Vacuum conveyor
AssigneeLaitram, L.L.C.
InventorJoseph M. DePaso
Life of this patent
Estimating the term…
Abstract
A closed-loop vacuum conveyor controlling the pressure in a plenum. Pressure sensors in the plenum send pressure signals to a processor that controls the speed of a blower motor sucking air from the plenum and through openings in a foraminous conveyor belt against which conveyed aluminum cans are held by air pressure. The processor controls the blower speed with a variable-frequency drive to adjust the pressure in the plenum to accommodate a varying product density or the shape, size, or weight of conveyed products on the outer surface of the conveyor belt. The plenum may be divided into separate chambers by partitions or adjustable dampers. The pressure in the chambers can be controlled by adjusting each chamber's blower speed or the opening of its dampers.
Claims22
A vacuum conveyor for securely holding products comprising:
- a plenum having an open side;
- a carryway extending along the open side of the plenum;
- a foraminous conveyor belt configured to advance along the carryway and seal the open side of the plenum and having an outer surface and a plurality of openings;
- one or more pressure sensors disposed in the plenum at sensor locations to measure the air pressure at the sensor locations and provide one or more air-pressure signals;
- a blower coupled to the plenum to suck air from the plenum to lower its air pressure and draw air through the openings in the conveyor belt and hold conveyed products to the conveyor belt's outer surface;
- a variable-frequency drive adjusting the speed of the blower;
- a processor receiving the one or more air-pressure signals from the one or more pressure sensors and controlling the variable-frequency drive to adjust the speed of the blower to adjust the air pressure in the plenum to accommodate a varying product density or the shape, size, or weight of conveyed products on the outer surface of the conveyor belt;
- wherein the processor limits the maximum speed of the blower to a predetermined value.
A vacuum conveyor for securely holding products comprising:
- a plenum having an open side;
- a foraminous conveyor belt configured to advance along and seal the open side of the plenum and having an outer surface and a plurality of openings through the outer surface;
- one or more adjustable dampers dividing the plenum into two or more plenum chambers opening onto the open side of the plenum;
- one or more pressure sensors disposed in the plenum chambers at sensor locations to measure the air pressure at the sensor locations in the plenum chambers and provide air-pressure signals;
- a blower coupled to the plenum to suck air from the plenum to lower its air pressure and draw air through the openings in the conveyor belt and hold conveyed products to the conveyor belt's outer surface;
- a processor receiving the one or more air-pressure signals from the one or more pressure sensors and controlling the adjustable dampers to adjust the air pressure in the plenum chambers to accommodate a varying product density or the shape, size, or weight of conveyed products on the outer surface of the conveyor belt.
A vacuum conveyor for securely holding products comprising:
- a plenum having walls and an open side;
- a foraminous conveyor belt configured to advance along and seal the open side of the plenum and having an outer surface and a plurality of openings through the outer surface;
- one or more pressure sensors disposed in the plenum at sensor locations to measure the air pressure at the sensor locations and provide one or more air-pressure signals;
- a blower having a pressure-flow performance curve and being coupled to the plenum to suck air from the plenum to lower its air pressure and draw air through the openings in the conveyor belt and hold conveyed products to the conveyor belt's outer surface;
- an exhaust through which the blower discharges air sucked from the plenum;
- a variable-frequency drive adjusting the speed of the blower;
- wherein the foraminous conveyor belt, the blower, and the exhaust resist airflow as characterized by a net resistive airflow curve;
- a processor receiving the one or more air-pressure signals from the one or more pressure sensors and controlling the variable-frequency drive to shift the pressure-flow performance curve of the blower to match the net resistive airflow curve.
Dependencies are inferred from the claim text.