Floor system with stell joists having openings with edge reinforcements and method

Abstract

A steel joist member for use in supporting floor structures giving great strength and convenience and improved acoustical performance having a web defining side edges and an axis, a flange on at least one side edge, openings through said web at spaced intervals therealong, having rounded ends and parallel linear sides, portions of said web displaced from said opening remaining attached integrally to the web by bend lines formed on the linear sides of the opening along axes parallel to the web axis, and forming reinforcing channels alongside the opposite sides of the opening. Also disclosed is a composite joist member made up of two such members joined together back to back with their openings in registration creating an H shape or an I shape. Also disclosed is a rim member for supporting the composite joists to form a floor structure. Also disclosed is a method of making such a floor joist member. Also disclosed is a floor panel system wherein floor panels can be prefabricated in a factory and transported to a construction site ready for installation in a building.

1 . A steel joist member for use in floor structures and having reduced weight, and improved acoustical performance characteristics as compared with solid web steel joists, and comprising; 
 a web defining side edges and an axis;    a flange on at least one side edge;    openings through said web at spaced intervals therealong, of generally elongated oval shape, and defining curved ends and opposed linear sides;    edge flanges extending around said opening substantially at right angles thereto;    two bracing lip portions of said web being displaced from said opening and remaining attached integrally by edge flanges to said web along opposite linear sides of said opening;    a right angle bend in each said lip portion bent parallel to but displaced away from said web, thereby forming said lip portions into channel shapes in section for strengthening said joist in the regions of said openings.    
   
   
       2 . A steel joist member as claimed in  claim 1  including depressions formed in said web at spaced intervals, and openings formed in said depressions to reduce sound transfer through the joist.  
   
   
       3 . A steel joist member as claimed in  claim 1  wherein there are two said flanges one on each side of said web, being formed normal to said web, and lips formed along said flanges normal to said flanges.  
   
   
       4 . A steel joist member as claimed in  claim 1  said openings are identical and symmetrical, and are arranged in uniform aligned orientation and define between them transverse struts extending transversely across said web.  
   
   
       5 . A steel joist member as claimed in  claim 4  including openings formed in said web at opposite ends of each said strut.  
   
   
       6 . A steel joist member as claimed in  claim 5  including an embedment flange formed on a said edge flange on said one side of said web whereby to permit embedment in a concrete panel.  
   
   
       7 . A composite joist member formed of two steel joist members as claimed in  claim 1 , said two joist members being arranged back to back with their respective flanges extending away from one another, and with their openings registering with one another to form a composite joist member  
   
   
       8 . A steel joist as claimed in  claim 1  for partial embedment in concrete and including an angled flange formed with openings for flow of concrete therethrough, and a locking strip formed along said angled flange.  
   
   
       9 . A floor system for supporting a floor and comprising; 
 a plurality of composite steel joist member made up of two steel joists each said steel joist in turn comprising;    a web defining side edges and an axis;    a side flange on at least one side edge;    openings through said web at spaced intervals therealong, each said opening being of generally elongated oval shape, and defining curved ends and opposed linear sides;    edge flanges extending around each said opening substantially at right angles thereto;    two bracing lip portions of said web being displaced from said opening and remaining attached integrally by edge flanges to said web along opposite linear sides of said opening;    a right angle bend in each said lip portion bent parallel to but displaced away from said web, thereby forming said lip portions into channel shapes in section for strengthening said joist in the regions of said openings;    at least two rim members, each said rim member in turn comprising;    a web, and a support flange extending from said web at right angles;    a top flange for engaging a wall structure;    a plurality of tabs displaced from said web, for attachment to respective said composite joist members.    
   
   
       10 . A floor system for supporting a floor as claimed in  claim 9  wherein said composite joist members are formed with embedment flanges and locking strips along one of their sides, and wherein a portion of said embedment flanges and locking strips are removed adjacent said tabs, to facilitate interconnection with said tabs.  
   
   
       11 . A floor system for supporting a floor as claimed in  claim 9  wherein said rim member is formed with abutments for engaging sides of said composite joist members.  
   
   
       12 . A floor system for supporting a floor as claimed in  claim 9  wherein said rim members incorporate an upstanding edge flange.  
   
   
       13 . A floor system for supporting a floor as claimed in  claim 9  wherein said rim members incorporate an downward edge flange.  
   
   
       14 . A floor system for supporting a floor as claimed in  claim 9  wherein said top flanges of said rim members incorporate upstanding embedment loops.  
   
   
       15 . A floor system for supporting a floor as claimed in  claim 9  wherein said joist members and said rim members are assembled into a prefabricated panel ready for delivery to a building site.  
   
   
       16 . A floor system as claimed in  claim 15  and including an embedment flange formed on a said edge flange on said one side of said web whereby to permit embedment in a concrete panel, and a concrete slab poured and set embedding said embedment flanges.  
   
   
       17 . A method of making a composite steel joist member formed of two steel joists each having a web and side edges, and a flange along at least one said side edge, and openings through said web, said method characterized by the steps of; 
 forming said openings which are identical and symmetrical spaced along said web at spaced intervals therealong, with portions of said web being displaced to one side of said opening leaving two side portions attached to said web, and, forming said side portions by bending said side portions along bend lines parallel to the web axis, to define channel shapes in section,    and arranging said two joists back to back with their openings in registration with one another.    
   
   
       18 . A method of making a composite steel joist member as claimed in  claim 17  and including the step of forming struts extending transversely across said web between said openings and forming openings in said web adjacent each end of each strut.