|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||137/62562 ; 137/62563 ; 137/62564 ; 91/382|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 32 인용 특허 : 0|
A proportional flow control valve comprises a directional control valve having a valve spool, a servo actuator or servo means for operating said directional control valve, and manual override means for operating the valve spool. The servo means comprises a movable ram or piston for moving the valve spool to thereby operate the directional control valve and the ram has a pair of equally sized piston areas connected thereto. The servo actuator also comprises a pilot valve having a null position and is selectively operable to apply fluid alternately to eith...
In a servo means: a piston movable in one direction or another from a null position to perform a function; first and second equally sized piston areas connected to said piston; a selectively operable pilot valve comprising first and second adjustable orifice means each having a null position and other selective positions for applying fluid pressure to said first and second piston areas, respectively, to move said piston in said one direction or another, respectively, the extent of piston movement being proportional to the amount of fluid applied; feedbac...