Jetting discrete volumes of high viscosity liquid

Patent metadata

Field	Value
Publication number	US-9314812-B2
Application number	US-201113515610-A
Country	US
Kind code	B2
Filing date	Jan 7, 2011
Priority date	Jan 14, 2010
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

In one aspect, an adhesive dispensing system 30 includes a dispensing module 32 having an inlet and an outlet, a supply 35 of hot melt adhesive maintained at low pressure, and a low pressure liquid passageway 44 communicating between the supply 35 and the inlet of the dispensing module 32 . Liquid material is received through the inlet at a low pressure, and the dispensing module 32 rapidly develops high pressure at the outlet 78 to jet the liquid material from the outlet 78 . In another aspect, an apparatus for jetting liquid material includes a dispenser body 38 having a liquid chamber 40 . A piston 54 is movably disposed within the liquid chamber 40 , from a position wherein a piston tip 58 is spaced from a complimentary shaped recess 76 , to a position wherein the piston tip 58 effectively seals off the recess 76 , then to a position wherein the piston tip 58 is received within the recess 76 to displace a discrete volume of liquid material from the recess 76.

First claim

What is claimed is:

1. An adhesive dispensing system, the system comprising:
an adhesive dispensing module having an inlet and an outlet, said adhesive dispensing module receiving liquid material through said inlet at low pressure and rapidly developing high pressure at said outlet to thereby jet the liquid material therefrom;
a supply of hot melt adhesive maintained at low pressure;
a low pressure liquid passageway communicating between said adhesive dispensing module inlet and said supply;
a liquid chamber communicating with said outlet;
a recess proximate said outlet; and
a piston tip disposed in said liquid chamber, wherein:
said recess is shaped complementary to said piston tip and adapted to receive said piston tip therein,
said piston tip develops said high pressure when said piston tip is moved into said recess, and
said piston tip is reciprocatingly movable within said liquid chamber between a first position wherein hot melt adhesive from said supply is admitted to said recess, a second position wherein said piston tip seals the liquid chamber from said supply of hot melt adhesive, and a third position wherein hot melt adhesive is jetted from said outlet under high pressure.

2. The adhesive dispensing system of claim 1 , wherein said supply of hot melt adhesive is adapted to contain hot melt adhesive in solid form.

3. The adhesive dispensing system of claim 2 , further comprising an auger for feeding hot melt adhesive toward said adhesive dispensing module.

4. The adhesive dispensing system of claim 2 , further comprising a vacuum feed device for feeding hot melt adhesive toward said adhesive dispensing module.

5. The adhesive dispensing system of claim 1 , further comprising first and second adhesive dispensing modules having respective first and second inlets and first and second outlets, said first and second inlets receiving liquid material at the same low pressure from said supply through respective first and second low pressure liquid passageways and generating high pressure proximate said respective outlets to jet liquid material therefrom at different rates.

6. The adhesive dispensing system of claim 1 , wherein said supply is supported on said adhesive dispensing module.

7. An apparatus for jetting liquid material, the apparatus comprising:
a dispenser body couplable to a source of liquid material, said dispenser body including a liquid chamber;
a piston movably disposed within said liquid chamber and having a piston tip; and
a recess in fluid communication with said liquid chamber and with a liquid outlet, said recess shaped complimentary to said piston tip such that said piston tip is receivable within said recess, wherein:
said piston tip develops a high pressure when said piston tip is moved into said recess, and
said piston is reciprocatingly movable from a first position wherein said piston tip is spaced from said recess for liquid material from said source of liquid material to be admitted to said recess, to a second position for said piston tip to effectively seal off said recess from said source of liquid material to define a discrete volume between said piston tip and said recess, and then to a third position wherein said piston tip is received within said recess to displace said discrete volume from said recess through said liquid outlet for said liquid material to jet from said outlet under said high pressure.

8. The apparatus of claim 7 , further comprising:
an open end in said dispenser body, said open end communicating with said liquid chamber; and
a nozzle operatively coupled to said dispenser body at said open end,
wherein said recess being formed in said nozzle.

9. The apparatus of claim 7 , wherein said piston tip has a spherical shape.

10. A method of dispensing liquid material, the method comprising:
supplying liquid material to a liquid chamber at a pressure sufficient to fill the liquid chamber, but not to dispense the liquid material from an outlet associated with a recess and communicating with the liquid chamber;
effectively sealing off a discrete volume of liquid material proximate the recess by a piston tip disposed in the liquid chamber, wherein the recess is shaped complementary to the piston tip and adapted to receive the piston tip therein; and
generating a high pressure at the recess to jet the discrete volume of liquid material from the outlet when the piston tip is moved into said recess, wherein hot melt adhesive is jetted from said outlet under said high pressure.

11. The method of claim 10 , wherein the high pressure generated is in the range of about 400 psi to about 2500 psi.

Assignees

• Clark Justin A
• Riney John M
• Taylor Edward C
• Nordson Corp

Inventors

• Clark Justin A
• Riney John M
• Taylor Edward C

Classifications

• B05C5/001

  incorporating means for heating or cooling the liquid or other fluent material (B05C11/1042 takes precedence) · CPC title

• B05C11/1034 Primary

  specially designed for conducting intermittent application of small quantities, e.g. drops, of coating material (B05C5/0225, B05C11/1026 take precedence) · CPC title

• B05C5/0225 Primary

  characterised by flow controlling means, e.g. valves, located proximate the outlet (B05C5/0258, B05C5/0275 take precedence; supply valves upstream the coating head B05C11/1036) · CPC title

• B05C5/0275

  flow controlled, e.g. by a valve · CPC title

• B23K3/0638

  for viscous material feeding, e.g. solder paste feeding (B23K3/0623 takes precedence) · CPC title