Chair base

Abstract

An anti-tipping chair base has a central support member with a generally upright axis, and a plurality of arms that extend generally radially outwardly from the axis and each of which is provided with a caster. An outer end portion of the arm has a shape that curves downwardly around the caster to an end edge outwardly of the caster. As seen in plan, the outer end portion of the arm has side edges that diverge in a direction towards the end edge and between which the end edge extends generally normal to the radial direction of the arm. The end portions of the arm comprise support elements that contact a surface on which the base is disposed in the event that the base tips in use.

I claim:  
     
         1 . An anti-tipping chair base comprising a central support member having a generally upright axis, and a plurality of arms that extend generally radially outwardly from said axis and each of which is provided with a caster adjacent an outer end portion of the arm, wherein said outer end portion of each arm has a shape that curves downwardly around the caster to an end edge outwardly of the caster and that is defined as seen in plan by side edges that diverge in a direction towards said end edge and between which said end edge extends generally normal to the radial direction of the arm, said end portions of the respective arms comprising support elements for contact with a surface on which the base is disposed in the event that said base tips in use.  
     
     
         2 . A chair base as claimed in  claim 1 , wherein the outer end portion of each arm comprising a said supporting element is fork-shaped, comprising a pair of divergent limbs and a transverse bar connecting outer ends of said limbs.  
     
     
         3 . A chair base according to  claim 2 , wherein the connecting bar is arcuate in a direction outwardly from the axis of the central support member.  
     
     
         4 . A base according to any one of the preceding claims, wherein the outer end portion of each arm comprising said support element is a component separate from the remainder of the arm.