US3661485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compression molding system
Assignee: First National Bank of Minneapolis
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Filing: 1970-06-10
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Granted: 1972-05-09
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Expires: 1990-06-10
Abstract
Abstract An automatic compression molding system, especially for thermosetting materials, in which an extrusion screw or a number of extrusion screws preplasticize the powder and charge the preplasticized mass into preforms. The preheated and preformed masses are immediately delivered and loaded into the mold cavities to reduce the time of the cure cycle up to 80 percent of that required in cold powder compression molding.
Inventors
- 👤 Vasken F Arpajian
- 👤 Quentin M White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:52
CPC Classifications
B; B29; B29C; B29C31/00; B29C31/04; B29C31/06; B29B; B29B11/00; B29B11/06; B29B11/08; B29C31/042; B29C31/048; B29C43/00; B29C43/02; B29C43/14; B29C43/32; B29C43/34; B29C2043/3433; B29C45/00; B29C48/00; B29C48/022; B29C48/03; B29K; B29K2101/00; B29K2101/10; B29K2301/00; B29K2301/10; B29L; B29L2001/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
121 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for plasticizing a predetermined charge of thermosetting powder at an elevated temperature and expressing the plasticized charge through a nozzle as an elongate preheated extrusion, preforming means for constraining and cumulatively shaping the preheated extrusion into a generally compact bulbous mass, said preforming means being interposed adjacent the nozzle in the path of travel of said preheated extrusion, means for severing the preheated and preformed bulbous mass from the charge being expressed, and means for delivering the preheated and preformed mass to the mold cavity immediately prior to closure of the press whereby the compression molding cycle for thermosetting materials is appreciably shortened.
Claim 2
Dependent Claim
121 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for plasticizing a predetermined charge of thermosetting powder at an elevated temperature and expressing the plasticized charge through a nozzle as an elongate preheated extrusion, preforming means for constraining and cumulatively shaping the preheated extrusion into a generally compact bulbous mass, said preforming means being interposed adjacent the nozzle in the path of travel of said preheated extrusion, means for severing the preheated and preformed bulbous mass from the charge being expressed, and means for delivering the preheated and preformed mass to the mold cavity immediately prior to closure of the press whereby the compression molding cycle for thermosetting materials is appreciably shortened.
Claim 3
Dependent Claim
13 words
The invention of claim 1 wherein said means for delivering comprises a chute.
Claim 4
Dependent Claim
27 words
The invention of claim 1 wherein the mold cavity element includes a plurality of mold cavities, and said preforming means includes a shaping member for each cavity.
Claim 5
Dependent Claim
22 words
The invention of claim 2 wherein said means for severing comprises a blade for shearing the preheated preformed mass from the nozzle.
Claim 6
Dependent Claim
20 words
The invention of claim 4 wherein said preforming means comprises a cup which is reciprocable with respect to the nozzle.
Claim 7
Dependent Claim
21 words
The invention of claim 5 including means for ejecting the preformed mass from said cup upon retraction thereof from said nozzle.
Claim 8
Dependent Claim
18 words
The invention of claim 6 including means for cooling said cup upon retraction thereof from the preformed mass.
Claim 9
Dependent Claim
39 words
The invention of claim 6 including means for moving said chute between the mold plunger and mold cavity element immediately after the press opens, and means coupled with said chute for expelling finished molded parts from within the press.
Claim 10
Dependent Claim
15 words
The invention of claim 8 wherein said means for expelling comprises a stream of air.
Claim 11
Dependent Claim
35 words
The invention of claim 1 wherein the nozzle includes a restricted orifice annularly arranged with respect to the adjacent end of an extrusion screw so as to impart heat frictionally to the charge being extruded.
Claim 12
Dependent Claim
10 words
The invention of claim 10 wherein the annulus is adjustable.
Claim 13
Dependent Claim
20 words
The invention of claim 11 wherein the annulus is adjustable by longitudinally positioning the screw with respect to the orifice.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |