Excavating – Ditcher – Condition responsive
Reexamination Certificate
2002-11-01
2009-02-10
Beach, Thomas A (Department: 3671)
Excavating
Ditcher
Condition responsive
C037S414000, C414S699000, C701S050000
Reexamination Certificate
active
07487609
ABSTRACT:
To permit smooth performance of both of an operation requiring a high pressure and an operation desired to produce a pressure at a suppressed level, a shuttle block positioned between pilot operating units and flow control valves and pump regulators is arranged in association with shuttle valves, which select maximum pressures of groups of operation signal pressures produced by the pilot operating units, respectively, and at least one of the plural groups of operation signals, and is constructed to include hydraulic selector valves and a boom-lowering, hydraulic selector valve that are operable in particular ways.
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Ishikawa Koji
Nakamura Tsuyoshi
Nishimura Masao
Toyooka Tsukasa
Beach Thomas A
Buck Matthew R
Crowell & Moring LLP
Hitahi Construction Machinery Co., Ltd.
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