Plastic article or earthenware shaping or treating: apparatus – With means to gather excess or rejected stock material
Reexamination Certificate
1999-05-28
2001-03-06
Heitbrink, Tim (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
With means to gather excess or rejected stock material
C425S564000, C425S566000, C425S572000
Reexamination Certificate
active
06196826
ABSTRACT:
FIELD OF INVENTION
The present invention relates to an improved injection molding apparatus. More specifically, it relates to a seepage system for a valve-gated injection molding apparatus.
BACKGROUND OF THE INVENTION
Valve-gated injection molding devices are well-known in the art. These devices use a reciprocating valve pin seated within a bushing to open and close the front opening of a nozzle, thereby establishing or cutting off the flow of material out the nozzle. One common problem that is faced by these valve-gated injection molding devices is the seepage of excess material backward into the bushing, rather than out of the nozzle. The seepage of excess material into the bushing, or worse yet, through the bushing and into the actuating mechanism that drives the valve pin, can cause the valve pin to lock-up or jam, and render the injection molding device inoperable.
In order to avoid this problem, prior art injection molding devices have typically used a tight fit between the valve pin and its bushing to block the leakage of excess material. The tight fit between the valve pin and its bushing, however, usually results in the break down of the melt material caused by the shearing action from the reciprocating motion of the valve pin on the material confined in the small space between the valve pin and its bushing. Consequently, the breakdown causes the formation of hot pressurized gases and acids that attack the surface of the valve pin and its bushing. The resulting corrosion, wear, and build-up of solidified material usually results in seizure of the valve pin, thereby shortening the operative life of the injection molding device.
One solution to the problems caused by this seepage of excess material into the bushing is disclosed by U.S. Pat. Nos. 4,026,518, 4,433,969, and 5,387,099 to Gellert. Each of the injection molding devices disclosed in these patents has a circumferential opening in its bushings that is vented to the atmosphere through one or more ducts in the bushings and the manifold retaining the bushings. The vented circumferential opening relieves the pressure on the seeping material, allows harmful gases to escape, and permits the excess material trapped between the valve pin and its bushing to remain partially fluid. While this vented circumferential opening has been found to substantially extend the operative life of the injection molding device, providing such a vented circumferential opening, especially its ducts, involves a complex and expensive drilling operation into both the bushing and its corresponding manifold. Moreover, the separate individual ducts do not provide an efficient central channel or passage system for collecting and disposing of the seeping material.
Accordingly, it would be desirable to provide a seepage system that relieves excess material and harmful gases, but does not involve complex and expensive drilling operations. It would also be desirable to provide a seepage system with an efficient central seepage passage for collecting and disposing of seeping material.
SUMMARY OF THE INVENTION
The present invention provides a seepage system for an injection molding apparatus comprising a manifold plate with a first portion and a second portion abutting the first portion, and a seepage passage positioned between the first and second portions. The seepage system also comprises a plurality of seepage channels, with each seepage channel being connected to and in communication with the seepage passage. Moreover, the seepage system also comprises a plurality of seepage bores for receiving the flow of excess material, with each seepage bore being connected to and in communication with one of the seepage channels. Gravity may be used to assist the flow of excess material from the seepage bores through the seepage channels and the seepage passage.
In addition, the present invention provides a seepage system for an injection molding apparatus comprising a manifold plate having a first plate with a first face, and a second plate with a second face abutting the first face. The second plate also has at least a portion of a melt passage. The seepage system further comprises a seepage passage between the first and second plate. The seepage passage is defined by at least a portion of the first and second faces, and has an outlet. Also, the seepage system includes a seepage channel connected to and in communication with the seepage passage, and a seepage bore for receiving the flow of excess material. The seepage bore has an annular channel connected to and in communication with the seepage channel.
REFERENCES:
patent: Re. 34552 (1994-02-01), Krishnakumar et al.
patent: 3947177 (1976-03-01), Eckardt
patent: 4026518 (1977-05-01), Gellert
patent: 4035466 (1977-07-01), Langecker
patent: 4082512 (1978-04-01), Wingard et al.
patent: 4174413 (1979-11-01), Yasuike
patent: 4376625 (1983-03-01), Eckardt
patent: 4433969 (1984-02-01), Gellert
patent: 4436778 (1984-03-01), Dugal
patent: 4472131 (1984-09-01), Ryder
patent: 4497621 (1985-02-01), Kudert et al.
