Patent ID: 8801320

Claim:
A joint device comprising: a housing having a slide surface and a guide surface; a first rotating member supported for rotation by the housing; a slide member supported for movement on and relative to the slide surface; and a spring member supported on the slide member, the spring member having a spring arm operatively coupled to the first rotating member, and a second spring arm arranged for movement along the guide surface as the slide member moves along the slide surface; a gear member arranged in a fixed relation to the first rotating member, for rotating with the first rotating member, the gear member having a plurality of gear teeth; wherein the slide member has a plurality of teeth arranged to engage gear teeth of the gear member, such that rotation of the gear member with rotation of the first rotating member causes the gear member to move the slide member in a linear direction along the slide surface; wherein rotation of the first rotating member with respect to the housing causes the spring member to impart a bias torque on the first rotating member, the bias torque having a magnitude that changes as the slide member moves linearly along the slide surface.