(19)
(11) EP 0 134 744 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
16.03.1988 Bulletin 1988/11

(43) Date of publication A2:
20.03.1985 Bulletin 1985/12

(21) Application number: 84420120

(22) Date of filing: 06.07.1984
(84) Designated Contracting States:
AT BE CH DE FR GB IT LI LU NL SE

(30) Priority: 07.07.1983 US 511576

(71) Applicants:
  • Zeuner, Kenneth W.
     ()
  • Zeuner, Steven K.
     ()
  • Zeuner, Thomas A.
     ()

(72) Inventor:
  • Zeuner, Kenneth W.
     ()

   


(54) Proportional follower spool valve system


(57) @ A proportional follower spool valve system having a main spool (12) slidable between end chambers (55, 56) maintained at substantially return pressure. First fluid connections (40) are controlled by the main spool (12) and they are effective to control output fluid flow in accordance with the position of the main spool (12). A pilot spool (11) is slidable within an inner passage (12a) of the main spool. A first (20) and second (21) driving chamber is formed by the main spool (12) each having a driving area substantially less than the largest cross-sectional solid area of the main spool (12). Second fluid connections (11a, 11b) are controlled by the pilot spool (11) for admitting fluid under pressure 1/ to the first chamber (20) when the pilot spool moves in a first direction away from the first chamber and 2/ to the second chamber (21) when the pilot spool (11) moves in a second direction away from the second chamber (21). Each of the first and second driving chambers are disposed between a respective end chamber and a passage for return pressure.







Search report