Lattice girder supporting frame having oblique cut truss braces

Abstract

A lattice girder supporting frame for mine and tunnel lining has a plurality of boom members arranged in parallel relative to each other, forming a triangle. The boom members are spatially connected to each other by straight braces arranged along the edges of a pyramid so as to form a truss brace. The braces are each welded to the boom members at the contact faces between a straight brace part and an upper boom and a straight brace part and a lower boom. The lower booms are connected to each other via cross-ties arranged at right angle relative to such booms and the cross-ties form two sides of the pyramid base surface wherein four comer points of the base are defined by the truss braces at the contact points between the lower booms and braces.

What is claimed is:  
     
         1 . A lattice girder supporting frame comprising: 
 boom members arranged in parallel to each other, spaced apart in a triangle shape, wherein two of said boom members are lower boom members and one of said boom members is an upper boom member; and    four straight truss braces welded to said boom members, wherein a length of said truss braces define outer edges of a pyramid shape, a first end of each of said truss braces defining the four corner points of the base of the pyramid and a second end of each of said truss braces defining a truncated top of the pyramid,    wherein a welded connection is provided to connect at least one of said first and second ends of said truss braces to at least one of said upper and lower boom members.    
     
     
         2 . A lattice girder supporting frame according to  claim 1 , wherein at least one of said first and second ends of said truss braces has an oblique surface.  
     
     
         3 . A lattice girder supporting frame according to  claim 1 , wherein at least one of said first and second ends of said truss braces has a chambered surface.  
     
     
         4 . A lattice girder supporting frame according to  claim 1 , wherein the pyramid base is a square or a rectangle shape.  
     
     
         5 . A lattice girder supporting frame according to  claim 4 , further comprising cross ties disposed perpendicular to said lower boom members, wherein two of said cross-ties define two opposed edges of the pyramid base and said lower boom members define the other two opposed edges of the pyramid base.  
     
     
         6 . A lattice girder supporting frame according to  claim 2 , wherein said oblique surface of said truss member is angled so as that an entire surface area of said oblique surface contacts said boom member being welded thereto.  
     
     
         7 . A lattice girder supporting frame according to  claim 3 , wherein said chamfered surface of said truss member is arranged so that a surface area of said chamfered surface is welded to said at least one of said upper and lower boom members.  
     
     
         8 . A lattice girder supporting frame according to  claim 4 , further comprising a third cross-tie welded to said second ends of said truss members at an interior portion of the pyramid.  
     
     
         9 . A lattice girder supporting frame comprising: 
 boom members disposed in parallel with respect to each other and forming a triangle; and    straight truss braces connected to said boom members, wherein each of said straight truss braces has at least one oblique end connected to said boom members.    
     
     
         10 . A lattice girder supporting frame for mine tunnel lining having at least three boom members arranged in parallel relative to each other and forming a triangle, spatially connected to each other by means of bracing elements wherein each of the bracing elements consists of four straight braces arranged along edges of a pyramid, which are welded to each other at contact faces between a straight brace part and an upper boom and a straight brace part and a lower boom, so as to form a truss brace, wherein the plane of symmetry of each truss brace is located in the plane extending from the axes of each of the upper booms and the lower booms, while the lower booms are connected to each other via cross-ties arranged at right angles relative to the lower booms and wherein said cross-ties form two sides of a pyramid base surface, and wherein four comer points of the truss brace define pyramid base comers at the contact points between said lower booms and said straight brace parts.  
     
     
         11 . A lattice girder supporting frame as defined in  claim 1 , wherein the pyramid base surface is a square or rectangle.  
     
     
         12 . A lattice girder supporting frame according to  claim 10 , wherein two opposed lines of the base surface each are formed by the lower boom members or by the cross-ties respectively.  
     
     
         13 . A lattice girder supporting frame according to  claim 10 , wherein the four straight braces are arranged along the edges of the pyramid.  
     
     
         14 . A lattice girder supporting frame according to  claim 10 , wherein ends of the straight braces are cut to have an oblique surface according to the pyramid angle in such a manner that the oblique surfaces are in contact with the boom members over the whole surfaces of the oblique surfaces, and the oblique surfaces are chamfered so as to accommodate a welding seam between the boom member and the straight braces.  
     
     
         15 . A lattice girder supporting frame according to  claim 10 , wherein the pyramid formed by the straight braces is truncated near the upper boom member so that a pyramid trunk is produced at an area where the four straight truss braces meet.  
     
     
         16 . Lattice girder supporting frame as defined in  claim 15 , wherein the four straight braces meeting at the top of the pyramid are fixedly secured in position by a cross tie.  
     
     
         17 . Lattice girder supporting frame as defined in  claim 16 , wherein a surface of the pyramid trunk created in the area of the upper boom has the same side ratio as the pyramid base surface.  
     
     
         18 . A bracing element for a lattice girder supporting frame having four straight truss braces arranged along edges of a pyramid, wherein parts of the truss braces in the area of a base surface of the pyramid are connected to each other by cross-ties that have been welded to the brace parts.  
     
     
         19 . A bracing element for a lattice girder supporting frame according to  claim 18 , wherein the four straight braces meet at a top of the pyramid and are fixedly secured in their positions by a cross tie.  
     
     
         20 . A bracing element for a lattice girder supporting frame as defined in  claim 18 , wherein sections of the truss braces in the area of the pyramid base surface and the top of the pyramid are arranged in oblique positions to conform to the pyramid angle so that so that a tapered horizontal surface is created in the two areas at the contact surfaces of the boom members.