(19)
(11) EP 0 169 307 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.01.1987 Bulletin 1987/02

(43) Date of publication A2:
29.01.1986 Bulletin 1986/05

(21) Application number: 85103674

(22) Date of filing: 27.03.1985
(84) Designated Contracting States:
BE CH DE FR GB IT LI

(30) Priority: 18.05.1984 US 611945

(71) Applicant: NORDSON CORPORATION
 ()

(72) Inventors:
  • Klein, Richard G.
     ()
  • Schmitkons, James W.
     ()

   


(54) Hot melt adhesive pump with ported gears


(57) A hot melt adhesive pump having a first stage gear pump for metering molten hot melt adhesive into a second stage gear pump where gas is mixed and driven into solution with the adhesive is provided with ports extending between opposed gear faces permitting the leakage of adhesive under pressure between gear faces. Pressure imbalances which might otherwise exist due to the accumulation of hot melt adhesive in an interface between the gear faces and adjacent surfaces, e.g., a pair of plates, between which the gears are sandwiched, are alleviated because adhesive under pressure in this interface can pass through the ports, thereby balancing the thrust forces on the opposed gear faces. The result is reduced gear and end plate wear and increased pump life.







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