US Patent 11184974 Operating device and household appliance having the operating device

An operating device contains a cover plate having an opening, a rotatable operating element having an operating head on the cover plate, and a shaft running through the opening. Behind the cover plate and at a distance therefrom, there is a circuit board having an opening through which the shaft extends. The operating device includes a tube element which has a hollow-cylindrical base body that runs, between the cover plate and the shaft of the operating element, at least partially through the opening of the cover plate, and a radial inner side that forms, between the tube element and the shaft of the operating element, an inner flow channel that runs through the opening of the cover plate and past the opening of the circuit board, to protect the circuit board against extraneous substances which may enter the operating device through the opening of the cover plate.