Patents by Inventor Frank M. Fritz

Frank M. Fritz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5011113
    Abstract: A direct-operated, two-way solenoid valve is disclosed. The valve balances the hydraulic flow forces acting on a poppet in order to achieve fast-acting, high-flow operation. The valve has a housing with the poppet mounted in a main bore. The poppet has a sealing end with a longitudinal central bore that is open at the sealing end and terminates in a pressure wall. A radial cross bore in the poppet provides fluid communication between the central bore and an outlet port formed in the housing. The sealing end of the poppet may contact a valve seat to prevent fluid communication between an inlet port formed in the housing and the central bore of the poppet. The sealing end of the poppet is biased into contact with the valve seat to prevent fluid communication between the inlet port and the central bore. An actuator generating a magnetic flux path tends to move the poppet out of contact with the valve seat.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: April 30, 1991
    Assignee: Applied Power Inc.
    Inventors: Thomas J. Stobbs, Kishor J. Patel, Frank M. Fritz, Dale A. Knutson, James P. Janecke
  • Patent number: 5005803
    Abstract: A compact, high response regulating valve has a solenoid modulated armature and plunger construction. The solenoid assembly and armature minimize magnetic flux leakage by maintaining the armature in close proximity to the induced magnetic field. In one embodiment, the lightweight armature has a number of holes to increase the speed at which it may be modulated. Mounted to the armature is a regulator plunger which controls fluid communication between the valve's inlet and outlet ports. Normally spring-biased closed, the plunger uses a line seal to maximize flow with minimal longitudinal plunger movement. Plunger response time is enhanced by eliminating elastomeric friction (i.e., eliminating O-rings and replacing them with a number of notches about the plunger periphery). A conical seat and bevelled plunger provide an effective line seal.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: April 9, 1991
    Assignee: Applied Power Inc.
    Inventors: Frank M. Fritz, Dale A. Knutson, James P. Janecke