Sealing arrangement for the stem of suspended valves of internal combustion engines

Claim 1

A VALVE STEM SEAL FOR THE AXIALLY RECIPROCABLE VALVE STEM OF SUSPENDED VALVES, ESPECIALLY OF INTERNAL COMBUSTION ENGINES, IN WHICH THE VALVES STEM IS AT ONE END WITH A VALVE DISC AND IS GUIDED WITHIN A VALVE GUIDE, SAID SEAL COMPRISING: A FIRST TUBULAR PORTION HAVING OPPOSITE AXIAL ENDS; A SECOND TUBULAR PORTION HAVING OPPOSITE AXIAL ENDS AND BEING OF A SUBSTANTIALLY SMALLER DIAMETER THAN SAID FIRST PORTION; A THIRD ANNULAR NECK PORTION CONNECTED SAID FIRST AND SECOND PORTIONS AT THEIR ADJACENT ENDS; SAID FIRST PORTION AND SAID SECOND PORTION BEING SUBSTANTIALLY COAXIAL WITH RESPECT TO EACH OTHER; SAID SECOND PORTION INCLUDING AN ANNULAR PROJECTING SEALING LIP EXTENDING INWARDLY TOWARD THE VALVE STEM AND CONSTITUTING SEALING MEANS FOR SEALINGLY ENGAGING AROUND THE VALVE STEM; SAID FIRST PORTION CONSTITUTING SUPPORT MEANS FOR TIGHTLY ENGAGING AROUND THE VALVE STEM AND CONSTITUTING SEALING LIP; SAID SEALING LIP BEING LOCATED AT THE FREE END OF SAID SECOND PORTION SPACED A SUBSTANTIAL DISTANCE FROM THE CORRESPONDING ONE OF SAID ADJACENT ENDS; SAID SECOND PORTION CONSISTING ESSENTIALLY OF A RELATIVELY THICK PORTION ADJACENT SAID FIRST PORTION AND A RELATIVELY THICK REINFORCED PORTION HAVING SAID SEALING LIP TO CONSTITUTE MEANS FOR FIRMLY SUPPORTING SAID SEALING LIP AD FACILITATING RELATIVE RADIAL MOVEMENT BETWEEN SAID SEALING LIP AND REINFORCED PORTION AND SAID FIRST PORTION TO COMPENSATE FOR UNEVEN SPOTS AND ECCENTRICITY OF THE VALVE STEM; AND INCLUDING A RELATIVELY RIGID TUBULAR REINFORCEMENT SURROUNDING SUBSTANTIALLY THE ENTIRE OUTER CIRCUMFERENCE OF SAID FIRST PORTION AND SAID THIRD PORTION TO PROVIDE A RELATIVELY RIGID SUPPORT FOR SAID SECOND PORTION.