Vintage tomy train

They are not related to Lego, but they are, or were, intended to be compatible with Lego.
I've often wondered if Tomy had to pay any kind of patent / copyright fee or similar, to Lego.
Maybe they simply engaged in a partnership, to further promote the Lego brand by making the Tomy trains compatible with it ?

i found this pic on ebay years ago. the blurb mentions about lego and tyco building blocks.



the red diesel set from this advert is what i got started on. the thing i love about the vintage gears, is you never know whats inside! some ive opened have been plain white, others a mix of greens and some look like that vegetable pasta, lol. i love the mystery. the same stands for the big loader chassis too.