Abstract
The present invention surrounds an apparatus and method for the use in injection molding of articles of manufacture using an injection molding apparatus having a valve-gate pin or a plurality of valve-gate pins for actuation to extend and retract from a cavity within an injection mold. The valve-gate pin may have a retention feature or retention features configured for the retention of molded parts such that the retraction or extension of the valve-gate pin provides part removal from an associated injection mold. Further, the valve-gate pin may have a feature or features to facilitate the injection of fluids, gases or particles during or after the primary injection process. Additionally, a plurality of such valve-gate pins may be employed within each mold cavity, or within each valve-gate actuation system.
Claims
1. An injection molding apparatus for the extraction of a part comprising: a first side of an injection mold and a second side of an injection mold having a cavity therebetween; said first side of said injection mold further comprising a material delivery chamber and an aperture extending from said material delivery chamber to said cavity; a first valve-gate pin having a first end, said first end of said first valve-gate pin disposed through said aperture with said first end protruding into said cavity; said valve-gate pin having a retention feature proximate to said first end of said first valve-gate pin; said retention feature comprising a first dimension proximate to said first end of said first valve-gate pin, and a second dimension offset from said first dimension toward a second end of said first valve-gate pin; said first dimension is greater than said second dimension; and said first valve-gate pin having connection to an actuating mechanism wherein said actuating said first valve-gate pin is positionable through said aperture.
2. The injection molding apparatus of claim 1, wherein said retention feature comprises an annular recess.
3. The injection molding apparatus of claim 1, wherein said retention feature comprises a threaded feature.
4. The injection molding apparatus of claim 1, wherein said retention feature comprises a projecting feature.
5. The injection molding apparatus of claim 1, wherein said first valve-gate pin further comprises a pathway.
6. The injection molding apparatus of claim 5, wherein said pathway is consistent with a central axis of said first valve-gate pin.
7. The injection molding apparatus of claim 1, wherein said valve-gate pin is constructed of a material selected from the list consisting of: metals, polymeric, composite, nano-particle enhanced composite.
8. The injection molding apparatus of claim 1, wherein said injection molding apparatus further comprises a second valve-gate pin.
9. The injection molding apparatus of claim 1, wherein said actuating mechanism is programmably controlled.
10. A method for the injection molding of a part comprising: clamping a first side of an injection mold to a second side of an injection mold creating a cavity therebetween; a first positioning step to position a valve-gate pin to an open position; injecting a first material into said cavity; a maintaining step to hold said injected material under pressure within said injection mold for a predetermined period of time; a second positioning step to position a valve-gate pin to a closed position; and opening said injection mold, to separate said first side of said injection mold from said second side of said injection mold;
11. The method of claim 10 further comprising a fourth positioning step following said third positioning step to position the valve-gate pin to force the part away from the first side of the injection mold.
12. The method of claim 10 further comprising pushing a second material through a pathway in said valve-pin.
13. The method of claim 11, wherein said second material comprises a gaseous material.
14. The method of claim 10, wherein said first positioning step occurs prior to said clamping step.
15. The method of claim 10 further comprising a third positioning step to retract said valve-gate pin thereby breaking a connection between said valve-gate pin and said part.
