Metal founding – Process – Shaping a forming surface
Patent
1996-01-18
1998-07-28
Batten, Jr., J. Reed
Metal founding
Process
Shaping a forming surface
164165, 164166, B22C 1308
Patent
active
057851085
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for changing pattern plates in the production of Croning shell molds, wherein the pattern plate being in use has a working temperature from about 250.degree. C. to 330.degree. C. Furthermore, the invention relates to a method of changing pattern plates during the production of Croning shell molds, in particular with the use of the tool changing apparatus in accordance with the invention.
Croning shell molds are casting molds for sand casting, which are used in the so-called Croning shell molding process. Croning shell molds are produced by means of rotatable, heated pattern plates, over which a molding box or a pouring vessel is placed. On its side carrying the pattern contour, the pattern plate is supplied or coated with a pourable, thermosetting molding material, for example, molding sand. A Croning shell mold, also known as mold shell is formed, if possible, under the action of a vacuum applied to the rear side of the pattern plate, and by the caking as well as curing of the molding material on the heated surface of the pattern plate. The thickness of the shell is dependent on the curing time or temperature. Once the desired thickness of the shell formed by the molding material is reached, the entire arrangement is tilted by 180.degree.. In this process, the molding material that has not cured drops from the shell under the action of gravity, or falls again into the pouring vessel. Since such a mold shell alone is unable to resist high casting pressures, it is often backfilled and compacted on its rear side with a conventional molding material. This occurs normally, in that the pattern plate, together with the mold box or the pouring vessel is tilted again by 180.degree. and filled thereafter with a molding sand as is commonly used in the foundry practice, such as green sand, which may again be compacted under the action of a pressure difference between the pattern plate and the sand surface. Subsequently, the pouring vessel together with the thus-produced casting mold is raised upward from the pattern plate. This upward movement may be assisted by an overpressure which acts upon the shell mold surface from the side of the pattern plate.
An apparatus for making Croning shell molds of the above-described type is known, for example, from DE-OS 34 44 342 and corresponding European Patent 0184090. This type of apparatus includes pattern plates--in single station or multistation arrangements--that are generally mounted by mechanical means, such as, for example, screws or the like, to a pattern plate carrier. In this arrangement, a change of pattern plates is always connected with a prolonged shutdown of the entire arrangement. During such a change, the operating personnel are exposed to considerable thermal and physical stress as a result of the pattern plates that are heated in the machine to temperatures from 250.degree. C. to 330.degree. C.
A further and quite considerable disadvantage of the known arrangement may be seen in that during a tool change, the substituting pattern plates are supplied to the pattern plate carrier substantially at room temperature, so that prior to a renewed production of shell molds, it is necessary to heat the substituting pattern plate in the machine. This is time-intensive and requires a prolonged shutdown of the machine in the form of a preparation time.
It is therefore the object of the present invention to provide a tool changing device for changing pattern plates during the production of Croning shell molds, which facilitates a faster and yet simpler exchange of pattern plates in the machine without prolonged shutdown times. It is a further object to provide a corresponding method of changing pattern plates during the production of Croning shell molds.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by the provision of an apparatus and method for exchanging pattern plates used in the production of shell casting molds and wherein the removed patt
REFERENCES:
patent: 4059144 (1977-11-01), Esche
Patent Abstracts of Japan, vol. 13, No. 83, Feb. 27, 1989, Publication No. JP63281748 (Otaki Katsuharu) Nov. 18, 1988.
Rommel Reiner
Stangier Ulf
Adolf Hottinger Maschinenbau GmbH
Batten, Jr. J. Reed
LandOfFree
Apparatus and method for changing pattern plates on shell castin 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 and method for changing pattern plates on shell castin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for changing pattern plates on shell castin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-15593