This chair was designed by 1950. If you apply for a patent, it will have expired long ago, but the copyright or copyright of his design still exists. In China, the copyright term is 50 years, so it can be copied. In China, if you want to copy and export to other countries, you should check the copyright validity of the country you are going to.
Sorry, the copyright or copyright is 50 years after the death of the original author.