Patents by Inventor John D. Petro

John D. Petro 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: 4777981
    Abstract: A magnetic detent joy stick and stack remote control valve is provided having a traction magnet detent in which a magnet plate activated by the detent is constantly urged against the coil housing to prevent dirt from getting between the coil plate and coil housing face when the power is cut off and/or the valve is in neutral.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: October 18, 1988
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4682939
    Abstract: A gear pump and motor is provided having increased life and efficiency as a result of improved wiping action of the gear teeth on the inner periphery of the pump chamber. This is accomplished by providing a non-smooth surface layer of a dissimilar metal such as a carbide on the tip ends of the teeth.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: July 28, 1987
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4569367
    Abstract: An inlet unloader valve is provided for insertion ahead of one or more open center valve work sections having a pressure beyond port, which unloader valve has a spring biased spool, normally closing communication from the inlet to exhaust and proportionally opened by signal pressure from the pressure beyond port and the inlet and exhaust chambers to control flow through the work sections.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: February 11, 1986
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4519420
    Abstract: A hydraulic valve is provided which can be modified to provide priority compensation, parallel pressure compensation, inlet check functions and a float function by changing a flow through inlet valve portion in the inlet chamber of the valve.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: May 28, 1985
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4519419
    Abstract: A hydraulic valve is provided which can be modified to provide priority compensation, parallel pressure compensation, inlet check functions and a float function by changing a flow through inlet valve portion in the inlet chamber of the valve.
    Type: Grant
    Filed: June 15, 1982
    Date of Patent: May 28, 1985
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4338962
    Abstract: A pump control valve and relief valve assembly are provided in the form of a valve housing having a main bore therethrough, a spool movable in said bore and having a pair of spaced annular grooves therein, a spaced relief bore in said housing, a pump chamber and a work chamber in said housing intersecting both bores, a pair of tank chambers, one on each opposite side of the pump and work chambers intersecting said main bore, said tank chamber adjacent the work chamber intersecting the relief bore, a tank bore connecting said tank chambers, an inlet return bore intersecting said tank chamber adjacent the work chamber, an inlet port connected to said relief bore and jump chamber and adapted to connect to a pump outlet port, a tank port connected to said tank bore, a pump inlet port and a return port connected to said inlet return bore, said pump inlet port adapted to connect to a pump inlet port and the return port adapted to be connected to a source of return fluid, and a combination check and relief valve ass
    Type: Grant
    Filed: August 13, 1980
    Date of Patent: July 13, 1982
    Assignee: Commercial Shearing, Inc.
    Inventors: John D. Turko, John D. Petro
  • Patent number: 4194366
    Abstract: A two speed valve and bi-directional motor system is provided having a pair of motors, means for delivering pressure fluid selectively to either side of said motors, a two speed valve means receiving fluid on one side of said motors to selectively direct the fluid to one or both motors to provide high or low speed operation thereof and flow sensing means automatically connecting the discharge from the motors to the one motor not receiving fluid when the two speed valve is shifted to divert all fluid to one motor so that fluid is recirculated through said motor.
    Type: Grant
    Filed: June 13, 1978
    Date of Patent: March 25, 1980
    Assignee: Commerical Shearing, Inc.
    Inventor: John D. Petro
  • Patent number: 4187877
    Abstract: A compensated work port fluid valve is provided wherein a directional control valve having an inlet chamber, an outlet chamber and a work chamber is provided with a compensator valve connected to the work chamber and having a pressure sensing compensator valve controlling the flow of fluid from the work chamber to a work port to maintain constant pressure at the work port.
    Type: Grant
    Filed: July 25, 1978
    Date of Patent: February 12, 1980
    Assignee: Commercial Shearing Inc.
    Inventors: Robert F. Hodgson, John D. Petro
  • Patent number: 4058135
    Abstract: A compensated work port fluid valve is provided wherein a directional control valve having an inlet chamber, an outlet chamber and a work chamber is provided with a compensator valve connected to the work chamber and having a pressure sensing compensator valve controlling the flow of fluid from the work chamber to a work port to maintain constant pressure at the work port.
    Type: Grant
    Filed: December 16, 1976
    Date of Patent: November 15, 1977
    Assignee: Commercial Shearing, Inc.
    Inventor: John D. Petro