|warning: grill has tendency to cook on dark side|
There's no doubt that your grill would be a hot item. Darth Vader is the most profitable of the Star Wars characters -- a video of an unlicensed Darth Vader wood stove got 11 million hits on Facebook!
The Force won't be with you. We're not sure what you mean when you say your grill will make "no reference to the character." We're guessing that the point of your design is to conjure up Darth Vader in some manner. If it does so, even without using his name or his helmet, you'll soon have a Disney attorney breathing down your neck. That's because Disney is expecting to reap over $5 billion dollars in Star Wars merchandising next year -- far more than from movie tickets. And with so much at stake the lawyers who discover unlicensed merch will organize some claim to stop your stylized grill -- whether it is trade dress, false advertising, or copyright infringement. (Yes, we know copyright does not protect style per se, but courts have been swayed by strong style similarities.) Even if your design is so far removed from the character that you will prevail in court, we doubt whether you want to expend the time or money for your defense. For now, Star Wars chefs will have to make do with toasters, oven gloves, and waffle makers.