Engineering around a lose/vague patent if you find a good patent attorney isn't that difficult. Also remember that even if you violate a patent, most patent's aren't enforced because the company owning the patent doesn't have the resources to file suit or no longer exists.
Read the claims within the patent, if yours varies from the written claim or can modify it in such a way then you have little worry (depending on the company). For the best advice find a patent attorney and talk to them. There are entrepreneurial law firms that will give you an hour or two for free in the hope of future business. This is what I did when I was starting out. Bring in the potential patents and your idea and get advice from an expert. Trust me you'll save a lot of time.
Read the claims within the patent, if yours varies from the written claim or can modify it in such a way then you have little worry (depending on the company). For the best advice find a patent attorney and talk to them. There are entrepreneurial law firms that will give you an hour or two for free in the hope of future business. This is what I did when I was starting out. Bring in the potential patents and your idea and get advice from an expert. Trust me you'll save a lot of time.