Pick-and-place head and method for picking work-pieces

A pick-and-place head for transporting a plurality of work-pieces from at least one first location to at least one second location, the pick-and-place head comprising:

• a plurality of nozzles with each nozzle configured to engage one of the plurality of work-pieces, the plurality of nozzles arranged in rows with at least a first and second row;
• a plurality of independent vacuum supplies with each configured to attach to each nozzle of the plurality of nozzles in the first row;
• a shared vacuum supply configured to attach to the second row of nozzles;
• a plurality of vacuum sensors configured to indicate whether or not a sufficient force is being applied to the plurality of work-pieces, wherein the shared vacuum supply and each of the plurality of independent vacuum supplies have one vacuum sensor.

A method for picking a plurality of work-pieces with a plurality of nozzles by action of a vacuum, for placing the work-pieces at a different location, the method comprising the steps of:

• approaching at least one of the plurality of work-pieces with a respective nozzle;
• and,
• generating a vacuum at each respective nozzle;
• wherein the generating step is achieved in at least one of the plurality of nozzles by an individual vacuum supply of the at least one of the plurality of nozzles and in at least two further nozzles of the plurality of nozzles by a shared vacuum supply of the at least two further nozzles.

A method for picking a plurality of work-pieces with a plurality of nozzles by action of a vacuum, for placing the work-pieces at a different location, wherein the plurality of work-pieces and the plurality of nozzles are arranged in respective rows, the nozzles of one first row of nozzles each having an individual vacuum supply, the nozzles of the remaining at least one second row of nozzles having a shared vacuum supply, the method comprising the steps of:

• a) positioning, by relative movement between the nozzles and the work-pieces, each row of nozzles above a row of work-pieces;
• b) attempting to pick up a respective work-piece with each nozzle;
• c) placing the picked-up work-pieces at a different location;
• d) verifying if work-pieces failed to be picked up in step b);
• e1) positioning the first row of nozzles over a verified work-piece that has been verified by step d) as being failed to be picked up;
• f1) picking up the verified work-piece with a nozzle of the first row of nozzles and placing the verified work-piece at the different location intended for it in step c);
• g1) repeating steps e1) and f1) until no verified work-pieces which failed to be picked up in step b) remain;
• e2) testing, if step d) does not indicate work-pieces that failed to be picked up, if at least as many rows of work-pieces remain to be picked up as there are rows of nozzles, and if so, repeat from step a), else consider any remaining rows of work-pieces as if they had failed to be picked up in step b) and proceed from step e1), picking up all the work-pieces in such a row with the nozzles in the first row of nozzles.