Abstract: A spring mechanism for returning a seat plate to a desired angular position relative to a toilet seat includes a rotatable pivot shaft mounted on the toilet seat and interactable with the seat plate so that the shaft is rotated whenever the seat plate is rotated over its angular travel, a first spring interconnecting the toilet seat and the pivot shaft for biasing the seat plate towards the desired angular position, and a pawl engageable with the rotatable pivot shaft as the pivot shaft is urged by the first spring to rotate in a first direction for moving the seat plate to the desired angular position. The engagement temporarily holds the rotation of the seat plate in the first direction for a period of time until the pivot shaft disengages the pawl due to the spring force exerted thereon by the first spring. In an exemplary toilet seat embodiment according to an aspect of the invention, when the seat plate returns to the desired angular position, the seat plate can be sterilized automatically.