Did ole kirk christainsen crate any other inventions?

Ole Kirk Christiansen, the founder of LEGO, is primarily known for creating the interlocking plastic brick system that revolutionized the toy industry. While he initially produced wooden toys and household items, his most notable invention remains the LEGO brick itself, introduced in 1958. Christiansen's focus was on enhancing play and creativity, leading to the development of various LEGO sets and themes over the years, but the core invention of the brick is his most significant contribution.