Rotary Member Patents (Class 4/264)
  • Patent number: 4307475
    Abstract: The specification discloses an improved dental cuspidor having a vacuum drain means. The specification also discloses a drain having a drain chamber of which one side is formed by a diaphragm so that when water reaches a given height in the chamber, the diaphragm actuates an air valve to drive a piston to open a drain valve to a vacuum drain.
    Type: Grant
    Filed: October 5, 1979
    Date of Patent: December 29, 1981
    Assignee: A-Dec, Inc.
    Inventor: Theodore E. Schmidt