)

A PPM coupled-cavity traveling wave tube has an RF structure comprising a re-entrant double-staggered ladder circuit. Several cavities are separated by iron pole pieces with penetrating slots to provide RF coupling between the cavities. Re-entrant copper bars are attached to both sides of the pole p ...


24
Giampaolo Levi: Pumping state turbomolecular pumps. Varian Associates, Edward H Berkowitz, David J Power, Bella Fishman, February 7, 1995: US05387079 (1 worldwide citation)

The present invention refers to a pumping stage for turbomolecular pumps comprising a rotor disk (3), integral with a rotating shaft (4) operated by a motor, and a stator disk (1) said stator disk (1), integral with the pump body (2), where the stator disk (1) is a disk whose surface is substantiall ...


25
Giampaolo Levi, John C Helmer: Tangential flow pumping channel for turbomolecular pumps. Varian Associates, Bella Fishman, David J Power, September 12, 1995: US05449270 (1 worldwide citation)

The present invention relates to turbomolecular pumps comprising one or more tangential flow pumping stages in addition to axial flow pumping stages, so as to raise the pump exhaust pressure up to the atmospheric pressure, wherein at least one tangential flow pumping stage having a tangential flow p ...