An automatic product vending machine is provided where the user can withdraw the selected product directly from the machine, the storage area for the products is a rack and the dispensing device of the single product is a frame on which a pusher is mounted which causes the selected product to fall into a tray, which positions the product at an opening which permits its withdrawal by the user. The computer chassis secures a plurality of expansion cards and includes a cover. A resistance heater is helically wound around the exterior cylindrical surface of the heat pipe, and rests between the inner cylindrical surface of the fusing roller and the exterior cylindrical surface of the heat pipe.