Powder feeder apparatus

A powder feeder apparatus, comprising:

• a) a container for powder including an upper portion and a lower portion having a chamber;
• b) a vertical rotatable shaft substantially in alignment with an axial axis and further substantially in alignment with, and at least contained partially in said container, wherein said rotatable shaft includes agitating means extending substantially radially and outwardly from said shaft in said container for agitating and preventing clumping of said powder in said container;
• c) metering means for selectively metering predetermined amount of said powder to said chamber of said container, said metering means disposed in said lower portion of said container and operatively attached to said rotatable shaft, said chamber being a vertically elongated cavity in the aforesaid lower portion with the top end thereof open and disposed beneath the metering means to receive by gravitational force powder from the metering means and with the bottom end thereof open to permit discharge from the container of the powder therein by gravitational force;
• and wherein said metering means comprises a stationary section having an exit cavity and a rotatable section having a metering port, said rotatable section being rotable horizontally from a first position filling said metering port with said powder by gravitational force when said exit cavity of said stationary section and said metering port of said rotatable section are in substantial alignment, to a second position emptying said powder from said metering port by gravitational force when said metering port of said rotatable section and the upper end of said chamber in said lower portion of said container are in substantial alignment;
• d) means for selectively purging said powder downward from said metering means and downward through said chamber in said lower portion of said container disposed in said lower portion of said container, wherein said purge means includes stationary conduit means extending radially along a portion of said stationary section of said metering means including a downwardly facing entrance and exit, and rotatable conduit means extending radially along a portion of said rotatable section including an outwardly facing entrance and upwardly facing exit being moveable from a first-non-purge position when said stationary conduit means is not in substantial alignment with said rotatable conduit means and said metering port of said rotatable section and said chamber of said container are not in substantial alignment, to a second-purge position when said upwardly facing exit of said rotatable conduit means is in substantial alignment with said downwardly facing entrance of said stationary section and said metering port of said rotatable section and said chamber of said container are in substantial alignment thereby allowing a gaseous material to substantially evacuate said powder in said metering port and said chamber in said second-purge position.