Earthquake-damping rack

Abstract

A plurality of column members 6 a, 6 b of a rack are joined with an earthquake-damping joint 21. The earthquake-damping joint 24 comprises a deformation portion 24, which is narrower so as to gain increased plastic formability, and a pair of fixing portions 26, which are strengthened with increased thickness, to join an upper joint section 20 a and a lower joint section 20 b with a plurality of bolts 28 or the like. Said deformation portion 24 is deformed by the horizontal stress applied in the direction perpendicular to the longitudinal direction of the rack and the upper column member 6 a moves upwardly, absorbing the vibration energy. Said fixing portions 26 are strengthened by increased thickness so that the bolts 28 do not yield to the shock.

1 . An earthquake-damping rack comprising a plurality of columns, each column composed of an upper column member and a lower column member combined by a joint which comprises an upper joint and a lower joint, with at least one of the upper joint and the lower joint having a deformation portion that allows the upward movement of the upper column member through deformation, and a plurality of fixing portions that are stronger than the deformation portion.  
     
     
         2 . An earthquake-damping rack as in    claim 1   , wherein the upper joint and the lower joint are superposed, the deformation portion made narrower or thinner than the fixing portion.  
     
     
         3 . An earthquake-damping rack as in    claim 1    or    claim 2   , wherein the length along the longitudinal direction is substantially longer than the length along the depth direction, and the deformation in the deformation portion of the joint damps the vibration caused by the horizontal stress applied in the direction perpendicular to the longitudinal direction.  
     
     
         4 . An earthquake-damping rack as in    claim 1   , wherein the upper joint and lower joint are superposed, the deformation portion having grooves or holes.  
     
     
         5 . An earthquake-damping rack as in    claim 1   , wherein the upper joint and the lower joint are superposed, and the fixing portions have ribs installed for the reinforcement.  
     
     
         6 . An earthquake-damping rack characterized in that the columns are divided at a position at least lower than the middle of the whole height of the columns, and the upper column member and the lower column member are joined with the joints that allow upward movements of the upper column members.