Fluid handling – Systems – Multi-way valve unit
Reexamination Certificate
2008-03-18
2008-03-18
Rivell, John (Department: 3753)
Fluid handling
Systems
Multi-way valve unit
C137S625690, C251S050000
Reexamination Certificate
active
11107291
ABSTRACT:
A proportional pressure control valve which includes an electric first stage pilot having a single outlet port configured to provide a variable pressurized hydraulic fluid to the outlet port and at a pressure that is proportional to an electric input signal and which is variable between first and second values and further includes a second stage hydraulic valve which has a spool reciprocally moveable in a bore between first and second positions indicative of a full ON and a full OFF condition. A fluid isolation chamber is oriented in the bore and in a region between a control port and a tank port in the fluid pathway therebetween. The interior wall of the bore and the first and second diameter regions on the spool are configured to always provide a controlled volume fluid flow rate between the control port and the fluid isolation chamber.
REFERENCES:
patent: 3176721 (1965-04-01), Gordon
patent: 3589401 (1971-06-01), Harding
patent: 3777482 (1973-12-01), Canale et al.
patent: 3865140 (1975-02-01), Greenwood
patent: 4741364 (1988-05-01), Stoss et al.
patent: 4785849 (1988-11-01), Masuda
patent: 4827981 (1989-05-01), Livecchi et al.
patent: 4966195 (1990-10-01), McCabe
patent: 5031663 (1991-07-01), Fukuta et al.
patent: 5058626 (1991-10-01), Takaoka et al.
patent: 5546847 (1996-08-01), Rector et al.
patent: 5984259 (1999-11-01), Najmolhoda et al.
patent: 6021876 (2000-02-01), Bowden et al.
patent: 6029703 (2000-02-01), Erickson et al.
patent: 6571828 (2003-06-01), Harms et al.
Bowden Charles J.
Pride, II Steven R.
Fema Corporation of Michigan
Flynn ,Thiel, Boutell & Tanis, P.C.
Rivell John
LandOfFree
Proportional pressure control valve with control port... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Proportional pressure control valve with control port..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Proportional pressure control valve with control port... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3908997