Valve for air conveyor

Claim 2

An air conveyor including a substantially horizontal bottom plate having a plurality of perforations therein, an air chamber on the underside of said plate, means for supplying a quantity of pressurized air to said chamber, valving means controlling airflow through said perforations comprising a housing with an apertured end plate surrounding the underside of said perforations, a reciprocable piston in each housing having a stem traversing the aperture in the end plate to subject the end face thereof to the pressurized air of said air chamber, an aperture in said housing above the piston adapted to permit pressurized airflow therethrough when the force of air on the top of said piston exceeds the force of air on the bottom face of said stem and moves the piston downward, and a bleed port in said housing vertically spaced above the aperture in said housing wall adapted to permit pressurized air to bleed continuously from said chamber on the underside of the apertured plate to the chamber on the upperside of said piston.

Claim 3

An air conveyor including a horizontal bottom plate having a plurality of spaced perforations therein, sidewalls extending longitudinally along said bottom plate to form an upwardly facing channel, openings in said sidewalls inclined similarly toward one end of said conveyor to form propulsion passageways, means for supplying compressed air to each of said passageways, a chamber for pressurized air secured to the underside of said plate, means for supplying a quantity of pressurized air to said chamber, valve means controlling airflow through the perforations of said plate comprising a cylindrical housing secured to the underside of each perforation, an end plate having a concentric aperture therein enclosing the bottom of said cylindrical housing, a reciprocable piston valve in each housing having a stem traversing the aperture in said end plate, apertures in the wall of said cylindrical housing spaced from said end plate a distance greater than the thickness of said piston valve whereby the apertures will be open when the force of air on top of said piston exceeds the force on the bottom face of said stem forcing the piston to an extreme downward position, and a bleed port in the cylindrical housing vertically spaced above the apertures in said housing wall adapted to permit pressurized air to bleed continuously from said chamber on the underside of the apertured plate to the chamber on the upperside of said piston.

Claim 4

An air conveyor including a horizontal bottom plate having a plurality of spaced perforations therein, sidewalls extending longitudinally along said bottom plate to form an upwardly facing channel, openings in said sidewalls inclined similarly toward one end of said conveyor to form propulsion passageways, means for supplying compressed air to each of said passageways, a chamber for pressurized air secured to the underside of said plate, means for supplying a quantity of pressurized air to said chamber, valve means controlling airflow through the perforations of said plate comprising a cylindrical housing secured to the underside of each perforation, an end plate having a concentric aperture therein enclosing the bottom of said cylindrical housing, a reciprocable piston valve in each housing having a stem traversing the aperture in said end plate, apertures in the wall of said cylindrical housing spaced from said end plate a distance greater than the thickness of said piston valve whereby the apertures will be open when the force of air on top of said piston exceeds the force on the bottom face of said stem forcing the piston to an extreme downward position, and a bleed port in the cylindrical housing vertically spaced above the apertures in said housing wall adapted to permit pressurized air to bleed continuously from said chamber on the underside of the apertured plate to the chamber on the upperside of said piston.

Claim 5

An air conveyor as defined in claim 2, having stop means that permit movement of said piston valve a distance somewhat greater than the distance of said apertures above the lowermost position of said piston.