As it turns out, there are as many origin stories for barbecue as there are spellings of the word on neon signs. These explanations range from a linguistic attempt to connect barbecue to boucan (also French) to a tall tale tracing barbecue to a Texas rancher who happened to brand the initials B.Q. on his livestock.
Patent protection usually ends when the patent expires. Here are the expiration dates: For all utility patents filed before June 8, 1995, the patent term is 20 years from date of filing, or 17 years from date of issuance, whichever period is longer.
Researching expiration dates and terminal disclaimers in a patent family that takes two patent pages to explain is too large a task for idle curiosity. So, the idle curiosity answer is that the important SawStop patents probably expire somewhere around 2021, give or take two or three years. Remember, it would be foolish to use this information for anything other than satisfying idle curiosity or impressing friends at the TechShop.