Modular screw anchor having lead point non-integral with helix plate

Abstract

A high strength, modular screw anchor is disclosed which exhibits enhanced failure resistance notwithstanding use of essentially the same amount of material as conventional anchors, and which can be installed using existing installation equipment. The preferred screw anchors of the invention include an elongated rod having one or more separate, specialized anchor members supported thereon, and an improved, obliquely oriented, beveled earth-penetrating lead to facilitate installation, particularly in rocky soils. The anchor member includes a tubular, central, rod-receiving hub presenting a polygonal in cross-section bore therethrough, and an outwardly extending helical blade affixed to and coaxial with the hub. In installation procedures the anchor rod is passed through the hub bore and the anchor member is operably coupled to the rod (as by resting it atop an outwardly extending shoulder provided on the rod); the tubular shank of a standard anchor wrench is next telescoped over the anchor rod and inserted into the hub bore such that a driving connection is established between the rod, shank and anchor member. Axial rotation of the wrench thus effects corresponding rotation of the screw anchor for installation purposes. The earth-penetrating lead of the screw anchor may be formed integrally with the major portion of the rod, or threaded thereon; in the latter case the overall length of the rod can be adjusted as desired. The modular nature of the screw anchors hereof permits stocking of only a relatively few standard components which can be used as needed in the field to achieve a desired anchor configuration.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is: 
     
       1. In combination: an elongated rod .Iadd.having earth penetrating lead means adjacent one end thereof.Iaddend.;   and anchor member .Iadd.initially separate from said rod and .Iaddend.including a hub presenting a bore.[.therein.]. .Iadd.extending completely through said hub.Iaddend., and an outwardly extending, load-bearing element affixed to the exterior of said hub,   .Iadd.said hub being slidably received on said rod such that .Iaddend.said rod l .[.extending into.]. .Iadd.extends completely through .Iaddend.said hub bore;   means for operably coupling said anchor member to said rod;   a wrench including an elongated, tubular shank telescoped over said rod and extending into said hub bore such that the portion of said shank .[.extended.]. .Iadd.which extends .Iaddend.into the hub bore is .[.disposed between said rod and .Iadd.said .Iaddend.hub;.]..Iadd., .Iaddend.   .[.structure for drivingly connecting said shank to both of said rod and said anchor member such that axial rotation of said shank effects corresponding rotation of said rod and anchor member and distribution of driving forces from said shank to said rod and anchor member, .[.whereby.]. .Iadd.said wrench shank having outer wall surfaces for cooperative, driving engagement with an internal portion of said hub defining at least a part of said bore,   said wrench shank having inner wall surfaces,   said rod having structure for complemental, mating fit with said inner wall surfaces of said wrench shank such that said wrench, in disposition over said rod and within the hub bore of said anchor member, is operable to prohibit free lateral play of said rod relative to said anchor member and establish a connection of sufficient strength to enable driving rotation of said anchor member as well as independent, driving rotation of said rod lead means under forces such that .Iaddend.installation of the rod and anchor member into the earth is facilitated without .Iadd.collapse of said wrench shank or .Iaddend.breakage .[.thereof; and means defining an earth-penetrating lead adjacent one end of said rod.]. .Iadd.of said rod or anchor member.Iaddend..   
     
     
       2. The combination as set forth in claim 1, said hub being defined by an elongated, tubular member. 
     
     
       3. The combination as set forth in claim 1 said hub being defined by a pair of elongated, opposed, metallic angles cooperatively defining said bore therebetween. 
     
     
       4. The combination as set forth in claim 1, said hub having one end thereof of lesser diameter than the remainder of the hub. 
     
     
       5. The combination as set forth in claim 1, said load-bearing element comprising a helical blade. 
     
     
       6. The combination as set forth in claim 1 wherein said coupling means comprises engagement structure on one of said hub or rod for supporting said anchor member. 
     
     
       7. The combination as set forth in claim 6 wherein said engagement structure comprises outwardly extending shoulder means on said rod. .[.8. The combination as set forth in claim 1 wherein said connecting structure comprises cooperative mating fit wall surfaces on said wrench shank, rod, 
     
     
        and hub respectively..]. 9. The combination as set forth in claim 1, wherein said internal portion of said hub defining said bore includes walls at least in part defining said hub bore and presenting a section thereof of polygonal cross-section, said wrench shank being of 
     
     
        non-circular cross-section for operatively engaging said walls. 10. The combination as set forth in claim 1 wherein said .[.lead-defining.]. 
     
     
        .Iadd.lead .Iaddend.means comprises an elongated terminal section. 11. The combination as set forth in claim 10, said terminal section being oriented 
     
     
        at an angle relative to the major portion of said rod. 12. The combination as set forth in claim 10 wherein said terminal section is threadably 
     
     
        coupled to said major portion of said rod. 13. The combination as set forth in claim 10, said terminal rod section being provided with an elongated, threaded bore therethrough, said rod being threaded for reception in said bore for adjustment of the overall length of the entire rod, including said terminal section. .[.14. The combination as set forth in claim 1 wherein said lead-defining means comprises at least one earth penetrating portion connected to said hub..]. .[.15. The combination as set forth in claim 1, said anchor member being free of permanent connection to said rod, whereby said combination is modular in nature..]. 
     
     
         6. In a method of driving an anchor into the earth wherein the anchor includes an elongated rod .Iadd.having lead means .Iaddend.and an outwardly extending load-bearing element operably coupled to the rod, and wherein the method includes the steps of telescoping an elongated, tubular wrench shank over said rod, drivingly connecting said wrench shank and rod, and axially rotating said shank to effect corresponding rotation of the rod and element to install said anchor into the earth, the improved method which comprises: providing an anchor member having an open-ended hub presenting a bore therethrough, with said element affixed to the exterior of the hub;   passing said rod .Iadd.completely .Iaddend.through said hub and operably coupling said anchor member to the rod;   telescoping said wrench shank over said rod, .Iadd.and .Iaddend.inserting the end of said shank into said hub bore such that said shank end is disposed between said rod and hub.[., and drivingly engaging said connecting said shank, rod and anchor member.]. .Iadd.and to prohibit free lateral play of said rod relative to said anchor member and for establishment of a connection of sufficient strength to enable driving rotation of said anchor member as well as independent, driving rotation of said rod lead means.Iaddend.; and   axially rotating said wrench shank to effect distribution of rotative driving forces from the shank .Iadd.directly and independently .Iaddend.to said rod and .Iadd.also directly and independently to said .Iaddend.anchor member.Iadd., .Iaddend.and .[.corresponding rotation of.]. .Iadd.to correspondingly rotate .Iaddend.said rod and anchor member .Iadd.such that installation of said rod and anchor member into the earth is facilitated without collapse of said wrench shank or breakage of said rod or anchor   
     
     
        member. .Iaddend. 17. An earth anchor, comprising: an elongated rod having an earth-penetrating lead .Iadd.means .Iaddend.adjacent one end thereof, and outwardly extending, polygonal shoulder-defining structure proximal to said lead;   an anchor member including an open-ended hub having interior walls defining a bore therethrough extending between said open ends, and an outwardly extending load-bearing member secured to said hub,   .Iadd.said hub being slidably received on said rod .[.passing.]. .Iadd.extends completely .Iaddend.through said hub bore, with portions of said bore-defining walls surrounding said shoulder-defining structure being in spaced relationship from said structure and cooperatively defining a polygonal structure-receiving opening; and   means operably coupling said anchor member to said rod,   the cross-sectional dimensions of said bore, and the spacing between said shoulder-defining structure and said wall portions, being sufficient for passage of a complemental wrench tube between said interior walls and said rod, and between said wall portions and said shoulder-defining structure.[., for establishing a driving engagement and connection between said tube, shoulder-defining structure and opening-defining wall portions, whereby axial rotation of the tube distributes rotative driving forces from the tube to the rod and anchor member and effects corresponding rotation in unison to said rod and anchor member, in order to facilitate installation of the anchor into the earth without anchor breakage.]. .Iadd.to prohibit lateral free play of said rod relative to said anchor member and to establish a connection of sufficient strength to enable driving rotation of said anchor member as well as driving rotation of said rod lead means under forces such that installation of the rod and anchor member into the earth is facilitated without collapse of said wrench shank   
     
     
        or breakage of said rod or anchor member.Iaddend.. 18. The earth anchor as set forth in claim 17, said hub bore being polygonal and of substantially constant cross-sectional dimensions throughout the length thereof between 
     
     
        said open ends. 19. An anchor rod, comprising: an elongated rod presenting an upper end and an opposed lower end;   a radially outwardly extending flange adjacent the lower end of said rod.Iadd., said flange being engageable with an anchor member having an outwardly extending load bearing member.Iaddend.;   an elongated earth-penetrating lead below said flange, the longitudinal axis of said lead being disposed at an angle relative to the longitudinal axis of said rod; and   radially outwardly extending, polygonal shoulder-defining structure above said flange and proximal thereto, said flange extending radially outwardly from said rod farther than said shoulder-defining structure,   said lead serving to cut through the earth during rotative installation of the rod to facilitate installation thereof, particularly in densse or rocky soils.Iadd.,   said shoulder-defining structure being engageable with internal walls of a tubular wrench shank for a cooperative, mating fit connection such that as said shank is rotated, the rotative forces are evenly distributed to said rod without breakage thereof.Iaddend.. .Iadd.20. The combination as set forth in claim 1, said rod being of integral construction. .Iaddend. .Iadd.21. The combination as set forth in claim 1, said rod being formed of separable components threadably coupled together. .Iaddend.