US3826224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic dispenser system having non-clogging melting zone
Assignee: Nordson Corp
•
Filing: 1971-11-02
•
Granted: 1974-07-30
•
Expires: 1991-11-02
Abstract
Abstract This invention relates to a system for dispensing thermoplastic materials and particularly to a system for dispensing so-called ''''high performance'''' hot melt adhesives. More specifically, the invention relates to dispensing systems in which solid thermoplastic or hot melt material is melted in small charges or batches and is then supplied upon demand in liquid form to a dispensing gun, the quantity of molten material being maintained at a minimum from the area in which it is melted to the dispensing nozzle of the gun.
Inventors
- 👤 R Baker
- 👤 A Reighard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:14
CPC Classifications
B; B29; B29B; B29B13/00; B29B13/02; B29B13/022; B05; B05C; B05C9/00; B05C9/08; B05C9/14; B29C; B29C65/00; B29C65/48; B29C65/4805; B29C65/481; B29C65/4815
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
292 words
A system for dispensing molten thermoplastic material comprising a frame including a hopper, a cylinder, and a barrel, said barrel projecting from the forward end of said frame and including a melting zone, a molten material transfer zone, and an outlet port, said outlet port being located adjacent the front of said barrel, a heating chamber located in said barrel, said chamber including a metallic core mounted in said chamber in radially spaced relation to the inside wall of said barrel, said chamber including at least one heater operable to heat the inner surface of said barrel and the outer surface of said core to at least the melting temperature of said thermoplastic material, said cylinder being in fluid communication with said barrel and sealingly connected to the rearward end thereof, a piston mounted to reciprocate in the bore of said cylinder, a motor mounted on said frame rearwardly of said cylinder and operable to effect reciprocation of said piston, said hopper being mounted on said frame and operable when said piston moves rearwardly in said barrel to deliver a charge of solid material into said cylinder between said piston and said heating chamber such that the material is forced by said piston forwardly successively into and through said cylinder and said barrel upon forward movement of said piston, a dispenser gun including an inlet port, a flow control valve, and an outlet orifice, fluid conduit means connecting the inlet port of said gun to the outlet port of said barrel, and said barrel having a constant flow area throughout the melting zone so as to enable a relatively uniform even rate of flow of molten material to be maintained from the outlet orifice of said gun when said valve is open.
Claim 2
Independent Claim
292 words
A system for dispensing molten thermoplastic material comprising a frame including a hopper, a cylinder, and a barrel, said barrel projecting from the forward end of said frame and including a melting zone, a molten material transfer zone, and an outlet port, said outlet port being located adjacent the front of said barrel, a heating chamber located in said barrel, said chamber including a metallic core mounted in said chamber in radially spaced relation to the inside wall of said barrel, said chamber including at least one heater operable to heat the inner surface of said barrel and the outer surface of said core to at least the melting temperature of said thermoplastic material, said cylinder being in fluid communication with said barrel and sealingly connected to the rearward end thereof, a piston mounted to reciprocate in the bore of said cylinder, a motor mounted on said frame rearwardly of said cylinder and operable to effect reciprocation of said piston, said hopper being mounted on said frame and operable when said piston moves rearwardly in said barrel to deliver a charge of solid material into said cylinder between said piston and said heating chamber such that the material is forced by said piston forwardly successively into and through said cylinder and said barrel upon forward movement of said piston, a dispenser gun including an inlet port, a flow control valve, and an outlet orifice, fluid conduit means connecting the inlet port of said gun to the outlet port of said barrel, and said barrel having a constant flow area throughout the melting zone so as to enable a relatively uniform even rate of flow of molten material to be maintained from the outlet orifice of said gun when said valve is open.
Claim 3
Dependent Claim
63 words
The dispensing system of claim 1 in which said metallic core includes a tapered end located adjacent the rearward end of said barrel in said melting zone, said barrel having a tapered inside surface located adjacent said tapered end of said core so as to maintain a constant flow area between said core and said inside surface of said barrel adjacent said core.
Claim 4
Dependent Claim
38 words
The dispensing system of claim 1 which further includes fluid flow means for cooling said cylinder so as to preclude molten thermoplastic material from flowing rearwardly into said cylinder and into contact with the surface of said piston.
Claim 5
Dependent Claim
38 words
The dispensing system of claim 3 in which said fluid flow means includes fins on the exterior of said cylinder and a motor driven fan for moving air over the surface of said fins to cool said cylinder.
