Torsional energy joint for seating unit
AssigneeSteelcase Development Corporation
InventorsRobert J. Battey, Gary L. Karsten
Life of this patent
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Abstract
A joint is provided that automatically pre-tensions itself during assembly. The joint includes first and second structural members, such as a back upright and a pivot link in a chair. A torsion spring bushing and a pair of threaded anchors pivotally connect the first structural member to the second structural member. The anchor and back upright include mating angled surfaces that inter-engage and rotate the torsion spring bushing during assembly in a manner that pre-tensions the spring bushing while engaging the anchors in a direction parallel an axis of rotation defined by the joint.
Claims21
A jointed apparatus comprising:
- first and second structural members;
- a torsion spring adapted to pivotally support and rotationally bias the first structural member relative to the second structural member about a joint;
- an anchor for holding the first and second structural members together;
- and
- a pre-tensioning device that torsionally tensions the torsion spring as the first and second structural members, the torsion spring and the anchor member are assembled together.
A seating unit comprising:
- first and second elongated structural members pivoted together and defining a joint;
- a bushing including a first section attached to the first structural member, a second section, and a torsion spring connecting the first and second sections;
- and
- a pre-tensioning device engaging the second section and the second structural member, the pre-tensioning device having angled surfaces that inter-engage to rotate the second section during assembly to pre-tension the torsion spring during assembly.
A method comprising steps of:
- attaching first and second structural members and a torsion spring together with an anchor to form a joint, including torsionally pre-tensioning the torsion spring simultaneously and increasingly as the anchor is tightened in a direction parallel an axis of rotation defined by the joint and the joint is assembled together.
Dependencies are inferred from the claim text.