Description
BRIEF DESCRIPTION OF FIGURES
[0020] FIG. 1AA cross-sectional view of an embodiment of an injection molding apparatus
[0021] FIG. 1BA cross-sectional detail view of an embodiment of an injection molding apparatus
[0022] FIG. 2A perspective view of an embodiment of a valve-gate pin
[0023] FIG. 3AA cross-sectional detail view of an embodiment of an injection molding apparatus with a valve-gate pin in an open position
[0024] FIG. 3BA cross-sectional detail view of an embodiment of an injection molding apparatus with a valve-gate pin in a closed position
[0025] FIG. 4A cross-sectional view of an embodiment of an injection molding apparatus with a first-side of an injection mold separated from a second side of an injection mold
[0026] FIG. 5A cross-sectional view of an embodiment of an injection molding apparatus with a first-side of an injection mold separated from a second side of an injection mold
[0027] FIG. 6AA detailed view of an embodiment of a valve-gate pin showing an embodiment of a retention feature
[0028] FIG. 6BA detailed view of an embodiment of a valve-gate pin showing an embodiment of a retention feature
[0029] FIG. 6CA detailed view of an embodiment of a valve-gate pin showing an embodiment of a retention feature
[0030] FIG. 6DA detailed view of an embodiment of a valve-gate pin showing an embodiment of a retention feature
[0031] FIG. 7A cross-sectional view of an embodiment of an injection molding apparatus with a first-side of an injection mold separated from a second side of an injection mold
[0032] FIG. 8A cross-sectional view of an embodiment of an injection molding apparatus
[0033] FIG. 9An embodiment of an injection molding method
[0034] FIG. 10An embodiment of an injection molding method
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
[0035] Certain embodiments of the present invention, shown in FIG. 1A and FIG. 1B, surrounds an injection molding apparatus 1000 comprising a valve-gate pin 1005 installed on a first side 1010 of an injection mold 1020. The valve-gate pin 1005, having a shaft 1025, further comprises a first end 1030 for protruding into a cavity 1040 defined by a first side 1010 and a second side 1050 of the injection mold, with the second side having a vent mechanism 1052. The first end 1030 of the valve-gate pin comprises a retention feature 1060. The retention feature 1060 comprises a first dimension 1070 and a second dimension 1080. The first dimension, proximate to the first end 1030 of the valve-gate pin, is larger than the second dimension 1080. Due to the retention feature 1060, when a part 1090 forms in the injection mold 1020, a connection is formed between the first end 1030 of the valve-gate pin and the part 1090. Although a retention feature 1060 is typically consistent with the first end 1030 of the valve-gate pin, it will be appreciated that a retention feature 1060 may be offset from the first end 1030 of the valve-gate pin. The valve-gate pin 1005 traverses through a material delivery chamber 1095, through which material passes for the injection into the cavity 1040 of the injection mold. The valve-gate pin 1005 protrudes into the cavity 1040 through an aperture 1055 extending between the material delivery chamber 1095 and the cavity 1040.
[0036] A valve-gate pin 1005 as shown in FIG. 1A and FIG. 1B, and disclosed herein, may comprise a material composition of metal, composite materials such as nano-particle enhanced composites, plastics or other materials appreciated by those skilled in the art.
[0037] Certain embodiments of a valve-gate pin 1005, for example shown in FIG. 2, comprise a first end 1030 with a retention feature 1060. In such embodiments, the valve-gate pin 1005 comprises a round profile having a plurality of diameters. The retention feature comprises a first diameter 1100 consistent with the first end 1030 of the valve-gate pin and a second diameter 1110 offset from the first end 1030. In such embodiments, the second diameter 1110 is equal to the minor diameter 1130 of an annular recess 1140. In such embodiments, the second diameter 1110 of the valve-gate pin 1005 is equal with the major diameter 1150 of the annular recess. It will be appreciated, that in other embodiments, the minor diameter 1130 of the annular recess may not equal the second diameter 1110 of the valve-gate pin. Furthermore, in other embodiments, the major diameter 1150 of the annular recess may not equal the first diameter 1100 of the valve-gate pin. Alternatively, it will be further appreciated that a retention feature 1060 may comprise a feature providing differing form from the first diameter 1100 or the second diameter 1110 of the valve-gate pin 1005. Certain embodiments of a valve-gate pin may comprise a form which protrudes from the valve-gate pin.
[0038] In embodiments of the present invention, a valve-gate pin 1005, for example shown in FIG. 3A, is longitudinally positionable to allow the extension and retraction of the valve-gate pin through an aperture 1055 and in relation to a cavity 1040 of an injection mold 1020. It will be appreciated that when a valve-gate pin 1005 is in an open position, a second dimension 1080 of a valve gate pin is configured to interface an aperture 1055 such that material for injecting into a cavity 1040 can bypass the valve-gate pin 1005 into the cavity 1040. In other embodiments of the present invention, for example shown in FIG. 3B, it will be appreciated that when a valve-gate pin 1005 is in a closed position, a first dimension 1070 is configured to be offset from an aperture 1055 such that material for injecting into a cavity 1040 cannot bypass the valve-gate pin 1005 into the cavity 1040.
