US Patent 7731042 Closure with hinged lid and stress relief recesses

A closure is provided for a container opening. The closure includes a body for mounting to the container and a lid movable between a closed position and an open position. The lid and body are connected by a bistable, snap-action hinge structure having a web between two hinges. Stress-relief recesses are provided at an end edge of either the body hinge or the lid hinge or both.