When was Arthur Grandjean born?

Answer 1

There is no biographical info on this person, an accountant for the French plastics firm MAI in 1959.

He was once erroneously credited as the inventor of the Etch-A-Sketch drawing toy, invented in France around 1957 by Andre Cassanges.

Answer 2

Note, for further information, SEE:
Andre Cassagnes dies at 86; Etch A Sketch inventor: A French electrician, Cassagnes invented the drawing toy in Paris in the late 1950s. When an Ohio firm introduced it in 1960, it became a hit, ranked one of the top 100 toys of the century.Published February 02, 2013byValerie J. Nelson, writer for the Los Angeles Times.

Andre Cassagnes died died Jan. 16, 2013 "in a Paris suburb, the Toy Industry Assn. announced." "Since he couldn't afford to pay for a patent, he borrowed money from an investor who sent his treasurer, Arthur Granjean, to complete the paperwork. But Granjean's name ended up on the patent, helping to obscure Cassagnes' role. When the New York-based National Toy Hall of Fame inducted Etch A Sketch in 1998, it wrongly listed Granjean as the toy's creator.

An official history on Ohio Art's website gives Cassagnes credit for the invention."

SEE also this text which quotes two source documents from the Ohio Art Company (see bottom half of the page):

"During 1957-58 time frame, after deciding upon a satisfactory design, Cassagnes sought advice on potential manufacturers of his concept. He initially presented his proposal to Nion Company, a plastic injection molder, located in his hometown of Vitry. Philippe Mayer, who later became involved in distributing the Telecran Drawing Toy and, who introduced Bill and Susan Killgallon to André Cassagnes in June, 2006, coincidently worked for Nion Company.Nion Company management had no interest in producing the drawing toy concept for Cassagnes, but did refer him to Paul Chaze, owner of another smaller plastic injection molding company named MAI. This company produced automatic cigarette rolling devices and was also conveniently located. MAI produced the initial tracing device samples.Paul Chaze agreed to invest in and produce the initial tooling as well as agreeing to loan Cassagnes the funds to officially register his patent. Not being familiar with legal matters, Cassagnes permitted Chaze to prepare and send the paperwork on 5/28/59 to the French Ministre De L’Industrie. Unbeknown to Cassagnes at the time, Chaze instructed his accountant, Arthur Grandjean, to file and pay for the “tracing device” patent, which is why Grandjean’s name appears on the French #1,242,370 and U.S. #3,055,113 “Letters Patent” certificates.Grandjean soon thereafter assigned the French patent rights to Paul Chaze, who proceeded to arrange for the manufacture, marketing and licensing of the drawing toy."