United States Patent im
[li] Patent Number: 4,513,195  Date of Patent: Apr. 23, 1985
 METHOD AND APPARATUS FOR THE LATERAL POSITIONING OF A MEMBER RELATIVE TO A JOINT
 Inventor: Jean-Marie Detriche, Saint Germain en Laye, France
 Assignee: Commissariat a I'Energie Atomique, Paris, France
 Appl. No.: 532,394
 Filed: Sep. 15,1983
 Foreign Application Priority Data
Sep. 15, 1982 [FR] France 82 15569
 Int. C1.3 B23K 9/12
 U.S. Q 219/124.34; 318/576;
 Field of Search 219/124.34, 124.22;
 References Cited
U.S. PATENT DOCUMENTS
4,206,391 6/1980 Varacins 318/576
4,441,010 4/1984 Cornu et al 219/124.34
FOREIGN PATENT DOCUMENTS
0036358 9/1981 European Pat. Off. .
0064454 11/1982 European Pat. Off. .
1615529 12/1970 Fed. Rep. of Germany .
2267854 11/1975 France .
Primary Examiner—Clifford C. Shaw
Attorney, Agent, or Firm—Obion, Fisher, Spivak,
McClelland & Maier
The invention relates to a method and apparatus for the lateral positioning of a member relative to a joint formed between two metal surfaces and having discontinuities.
Use is made of an eddy current sensor having at least two probes staggered in the direction of the joint. The signals supplied by each probe are processed separately to obtain a signal representing the lateral displacement. By comparing said signal with a given threshold below the amplitude of the signal in the presence of a discontinuity, it is possible to only transmit to a servomotor signals which are below this threshold, which correspond to an effective measurement of the lateral displacement.
Application is to automatic welding machines. 12 Claims, 9 Drawing Figures