Fastener assembly with axially slidable sleeve and floating retainer

A fastener comprising an elongated shank having an upper end with an enlarged driving head and having a lower tip end, said head having a lower side, said shank having a threaded section defined by a helical thread extending along said shank, said thread having upper and lower ends and having a predetermined major diameter, a sleeve having upper and lower ends, the inner diameter of said sleeve adjacent the upper end thereof being less than the inner diameter of said sleeve adjacent the second end thereof and being greater than the major diameter of said thread whereby said sleeve may be slipped onto said shank from the tip end thereof and slipped upwardly along said threaded section to a fully installed position in which the upper end of said sleeve engages the lower side of said head, said sleeve having a pre-installed position in which the upper end of said sleeve is spaced downwardly from the lower side of said head, the lower end of said thread being disposed no lower than the lower end of said sleeve when said sleeve is in said pre-installed position, and a resiliently yieldable retainer extending at least partially around the threaded section of said shank, said retainer fitting between two adjacent turns of said thread when said sleeve is in said pre-installed position and fitting between two different adjacent turns of said thread when said sleeve is in said fully installed position, said retainer being located nearer to the upper end of said thread when said sleeve is in said fully installed position than when said sleeve is in said pre-installed position, said retainer having an inner diameter and an outer diameter, the inner and outer diameters of said retainer being less than and greater than, respectively, the major diameter of said thread, the outer diameter of said retainer being less than the inner diameter of said sleeve adjacent the lower end thereof and greater than the inner diameter of said sleeve adjacent the upper end thereof whereby said sleeve is free to slide back and forth on said shank but is captivated against slipping downwardly off of said shank by virtue of the upper end of said sleeve engaging said retainer, the interior of said sleeve adjacent the upper end thereof being sized and shaped to compress said retainer radially inwardly against said threaded section and thereby prevent said retainer from being pulled downwardly off of said threaded section by a downward axial force exerted on said sleeve.