Metal founding – Process – Shaping a forming surface
Reexamination Certificate
1999-04-30
2001-07-03
Nguyen, Nam (Department: 1722)
Metal founding
Process
Shaping a forming surface
C164S200000, C164S195000, C164S029000
Reexamination Certificate
active
06253827
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is a method of compressing molding sand and an apparatus for compressing molding sand. More specifically, this invention is a method of compressing molding sand by blowing compressed gas through a plurality of compressed gas conductors onto the entire surface of molding sand inserted within a molding frame that is separated from a model but that encloses its sides. The frame and the model are both placed on a molding plate that is provided with a vent for exhaust.
2. Background Information
Many methods and apparatuses in this technical field are publicly known. For instance, EP No. 0263977 teaches a device in which molding sand inserted within a molding frame encloses a model from its sides, and to compress the molding sand a squeezing device is provided above the molding frame, the squeezing device and the molding frame being complementary to each other, said squeezing device comprising a plurality of squeezing members and compressed gas pipes.
In that device compressed gas is blown onto the molding sand at a uniform flow rate through compressed gas pipes so that the gas is simultaneously blown onto the molding sand through all compressed gas pipes of the squeeze device and flows into the sand. Then the molding sand is pressed mechanically by the squeezing members. In this way the mold is compressed uniformly within the molding frame.
But by using the above prior art, especially when forming a mold using a model consisting of sections with a great difference in their heights, compressing the higher sections and lower sections of the model to give a mold that precisely conforms may cause a part of it, e.g., a protruding part of it that corresponds to a pocket section of the model, to break during the time the completed mold is released from the molding frame after the compression is over.
This invention is designed to overcome such a problem. This invention aims to provide a method and an apparatus to compress molding sand so that different parts of the mold are compressed independently from the other parts and to minimize the energy consumed for compressing molding sand.
SUMMARY OF THE INVENTION
The method of compression of this invention comprises the steps of placing a model and a molding frame on a model plate provided with an exhaust vent, said molding frame being spaced away from, and enclosing, the model, pouring molding sand to fill the space within the molding frame, and blowing compressed gas through a plurality of compressed gas pipes over the upper surface of the molding sand within the molding frame, characterized by blowing the gas from said plurality of compressed gas pipes in such a way that each pipe can be independently closed or independently placed under pressure control.
In contrast to the prior art, by using the method of this invention, the model can be compressed such that various sections of the mold are compressed to various degrees by blowing compressed gas onto specific parts of molding sand in predetermined degrees of strength.
The molding sand compression apparatus of this invention is provided with independent compression gas pipes arranged over substantially the entire surface of the molding sand. It also has a mechanism in which compressed gas blown out from at least some of compressed gas pipes is independently controllable.
REFERENCES:
patent: 44 09 791 (1994-03-01), None
patent: 44 09 791 A1 (1994-03-01), None
patent: 0 263 977 (1991-12-01), None
patent: 0 263 977 B1 (1991-12-01), None
patent: 6-277800 (1994-10-01), None
Hirata Minoru
Kaneto Kimikazu
Gray Cary Ware & Freidenrich LLP
Lin I.-H.
Nguyen Nam
Sintokogio Ltd.
LandOfFree
Method of compressing molding sand using independently... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of compressing molding sand using independently..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of compressing molding sand using independently... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2468095