US3728056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extruder control system
Assignee: Individual
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Filing: 1971-06-07
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Granted: 1973-04-17
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Expires: 1991-06-07
Abstract
Abstract A screw type extruder having a rotary extruder screw is provided with a variable speed drive motor for rotationally driving the extruder screw, material feeding means for feeding plasticizable material at a variable flow rate into the extruder, and a control system for controlling both the extruder screw speed and the flow rate of material fed into the extruder. The control system comprises a pressure sensor for sensing the plastic compound pressure within the extruder and a control device for controlling the rotational speed of the extruder screw in dependence upon the sensed pressure to maintain the compound pressure at a constant value. The control system further comprises a speed sensor for sensing the actual rotational speed of the extruder screw and another control device for controlling the volume of the plasticizable material fed into the extruder in dependence upon the sensed extruder screw speed to maintain the flow rate of the plasticizable material fed into the extruder at a constant value.
Inventors
- 👤 H Theysohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:50
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/285; B29C48/288; B29C48/2888; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92019; B29C2948/92085; B29C2948/92095; B29C2948/92323; B29C2948/92361; B29C2948/9238; B29C2948/9239; B29C2948/92409; B29C2948/92504; B29C2948/92514; B29C2948/9258; B29C2948/9259; B29C2948/926; B29C2948/92819; B29C2948/92828; B29C2948/92857; B29C2948/92876; B29C2948/92885; B29C2948/92895; B29C48/03; B29C48/07; B29C48/09
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
275 words
In combination with an extruding apparatus having means defining a screw chamber having a material inlet for receiving a plasticizable material and a material outlet; an extruder head connected to said material outlet; a rotatable extruder screw positioned within said screw chamber cooperative with said screw chamber to plasticize the plasticizable material fed into said material inlet and advance same through said material outlet and out said extruder head as an extruded product; variable speed drive means for rotationally driving said extruder screw at a variable rotational speed; and material feeding means for feeding plasTicizable material at a variable flow rate into said material inlet, a control system for controlling both the extruder screw speed and the flow rate of material fed into said material inlet comprising: pressure sensing means for sensing the pressure of the plasticized material contained within said extruder head and providing a corresponding electrical pressure signal; first control means receptive of said electrical pressure signal and coacting with said variable speed drive means for controlling the rotational speed of said extruder screw in accordance with said pressure signal to maintain the pressure of the plasticized material within said extruder head at a substantially constant value speed sensing means for providing a speed signal proportional to the actual rotational speed of said extruder screw; and second control means receptive of said speed signal and coacting with said material feeding means for controlling the feeding flow rate of the plasticizable material into said material inlet as a function of the actual extruder screw speed to maintain the flow rate of the plasticizable material fed into said material inlet at a substantially constant value.
Claim 2
Dependent Claim
275 words
In combination with an extruding apparatus having means defining a screw chamber having a material inlet for receiving a plasticizable material and a material outlet; an extruder head connected to said material outlet; a rotatable extruder screw positioned within said screw chamber cooperative with said screw chamber to plasticize the plasticizable material fed into said material inlet and advance same through said material outlet and out said extruder head as an extruded product; variable speed drive means for rotationally driving said extruder screw at a variable rotational speed; and material feeding means for feeding plasTicizable material at a variable flow rate into said material inlet, a control system for controlling both the extruder screw speed and the flow rate of material fed into said material inlet comprising: pressure sensing means for sensing the pressure of the plasticized material contained within said extruder head and providing a corresponding electrical pressure signal; first control means receptive of said electrical pressure signal and coacting with said variable speed drive means for controlling the rotational speed of said extruder screw in accordance with said pressure signal to maintain the pressure of the plasticized material within said extruder head at a substantially constant value speed sensing means for providing a speed signal proportional to the actual rotational speed of said extruder screw; and second control means receptive of said speed signal and coacting with said material feeding means for controlling the feeding flow rate of the plasticizable material into said material inlet as a function of the actual extruder screw speed to maintain the flow rate of the plasticizable material fed into said material inlet at a substantially constant value.
Claim 3
Dependent Claim
42 words
A combination according to claim 1; wherein said material feeding means comprises means for feeding plasticizable material to said material inlet in an elongated strip configuration, and means for selectively varying the width of the elongated strip fed into said material inlet.
Claim 4
Dependent Claim
47 words
A combination according to claim 2; wherein said last-mentioned means comprises a pair of movably mounted cutting knives operative to cut the plasticizable material into an elongated strip, and means for effecting movement of said cutting knives to selectively vary the width of the cut elongated strip.
Claim 5
Dependent Claim
42 words
A combination according to claim 1; wherein said material feeding means comprises means for feeding plasticizable material to said material inlet in an elongated strip configuration, and means for selectively varying the thickness of the elongated strip fed into said material inlet.
Claim 6
Dependent Claim
43 words
A combination according to claim 1; wherein said material feeding means comprises means for feeding plasticizable material to said material inlet in an elongated strip configuration, and means for selectively controlling the feeding speed of the elongated strip fed into said material inlet.
Claim 7
Dependent Claim
38 words
A combination according to claim 1; wherein said speed sensing means comprises a tachometer connected to said variable speed drive means operable to provide an electrical speed signal proportional to the actual rotational speed of said extruder screw.
Claim 8
Dependent Claim
63 words
A combination according to claim 6; wherein said second control means includes means responsive to said electrical speed signal for providing an electrical command signal of either positive or negative polarity to said material feeding means to accordingly effect either an increase or decrease in the flow rate of the plasticizable material in accordance with the change in speed of said extruder screw.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |