Take-up devices for use in building structure

Abstract

A take up device for a building structure, e.g. holdown for securing the building structure to a foundation, has a housing secured by fasteners to the building structure, the housing defining a cylindrical chamber containing a piston and fluid, with a piston rod projecting from the housing. The piston rod is connected to a foundation anchor, and a fluid passage interconnects portions of the cylindrical chamber at opposite sides of the piston. The fluid passage is provided with a one-way valve, which allows the housing to move upwardly relative to the piston, to maintain the tightness of the connection to the anchor bolt, but resists opposite movement of the housing.

We claim:  
     
         1 . A take up device, comprising: 
 a housing;    said housing defining the cylindrical chamber within said housing and said cylindrical chamber having a cylindrical wall;    a piston within said cylindrical chamber, said piston having a piston rod projecting from said housing; and    a fluid within said chamber;    a one-way valve which is deflectable by pressure of the fluid to prevent displacement of said piston and said piston rod in a first axial direction along said cylindrical chamber toward said anchor and resisting displacement of said piston and said piston rod in an opposite axial direction along said cylindrical chamber;    fasteners for securing said housing to a building structure; and    an anchor for securing said take up device to a building foundation; and    a connector between said anchor and said piston rod.    
     
     
         2 . A take up device as claimed in  claim 1 , including a fluid passage interconnecting portions of said cylindrical chamber at opposite sides of said piston.  
     
     
         3 . A take up device has claimed in  claim 1 , wherein said fluid passage extends through said piston.  
     
     
         4 . A take up device as claimed in  claim 2 , wherein said fluid passage extends within said housing and outwardly of said piston.  
     
     
         5 . A take up device has claimed in  claim 2 , wherein said fluid passage extends exteriorly of said housing.  
     
     
         6 . A take up device as claimed in  claim 1 , wherein said one-way valve comprises an annular seal of elastomeric material extending around said piston.  
     
     
         7 . A take up device as claimed in  claim 6 , wherein said annular seal has a cross-sectional shape having a first limb thereof in sealing contact with said piston and a second limb thereof in sealing contact with said cylindrical wall.  
     
     
         8 . A take up device as claimed in  claim 7 , wherein said cross-sectional shape of said O-ring has an intermediate portion abutting said piston and interconnecting said first and second limbs.  
     
     
         9 . A take up device as claimed in  claim 7 , wherein said cross-sectional shape of said annular seal has third and fourth limbs extending oppositely from said first and second limbs, said third limb sealingly contacting said piston and said fourth limb being in sealing contact with said cylinder wall and abutting said piston.  
     
     
         10 . A take up device as claimed in  claim 6 , wherein said piston has an annular surface and a peripheral projection forming an annular shoulder on said piston and a frustoconical surface portion converging from said annular surface, said O-ring normally extending around said annular surface in abutment with said peripheral surface and being displaceable from said annular surface to said frustoconical surface by the fluid on displacement of said piston and said piston in said first direction relative to said housing.