To infringe on a copyright your product must be almost identical. The key is in the writing of the claim. You cannot patent the idea of leveling a cake. You must patent specific claims....otherwise there would only be 1 type of everything on the market. There are vast differences in my design. The way my blade is adjusted, the fact that it will have 3 blades rather than 2. The fact that the best on the market can be adjusted to 1/8 of an inch whereas mine will only go to 1/4 of an inch. They are not marketed to the same crowd and will not be set in the same price ranges. Are the Fat Daddio and Wilton patent copies? No. Is the Ford and the Chevy copies? They both do the same thing, right? http://inventors.about.com/od/patentsbasics/a/PatentClaims.htm
" In analyzing each claim, each element of the claim must be contained in the infringing device in order to show literal patent infringement. If even one element of the claim is missing from the allegedly infringing device, there is no literal infringement."
There are many things others do to make the product easier to use that mine does not. Therefore I would not meet all of the claims in another brands patent application.
Additionally for there to be a patent infringement I must be selling the item. Which I am not currently doing., and will not be doing until I have applied for my own patent.