Claim 6
Dependent Claim
19 words
The dispensing system of claim 1 which further includes a low friction material liner sleeve contained within said cylinder.
Claim 7
Dependent Claim
52 words
The dispensing system of claim 1 which further includes means for controlling reciprocation of said piston, said control means being operable to effect rearward and then forward recharging movement of said piston in response to removal from adjacent said dispenser gun outlet orifice of an article to which material has been applied.
Claim 8
Dependent Claim
52 words
The dispensing system of claim 6 in which said piston reciprocation motor comprises a pneumatic motor and in which said control means includes a solenoid operated valve and an electrical circuit including a product detection switch operable to detect removal of an article from adjacent the outlet orifice of said dispenser gun.
Claim 9
Independent Claim
203 words
A system for dispensing molten thermoplastic material comprising a frame including a cylinder and a barrel, said barrel projecting from the forward end of said frame and including a melting zone and a molten material transfer zone, a heating chamber located in said barrel, said chamber including a metallic core mounted in said chamber in radially spaced relation to the inside wall of said barrel, said chamber including at least one heater operable to heat the inner surface of said barrel and the outer surface of said core to at least the melting temperature of said thermoplastic material, said cylinder being in fluid communication with said barrel and sealingly connected to the rearward end thereof, a piston mounted to reciprocate in the bore of said cylinder, a motor mounted on said frame rearwardly of said cylinder and operable to effect reciprocation of said piston, a dispenser communicating with said barrel transfer zone and including a flow control valve and an outlet orifice, and said barrel having a constant flow area throughout the melting zone so as to enable a relatively uniform even rate of flow of molten material to be maintained from the outlet orifice of said dispenser when said valve is open.
Claim 10
Independent Claim
203 words
A system for dispensing molten thermoplastic material comprising a frame including a cylinder and a barrel, said barrel projecting from the forward end of said frame and including a melting zone and a molten material transfer zone, a heating chamber located in said barrel, said chamber including a metallic core mounted in said chamber in radially spaced relation to the inside wall of said barrel, said chamber including at least one heater operable to heat the inner surface of said barrel and the outer surface of said core to at least the melting temperature of said thermoplastic material, said cylinder being in fluid communication with said barrel and sealingly connected to the rearward end thereof, a piston mounted to reciprocate in the bore of said cylinder, a motor mounted on said frame rearwardly of said cylinder and operable to effect reciprocation of said piston, a dispenser communicating with said barrel transfer zone and including a flow control valve and an outlet orifice, and said barrel having a constant flow area throughout the melting zone so as to enable a relatively uniform even rate of flow of molten material to be maintained from the outlet orifice of said dispenser when said valve is open.
Claim 11
Dependent Claim
63 words
The dispensing system of claim 8 in which said metallic core includes a tapered end located adjacent the rearward end of said barrel in said melting zone, said barrel having a tapered inside surface located adjacent said tapered end of said core so as to maintain a constant flow area between said core and said inside surface of said barrel adjacent said core.
Claim 12
Dependent Claim
38 words
The dispensing system of claim 8 which further includes fluid flow means for cooling said cylinder so as to preclude molten thermoplastic material from flowing rearwardly into said cylinder and into contact with the surface of said piston.
Claim 13
Dependent Claim
38 words
The dispensing system of claim 10 in which said fluid flow means includes fins on the exterior of said cylinder and a motor driven fan for moving air over the surface of said fins to cool said cylinder.
Claim 14
Dependent Claim
19 words
The dispensing system of claim 8 which further includes a low friction material liner sleeve contained within saud cylinder.
Claim 15
Dependent Claim
52 words
The dispensing system of claim 8 which further includes means for controlling reciprocation of said piston, said control means being operable to effect rearward and then forward recharging movement of said piston in response to removal from adjacent said dispenser gun outlet orifice of an article to which material has been applied.
Claim 16
Dependent Claim
52 words
The dispensing system of claim 13 in which said piston reciprocation motor comprises a pneumatic motor and in which said control means includes a solenoid operated valve and an electrical circuit including a product detection switch operable to detect removal of an article from adjacent the outlet orifice of said dispenser gun.
References Cited (Backward Citations)
US2203299A
Cited
US2925800A
Cited
US2831214A
Cited
US2995159A
Cited
US3008188A
Cited
US3377012A
Cited
US3550815A
Cited
US3530772A
Cited
US3570725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |