Patent US3759648A successfully refreshed from Google Patents.
US3759648A
Expired / Lapsed
US
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Extruder control system
Assignee: HUNKER INSTR DEV LABOR Inc
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Filing: 1971-09-15
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Granted: 1973-09-18
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Expires: 1991-09-15
Abstract
Abstract An extruder control system for providing extruded products of equal lengths particularly for parison extruders in blow molding machines. A continuous feed extruder, when used with a plural mold apparatus, must extrude at a precise rate to provide a proper length parison to each mold. The control system measures errors in the length of the product delivered to each mold and makes a compensating adjustment in the extrusion rate of the extruder. The extrusion rate and product length are dependent on material viscosity which is varied by changing the rotational speed of the plasticizing screw. The control system compensates for material viscosity fluctuations and allows the extruder speed to follow that of the mold apparatus.
Inventors
- 👤 D Hunkar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:24
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/02; B29C49/04; B29C49/04102; B29C48/00; B29C48/03; B29C48/09; B29C48/13; B29C48/25; B29C48/30; B29C48/32; B29C48/325; B29C48/92; B29C49/0411; B29C49/04114; B29C49/42; B29C49/78; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92142; B29C2948/92161; B29C2948/922; B29C2948/92209; B29C2948/92295; B29C2948/92304; B29C2948/92323; B29C2948/92361; B29C2948/9238; B29C2948/924; B29C2948/92409; B29C2948/92504; B29C2948/9258; B29C2948/926; B29C2948/92609; B29C2948/92638; B29C2948/92647; B29C2948/92695; B29C2948/92704; B29C2948/92723; B29C2948/92819; B29C2948/92857; B29C2948/92876; B29C2948/92885; B29C2948/92895; B29C2948/92904; B29C2948/92942; B29C2948/92952
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
163 words
In a molding machine which comprises, in combination, a mold apparatus and an extruder for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means responsive to a condition of a mold for generating a timing signal; means responsive to said timing signal for measuring the presence of an extruded product at a point spaced from said orifice; means for generating a feedback signal in response to said measurement; and means for varying the extrusion rate of said product from said extruder in response to said feedback signal; said feedback signal generating means including a circuit for generating a first feedback signal in response to the presence of said product at said point and a second feedback signal in response to the absence of said product at said point; and said extrusion rate varying means being operative to decrease said rate in response to said first signal and increase said rate in response to said second signal.
Claim 2
Dependent Claim
163 words
In a molding machine which comprises, in combination, a mold apparatus and an extruder for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means responsive to a condition of a mold for generating a timing signal; means responsive to said timing signal for measuring the presence of an extruded product at a point spaced from said orifice; means for generating a feedback signal in response to said measurement; and means for varying the extrusion rate of said product from said extruder in response to said feedback signal; said feedback signal generating means including a circuit for generating a first feedback signal in response to the presence of said product at said point and a second feedback signal in response to the absence of said product at said point; and said extrusion rate varying means being operative to decrease said rate in response to said first signal and increase said rate in response to said second signal.
Claim 3
Dependent Claim
113 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a variable speed drive means for said rotary plasticizing screw, a control system for controlling the variable speed drive means comprising: means for sensing the length of an extruded product at a predetermined time in relation to the operation of said molding machine; means for generating a control signal responsive to said length; and said variable speed drive means being responsive to said control signal for changing the rate of rotation of said screw to vary the viscosity of said moldable product.
Claim 4
Dependent Claim
113 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a variable speed drive means for said rotary plasticizing screw, a control system for controlling the variable speed drive means comprising: means for sensing the length of an extruded product at a predetermined time in relation to the operation of said molding machine; means for generating a control signal responsive to said length; and said variable speed drive means being responsive to said control signal for changing the rate of rotation of said screw to vary the viscosity of said moldable product.
Claim 5
Dependent Claim
40 words
The apparatus of claim 2 in which said control signal generating means includes a negative closed loop feedback system for generating an error signal representative of a difference between said sensed length and a predetermined reference value of that parameter.
Claim 6
Dependent Claim
23 words
The apparatus of claim 2 further comprising means for synchronizing the operation of said sensing means with the operation of said mold apparatus.
Claim 7
Dependent Claim
91 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means for sensing the length of an extruded product; means for comparing said length with a preselected length; means for generating a control signal responsive to said comparison means; and means responsive to said control signal for changing the rate of rotation of said screw to vary the viscosity of the material which is subsequently extruded.
Claim 8
Dependent Claim
91 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means for sensing the length of an extruded product; means for comparing said length with a preselected length; means for generating a control signal responsive to said comparison means; and means responsive to said control signal for changing the rate of rotation of said screw to vary the viscosity of the material which is subsequently extruded.
Claim 9
Dependent Claim
23 words
The apparatus of claim 5 further comprising means for synchronizing the operation of said sensing means with the operation of said mold apparatus.
Claim 10
Dependent Claim
92 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means for deriving a cycle interval; means for sensing the length of a product extruded during said cycle interval; means for generating a control signal in response to the difference between the sensed length of said product and said predetermined length; and means responsive to said control signal for changing the rate of rotation of said screw.
Claim 11
Dependent Claim
92 words
In a molding machine which comprises in combination a mold apparatus and an extruder including a rotary plasticizing screw for extruding a moldable product from an orifice to said mold apparatus, a control system comprising: means for deriving a cycle interval; means for sensing the length of a product extruded during said cycle interval; means for generating a control signal in response to the difference between the sensed length of said product and said predetermined length; and means responsive to said control signal for changing the rate of rotation of said screw.
Claim 12
Dependent Claim
20 words
The apparatus of claim 7 further comprising means responsive to a condition of a mold for actuating said sensing means.
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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) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |