The track fitting of seats installation currently offered by the worldwide market does not offer proof installation against errors due to human mistakes, as a mere example, forgetting to fasten the fitting screws or not placing it properly into the track's holes.
The background art patents currently known are US No 2007/0228215 and FR No 2735443; they refer to seats track fittings endowed with a main body, in which the lower portion may be fitted into the track and locked with fitting screws to switch from the scrolling position to a blocked position on the track.
In the above mentioned documents the fitting screws work along with an axis substantially vertical, moreover there aren't any safety devices able to avoid the unintentional unlocking of the device from the tracks. Moreover, the known fitting systems do not have a safety block in case of worn out tracks. In particular, in the US patent application the seat track fittings are locked in the tracks after they have been lifted up towards the inner surface of the track, not allowing the option of regulating the track fitting, but with fixed blocking sizes so that in case of variation of the thickness of the track, for example because of wearing out, no adjustment during the fitting of the screw is possible, therefore the blockage of the system does not occur in safety terms, due to default of adaptation to wear conditions.