Shaft seal with clinch-butt metal case and method of making same

A radial lip shaft seal including, in combination:

• a rigid generally cylindrical reinforcing case having a cylindrical portion with a free end, a flange portion extending radially from said cylindrical portion at an end thereof opposite said free end, said flange portion also having a free end,
• said case being formed initially from a flat rigid rectangular strip bent along its major axis to define said cylindrical portion and said flange portion, the ends of said strip defining a continuous parting line extending throughout the axial length of said case including said cylindrical portion and said flange portion, the ends of said strip along the parting line within the area of said cylindrical portion being in abutting engagement with one another, and the ends of said strip along the remainder of said parting line within the flange portion being in spaced relation with one another, elastomeric seal means supported by said case and including a main body portion bonded to said case and a shaft engaging main lip portion integral with and extending radially inwardly from said main body portion, and preventive means for preventing egress of lubricant from said parting line, said preventive means including said main body portion completely covering at least the entire said parting line along said cylindrical portion of the case and completely covering at least one of said free ends of the case, and
• said main lip portion including a continuous, inseparable, circumferential lip adapted to engage a cylindrical shaft at an uninterrupted edge defined by the intersection of two radially inwardly mutually converging surfaces of said main lip portion.