US3924840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Viscosity control for a plastic molding machine
Assignee: General Electric Co
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Filing: 1972-09-18
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Granted: 1975-12-09
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Expires: 1992-09-18
Abstract
Abstract A control for a plastic molding machine of the type employing a moving screw, disposed within a barrel, operative to act upon plastic material in a solid state to impart to that material energy which is substantial in providing the total amount of heat required to convert (plasticize) the solid material to liquid form to provide what is known as ''''melt''''. The control includes means for sensing velocity and pressure factors with respect to the melt, and by properly relating the velocity and pressure factors, the control provides a viscosity measurement which is utilized to control various machine operating parameters.
Inventors
- 👤 Jr Philip H Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:19
CPC Classifications
G; G05; G05D; G05D24/00; G05D24/02; B; B29; B29C; B29C45/00; B29C45/17; B29C45/76; B29C45/7646
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
106 words
A control for a plastic molding machine of the type in which plastic material is rendered molten through the application of energy by variable means associated with the machine, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto, said means comprising means for determining pressure and velocity parameters associated with said molten plastic material; and, b. control means responsive to said output signal to effect a variation in said variable means whereby the amount of energy Applied to said material is changed to thereby change the viscosity of said material.
Claim 2
Dependent Claim
106 words
A control for a plastic molding machine of the type in which plastic material is rendered molten through the application of energy by variable means associated with the machine, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto, said means comprising means for determining pressure and velocity parameters associated with said molten plastic material; and, b. control means responsive to said output signal to effect a variation in said variable means whereby the amount of energy Applied to said material is changed to thereby change the viscosity of said material.
Claim 3
Dependent Claim
42 words
The invention in accordance with claim 1 wherein the variable means includes a plurality of means for applying energy to the plastic material and wherein said control means selective effects changes in the amount of energy applied by said plurality of means.
Claim 4
Dependent Claim
104 words
A control for a plastic injection machine of the type including a screw rotatably and linearly operable with a barrel of the machine and in which plastic material is rendered molten by the application of energy by variable means associated with the machine, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto; and, b. control means responsive to said output signal to effect a variation in said variable means whereby the amount of energy applied to said material is changed to thereby change the viscosity of said material.
Claim 5
Dependent Claim
104 words
A control for a plastic injection machine of the type including a screw rotatably and linearly operable with a barrel of the machine and in which plastic material is rendered molten by the application of energy by variable means associated with the machine, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto; and, b. control means responsive to said output signal to effect a variation in said variable means whereby the amount of energy applied to said material is changed to thereby change the viscosity of said material.
Claim 6
Dependent Claim
31 words
The invention in accordance with claim 3 wherein said means to determine the viscosity includes means to provide signals proportional to pressure and velocity parameters associated with said molten plastic material.
Claim 7
Dependent Claim
140 words
A control for a plastic injection molding machine of the type including a screw rotatably operated and held under pressure in a first mode of operation and moved linearly at a rate to eject molten plastic from the machine in a second mode of operation, and in which the operations of said screw serve to supply energy to plastic material in said machine to serve in rendering the material molten, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto; and, b. control means responsive to said output signal to selectively effect variations in the rate at which said screw is moved linearly in the second mode of operation and in the pressure under which said screw is held in the first mode of operation.
Claim 8
Dependent Claim
140 words
A control for a plastic injection molding machine of the type including a screw rotatably operated and held under pressure in a first mode of operation and moved linearly at a rate to eject molten plastic from the machine in a second mode of operation, and in which the operations of said screw serve to supply energy to plastic material in said machine to serve in rendering the material molten, said control comprising: a. means to determine the viscosity of the molten plastic material within the machine and to provide an output signal proportional thereto; and, b. control means responsive to said output signal to selectively effect variations in the rate at which said screw is moved linearly in the second mode of operation and in the pressure under which said screw is held in the first mode of operation.
Claim 9
Dependent Claim
29 words
The invention in accordance with claim 5 wherein said means to determine viscosity includes means to provide signals proportional to pressure and velocity parameters associated with the plastic material.
Claim 10
Dependent Claim
52 words
The invention in accordance with claim 5 wherein said control means acts to vary said rate during the period of time said screw is moved linearly and acts to vary said pressure under which said screw is held on a machine cycle next following that during which said output signal is provided.
Claim 11
Dependent Claim
29 words
The invention in accordance with claim 7 wherein said means to determine viscosity includes means to provide signals proportional to pressure and velocity parameters associated with the plastic material.
Claim 12
Dependent Claim
42 words
The invention in accordance with claim 5 wherein said molding machine further includes heating means for supplying heat energy to said plastic material and in which said control means further effects variations in the amount of heat supplied by said heating means.
Claim 13
Dependent Claim
59 words
The invention in accordance with claim 9 wherein said control means acts to vary the rate during the period of time said screw is moved linearly and acts to vary the pressure under which said screw is held and the variation in said heating means on a machine cycle next following that during which said output signal is provided.
Claim 14
Dependent Claim
29 words
The invention in accordance with claim 10 wherein said means to determine viscosity includes means to provide signals proportional to pressure and velocity parameters associated with the plastic material.
Claim 15
Dependent Claim
29 words
The invention in accordance with claim 9 wherein said means to determine viscosity includes means to provide signals proportional to pressure and velocity parameters associated with the plastic material.
