The invention relates to a method and an apparatus for encoding images, more particularly to an encoding unit in conjunction with a library of pictorial entities and image qualifiers. The outer ends of the rail bar members are connected to legs of the shelter by fixed corner connecting brackets. At least one of the at least one axial labyrinth and the at least one radial labyrinth which form the labyrinth seal is formed between an outer-ring-side sealing member mounted to the outer ring and the inner ring or between the outer-ring-side sealing member mounted to the outer ring and an inner-ring-side sealing member mounted to the inner ring. In the embodiment using a winch, one or more flexible, non-stretchable bands are provided for wrapping around the casing and pulling the casing into alignment, with the flange acting as a fulcrum. The control unit may be reconfigured with a different lock level by an administrator only when a security sequence is entered. The water flushes the cleaner head into the pool and rotates the hose reel in a first direction, causing the hose to unwind and travel into the pool.