EP 0372500 A3 19910605 - PLASMA ARC WELDING APPARATUS
Title (en)
PLASMA ARC WELDING APPARATUS
Publication
Application
Priority
US 28024088 A 19881205
Abstract (en)
[origin: US4929811A] A plasma arc torch system includes a fault detect circuit for sensing a short between the electrode and the nozzle and disabling the power supply when the short is sensed. A sensing circuit within the torch cable is provided for actuating the fault detect circuit when the cable is severely punctured. The sensing circuit includes a foil embedded within the cable which circumscribes the main conductor to which a drain lead is connected. The drain lead senses a short between the foil and main conductor from a penetrating foreign object and actuates the fault detect circuit. Additionally, the fault detect circuit is effective in combination with a unique continuity interlock circuit disclosed to insure a safe torch. Further, a rectified control circuit is provided to maintain a stable arc preventing erosion of the nozzle and subsequent exposure of the electrode.
IPC 1-7
IPC 8 full level
B23K 10/00 (2006.01); H05H 1/34 (2006.01); H05H 1/36 (2006.01)
CPC (source: EP KR US)
H05H 1/34 (2013.01 - EP US); H05H 1/3436 (2021.05 - EP KR); H05H 1/3473 (2021.05 - EP KR); H05H 1/36 (2013.01 - EP KR US); H05H 1/3436 (2021.05 - US); H05H 1/3473 (2021.05 - US)
Citation (search report)
- [A] DE 2541166 A1 19760422 - MANSFELD KOMBINAT W PIECK VEB
- [AD] US 4663515 A 19870505 - KNEELAND ROBERT D [US], et al
- [AD] US 3745321 A 19730710 - TKACHEV M, et al
- [A] GB 1195420 A 19700617 - WESTINGHOUSE BRAKE & SIGNAL [GB]
- [A] US 4247752 A 19810127 - STRINGER LOREN F
- [A] PATENT ABSTRACTS OF JAPAN vol. 12, no. 311 (M-734)(3158) 24 August 1988, & JP-A-63 084 774 (DAIHATSU MOTOR CO LTD) 15 April 1988,
Designated contracting state (EPC)
AT BE CH DE ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0372500 A2 19900613; EP 0372500 A3 19910605; AU 4593889 A 19900607; AU 614449 B2 19910829; DK 612489 A 19900606; DK 612489 D0 19891205; FI 895806 A0 19891204; JP H03114678 A 19910515; KR 900009206 A 19900702; KR 920004844 B1 19920619; NO 894831 D0 19891204; NO 894831 L 19900606; PT 92492 A 19900629; PT 92492 B 19950912; US 4929811 A 19900529
DOCDB simple family (application)
EP 89122434 A 19891205; AU 4593889 A 19891205; DK 612489 A 19891205; FI 895806 A 19891204; JP 31634289 A 19891205; KR 890018089 A 19891205; NO 894831 A 19891204; PT 9249289 A 19891205; US 28024088 A 19881205