Patent ID: 6929698

Claim:
A powder coating system having at least one dispenser for spraying powder onto objects transmitted to a powder spray booth, comprising: a primary hopper containing powder coating material, a second hopper; a transfer device, connected between said primary hopper and said second hopper, which transmits powder coating material under the application of negative pressure through a conduit connected between said primary hopper and said second hopper by means of a vacuum pump communicating with said conduit; a sensor which is effective to sense the quantity of powder coating material within said second hopper; and a controller which turns on said vacuum pump to transfer powder from said primary hopper to said second hopper when said sensor indicates that the quantity of powder coating material in said second hopper has reached a first predetermined amount, said controller turning off said vacuum pump to terminate the transfer of powder when said sensor indicates that the quantity of powder coating material in said second hopper has reached a second predetermined amount, said controller opening a valve communicating with said conduit and a compressed air source to supply compressed air into said conduit to push powder coating material through said conduit into said second hopper.