Patent US3632255A successfully refreshed from Google Patents.
US3632255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion apparatus
Assignee: Uniroyal Inc
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Filing: 1969-01-10
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Granted: 1972-01-04
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Expires: 1989-01-10
Abstract
Abstract Apparatus for the extrusion of thermoplastic materials. First and second worm-type extruders are provided, the first being designed to produce a uniformly extrudable material and having a capacity in excess of that of the second. The uniformly extrudable material discharged from the first extruder enters pressure relief and control means from which it is fed into the second extruder, to the extent of its lesser capacity, at a constant pressure. Excess material discharged from the first extruder passes through an orifice and is returned by feedback means to a preferred position in the feed means for the first extruder. The material fed into the second extruder is discharged therefrom at a uniform volumetric extrusion rate, thereby providing a metering effect, and without significant physical or dimensional variations in the extrudate.
Inventors
- 👤 Paul Geyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:42
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/72; B29C48/725; B29C48/03; B29C48/395; B29C48/505; B29C48/56; B29C48/68; B29C48/685; B29C48/686; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92504; B29C2948/92704; B29C2948/9279; B29C2948/92819; B29C2948/92857; B29C2948/92876; B29C2948/92961; B29C2948/92971
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
361 words
Apparatus for the extrusion of natural and synthetic rubber stocks, which comprises: a. a conventional extruder having a barrel and a rotor mounted within the barrel and adapted for rotational movement relative to the barrel; b. a supply extruder having a barrel and a rotor mounted within the barrel and adapted for rotational movement relative to the barrel, said supply extruder having a volumetric output rate capacity in excess of that of said conventional extruder, said supply extruder being designed to masticate, mix, warm, plasticize, and to otherwise work stock introduced therein, passed therethrough and discharged therefrom, the stock discharged from said supply extruder being a uniformly extrudable stock; c. drive means for said conventional extruder; d. drive means for said supply extruder; e. pressure relief and control means connected to the discharge end of said supply extruder and to the feed end of said conventional extruder, said pressure relief and control means comprising a conduit into which stock discharged from said supply extruder must enter, said conduit having an orifice therein, stock discharged from said supply extruder into said conduit passing therethrough and into the feed end of said conventional extruder to the extent of its volumetric output rate capacity, and stock in excess of the volumetric output rate capacity of said conventional extruder passing through the orifice in said conduit; f. the supply extruder has adjacent the orifice at least one start groove on the rotor, located after a helical groove in the barrel, which cooperates with a helical groove in the rotor, the depth of the helical groove in the rotor decreasing as the depth of the helical groove in the barrel increases, whereby the stock is forced from the rotor, through a plane of maximum shear stress, and into the barrel; g. feed means for introducing the stock into the feed end of said supply extruder; and h. feedback means for carrying such excess stock passing through the orifice back to said feed means; whereby the stock at the feed end of said conventional extruder is at constant pressure and is uniformly extrudable, the stock therefore being discharged from said conventional extruder at a uniform volumetric rate.
Claim 2
Dependent Claim
361 words
Apparatus for the extrusion of natural and synthetic rubber stocks, which comprises: a. a conventional extruder having a barrel and a rotor mounted within the barrel and adapted for rotational movement relative to the barrel; b. a supply extruder having a barrel and a rotor mounted within the barrel and adapted for rotational movement relative to the barrel, said supply extruder having a volumetric output rate capacity in excess of that of said conventional extruder, said supply extruder being designed to masticate, mix, warm, plasticize, and to otherwise work stock introduced therein, passed therethrough and discharged therefrom, the stock discharged from said supply extruder being a uniformly extrudable stock; c. drive means for said conventional extruder; d. drive means for said supply extruder; e. pressure relief and control means connected to the discharge end of said supply extruder and to the feed end of said conventional extruder, said pressure relief and control means comprising a conduit into which stock discharged from said supply extruder must enter, said conduit having an orifice therein, stock discharged from said supply extruder into said conduit passing therethrough and into the feed end of said conventional extruder to the extent of its volumetric output rate capacity, and stock in excess of the volumetric output rate capacity of said conventional extruder passing through the orifice in said conduit; f. the supply extruder has adjacent the orifice at least one start groove on the rotor, located after a helical groove in the barrel, which cooperates with a helical groove in the rotor, the depth of the helical groove in the rotor decreasing as the depth of the helical groove in the barrel increases, whereby the stock is forced from the rotor, through a plane of maximum shear stress, and into the barrel; g. feed means for introducing the stock into the feed end of said supply extruder; and h. feedback means for carrying such excess stock passing through the orifice back to said feed means; whereby the stock at the feed end of said conventional extruder is at constant pressure and is uniformly extrudable, the stock therefore being discharged from said conventional extruder at a uniform volumetric rate.
Claim 3
Dependent Claim
25 words
Apparatus in accordance with claim 1, wherein said supply extruder and said conventional extruder have a common barrel, a common rotor, and common drive means.
Claim 4
Dependent Claim
60 words
Apparatus in accordance with claim 1, wherein said feedback means comprises; a screw conveyor having a feed end and a discharge end; means for conducting stock passing through the orifice to the feed end of said screw conveyor; and means for conducting stock discharged from the discharge end of said screw conveyor to the feed means for said supply extruder.
Claim 5
Dependent Claim
48 words
Apparatus in accordance with claim 3, wherein said feed means includes means for combining unprocessed incoming stock with excess stock carried back by said feedback means and wherein said feed means includes means for introducing the excess stock into said supply extruder in preference to unprocessed incoming stock.
Claim 6
Dependent Claim
25 words
Apparatus in accordance with claim 4, wherein said supply extruder and said conventional extruder have a common barrel, a common rotor, and common drive means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |