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 automatically rotates during assembly and thus torsionally tensions the torsion spring as the first and second structural members, the torsion spring and the anchor member are assembled together in a coaxial direction.
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, wherein the pre-tensioning device includes angled surfaces and mating surface on the anchor and on at least one of the structural members, the angled surfaces forming ramps that engage the mating surfaces to thus angularly rotate the torsion spring relative to the first and second structural members during coaxial assembly of the anchor to the structural members.
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, wherein the torsion spring has an inner member keyed to the first structural member, an outer member keyed to one of the second structural member and the anchor, and an elastomeric member located between the inner and outer members.
A jointed apparatus 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 forming ramps on at least one of the pre-tensioning device and the structural members that inter-engage mating surfaces on another of the pre-tensioning device and the structural members to automatically rotate the second section during assembly to pre-tension the torsion spring during coaxial assembly.
Dependencies are inferred from the claim text.