US3853446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid injection molding apparatus
Assignee: Inter Polymer Research Corp
•
Filing: 1973-04-17
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Granted: 1974-12-10
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Expires: 1993-04-17
Abstract
Abstract In an apparatus for the liquid injection molding of multicomponent thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, an improvement is disclosed which comprises: A. MEANS FOR CONTINUOUSLY RECIRCULATING ONE PART OF EACH REACTION COMPONENT TO ITS RESPECTIVE HOLDING TANK WHILE SIMULTANEOUSLY DELIVERING THE OTHER PART OF THE REACTION COMPONENT TO A METERING, MIXING, AND INJECTING UNIT FOR INJECTING A PREDETERMINED AMOUNT OF HOMOGENEOUS REACTION MIXTURE INTO THE INJECTION PORT OF A MOLD UNDER SUBSTANTIALLY CONSTANT PRESSURE ONLY FOR THE DURATION OF THE INJECTION CYCLE; B. MEANS FOR PERMITTING DISCHARGE OF THE REACTION MIXTURE FROM THE METERING, MIXING, AND INJECTING UNIT INTO THE INJECTION PORT OF THE MOLD ONLY FOR THE DURATION OF THE INJECTION CYCLE; C. MEANS FOR MAINTAINING SUBSTANTIALLY CONSTANT PRESSURE FOR THAT PART OF THE REACTION COMPONENT BEING RECIRCULATED TO ITS RESPECTIVE HOLDING TANK REGARDLESS OF THE STATE OF OPERATION OF MEANS (B); AND D. AT LEAST ONE INJECTION CHANNEL EXTENDING FROM THE INJECTION PORT OF THE MOLD AND TERMINATING IN AT LEAST ONE GATE POSITIONED WITHIN THE MOLD CAVITY AT A POINT RELATIVELY PROXIMATE TO THE GEOMETRIC CENTER OR POINT OF BALANCE OF THE BOTTOM PLATE, THE INJECTION CHANNEL BEING DEFINED WITHIN THE WALL OF THE MOLD CAVITY AT A LEVEL BELOW THE UPPER SURFACE OF THE BOTTOM PLATE WHEN THE BOTTOM PLATE IS IN THE POSITION FOR THE COMMENCEMENT OF THE INJECTION CYCLE WITH THE BOTTOM PLATE WALL SERVING AS ONE WALL OF THE INJECTION CHANNEL, OR THE INJECTION CHANNEL IS DEFINED WITHIN THE BOTTOM PLATE WALL WITH THE WALL OF THE MOLD CAVITY SERVING AS ONE WALL OF THE INJECTION CHANNEL, OR THE INJECTION CHANNEL IS DEFINED WITHIN THE WALL OF THE MOLD CAVITY ANDA THE BOTTOM PLATE WALL IN THE AFORESAID MANNER WITH THE FLOW OF REACTION MIXTURE THROUGH THE GATE DURING THE INJECTION CYCLE BEING UNINTERRUPTED WHEN THE BOTTOM PLATE IS IN POSITION FOR THE COMMENCEMENT OF THE INJECTION CYCLE AND INTERRUPTED WHEN THE BOTTOM PLATE IS IN THE POSITION AT THE CONCLUSION OF THE INJECTION CYCLE.
Inventors
- 👤 F Hostettler
- 👤 P Graefe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:00
CPC Classifications
B; B29; B29D; B29D35/00; B29D35/0009; B29D35/0018
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
287 words
An apparatus for the liquid injection molding of multicomponent thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate from molding the reacting mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogeneous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. means for intercepting and deflecting the flow path of the reaction mixture injected into the mold, said means being positioned upon the upper surface of the bottom plate a short distance from the gate.
Claim 2
Independent Claim
287 words
An apparatus for the liquid injection molding of multicomponent thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate from molding the reacting mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogeneous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. means for intercepting and deflecting the flow path of the reaction mixture injected into the mold, said means being positioned upon the upper surface of the bottom plate a short distance from the gate.
Claim 3
Independent Claim
392 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined within the wall of the mold cavity at a level below the upper surface of the bottom plate when the bottom plate is in the position for the commencement of the Injection cycle with the bottom plate wall serving as one wall of the injection channel, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
Claim 4
Independent Claim
392 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined within the wall of the mold cavity at a level below the upper surface of the bottom plate when the bottom plate is in the position for the commencement of the Injection cycle with the bottom plate wall serving as one wall of the injection channel, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
Claim 5
Dependent Claim
30 words
The apparatus of claim 1 wherein means for interrupting the flow of additional reaction material through the gate without displacing the bottom plate from the injection cycle position is provided.
Claim 6
Dependent Claim
25 words
The apparatus of claim 1 wherein the mixing and injecting unit possesses a high speed mixing screw capable of speeds in excess of 10,000 r.p.m.
Claim 7
Independent Claim
366 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined within the bottom plate wall with the wall of the mold cavity serving as one wall of the injection channel, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
Claim 8
Independent Claim
366 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tank while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined within the bottom plate wall with the wall of the mold cavity serving as one wall of the injection channel, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
Claim 9
Independent Claim
401 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tanK while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined as the cooperation of two half-channels, one half-channel being disposed within the wall of the mold cavity at a level below the upper surface of the bottom plate when the bottom plate is in the position for the commencement of the injection cycle, the other half-channel being disposed within the wall of the bottom plate, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
Claim 10
Independent Claim
401 words
An apparatus for the liquid injection molding of multi-component thermosetting reaction mixtures having holding tanks for storing each component of the reaction mixture under vacuum, recirculating and metering pumps for recirculating each component to its respective holding vessel between injection cycles and alternately delivering metered amounts of each component to a mixing and injecting unit during the injection cycle and a mold having an internal configuration or cavity conforming to the surfaces of the article to be molded, a movable bottom plate and an injection port and short injection channel terminating in a gate positioned within the mold cavity at a point relatively remote from the geometric center or point of balance of the bottom plate for molding the reaction mixture to the desired configuration, wherein the improvement comprises: a. means for continuously recirculating one part of each reaction component to its respective holding tanK while simultaneously delivering the other part of the reaction component to a metering, mixing and injecting unit for injecting a predetermined amount of homogenous reaction mixture into the injection port of a mold under substantially constant pressure only for the duration of the injection cycle; b. means for permitting discharge of the reaction mixture from the metering, mixing, and injecting unit into the injection port of the mold only for the duration of the injection cycle; c. means for maintaining substantially constant pressure for that part of the reaction component being recirculated to its respective holding tank regardless of the state of operation of means (b); and d. at least one injection channel extending from the injection port of the mold and terminating in at least one gate positioned within the mold cavity at a point relatively proximate to the geometric center or point of balance of the bottom plate, the injection channel being defined as the cooperation of two half-channels, one half-channel being disposed within the wall of the mold cavity at a level below the upper surface of the bottom plate when the bottom plate is in the position for the commencement of the injection cycle, the other half-channel being disposed within the wall of the bottom plate, with the flow of reaction mixture through the gate during the injection cycle being uninterrupted when the bottom plate is in position for the commencement of the injection cycle and interrupted when the bottom plate is in the position at the conclusion of the injection cycle.
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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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |