US3957256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw extruder
Assignee: PLASTIC KOGSKU KENKYUSHO KK
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Filing: 1974-03-26
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Granted: 1976-05-18
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Expires: 1994-03-26
Abstract
Abstract A screw extruder having a screw including a plug formed with flutes by which the flow of material existing in the cross section of a screw channel is divided into a plurality of striations. The order of arrangement of inlets of the flutes is different from the order of arrangement of outlets communicating with the inlets with respect to the circumferential direction of the plug, whereby the flow is divided into rearranged striations.
Inventors
- 👤 Kenkichi Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:16
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/56; B29C48/03
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
198 words
A screw extruder comprising a screw having a screw flight for conveying a fluid and rotatably housed in a cylinder, at least one plug installed in a portion of the screw and a circumferentially continuous leakproof portion formed on at least one part of the plug with only a small clearance provided between the outer periphery of the leakproof portion and the inner surface of the cylinder, the plug being formed with a plurality of through connecting holes therein, interconnecting a space upstream of the leakproof portion and another space downstream thereof, with said connecting holes having inlet and outlet portions in the form of a plurality of auxiliary inlet flow passages circumferentially arranged in a definite order on a part of the leakproof portion of said plug and a plurality of corresponding auxiliary outlet passages circumferentially arranged on another part of the leakproof portion of said plug spaced downstream of said inlet flow passages on said plug, wherein the order of arrangement of the inlets of each of the connecting holes is different from the order of arrangement of the corresponding outlets designed to communicate with said inlets sequentially in a circumferential direction about said screw plug.
Claim 2
Dependent Claim
198 words
A screw extruder comprising a screw having a screw flight for conveying a fluid and rotatably housed in a cylinder, at least one plug installed in a portion of the screw and a circumferentially continuous leakproof portion formed on at least one part of the plug with only a small clearance provided between the outer periphery of the leakproof portion and the inner surface of the cylinder, the plug being formed with a plurality of through connecting holes therein, interconnecting a space upstream of the leakproof portion and another space downstream thereof, with said connecting holes having inlet and outlet portions in the form of a plurality of auxiliary inlet flow passages circumferentially arranged in a definite order on a part of the leakproof portion of said plug and a plurality of corresponding auxiliary outlet passages circumferentially arranged on another part of the leakproof portion of said plug spaced downstream of said inlet flow passages on said plug, wherein the order of arrangement of the inlets of each of the connecting holes is different from the order of arrangement of the corresponding outlets designed to communicate with said inlets sequentially in a circumferential direction about said screw plug.
Claim 3
Dependent Claim
33 words
The screw extruder as set forth in claim 1 wherein the plug has inlet flutes and outlet flutes which serve as the auxiliary flow passages to facilitate the arrangement of the connecting holes.
Claim 4
Dependent Claim
31 words
The screw extruder as set forth in claim 2 wherein the inlet flutes and the outlet flutes are in the shape of grooves formed in the circumferential surface of the plug.
Claim 5
Dependent Claim
27 words
The screw extruder as set forth in claim 2 wherein the inlet flutes and the outlet flutes are in the shape of bores formed in the plug.
Claim 6
Dependent Claim
24 words
The screw extruder as set forth in claim 2 wherein the inlet flutes and the outlet flutes are in parallel to the screw axis.
Claim 7
Dependent Claim
25 words
The screw extruder as set forth in claim 2 wherein the inlet flutes and the outlet flutes are not in parallel to the screw axis.
Claim 8
Dependent Claim
32 words
The screw extruder as set forth in claim 2 wherein the inlet flutes and the outlet flutes are in the shape of helical grooves formed in the circumferential surface of the plug.
Claim 9
Dependent Claim
26 words
The screw extruder as set forth in claim 7 wherein the helical grooves are twisted in the same direction as the twist of the screw flight.
Claim 10
Dependent Claim
26 words
The screw extruder as set forth in claim 7 wherein the helical grooves are twisted in the reverse direction to the twist of the screw flight.
Claim 11
Dependent Claim
45 words
The screw extruder as set forth in claim 1 wherein a column-like portion is provided at the downstream end of the plug to form a circumferentially continuous small space between the inner surface of the cylinder and the outer peripheral surface of the column-like portion.
Claim 12
Dependent Claim
18 words
The screw extruder as set forth in claim 1 wherein the screw flight is connected to the plug.
Claim 13
Dependent Claim
21 words
The screw extruder as set forth in claim 1 wherein a cutout is formed between the screw flight and the plug.
Claim 14
Dependent Claim
67 words
The screw extruder as set forth in claim 1 wherein the plug is formed with a plurality of guide grooves twisted in the same direction as the screw flight, at least one of the guide grooves being divided into an inlet flute and an outlet flute, the terminal end of the inlet flute and the starting end of the outlet flute being interconnected by the connecting hole.
Claim 15
Dependent Claim
18 words
The screw extruder as set forth in claim 13 wherein the screw flight is connected to the plug.
Claim 16
Dependent Claim
21 words
The screw extruder as set forth in claim 13 wherein a cutout is formed between the screw flight and the plug.
Claim 17
Dependent Claim
35 words
The screw extruder as set forth in claim 13 wherein the terminal end of the connecting hole is positioned downstream of the starting end of the connecting hole in the axial direction of the screw.
Claim 18
Dependent Claim
28 words
The screw extruder as set forth in claim 13 wherein the starting end and terminal end of the connecting hole are arranged in parallel to the screw axis.
Claim 19
Dependent Claim
29 words
The screw extruder as set forth in claim 13 wherein the outlet flute is positioned on the extension of a helical line on which the inlet flute is formed.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |