From what I have read, the 40 hour work week was not invented by the workers, but by the companies themselves.

Ok, I think it's becoming increasingly obvious you don't know how the 40 hour work week came to be, country by country. There were huge worker movements for decreasing the work hours. Many countries achieved these working conditions only eventually and by getting an appropriate labor reform law passed. And the stories behind such laws differed vastly depending on the country.

So I am forced to ask -- what is it that you have been reading? Can you link it?