Operationally reliable parking valve

A parking valve for manually actuating a spring-loaded parking brake, comprising:

• a housing with a port that is fluidically connectable to a release chamber of a spring-loaded brake cylinder, a port that is fluidically connectable to an air reservoir, and a vent port;
• a slide configured for manual actuation and being movable along an overall path between two end positions inside the housing, wherein the slide is configured to assume positions along the overall path in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the vent port, and to assume other positions along the overall path in which, as a result of the at least one seal, there is no fluidic connection between the port to the release chamber and the port to the air reservoir;
• and
• an inhibiting device, which, during movement at least along a partial path of the overall path, is configured to act on the slide in at least one direction with a continuously variable counterforce dependent on the position of the slide on the partial path,
• wherein
• the inhibiting device is configured to subject the slide, over a path section of the overall path which does not form part of the partial path, to an assisting force, dependent on the position of the slide on the path section, in the direction of the movement, or to no force,
• the inhibiting device has a chamber having an equalization channel, the chamber being
• fluidically closed by the slide and a part of the housing when the slide is moved over the partial path, and
• connected to the atmosphere or to a venting device via the equalization channel only when the slide is moved beyond the partial path,
• the chamber is designed to change volume in accordance with the movement of the slide, and
• the inhibiting device is designed to subject the slide to a counterforce which is formed by a vacuum and which increases in a first direction of movement since a volume of the chamber increases or which is formed by an excess pressure and which increases in a second direction of movement since air in the chamber is compressed giving rise in the chamber to the excess pressure.