If you’ve ever used a laptop or a flip-phone (remember those?) you’ve experienced a constant torque hinge. When you open a laptop screen to just the right angle, and it stays there, that’s a Constant Torque hinge in action.
These innovative hinges can do much more than that, though. These hinges can be configured to provide more (or less) resistance in one direction, or asymmetrical torque. This is very helpful with heavy doors or lids that need to be operated easily.
Check out Southco’s website for more details on their constant torque hinges.