I'm the translator for this story. I will do my best to answer!
Are you referring to God Thor's Hammer, Mjolnir? I'm not very familiar with the Norse hero stories, so I had to look this up online. But if this is what you are referring to, let me try to answer. It seems that the Japanese spelling for Mjolnir is myo-ru-ni-ru. But the machine in this story is called mi-ru-nyu-ru. It sounds very similar so I understand why someone might get confused if they did not see the small change or are unfamiliar with the Japanese spelling of Mjolnir. From my guess, I believe the name of the machine mi-ru-nyu-ru is a combination of mi-ru-ku (milk) and nyu-ru (the sound of something being shot out of something long). So maybe the most literal translation is that the name of the machine is the "Milk Squirt" machine. But when I translated this to English, it did not sound very cool. In Japanese, putting two or three words together to name something is normal, but in English, it sounds strange, I think. But since this is just translating a name, it could be called anything and would not effect the translation. So I decided to keep the word "milk" and call it the "milkmaid" since it fit the theme, and also sounded like something that someone who spoke English might name a machine. I thought it sounded more cool to call it the "milkmaid". But maybe calling it Mjolnir is even cooler! But Thor might sue me!!!
@SecretHimiko Yeah, to me it sounded like a combination of "milk" and "Mjolnir", with it being reffered to as a "hammer-like apparatus" it all made sense to me. I thought it was a pretty clever gag name, though I wasn't sure if I'm seeing things. But I see wherea are you coming from, I also wouldn't want to cross the god of thunder.
You had a question before about english about "go off". When the words are together like that, it is almost always going to mean to become active or trigger. An alarm can go off (ring), a bomb can go off (explode), a person can go off (slang, meaning they are 'exploding' in emotion towards something).