Leave-In Probe Thermometer: Stainless Probe on a Flexible Lead to a Programmable Timer (Chapman, US 6,568,848, 2003)

A meat thermometer you leave in the roast. A pointed stainless steel probe stays in the meat. A flexible lead runs out of the oven to a battery timer unit with a display, keys and a beeper. You pick the meat and how well done you want it; the unit shows the temperature and the time left, and beeps when it is done. Result: continuous reading of the inside of the meat without opening the oven. Source: P. A. Chapman and C.-A. Chang (Maverick Industries), US 6,568,848 (2003). The patent's main form sends the readings by radio; it also states this wired form. Unknown: the sensor, the circuit, the target temperatures and the materials. Picture: the patent drawing.