Brewing head of a hot-beverage preparation device, preparation device having a brewing head and operating method for said preparation device

A hot beverage machine comprising:

• a brewing head including a fixed brewing chamber part, a movable brewing chamber part movable in relation to the fixed brewing chamber part to define a brewing chamber for receiving a substrate capsule, a locking system for closing the fixed and movable brewing chamber parts to form the brewing chamber, and a seal for pressure-tight sealing of one of the two brewing chamber parts and the substrate capsule during beverage preparation, wherein the brewing chambers has three operating positions comprised of an opening position for loading the brewing chamber, a partially closed position in which the brewing chamber is closed and the seal is detensioned, and a closed position in which the brewing chamber is likewise closed and the seal is tensioned;
• and
• the locking system including a pre-locking facility for locking the fixed and movable brewing chamber parts together in the partially closed position.