EP 0435722 B1 19930609 - METHOD AND DEVICE FOR FORMING A SHEET METAL BLANK IN PARTICULAR FOR PRODUCING A MASK FOR A CATHODE RAY TUBE
Title (en)
METHOD AND DEVICE FOR FORMING A SHEET METAL BLANK IN PARTICULAR FOR PRODUCING A MASK FOR A CATHODE RAY TUBE
Publication
Application
Priority
FR 8916725 A 19891218
Abstract (en)
[origin: US5119658A] The subject of the present invention is a method for forming a sheet-metal blank (1), in particular in order to make a cathode ray tube mask, on a press, according to which the central part (1a) of the sheet-metal blank (1) is formed with a specified curvature under the effect of a punch (20) which deforms, in a mould (12), the upper die part (14), the load exerted on the punch (20) being distributed over the entire surface of the base (24) of the punch (20), and according to which, after the curving of the central part of the sheet-metal blank, a mechanical action is exerted on a peripheral forming member (30) so as to apply pressure to a ring (36), the ring (36) is deformed and presses against the free part (1b) of the sheet-metal blank (1) in order first to effect a controlled bending of the said free part, and then the said free part (1b) is applied, still under the action of the ring (36), along the side walls of the punch (20) in order to form the flanged edge.
IPC 1-7
IPC 8 full level
B21D 22/26 (2006.01); B21D 19/08 (2006.01); B21D 22/10 (2006.01); B21D 22/22 (2006.01); B21D 37/08 (2006.01); B21D 51/16 (2006.01); B21D 53/00 (2006.01); B30B 5/02 (2006.01); H01J 9/14 (2006.01)
CPC (source: EP KR US)
B21D 22/10 (2013.01 - EP US); B30B 5/02 (2013.01 - EP US); H01J 9/14 (2013.01 - KR); H01J 9/142 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0435722 A1 19910703; EP 0435722 B1 19930609; AT E90234 T1 19930615; CA 2032456 A1 19910619; CN 1025298 C 19940706; CN 1053762 A 19910814; CZ 281528 B6 19961016; CZ 610890 A3 19960612; DE 69001890 D1 19930715; DE 69001890 T2 19931202; ES 2041163 T3 19931101; FI 111487 B 20030731; FI 906211 A0 19901217; FI 906211 A 19910619; FR 2655892 A1 19910621; HU 206283 B 19921028; HU 908240 D0 19910628; HU T58571 A 19920330; JP H04210826 A 19920731; KR 100199461 B1 19990615; KR 910013409 A 19910808; PL 165004 B1 19941031; PL 288313 A1 19910812; RU 2041755 C1 19950820; US 5119658 A 19920609; YU 236990 A 19941115; YU 48025 B 19961009
DOCDB simple family (application)
EP 90403514 A 19901210; AT 90403514 T 19901210; CA 2032456 A 19901217; CN 90110424 A 19901217; CS 610890 A 19901207; DE 69001890 T 19901210; ES 90403514 T 19901210; FI 906211 A 19901217; FR 8916725 A 19891218; HU 824090 A 19901212; JP 41792290 A 19901218; KR 900020829 A 19901217; PL 28831390 A 19901218; SU 4894005 A 19901217; US 62868190 A 19901217; YU 236990 A 19901217