A few things about patents mentioned here.
Claiming Patent Pending, when there is no application on file is against the law. In order to be patent pending, you must have either a formal patent application or a provisional patent application on file with the patent office.
Patents do have a life span. Once a patent is expired, the claims now become public domain and anyone can use them. Most don't realize this, but the patent system was designed to get ideas out into the public domain. They do this by offering exclusivity and protection for a period of time, after which it's completely open to the public. If you have something and want to own it forever, then you just have to keep it a secret. The best example of that is the formula for Coca Cola. It's probably the best kept secret of all time, and it's not patented. If it was, it wouldn't be a secret any more.
As for making something around an existing patent, it really depends on how well the patent was written. If it's done well, then the key elements that really make the product what it is are very well protected without including non key elements that aren't necessary. I've seen many terrible patents. It's pretty tough to write a good one because it requires both the legal knowledge as well as the technical knowledge of the product.
I would say that the opener shown here would probably be a better candidate for a design patent than for a utility patent.
Anyway, I think it looks cool!
Royce