From the linked page...
//August Claas had already developed and marketed a tractor-like “carrier for a range of tools and implements” in 1957, called the “HUCKEPACK”. This was a self-propelled combine harvester, which could be converted into an implement carrier once the harvest was over. It was designed for use all year round, as the ultimate “all-purpose” machine, but it remained in production only until 1960.//
I was hoping that may have answered the query, sorry if it doesn't.