Driveshaft coupling with elastomer damper

Claim 1

A driveshaft coupling characterized by its vibration damping characteristics comprising, in combination, an elongated drive member having an axis of rotation, an outer end, an inner end, and an elongated central stem, a universal joint receiving yoke defined upon said outer end, said stem having four first flat surfaces extending the length thereof defining a rectangular transverse cross section and each surface having a width and length, an elongated tubular driven member surrounding said stem having an internal bore, an outer end and an inner end located adjacent said drive member inner end, said driven member internal bore comprising four second flat surfaces extending the length of said stem defining a rectangular transverse cross section complementary to said drive member transverse cross section, each first flat surface being in opposed radially spaced substantially parallel relationship to a second flat surface, an elastomer pad interposed between opposed flat surfaces each having a width, length and normal non-compressed radial thickness, the width of said pads being slightly less than the width of said first flat surfaces and said opposed first and second surfaces being radially spaced from each other a distance less than said normal pad radial thickness whereby said pads are under compression, a propeller shaft concentrically affixed to said driven member, a radially disposed thrust bearing interposed between said outer ends of said drive and driven members, a metal insert mounted upon said drive member inner end and maintained thereon by fastening means, said insert engaging said driven member inner end axially forcing said driven member toward said thrust bearing, said insert including means for preventing axial displacement of said driven member relative to said drive member and an axially extending tubular portion having flat outer surfaces complemental to and closely engaging said second surfaces preventing relative rotation between said insert and said driven member, said tubular portion further having rectangularly related inner surfaces in opposed radially spaced relation with said first surfaces, the radial spacing between opposed inner surfaces and said first surfaces being less than the radial spacing between said first and second surfaces whereby said first and inner surfaces are engageable upon a predetermined relative rotational movement between said drive and driven members to establish a direct torsional driving relationship between said drive and driven members.