Abstract: A multiple section control valve bank is provided having a control valve section and an inlet section operatively connected to provide smooth proportional metering control over a wide band of operating pressures while simultaneously metering the operation of two or more fluid actuated devices from a single fluid source. This is accomplished by providing metering and logic elements in the control valve section connected to a signal chamber in the inlet section to vary the flow of fluid through the inlet section to the control section in accordance with signals from the meter and logic elements.

Abstract: A control valve bank is provided having a working section and an inlet section wherein inlet fluid from a pump is proportionally metered at the inlet of each valve section so that the input volume to each work port is generally uniform regardless of pressure variations.

Abstract: A low friction drag seal is provided for use between a housing and a linearly movable cylindrical member subject to fluid pressure in the form of an annular chamber surrounding the cylindrical member in one of the housing and cylindrical member, a generally right triangular cross section elastomer ring in said annular chamber surrounding said cylindrical member and in contact with a relatively movable surface on one of the cylinder and housing at an apex of said elastomer ring and a generally rigid back up ring having an inclined surface extending away from said relatively movable surface and in contact with the hypotenuse of the generally triangular member.

Abstract: A relief valve assembly particularly in combination with yieldable pit posts is provided having an elongate housing, a first load chamber at one end of said housing, an inlet aperture into said housing, a non-return valve in said inlet aperture for admitting fluid non-returnably into said load chamber, a first valve seat in said housing communicating with said load chamber, a spring loaded relief valve movable lengthwise of the housing and normally engaging said seat to close the load chamber, a second valve seat in said housing spaced lengthwise from said first valve seat and relief valve and forming therebetween a balancing load chamber, a spring loaded pilot relief valve movable lengthwise of the housing and normally engaging said second seat to close the same, and a regulated orifice means in said relief valve connecting the first load chamber and the balancing load chamber whereby said balancing load chamber is normally pressurized to the pressure of the load chamber.