Class 417/256 - Stages comprise oppositely moving valved pumping members

Subclass of Class 417 - Pumps
Definition: Apparatus in which the pumping members are constrained to
No. of patents: 4
Last issue date: 08/12/2008

Number	Title	Issue Date
7410348	Multi-speed compressor/pump apparatus A pumping/compressing apparatus for use in a fluid handling system transferring a fluid from one location, e.g., a tank, to another location or to an end use is provided. The apparatus basically includes a motor and a multistage, e.g., two stage, device including at...	08/12/2008
7217110	Compact rotary compressor with carbon dioxide as working fluid A rotary compressor for compressing a working fluid includes a housing having an oil sump. A stationary shaft extends into the housing and includes a longitudinal passage. The longitudinal passage has an oil inlet in fluid communication with the oil sump. A working ...	05/15/2007
5020973	Air compressor shroud A V-twin, two-stage compressor has valve plates disposed between the head and cylinder of each stage and mounting free-floating flexible read intake and exhaust valves therein. The flexible reeds are movably captured between the floors of respective reed ...	06/04/1991
4478556	Three or four stage gas compressor The invention concerns a three- or four-stage gas compressor comprising two interconnecting compression units operated by hydraulic pistons; the first unit comprises a central hydraulic section flanked by two identical and symmetrical lateral sections eac...	10/23/1984

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