Well done Dieter
I didn’t know that there was a need for such a product, but apparently when milking cows, serious eye injury can occur from the switching of the cow tail. The device below is a cow tail holder, when in use the larger end clamps to the leg and the other end attaches to the tail.
It was patented in 1891, number 444,428, over 100 other patents for a wide range of contraptions that perform the same task can be found on Google patents.
According to a site, the inventor of a cow tail holder estimated that between 15,000 and 20,000 milkmaids or milkmen received severe eye injuries each year.
Safe Work Practices on a Dairy Farm has more information on the risks and dangers of dairy farming.