Global Patent Index - EP 0664172 A3

EP 0664172 A3 19970730 - Method for the production of negative form.

Title (en)

Method for the production of negative form.

Title (de)

Herstellungsverfahren für Negativformen.

Title (fr)

Procédé pour la production d'un moule négatif.

Publication

EP 0664172 A3 19970730 (DE)

Application

EP 95890005 A 19950110

Priority

AT 13194 A 19940125

Abstract (en)

[origin: EP0664172A2] Two-part negative moulds for coreless moulding are formed using patterns which (as a consequence of their outer shape) cannot be separated from the mould in a straightforward, simple manner. Parts of the model preventing separation of the mould are removed; these parts are replaced by parts with an identical shape made of a material which during casting of the mould is neither deformed nor separated from the pattern. The material of the replaced pattern parts remains sufficiently soft not to damage the mould in the pattern removal process. As a consequence of the opposite effects of shrinkage of the moulding and expansion of the negative mould, a clearance (of the order of 5% in the case of clay mouldings) is produced which makes mould separation possible. The mould itself is also claimed.

IPC 1-7

B22C 7/02; B22C 7/00

IPC 8 full level

B28B 7/00 (2006.01); B28B 7/34 (2006.01)

CPC (source: EP)

B28B 7/0064 (2013.01); B28B 7/346 (2013.01)

Citation (search report)

Designated contracting state (EPC)

CH DE FR GB IT LI

DOCDB simple family (publication)

EP 0664172 A2 19950726; EP 0664172 A3 19970730; AT A13194 A 19970215

DOCDB simple family (application)

EP 95890005 A 19950110; AT 13194 A 19940125