Patent US3813014A successfully refreshed from Google Patents.
US3813014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection moulding machine
Assignee: Individual
•
Filing: 1973-02-27
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Granted: 1974-05-28
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Expires: 1993-02-27
Abstract
Abstract An injection moulding machine of the type incorporating a rotatable and reciprocable screw has on the forward end of the barrel a nozzle portion providing within it a valve cylinder larger than the bore of the barrel. A differential valve plunger having an axial passage extending through it has larger and smaller diameter portions slidably and sealingly engaged in the valve cylinder and the bore of the barrel respectively. The smaller diameter end of the valve plunger can be abutted by the nose of the screw to form a seal preventing flow through the axial passage in the valve plunger and to enable the valve plunger to be driven along the valve cylinder to eject the softened material forwardly from the valve cylinder. A plug is provided which can be operated to open or close off the injection aperture in the valve cylinder. During rotation of the screw softened material passes forwardly through the passage in the valve plunger and by reason of the differential area urges the plunger rearwards towards the screw.
Inventors
- 👤 D Guerin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:52
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/47; B29C45/50; B29C45/52
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
186 words
An injection moulding machine comprising a barrel having an axial bore, a screw mounted in said bore, which screw is rotatable within the bore and is movable axially along the bore, said barrel having at its forward end a nozzle portion providing within it a valve cylinder which opens to and which is of larger diameter than the bore of the barrel, a valve plunger having smaller and larger diameter portions which are slidingly and sealingly engaged in the bore of the barrel and the valve cylinder respectively, the valve cylinder being vented at its end adjacent the bore in the barrel, said valve plunger having an axial passage extending therethrough, and said valve plunger being movable forwardly along the valve bore by the screw during forward injection movement of the latter, said axial passage being sealed by the screw during such forward movement, and the nozzle portion having a nozzle aperture at the forward end thereof, and a plug mounted in the aperture which plug is selectively operable to permit and to prevent the ejection of material from the valve cylinder through the nozzle aperture.
Claim 2
Dependent Claim
186 words
An injection moulding machine comprising a barrel having an axial bore, a screw mounted in said bore, which screw is rotatable within the bore and is movable axially along the bore, said barrel having at its forward end a nozzle portion providing within it a valve cylinder which opens to and which is of larger diameter than the bore of the barrel, a valve plunger having smaller and larger diameter portions which are slidingly and sealingly engaged in the bore of the barrel and the valve cylinder respectively, the valve cylinder being vented at its end adjacent the bore in the barrel, said valve plunger having an axial passage extending therethrough, and said valve plunger being movable forwardly along the valve bore by the screw during forward injection movement of the latter, said axial passage being sealed by the screw during such forward movement, and the nozzle portion having a nozzle aperture at the forward end thereof, and a plug mounted in the aperture which plug is selectively operable to permit and to prevent the ejection of material from the valve cylinder through the nozzle aperture.
Claim 3
Dependent Claim
68 words
An injection moulding machine as claimed in claim 1, wherein the screw has a tapered nose at its end nearer the valve plunger and wherein the valve plunger has its end adjacent the screw chamfered to form a seating for the tapered nose of the screw thereby to seal the passage through the valve plunger from the bore of the barrel when the screw abuts the valve plunger.
Claim 4
Dependent Claim
78 words
An injection moulding machine as claimed in claim 1, wherein the plug has one end thereof disposed within the valve cylinder which end tapers towards the valve plunger, the end of the valve plunger facing the tapering end of the plug having a recess with inclined sides which are substantially parallel to said tapering end of the plug whereby an annular passage is formed between the tapering end of the plug and said inclined sides of the recess.
Claim 5
Dependent Claim
160 words
An injection moulding machine as claimed in claim 1, wherein the nozzle aperture is formed at the forward end of an axial nozzle bore which opens at its rearward end to said valve cylinder, and wherein said plug comprises an elongate portion having a head on each end and sealingly mounted in the nozzle bore for axial sliding movement between two end positions in which the two heads of the plug respectively come into abutment with the nozzle portion at the forward and rearward ends of the nozzle bore, said plug having a transverse passage adjacent the head at the rearward end of the plug and an axial passage therein which extends from the forward end of the plug to said transverse passage, said transverse passage opening to the valve cylinder when the plug is in one of said end positions and being closed off by the nozzle portion when the plug is in the other of said end positions.
References Cited (Backward Citations)
US2265995A
Cited
US3395424A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |