Abstract: A mechanical timer switch assembly for replacing a mechanical on/off toggle switch includes a replacement cover plate having an inner and outer side and adapted to fit over and be attached to a conventional electrical receptacle box. The assembly also includes a mechanical spring actuated rotary timer switch having a spring, a rotatable shaft and a contact member which is movable by the shaft to open and close an electrical circuit. The spring actuated rotary timer switch is sized to fit into an electrical receptacle box and is fixed to the inner side of the replacement cover plate with a shaft extending through the cover. A knob having an indicator corresponds to time intervals indicated on the replacement cover plate to indicate the amount of time which will be elapsed by the movement of the timer before turning a light off.

Abstract: A mechanical timer switch assembly for replacing a mechanical on/off toggle switch includes a replacement cover plate having an inner and outer side and adapted to fit over and be attached to a conventional electrical receptacle box. The assembly also includes a mechanical spring actuated rotary timer switch having a spring, a rotatable shaft and a contact member which is movable by the shaft to open and close an electrical circuit. The spring actuated rotary timer switch is sized to fit into an electrical receptacle box and is fixed to the inner side of the replacement cover plate with a shaft extending through the cover. A knob having an indicator corresponds to time intervals indicated on the replacement cover plate to indicate the amount of time which will be elapsed by the movement of the timer before turning a light off.