Clothes dryer having variable position motor and moisture sensor

Claim 1

In a clothes dryer including a housing having a drying chamber, a perforated clothes drying drum of a electrically conductive material which is electrically coupled to a common potential, rotatably mounted in the drying chamber of the housing, a motor mounted in the housing, means, including a hollow drum drive shaft, coupled between the motor and the drum for rotating the drum, the drum being substantially cylindrical and having a central axis with the hollow drum drive shaft being substantially aligned with said drum axis, a heater mounted in the housing, and means driven by the motor for drawing air past the heater and through the perforated drum and drying chamber and for exhausting the air from the housing, a moisture-sensing arrangement comprising: a cone assembly forming a central portion of a rear wall of the drum including a frusto-conical electrically conductive cone body extending into the drum and electrically coupled thereto and to the housing, an electrically conductive tip mounted on and forming the tip of the cone body, and an insulator interposed between the electrically conductive tip and the cone body, the cone body and the insulator and the electrically conductive tip forming a continuous, relatively smooth generally conical surface in the interior of the drum, the electrically conductive tip being aligned with the axis of the drum and the hollow drum drive shaft, an electrical conductor coupled to the electrically conductive tip and passing through the cone and within the hollow drum drive shaft out of the housing terminating in an electrical contact, the contact and the conductor and the cone assembly being mechanically coupled together to rotate with the hollow drum drive shaft, a contact arm mechanically secured to the housing and electrically insulated therefrom having an end portion contacting the rotatable electrical contact which terminates the conductor, the contact arm being electrically coupled to means for producing an electrical potential which is coupled through the contact arm and the conductor to the tip so that the tip receives an electrical charge relative to that of the drum and the housing, the contact arm being further coupled to means for measuring electrical current flow between the tip and the drum in response to moist clothing in the drum contacting the tip and the electrically common cone and drum.