The parking brake device of a vehicle with emergency release as well as methods for operating such a parking brake device

The invention relates to a parking brake device 10 of a vehicle, in particular commercial vehicle, with emergency release and at least one spring brake cylinder 11 to release or insertion of a parking brake, a first electro-pneumatic parking brake circuit 14 having a first compressed-air reservoir 16 and a first control valve unit 17 for loading or venting the spring brake cylinder 11 having. Further, a second electro-pneumatic parking brake circuit 15 is provided for emergency release of the parking brake in case of failure of said first parking brake circuit 14, having a second compressed air reservoir 38 and a second control valve device 40 for venting the spring brake cylinder 11 in Notlosefall. The second control valve means 40 includes an output connected to the second compressed air reservoir 38 vent port 41, connectable to the atmospheric vent port 45 and connectable to the spring brake cylinder 11 third port 42. In order to improve the solubility of the parking brake in Notlosefall according to a first aspect of the vent port 45 of the second control valve means 40 is connected to a compressed air line 46 which terminates at an outer portion of the vehicle, whereby this compressed air line 46. compressed air from an external compressed air source 48 through the exhaust port 45 and the third port of the second control valve means 40 42 which ...