×

Methods and apparatus for applying powder to workpieces

  • US 5,474,609 A
  • Filed: 06/30/1992
  • Issued: 12/12/1995
  • Est. Priority Date: 06/30/1992
  • Status: Expired due to Fees
First Claim
Patent Images

1. An apparatus for use in sequentially applying an annular band of powder to a surface of each can lid of a plurality of can lids, said apparatus comprising a conveyor having can lid retainers to hold can lids, said conveyor being operable to move each of said can lids in turn to and from a work station, a spray device disposed adjacent to said conveyor, said spray device being operable to spray an annular band of powder on one surface of each of said can lids in turn while each of said can lids is at said work station in a spaced apart relationship with said spray device, said spray device including a body section in which a flow of air with powder entrained therein is conducted, a charging apparatus connected with said body section to electrostatically charge powder entrained in said flow of air in said body section, a nozzle connected with said body section and spaced apart from said one surface of each of said can lids during movement of each of said can lids in turn to and from said work station and during spraying of an annular band of powder onto each of said can lids at said work station, a diverter connected with said body section at a location between said charging apparatus and said nozzle and operable to divert a flow of air and electrostatically charged powder being conducted in said body section away from said nozzle to interrupt a flow of powder from said nozzle toward said can lid at said work station, and an excess powder collector at least partially enclosing said nozzle to draw a flow of excess powder away from said one surface of a can lid at said work station and into said excess powder collector, said excess powder collector being spaced apart from said one surface of said can lid at said work station during flow of the stream of air and powder through said space between said nozzle and said one surface of said can lid at said work station and during a flow of excess powder away from said one surface of said can lid at said work station into said excess powder collector, a source of powder, a pump connected in communication with said source of powder and said nozzle to induce a flow of powder from said source of powder toward said nozzle, said pump being operable between an active condition in which said pump is effective to induce a flow of powder from said source of powder and an inactive condition in which said pump is ineffective to induce a flow of powder from said source of powder, and control means for effecting operation of said pump between the active condition and the inactive condition to produce pulses of air with powder entrained therein, said diverter being operable between an active condition in which said diverter is effective to divert a flow of air and powder away from said nozzle and an inactive condition in which said diverter is ineffective to divert a flow of air and powder, said control means being operable to effect operation of said diverter between said inactive condition and said active condition to divert a portion of each pulse of powder away from said nozzle.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×