Power transmitting apparatus

A power transmitting apparatus comprising:

• an electrically operated motor having a shaft which is rotatable in opposite directions;
• a worm-gear provided at an outer periphery thereof with a geared portion at which an angle of load is established at a set value so as to be larger than an angle of friction and fixedly mounted on said shaft of said motor;
• a worm-wheel provided at an outer periphery thereof with a geared portion which is in mesh engagement with said geared portion of said worm-gear;
• a lever operatively connected to said worm-wheel for transmitting the rotational torque therefrom to a driven member;
• and
• a return mechanism for returning said worm-wheel to an original position after rotation of said worm-wheel, said return mechanism including an expanding spring, a guide means for accommodating said expanding spring, said guide means having a narrowed portion, a prominence formed on a lower surface of said worm-wheel and extended into said narrowed portion, and a pair of equally pitched projections formed on an upper surface of said worm-wheel, each of said projections being engagable with said lever after rotation of said worm-wheel.