Patents Assigned to Spears Speciality Oil Tools, Inc.
  • Wall pump having backwash valve actuator
    Patent number: 5382142
    Abstract: A backwash valve for use in a sucker-rod actuated fluid pump, may be selectively actuated to permit both the standing and traveling ball valves to be unseated at the same time permit the pump to be backwashed and/or the production tubing string drained.
    Type: Grant
    Filed: April 6, 1993
    Date of Patent: January 17, 1995
    Assignee: Spears Speciality Oil Tools, Inc.
    Inventor: Harry L. Spears