Patent ID: 7422200

Claim:
A ring bearing, comprising: an upper casing; a lower casing; and a plastic ring engaged between the upper and lower casings, thereby forming said ring bearing; said upper and lower casings respectively defining upper and lower annular facing surfaces for engaging said plastic ring therebetween; said upper and lower facing surfaces each having radially inner and outer portions; said upper and lower facing surfaces each being substantially curved in a direction between said inner and outer portions thereof; said plastic ring having upper and lower spacing portions, each being centrally located between said inner and outer portions of said upper and lower facing surfaces, thereby defining respective spaces oriented longitudinally of said ring between said plastic ring and said upper and lower facing surfaces which reduce contact friction with the respective facing surfaces; and additional grooves or recesses in the upper and/or lower surfaces of the plastic ring which further reduce contact friction with the respective facing surfaces of the upper and lower casings.