Heating and ventilating apparatus for the cabin of a motor vehicle

Heating and ventilating apparatus for the cabin of a motor vehicle having a windshield with a rear surface, wherein the apparatus comprises:

• an air inlet duct;
• an admission and heating circuit connected to the cold air admission duct for producing a stream of cold or heated air;
• a distribution circuit connected to the admission and heating circuit and having an inlet for the introduction of the cold or heated air stream, a plurality of air outlet ducts, and distribution means arranged between the said inlet of the distribution circuit and the said air outlet ducts thereof for distributing the said air stream into different parts of the cabin of the vehicle, with at least one of the said outlet ducts being open adjacent to the rear surface of the windshield for demisting the latter, and wherein the apparatus further includes:
• a priority demisting duct separate from the said distribution circuit, the priority demisting duct having an inlet communicating with the admission and heating circuit, together with an outlet disposed adjacent to the rear surface of the windshield;
• a first shut-off valve;
• means mounting the first shut-off valve for displacement of the latter between a priority demisting position closing the said inlet of the distribution circuit, and a normal position closing the inlet of the priority demisting duct;
• and control means operatively connected with the first shut-off valve, for controlling the displacement of the latter.