Patent ID: 7147596

Claim:
A low-mass roller, comprising: a cylindrical body having an exterior surface, first and second open ends and defining an interior tubular space along a longitudinal axis therethrough for receiving an axle therein, said cylindrical body formed of polymeric material said cylindrical body having a diameter at said first and second ends that is smaller than a diameter thereof at at least one intermediate location along the longitudinal axis thereof with at least a portion of the exterior surface from the first end to the intermediate location and the second end to the intermediate location has a positive slope with respect to the longitudinal axis; and an outer shell formed of metal proximately and conformally covering said exterior surface of and having a formed circular opening surrounding each said first and second ends of said cylindrical body, wherein said cylindrical body, said outer shell and said circular openings are concentric with said longitudinal axis, said outer shell disposed about said cylindrical body after formation of said cylindrical body; wherein said outer shell comprises an assembly of first and second thin-walled tubular shells having inside diameters, at first respective ends thereof, equal within a predetermined tolerance wherein said first respective ends are joined together and welded; wherein said assembly further comprises a weld ring having an outside diameter smaller than said inside diameters of each said first respective end of said first and second thin-walled tubular shells by a predetermined value, said weld ring disposed between and nested within said first respective ends of first and second thin-walled tubular shells such that said shells are held in alignment during said welding.