Claim 16
Dependent Claim
210 words
A controlled plastic injection molding machine comprising: a. a supply source of plastic material; b. a barrel having a centrally extending bore in communication with said source; c. a screw disposed within said bOre, said screw adapted for both rotational and linear motion within said bore whereby under the rotational and linear motions of said screw, energy is supplied to said material, said material is rendered molten and is delivered to a mold associated with said machine; d. first controlled means to effect said rotary screw motion; e. second controlled means to maintain a pressure on said screw means, in its rotary mode of operation, in opposition to a pressure developed by the molten plastic material; f. third controlled means to effect said linear motion of said screw at a prescribed rate; g. means to determine the viscosity of the molten plastic material with said barrel and to generate a viscosity signal proportional thereto; and, h. means intermediate said means to determine the viscosity and said second and third controlled means to develop first and second control signals in response to said viscosity signal, said second and third controlled means being responsive, respectively, to said first and second control signals to selectively effect variations in said pressure and said rate.
Claim 17
Dependent Claim
210 words
A controlled plastic injection molding machine comprising: a. a supply source of plastic material; b. a barrel having a centrally extending bore in communication with said source; c. a screw disposed within said bOre, said screw adapted for both rotational and linear motion within said bore whereby under the rotational and linear motions of said screw, energy is supplied to said material, said material is rendered molten and is delivered to a mold associated with said machine; d. first controlled means to effect said rotary screw motion; e. second controlled means to maintain a pressure on said screw means, in its rotary mode of operation, in opposition to a pressure developed by the molten plastic material; f. third controlled means to effect said linear motion of said screw at a prescribed rate; g. means to determine the viscosity of the molten plastic material with said barrel and to generate a viscosity signal proportional thereto; and, h. means intermediate said means to determine the viscosity and said second and third controlled means to develop first and second control signals in response to said viscosity signal, said second and third controlled means being responsive, respectively, to said first and second control signals to selectively effect variations in said pressure and said rate.
Claim 18
Dependent Claim
29 words
The invention in accordance with claim 13 wherein said means to determine viscosity includes means to provide signals proportional to pressure and velocity parameters associated with the plastic material.
Claim 19
Dependent Claim
64 words
The invention in accordance with claim 13 wherein said third controlled means effects a variation in said rate in response to said second control signal during the period of time said screw is moved linearly and said second controlled means effects a variation in the pressure under which said screw is maintained on a machine cycle next following the generation of the viscosity signal.
Claim 20
Dependent Claim
79 words
The invention in accordance with claim 13 further including: a. heating means associated with said barrel for supplying heat to the plastic material within said barrel; b. a fourth controlled means for governing the amount of heat supplied by said heating means; and, c. means within said means intermediate to develop a third control signal to effect a change in the output of said fourth controlled means to thereby change the amount of heat supplied by said heating means.
Claim 21
Dependent Claim
97 words
The invention in accordance with claim 16 wherein said third controlled means effects a variation in said rate in response to said second control signal during the period of time said screw is moved linearly, said second controlled means effects a variation in the pressure under which said screw is maintained in a machine cycle next following the generation of the viscosity signal and said fourth controlled means effects a change in the output of said heating means in response to said third control signal in a machine cycle next following the generation of the viscosity signal.
Claim 22
Independent Claim
62 words
A method of controlling a plastic molding machine comprising the steps: a. supplying plastic material to said machine; b. supplying energy to said material to render it molten; c. determining the viscosity of the molten material by measuring the pressure and velocity of the material; and, d. varying the amount of energy supplied to said material in response to the determined viscosity.
Claim 23
Independent Claim
62 words
A method of controlling a plastic molding machine comprising the steps: a. supplying plastic material to said machine; b. supplying energy to said material to render it molten; c. determining the viscosity of the molten material by measuring the pressure and velocity of the material; and, d. varying the amount of energy supplied to said material in response to the determined viscosity.
Claim 24
Independent Claim
89 words
A method of controlling a plastic injection molding machine comprising the steps: a. supplying plastic material to said machine; b. supplying energy to said material to render it molten by a pluraliity of energy input means; c. determining the viscosity of the molten material and providing an output signal in proportion thereto; d. deriving control signals in response to said output signal; and, e. selectively applying said control signals to the plurality of energy input means to vary in amount of energy supplied to said material by said means.
Claim 25
Independent Claim
89 words
A method of controlling a plastic injection molding machine comprising the steps: a. supplying plastic material to said machine; b. supplying energy to said material to render it molten by a pluraliity of energy input means; c. determining the viscosity of the molten material and providing an output signal in proportion thereto; d. deriving control signals in response to said output signal; and, e. selectively applying said control signals to the plurality of energy input means to vary in amount of energy supplied to said material by said means.
Claim 26
Independent Claim
136 words
A method of controlling a plastic injection molding machine comprising the steps: a. supplying plastic material in solid form to said machine; b. supplying energy to said material to render it molten by a pLurality of energy input means; c. measuring the pressure of the molten material within the machine to provide a pressure signal; d. determining a velocity factor with respect to said molten to provide a velocity signal; e. combining said pressure signal and said velocity signal to generate a viscosity signal; f. comparing said viscosity signal to a predetermined reference signal to generate a viscosity error signal; g. deriving control signals from said viscosity error signal; and, h. selectively applying said control signals to the plurality of energy input means to vary the amount of energy supplied to said material by said means.
Claim 27
Independent Claim
136 words
A method of controlling a plastic injection molding machine comprising the steps: a. supplying plastic material in solid form to said machine; b. supplying energy to said material to render it molten by a pLurality of energy input means; c. measuring the pressure of the molten material within the machine to provide a pressure signal; d. determining a velocity factor with respect to said molten to provide a velocity signal; e. combining said pressure signal and said velocity signal to generate a viscosity signal; f. comparing said viscosity signal to a predetermined reference signal to generate a viscosity error signal; g. deriving control signals from said viscosity error signal; and, h. selectively applying said control signals to the plurality of energy input means to vary the amount of energy supplied to said material by said means.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |