Patents Represented by Attorney, Agent or Law Firm Dickinson McCormack & Heuser, PC
  • Vacuum-assisted pump
    Patent number: 6409478
    Abstract: A self-priming centrifugal pump including a supplementary vacuum pump and a float valve. The vacuum pump serves to draw liquid to the pump for priming and the float valve shut of flow to the vacuum pump when liquid reaches a predetermined level to prevent entry of liquid into the vacuum pump. In some embodiments the float valve includes an o-ring valve seal and the vacuum pump includes an oil delivery system to distribute oil from an oil reservoir to improve lubrication.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: June 25, 2002
    Assignee: Roper Holdings, Inc.
    Inventors: William B. Carnes, Milton K. Leonard, Robert B. Ray