Plastic article or earthenware shaping or treating: apparatus – Control means responsive to or actuated by means sensing or... – Molding pressure control means responsive to pressure at...
Patent
1988-09-20
1990-02-13
Woo, Jay H.
Plastic article or earthenware shaping or treating: apparatus
Control means responsive to or actuated by means sensing or...
Molding pressure control means responsive to pressure at...
2643287, 425150, 425555, 425556, 425593, 425808, B29C 4577
Patent
active
049002422
ABSTRACT:
Apparatus for injection compression molding of thermoplastic parts. A preferred apparatus (100) includes a platen assembly 106, a toggle clamp assembly 102, a screw injection assembly 101, a hydraulic system suitable for providing power to the toggle clamp assembly 102 and the screw injection assembly 101, and a control system 88 for operatively controlling the various hydraulic devices associated with the molding apparatus. The platen assembly 106 provides for a plurality of variable-volume mold cavities 7. In one embodiment, enlarged mold cavities 7 receive plasticized resin from the screw injection assembly 101, and compression of the injected resin is provided by the toggle clamp assembly 102. In another embodiment, the platen assembly 106 includes a floating die assembly wherein pressure created by injected resin causes die inserts 5 and support pillars 15 to slide relative to a molding plate 74. Compression in this embodiment is also preferably provided by the main toggle clamp assembly 102. Preferably, the toggle clamp assembly 102 provides multiple-stage compression of the resin to first redistribute the resin and vent the cavities and, second, compress the resin to compensate for cooling-induced shrinkage thereof. In the multiple cavity embodiment, because all cavities 7 are equally compressed simultaneously, control of the molding process and balancing of the mold are readily accomplished. The apparatus is particularly well suited for molding optical lenses and disks. Printed circuit substrates can also be molded thereby.
REFERENCES:
patent: 2292917 (1942-08-01), Williams
patent: 2319014 (1943-05-01), Smith
patent: 2333131 (1943-11-01), Tillyer et al.
patent: 2443826 (1948-06-01), Johnson
patent: 2516373 (1950-07-01), Ehlert et al.
patent: 2938232 (1960-05-01), Martin
patent: 4008031 (1977-02-01), Weber
patent: 4091057 (1978-05-01), Weber
patent: 4128613 (1978-12-01), Allen
patent: 4184835 (1980-01-01), Talbot
patent: 4185955 (1980-01-01), Holmes et al.
patent: 4260360 (1981-04-01), Holmes et al.
patent: 4364878 (1982-12-01), Laliberte et al.
patent: 4374636 (1983-02-01), Holmes
patent: 4409169 (1983-10-01), Bartholdsten et al.
patent: 4442061 (1984-04-01), Matsuda et al.
patent: 4519763 (1985-05-01), Matsuda et al.
patent: 4540534 (1985-09-01), Grendol
patent: 4569807 (1986-02-01), Boudet
patent: 4678420 (1987-07-01), Inoue
"Molding of Plastics", by J. E. Teagarden et al, Chemical Engineers' Handbook, 34d Ed., MacGraw-Hill, 1950.
"Injection Molding Machines", by F. Johannabur, MacMillan Press, New York, NY 1983. Section 2.4.2.1.
"Injection Molding of Plastic Objects", U. Greis et al, Symposium on Optical Surface Technology, SPIE vol. 381.
"Bubble Theory of Mold Filling" by John R. Byrne, Society of Plastic Engineers, Inc., 41st Annual Technical Conference Technical Papers Reprint, vol. XXIX, 1983, pp. 702-704.
Engel brochure A-24-TV-4/75, Ludwig Engle, Canada Ltd., Guelph, Ontario, Canada.
Galic George J.
Maus Steven M.
Heitbrink Timothy W.
Woo Jay H.
LandOfFree
Apparatus for injection molding articles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for injection molding articles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for injection molding articles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1164350