US3733059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic extruder temperature control system
Assignee: Rosemount Inc
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Filing: 1971-08-10
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Granted: 1973-05-15
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Expires: 1991-08-10
Abstract
Abstract A temperature control system for controlling plastic extruders wherein a tachometer generator signal dependent upon motor speed is utilized to compensate for temperature changes in an extruder caused by changes in the speed of the extruder screw.
Inventors
- 👤 G Pettit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:25
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/22; B; B29; B29C; B29C48/00; B29C48/25; B29C48/92; G05D23/1927; G05D23/193; G05D23/1932; G05D23/1934; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92209; B29C2948/92504; B29C2948/9258; B29C2948/9259; B29C2948/92819; B29C2948/92857; B29C2948/92876; B29C2948/92885; B29C2948/92895; B29C2948/92952; B29C48/03
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
162 words
A control system for forming machinery for plastic materials wherein the forming machinery includes a working element for plastic materials, power means for driving said working element, and wherein the speed of movement of said working element driven by the power means affects the temperature of the materials, the improvement comprising means providing a substantially continuous signal which is a function of the speed of said working element, control means on said machinery including means providing a signal representing a set point temperature, said control means being operative to maintain temperature within a selected range in at least one portion of said machinery and including means responsive to differentials in temperature of said portion and said set point temperature, and means responsive to said substantially continuous signal which is a function of said speed of movement of said working element to change the signal representing the set point temperature as a function of change of speed of movement of the working element.
Claim 2
Dependent Claim
162 words
A control system for forming machinery for plastic materials wherein the forming machinery includes a working element for plastic materials, power means for driving said working element, and wherein the speed of movement of said working element driven by the power means affects the temperature of the materials, the improvement comprising means providing a substantially continuous signal which is a function of the speed of said working element, control means on said machinery including means providing a signal representing a set point temperature, said control means being operative to maintain temperature within a selected range in at least one portion of said machinery and including means responsive to differentials in temperature of said portion and said set point temperature, and means responsive to said substantially continuous signal which is a function of said speed of movement of said working element to change the signal representing the set point temperature as a function of change of speed of movement of the working element.
Claim 3
Dependent Claim
155 words
An extruder assembly comprising a barrel and an extruder screw rotatably mounted in said barrel, power means for rotating said screw, means on at least one portion of said barrel for regulating the heat in said barrel, means to sense the heat in said portion, a controller means having a set point against which the sensed temperature in that portion of the barrel is compared, said controller further controlling heating or cooling to regulate the temperature in response to the signal from the sensor in respect to the set point, means to sense the temperature of material in a preselected location on said extruder assembly and to provide a first signal proportional thereto, means providing a second signal which varies as a function of the speed of said screw, and control means summing the first and second signals to provide a third signal to adjust the set point of said controller in a preselected manner.
Claim 4
Dependent Claim
155 words
An extruder assembly comprising a barrel and an extruder screw rotatably mounted in said barrel, power means for rotating said screw, means on at least one portion of said barrel for regulating the heat in said barrel, means to sense the heat in said portion, a controller means having a set point against which the sensed temperature in that portion of the barrel is compared, said controller further controlling heating or cooling to regulate the temperature in response to the signal from the sensor in respect to the set point, means to sense the temperature of material in a preselected location on said extruder assembly and to provide a first signal proportional thereto, means providing a second signal which varies as a function of the speed of said screw, and control means summing the first and second signals to provide a third signal to adjust the set point of said controller in a preselected manner.
Claim 5
Dependent Claim
19 words
The combination of claim 2 wherein the second signal is substantially proportional to the square of the screw speed.
Claim 6
Dependent Claim
52 words
The combination as specified in claim 3 wherein there are a plurality of zones in said barrel separately regulated for heat control, and a plurality of controllers, one for each zone in said barrel, said control means having means to provide a separate third signal to each controller for said barrel zones.
Claim 7
Dependent Claim
63 words
The combination as specified in claim 3 wherein said means providing said second signal comprises a tachometer generator responsive to the speed of rotation of said screw delivering an electrical signal, and circuit means to receive the electrical signal from said tachometer generator and to deliver an electrical signal proportional to the square of the speed of said screw to said control means.
Claim 8
Dependent Claim
73 words
The control system of claim 1 and temperature sensing means to sense temperature of plastic material in a second portion of said forming machinery and to provide a second temperature signal, said means responsive to the substantially continuous signal including means to combine the substantially continuous signal and said second temperature signal to change the signal representing the set point temperature as a function of the combined substantially continuous and second temperature signals.
Claim 9
Dependent Claim
42 words
The control system of claim 6 wherein said working element is a rotating element, said means providing said substantially continuous signal including means providing said substantially continuous signal as a function of the square of the rotational speed of said rotating element.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |