Powder dispensing apparatus and method

A system for producing three-dimensional articles by an additive manufacturing process comprising,

• a build-chamber;
• a lowerable build plate for supporting powder to define a build surface;
• a spreader for spreading powder over the build surface;
• an irradiation means for irradiating selected portions of the build surface of the powder corresponding to a cross-section to be formed;
• and
• a powder dispenser comprising,
• a metering member defining one or more metering voids extending through the metering member, the or each metering void having an entrance opening defined in a first face of the metering member and an exit opening defined in a second face of the metering member, and
• upper and lower retaining members,
• wherein the metering member is reciprocally movable relative to the upper and lower retaining members such that, for the or each metering void, the metering member is movable between a first position, in which powder is able to pass into and be retained within the metering void through the entrance opening, and a second position, in which the powder in the metering void is able to be dispensed from the metering void through the exit opening, and
• wherein the one or more metering voids are arranged to dispense powder to form a line of powder to be spread by the spreader.

A system for producing three-dimensional articles by an additive manufacturing process comprising,

• a build-chamber;
• a lowerable build plate for supporting powder to define a build surface;
• a spreader for spreading powder over the build surface;
• an irradiation means for irradiating selected portions of the build surface of the powder corresponding to a cross-section to be formed;
• a powder dispenser for dispensing a predetermined volume of powder comprising,
• a movable metering member defining one or more elongate metering voids extending through the metering member, the or each metering void having an entrance opening defined in a first face of the metering member and an exit opening defined in a second face of the metering member, the volume defined by the one or more metering voids being equivalent to the predetermined volume of powder, the elongate metering void being elongate in a plane parallel with a direction of movement of the metering member.

A system for producing three-dimensional articles by an additive manufacturing process comprising,

• a build-chamber;
• a spreader for spreading a layer of powder over a build surface within the build chamber;
• an irradiation means for irradiating selected portion of the build surface corresponding to a cross-section to be formed;
• and
• a powder dispenser for dispensing a volume of powder to be spread by the spreader, the powder dispenser comprising a movable metering member defining one or more metering voids,
• wherein the spreader is arranged to engage the movable member to move the metering member to cause the metering member to dispense a volume of powder from the one or more metering voids.

A system for producing three-dimensional articles by an additive manufacturing process comprising,

• a build-chamber;
• a spreader for spreading a layer of powder over a build surface within the build chamber;
• an irradiation means for irradiating selected portion of the build surface corresponding to a cross-section to be formed;
• a powder dispenser for dispensing varying volumes of powder to be spread by the spreader;
• and
• a controller arranged to calculate a volume of powder required for each layer and for actuating the powder dispenser to deliver that volume of powder.