[0039] Certain embodiments of an injection molding apparatus 1000, shown in FIG. 4, are used in conjunction with an injection mold 1020 comprising a first side 1010 and a second side 1050. The connection of a part 1090 to a valve-gate pin 1005 is accomplished by accounting for material properties such as thermal expansion characteristics, stress/strain considerations and elasticity of the selected material or composition used for manufacturing the part 1090. After forming, the part 1090 solidifies and contracts in volume causing the part 1090 to be affixed to a retention feature 1060 of the valve-gate pin. The connection between the part 1090 and valve-gate pin 1005 has a retention force defined by the force required, directed axially away from the valve-gate pin 1005, to break the connection between the part 1090 and the valve-gate pin 1005. This retention may be equal to or greater than the force needed to remove the molded part from the second side 1050 of the injection mold. When the first side 1010 is separated from the second side 1050, the retention force of the attachment between the part 1090 and the valve-gate pin 1005 pin extracts the part 1090 from the second side 1050 of the injection mold. If the retention force between the part 1090 and the valve-gate pin 1005 is equal to the retention forces between the part 1090 and the second side 1050 of the injection mold, the part releases from the second side 1050 and the first side 1010 of the injection mold simultaneously. If the retention between the part 1090 and the valve-gate pin 1005 exceeds the retention forces between the part 1090 and the second side 1050 of the injection mold, the part 1090 will be pulled away from the second side 1050 and remain in contact with the valve-gate pin. In certain embodiments, it may be required for a machine operator to manually extract, or a mechanical device to be used to extract, the part 1090 from the first side 1010 of the injection mold 1020 by applying enough force to break the connection between the part 1090 and the valve-gate pin 1005.
[0040] Certain embodiments of an injection molding apparatus 1000, shown in FIG. 5, comprise a valve-gate pin 1005 configured to retract and extend. It will be appreciated to those skilled in the art that such retraction and extension actions may be performed by linear actuating mechanisms 1065 such as, but not limited to, electro-mechanical actuators, mechanical actuators, hydraulic actuators, pneumatic actuators, piezoelectric actuators or other mechanisms known to those skilled in the art. Typically such actuating mechanisms interface with a second end 1035 of the valve-gate pin, but it will be appreciated that the connection between a valve-gate pin 1005 and an actuation mechanism may comprise alternate configurations as appreciated by those skilled in the art. In such embodiments, if the part 1090 is still connected to the valve-gate pin 1005 after the injection mold 1020 has been opened, the valve-gate pin 1005 may be retracted. The retraction of the valve-gate pin 1005 pulls the valve-gate pin 1005 from the part 1090 with enough force to exceed the retention force between the part 1090 and the valve-gate pin 1005. The retraction distance of the valve-gate pin 1005 may be of distance less than, equal to, or greater than the distance which the valve-gate pin 1005 protrudes into the cavity 1040 of the injection mold 1020. Once the part 1090 has been molded and released, the valve-gate pin 1005 may be extended into the cavity 1040 of the injection mold, and the first side 1010 of the injection mold mated with the second side 1050 of the injection mold prior to manufacturing another part 1090.
[0041] Certain embodiments of an injection molding apparatus 1000, as shown in FIG. 6A-FIG. 6D, comprising a valve-gate pin 1005 further comprise a retention feature 1060. In such embodiments, the retention feature 1060 may comprise at least one alternate form configured to provide retention of a part 1090. Such embodiments may comprise an annular recess having a semi-circular undercut (FIG. 6A), a rectangular undercut (FIG. 6B), a threaded feature 1200 (FIG. 6C), or a projecting feature 1230 (FIG. 6D). It will be appreciated that a retention feature may comprise any form that provides a retention force between a retention feature 1060 and a part 1090.
[0042] In certain embodiments of an injection molding apparatus 1000, shown in FIG. 7, a valve-gate pin 1005 comprises a retention feature 1060 having a threaded feature 1200. In such embodiments, the retention feature 1060 protrudes into the cavity 1040 of the injection mold 1020. When a part 1090 is manufactured, the part 1090 cools and creates an attachment between the part 1090 and the retention feature 1060 of the valve-gate pin. In such embodiments, it may be desired to actuate the valve-gate pin 1005 rotatively to release the part from the retention feature 1060 using an actuating mechanism 1065. Such actuation may be performed using rotative actuating mechanism 1065 independently or in conjunction with a linear actuating mechanism 1065 to retract the valve-gate pin 1005 from the cavity 1040 of the injection mold. Rotative actuating mechanisms 1065 include technologies such as but not limited to servo motors, stepper motors, hydraulic actuators, and pneumatic actuators. Typically, such actuating mechanisms interface with a second end 1035 of the valve-gate pin, but it will be appreciated that the connection between a valve-gate pin 1005 and an actuation mechanism may comprise alternate configurations as appreciated by those skilled in the art. When the part 1090 is released from the retention feature 1060 in such embodiments, the part 1090 exhibits a negative threaded feature 1210 as a negative form of the threaded feature 1200 of the retention feature 1060.
