US3741699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable volume and controlled density forming mechanism for compression molding presses
Assignee: First National Bank of Chicago
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Filing: 1972-03-15
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Granted: 1973-06-26
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Expires: 1992-03-15
Abstract
Abstract An automatic compression molding system, especially for thermosetting materials, in which an extruder preplasticizes the powder and charges the preplasticized mass into preforms. The preheated and preformed mass can be varied in volume, density and temperature prior to being dispensed into the mold cavities.
Inventors
- 👤 V Arpajian
- 👤 Q White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:22
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/32; B29C43/34; B29B; B29B11/00; B29B11/06; B29B11/08; B29C31/00; B29C31/04; B29C31/042; B29C31/048; B29C31/06; B29C43/02; B29C43/14; B29C2043/3433; B29C33/00; B29C33/0022; B29C45/00; B29C48/00; B29C48/022; B29C48/03; B29K; B29K2101/00; B29K2101/10; B29K2301/00; B29K2301/10; B29L; B29L2001/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
154 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for screw plasticizing a charge of thermosetting powder and extruding the charge at an elevated temperature through a nozzle, preforming means for shaping the preheated extrusion into a generally compact mass, and means for delivering the preheated and preformed mass to the mold cavity element immediately prior to closure of the press, said preforming means constituting at least one cup having an open end adapted to be interposed over a corresponding nozzle and a closed wall portion slidably adjustable with respect to the open end whereby the volume of shaped masses within said cup may be varied to suit the size of the mold cavity, and sensing means associated with each said cup for shutting off said means for plasticizing when the pressure of the mass being shaped within said preforming means exceeds a predetermined level.
Claim 2
Dependent Claim
154 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for screw plasticizing a charge of thermosetting powder and extruding the charge at an elevated temperature through a nozzle, preforming means for shaping the preheated extrusion into a generally compact mass, and means for delivering the preheated and preformed mass to the mold cavity element immediately prior to closure of the press, said preforming means constituting at least one cup having an open end adapted to be interposed over a corresponding nozzle and a closed wall portion slidably adjustable with respect to the open end whereby the volume of shaped masses within said cup may be varied to suit the size of the mold cavity, and sensing means associated with each said cup for shutting off said means for plasticizing when the pressure of the mass being shaped within said preforming means exceeds a predetermined level.
Claim 3
Dependent Claim
54 words
The invention of claim 1 wherein said preforming means includes a cylinder and a piston slidable therein, and means for applying a predetermined loading force with respect to said piston in order to establish the level of charge pressure for actuating said sensing means whereby the density of the shaped masses may be controlled.
Claim 4
Dependent Claim
34 words
The invention of claim 2 wherein the mold cavity element includes a plurality of mold cavities arranged in rows and files and said pre-forming means includes a shaping member for each file of cavities.
Claim 5
Dependent Claim
38 words
The invention of claim 3 including means for ejecting the preformed masses from the respective cups open retraction thereof from said nozzle, and means for shearing the preformed masses from the nozzles after the cups have been retracted.
Claim 6
Dependent Claim
20 words
The invention of claim 4 includes means for cooling said preforming means upon retraction of the cups from the nozzle.
Claim 7
Dependent Claim
34 words
The invention of claim 5 wherein said means for cooling comprises a tubular finger having a closed end with ports, and a source of air applied to the open end of said tubular finger.
Claim 8
Dependent Claim
62 words
The invention of claim 6 including a chute with feed tubes interposed below said nozzles for funneling preformed masses sheared therefrom, and a feed board having pockets therein corresponding to the rows and files of the mold cavities, said feed board collecting preformed masses funneled by said feed tubes and depositing said masses into the mold cavities when the press is open.
Claim 9
Dependent Claim
16 words
The invention of claim 2 wherein said means for applying a predetermined loading force is adjustable.
Claim 10
Dependent Claim
23 words
The invention of claim 2 wherein said means for applying a predetermined loading force comprises means for applying air pressure behind said piston.
Claim 11
Dependent Claim
149 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for screw plasticizing a charge of thermosetting powder and extruding the charge at an elevated temperature through a nozzle as an elongate preheated extrusion, cup means for constraining and cumulatively shaping the preheated extrusion into a generally compact bulbous mass, means for advancing said cup means into closed disposition over the nozzle for receiving the preheated extrusion and then retracting after the mass is formed, sensing means associated with said cup means and operative to cut off said means for screw plasticizing when the pressure of the charge formed within said cup means exceeds a predetermined level. said sensing means being adjustable for controlling the density of the mass being formed, and means for delivering the preheated and shaped mass to the mold cavity element prior to closure of the press.
Claim 12
Dependent Claim
149 words
In a compression molding press having a mold plunger reciprocable with respect to a mold cavity element, means for screw plasticizing a charge of thermosetting powder and extruding the charge at an elevated temperature through a nozzle as an elongate preheated extrusion, cup means for constraining and cumulatively shaping the preheated extrusion into a generally compact bulbous mass, means for advancing said cup means into closed disposition over the nozzle for receiving the preheated extrusion and then retracting after the mass is formed, sensing means associated with said cup means and operative to cut off said means for screw plasticizing when the pressure of the charge formed within said cup means exceeds a predetermined level. said sensing means being adjustable for controlling the density of the mass being formed, and means for delivering the preheated and shaped mass to the mold cavity element prior to closure of the press.
Claim 13
Dependent Claim
48 words
The invention of claim 10 wherein said cup means includes an open end adapted to abut the nozzle and a closed wall portion slidably adjustable with respect to the open end whereby the volume of shaped masses may be varied to suit the size of the mold cavity.
Claim 14
Dependent Claim
28 words
The invention of claim 11 wherein said closed wall portion constitutes a piston and said sensing means includes means for applying a predetermined loading force on said piston.
Claim 15
Dependent Claim
17 words
The invention of claim 12 wherein said means for applying a predetermined loading force is air actuated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |