Power plants – Pressure fluid source and motor – Having condition responsive control in a system of distinct...
Reexamination Certificate
2006-10-31
2006-10-31
Nguyen, Hoang (Department: 3748)
Power plants
Pressure fluid source and motor
Having condition responsive control in a system of distinct...
C060S428000, C060S468000, C060S486000, C060S494000
Reexamination Certificate
active
07127887
ABSTRACT:
A joining directional control valve13is disposed to supply, to an arm cylinder4,not only a hydraulic fluid delivered from a first hydraulic pump1,but also a hydraulic fluid delivered from a second hydraulic pump2when an arm directional control valve14is driven. Respective delivery pressures of the hydraulic pumps1, 2are detected by pressure sensors101, 102,and the opening area of a recovery control valve6is controlled depending on a lower one of the detected pressures from the pressure sensors101, 102such that, even in the combined operation of the arm cylinder4and another actuator3, 4,the hydraulic fluid can be recovered for return to the arm cylinder4when the load pressure of the arm cylinder4is low. Thus, by supplying the hydraulic fluids from the two hydraulic pumps to the particular actuator for which the hydraulic fluid is to be recovered, a recovery flow rate is ensured when the load of the particular actuator is low in the combined operation.
REFERENCES:
patent: 3868821 (1975-03-01), Ratliff et al.
patent: 3994133 (1976-11-01), Pfeil et al.
patent: 4089166 (1978-05-01), Ratliff et al.
patent: 5442912 (1995-08-01), Hirata et al.
patent: 5481872 (1996-01-01), Karakama et al.
patent: 6192681 (2001-02-01), Tsuruga et al.
patent: 262098 (1988-03-01), None
patent: 629781 (1994-06-01), None
patent: 60-179504 (1985-09-01), None
patent: 6-117411 (1994-04-01), None
patent: 6-264471 (1994-09-01), None
patent: 8-219121 (1996-08-01), None
patent: 9-210006 (1997-08-01), None
patent: 2001-355603 (2001-12-01), None
patent: WO 94/13959 (1994-06-01), None
Ishikawa Kouji
Nakamura Tsuyoshi
Sugiyama Genroku
Toyooka Tsukasa
Hitachi Construction Machinery Co. Ltd.
Mattingly ,Stanger ,Malur & Brundidge, P.C.
Nguyen Hoang
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