Patent ID: 7552626

Claim:
A fuel filter comprising a device for indicating clogging of the fuel filter of internal combustion engines, the filter comprising an outer casing closed by a cover of amagnetic material, and a filter element which, together with a disc to which said filter element is connected, defines two chambers for fuel entry and exit respectively, said device comprising a pressure sensor means sensing the difference between the entry and exit fuel pressure and housed inside the filter outer casing, and a means for generating a signal proportional to said pressure difference which is not mechanically connected to the pressure sensor means and is located outside the filter casing, characterised in that the pressure sensor means comprises an elastically deformable element which defines a variable volume inside the fuel entry or exit chamber; a conduit which connects said volume to the other chamber; and a magnet which, associated with said elastically deformable element, moves to follow the elongation or contraction of said elastically deformable element, whereby said elastically deformable element is composed of an extendable membrane.