patent: 4525134 (1985-06-01), McHenry et al.
patent: 4526821 (1985-07-01), McHenry et al.
patent: 4541982 (1985-09-01), Upmeier
patent: 4542054 (1985-09-01), Fillmann
patent: 4550043 (1985-10-01), Beck
patent: 4568261 (1986-02-01), McHenry et al.
patent: 4609516 (1986-09-01), Krishnakumar et al.
patent: 4615925 (1986-10-01), Nilsson
patent: 4646925 (1987-03-01), Nohara
patent: 4657496 (1987-04-01), Ozeki et al.
patent: 4701292 (1987-10-01), Valyi
patent: 4710118 (1987-12-01), Krishnakumar et al.
patent: 4715802 (1987-12-01), Arai
patent: 4717324 (1988-01-01), Schad et al.
patent: 4728549 (1988-03-01), Shimizu
patent: 4740151 (1988-04-01), Schmidt et al.
patent: 4743479 (1988-05-01), Nakamura et al.
patent: 4744742 (1988-05-01), Aoki
patent: 4774047 (1988-09-01), Nakamura et al.
patent: 4775308 (1988-10-01), Schad et al.
patent: 4781954 (1988-11-01), Krishnakumar et al.
patent: 4808101 (1989-02-01), Schad et al.
patent: 4847129 (1989-07-01), Collette et al.
patent: 4863369 (1989-09-01), Schad et al.
patent: 4863665 (1989-09-01), Schad et al.
patent: 4892699 (1990-01-01), Kudert et al.
patent: 4895504 (1990-01-01), Kudert et al.
patent: 4910054 (1990-03-01), Collette et al.
patent: 4923723 (1990-05-01), Collette et al.
patent: 4931234 (1990-06-01), Schad et al.
patent: 4932858 (1990-06-01), Gellert et al.
patent: 4934915 (1990-06-01), Kudert et al.
patent: 4944909 (1990-07-01), Eckardt et al.
patent: 4950143 (1990-08-01), Krishnakumar
patent: 4954376 (1990-09-01), Krishnakumar et al.
patent: 4957682 (1990-09-01), Kobayashi et al.
patent: 4965028 (1990-10-01), Maus et al.
patent: 4978493 (1990-12-01), Kersemakers et al.
patent: 4990301 (1991-02-01), Krishnakumar
patent: 4994313 (1991-02-01), Shimizu
patent: 5022846 (1991-06-01), Schmidt
patent: 5028226 (1991-07-01), De'ath et al.
patent: 5030077 (1991-07-01), Orimoto et al.
patent: 5032341 (1991-07-01), Krishnakumar et al.
patent: 5040963 (1991-08-01), Beck et al.
patent: 5049345 (1991-09-01), Collette et al.
patent: 5051227 (1991-09-01), Brun, Jr. et al.
patent: 5077111 (1991-12-01), Collette
patent: 5093053 (1992-03-01), Eckardt et al.
patent: 5094603 (1992-03-01), Gellert
patent: 5098274 (1992-03-01), Krishnakumar
patent: 5106284 (1992-04-01), Kobayashi et al.
patent: 5125817 (1992-06-01), Yamachika
patent: 5131830 (1992-07-01), Orimoto et al.
patent: 5135377 (1992-08-01), Gellert
patent: 5141695 (1992-08-01), Nakamura
patent: 5143733 (1992-09-01), Von Buren et al.
patent: 5151025 (1992-09-01), Müller
patent: 5162121 (1992-11-01), Kawaguchi et al.
patent: 5200207 (1993-04-01), Akselrud et al.
patent: 5202074 (1993-04-01), Schrenk et al.
patent: 5215762 (1993-06-01), Eder et al.
patent: 5221507 (1993-06-01), Beck et al.
patent: 5223275 (1993-06-01), Gellert
patent: 5252268 (1993-10-01), Ohno
patent: 5260012 (1993-11-01), Arnott
patent: 5262119 (1993-11-01), Smith
patent: 5288451 (1994-02-01), Schad
patent: 5301838 (1994-04-01), Schmidt et al.
patent: 5380479 (1995-01-01), Schrenk et al.
patent: 5387099 (1995-02-01), Gellert
patent: 5407629 (1995-04-
Babin Denis L.
Gellert Jobst U.
Zhuang Helen Qun
Heitbrink Tim
McDonnell & Boehnen Hulbert & Berghoff
Mold-Masters Limited
Sullivan Sean M.
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