Patents Examined by Gaerald A. Michalsky
  • Patent number: 6325102
    Abstract: A pilot-type solenoid valve capable of driving a valve member by increasing a pilot fluid pressure from a pilot valve and reliably switching valve member. The pilot-type solenoid valve includes a main valve portion having a valve member capable of sliding in a valve hole to which ports P, A, B, EA and EB in a valve body are opened, a pilot driving mechanism for applying a pilot fluid pressure to a pushing member which pushes one end of the valve member, and a returning mechanism for applying a returning force to the valve member. The pushing member includes a first piston for applying the pilot fluid pressure, and a second piston which is pushed by the first piston and which pushes the valve member. A shaft of the first piston passes through a partition wall in a sealing manner and abuts against the second piston. The shaft is provided therein with a guide hole for guiding the pilot fluid pressure to a pressure chamber of the second piston.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: December 4, 2001
    Assignee: SMC Corporation
    Inventors: Keiji Misumi, Makoto Ishikawa