| 摘要 |
FIELD: furniture production, in particular, chair post and back supporting device. SUBSTANCE: chair base has sleeve with central axis and legs extending in radial directions from sleeve. Inner wall of sleeve defined by axial bore has upper conical portion extending between round first upper edge and round first lower edge. First upper edge has greater diameter that lower edge so that conical portion of inner wall is narrowing downward and inward. Inner wall has lower portion extending between second round upper edge and second round lower edge. Second upper edge of lower wall portion has diameter lesser than that of first lower edge of upper conical portion of wall. Annular wall portion is positioned between second upper edge of lower wall portion and first lower edge of conical wall portion to define step extending inward and adapted to engage lower end of pole, when pole is inserted into opening. As a result, pole is prevented from displacement downward through opening beyond predetermined point during usage of base. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. |
