Hub construction for a rotatable chair
AssigneeAF Solutions Ab Oy
InventorFredrik Kjellman
Life of this patent
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Abstract
The invention relates to a hub construction for a rotatable chair, which automatically returns to the initial position when the chair is relieved. In a prior art hub the return force was counteracted mainly by the friction in the hub bearing, which, regardless thereof that the hub was loaded, was not always sufficient for the hub to maintain its rotational position, for example, when the sitting person lifted his feet off the floor. For obtaining higher friction when the hub is loaded, it has been provided with a brake. The brake can preferably be a pair of spring discs which are compressed when the hub is loaded, whereby the brake disc makes contact with the brake surface.
Claims5
A hub construction for a rotatable chair, which automatically returns to its initial position when the chair is relieved, comprising a vertical shaft fastened to the underside of the seat of the chair, and a hub on the leg portion of the chair, to which hub the lower portion of the shaft is rotatably fastened, whereby the return movement is achieved by means of a cam surface acting in the axial direction on the end of a spring loaded sleeve enclosing the shaft, which cam surface is arranged to cooperate with a radially directed guide pin, which is fastened to the lower portion of the shaft and the spring loaded sleeve is mounted rotationally rigidly on the hub characterized in that the shaft is arranged movably in the axial direction in its bearings in the hub, and a spring device and a brake disc are arranged in the hub in such a way, that when the shaft is vertically loaded, the shaft is displaced in the axial direction, and the spring device is compressed such that the brake disc makes contact with a surface on the hub.
Dependencies are inferred from the claim text.