[0043] Certain embodiments of an injection molding apparatus 1000, shown in FIG. 8, comprise a valve-gate pin 1005 having a pathway 1250 longitudinally in the valve-gate pin 1005 such that such a pathway 1250 is exposed to the cavity 1040 of an injection mold 1020. Such a pathway 1250 and typically substantially consistent with a central axis 1260 of the valve-gate pin 1005. Such a pathway 1250 provides capability for processes including gas-assist injection molding, and gas assisted part ejection.
[0044] Certain embodiments of an injection molding process 1300, shown in FIG. 9, using injection valve-gate pins comprises: Clamping 1305 a first side of an injection mold to a second side of an injection mold creating a cavity between the first side of the injection mold and the second side of the injection mold, a first positioning step 1310 to position a valve-gate pin to an open position, injecting 1320 material into the cavity between the first side of the injection mold and the second side of the injection mold, dwelling 1330, maintaining the material substantially motionless under pressure, to ensure all voids of the cavity between the first side of the injection mold and the second side of the injection mold are filled, a second positioning step 1335 to position the valve-gate pin to a closed position, cooling 1340 to allow the part to properly cure and cool thereby creating a connection between the part and the retention feature of the valve-gate pin, separating 1350 the first side of the injection mold from the second side of the injection mold, and a third positioning step 1360 to retract the valve-gate pin away from the part thereby breaking the connection between the retention feature of the valve-gate pin and the part to release the part from the first side of the injection mold. Other embodiments surrounding an injection molding process 1300 comprise: a clamping 1305, a first positioning step 1310, an injecting step 1320, dwelling 1330, a second positioning step 1335, a cooling step 1340, and a separating step 1350. In such embodiments eliminating a third positioning step 1360, a part may be removed from a first side of an injection mold manually, mechanically, through the use of robotics or through the use of automated systems. In certain embodiments, breaking the connection between the retention feature of the valve-gate pin and the part may not release the part from the first side of the injection mold. In such embodiments, it may be desired to add fourth positioning step 1310 to position the valve-gate pin to force the part away from the first side of the injection mold. In certain embodiments of an injection molding apparatus which comprise a pathway in a valve-gate pin, as shown in FIG. 10, an additional step of pushing 1380 a fluid through the pathway may be desired. In such embodiments comprising a pushing step 1380, it will be appreciated that the pushing step 1380 may occur anywhere throughout the process dependent upon the intended purpose of the pushing step 1380. For instance, a pushing step may follow the injecting step for the introduction of a gas for gas-assist injection molding. However, a pushing step may occur following the dwelling step 1330 for the purposes of introducing a fluidincluding a gas, liquid, powder or flowable solidto encapsulate the fluid within the part. Furthermore, the pushing step may occur following the retracting 1360 step to provide gas-assisted ejection of a part from the injection mold. It will be appreciated by those skilled in the art that steps including, but not limited to, positioning 1310 the valve-gate pin and, retracting 1360 the valve-gate pin may occur at alternate stages of the process while remaining consistent with the inventive nature of the present invention.
[0045] In the foregoing specification, specific embodiments have been disclosed. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings. It is understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. The terms first, second, proximal, distal, etc., as used herein, are intended for illustrative purposes only and do not limit the embodiments in any way. Additionally, the term plurality, as used herein, indicates any number greater than one, either disjunctively or conjunctively, as necessary, up to an infinite number. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims.
[0046] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention. Further, the invention(s) disclosed herein are capable of other embodiments and of being practiced or of being carried out in various ways. Various embodiments of the present invention(s) have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. In addition, it is to be understood that the phraseology and terminology used herein is for the purposes of description and should not be regarded as limiting. The use of including, comprising, or adding and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof, as well as, additional items.
