Frame girder for underground drift and shaft construction
AssigneePantex-Stahl AG
InventorEdgar Arnold
Life of this patent
Estimating the term…
Abstract
The frame girder for underground drift construction comprises three or more retainer bars (3a, 3b) whose cross sections form a polygon, the retainer bars being affixed to one another by stiffener elements (4). Each stiffener element (4) comprises a number of cross struts (5) bent in their centers and inclined with respect to the retainer bars. The outer ends (9) of the struts (5) are each attached to one of the retainer bars. The stiffener element may be formed symmetrically with respect to a central plane extending obliquely to the retainer bars. The frame girder may be made from conventional round irons. It resists bending, torsion and buckling at very high loads, and no undesirable injection shadows are produced during concreting.
Claims4
Frame girder as support for and concrete reinforcement in underground drift and shaft construction, comprising
- (a) at least three retainer bars forming a polygon in cross section;
- (b) means for connecting said retainer bars in fixed, spaced relation to one another, said means comprising struts[corresponding in number to the number of retainer bars,], each [said strut being] bent so as to define a central [connecting] region and two terminal regions inclined toward [the] a corresponding retainer bar, said struts being located interiorly of said polygon formed by the cross sections of said retainer bars, the central connecting regions of said struts being rigidly connected together to form a strut cruciform[with a central stiffening joint], the outer end of each said strut being attached to a said retainer bar[.] ;
- (c) whereby said strut cruciform constitutes a sole element attached to all of said retainer bars and transmitting stresses to said retainer bars.
Dependencies are inferred from the claim text.