Hydraulic actuator for pressure switch of fluidic system
OwnerOsvaldo J. Valdesinventor
Life of this patent
Estimating the term…
Abstract
An hydraulic actuator of a constant pressure fluidic supply system is disclosed in which a movable shuttle disposed within a generally cylindrical housing forms therewith a plurality of piston and cylinder assemblies. Displacement of the shuttle within the housing is governed substantially by opposing hydrodynamic and hydrostatic forces balanced so as to selectively isolate a pump control pressure switch from system pressure during periods of moderate to high consumption demand and provide communication therewith during periods of low to zero consumption demand. An hydropneumatic tank or a conventional diaphragm tank may be used in combination with the actuator to provide fluidic capacitance to the system. Additional system valving and pressure regulation may be incorporated as desired.
Claims17
An hydraulic actuator for selectively communicating an internal fluidic pumping system pressure to a pressure port thereof for controlling a fluidic pump, said hydraulic actuator comprising:
- a housing having at least one inlet, one outlet and a pressure port;
- and
- a mobile shuttle disposed within and cooperating with said housing thereby constituting:
- a sensor assembly comprising a mobile sensor piston disposed in close fitting relation along at least a portion of a perimeter thereof with a fixed sensor cylinder;
- a tractor assembly comprising a fixed tractor piston disposed in close fitting relation along at least a portion of a perimeter thereof with a mobile tractor cylinder;
- and
- a blocker assembly comprising a mobile blocker piston disposed in close fitting relation along at least a portion of a perimeter thereof with a fixed blocker cylinder, wherein:
- said shuttle is displaced within said housing by opposing hydrodynamic and hydrostatic forces such that during periods of fluidic flow through said actuator greater than a predetermined volumetric flow rate, said shuttle is displaced such that said blocker piston prevents communication of system pressure with said pressure port;
- and
- during periods of fluidic flow through said actuator equal to or less than a predetermined volumetric flow rate, said shuttle is displaced such that said blocker piston permits communication of system pressure with said pressure port.
A fluidic pumping system comprising:
- a fluidic pump;
- an hydraulic actuator for selectively communicating an internal fluidic pumping system pressure to a pressure port thereof for controlling said fluidic pump, said hydraulic actuator comprising:
- a housing having at least one inlet in flow communication with an outlet of said fluidic pump, at least one outlet connectable in flow communication with a system consumption, and a pressure port;
- and
- a mobile shuttle disposed within and cooperating with said housing thereby constituting:
- a sensor assembly comprising a mobile sensor piston disposed in close fitting relation along at least a portion of a perimeter thereof with a fixed sensor cylinder;
- a tractor assembly comprising a fixed tractor piston disposed in close fitting relation along at least a portion of a perimeter thereof with a mobile tractor cylinder;
- and
- a blocker assembly comprising a mobile blocker piston disposed in close fitting relation along at least a portion of a perimeter thereof with a fixed blocker cylinder;
- and
- a pressure switch connected to said pressure port for selectively providing power to said fluidic pump according to at least one predetermined system pressure value sensed at said pressure port, wherein:
- said shuttle is displaced within said housing by opposing hydrodynamic and hydrostatic forces such that during periods of fluidic flow through said actuator greater than a predetermined volumetric flow rate, said shuttle is displaced such that said blocker piston prevents communication of system pressure with said pressure port;
- and
- during periods of fluidic flow through said actuator equal to or less than a predetermined volumetric flow rate, said shuttle is displaced such that said blocker piston permits communication of system pressure with said pressure port.
Dependencies are inferred from the claim text.