Self-drilling anchor screw and method of using the same

Abstract

A self-drilling anchor screw includes a shaft member. A drill bit portion is located at a first end of the shaft member. A threaded shaft portion is located along at least part of the shaft member. A transition shaft portion is located between the threaded shaft portion and the drill bit portion. A nut has nut threads adapted to thread onto the threaded shaft portion of the shaft member. The nut is located on the threaded shaft portion. A sleeve is located about the shaft member. At least part of the sleeve is located adjacent to the transition portion, and is capable of sliding along the shaft member for engaging the transition portion. A nut stop portion is located at a second end of the shaft member. The nut stop portion is adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member.

1 . A self-drilling anchor screw, comprising:
 a shaft member comprising a first end, second end, and a central portion extending between the first and second ends;   a drill bit portion at the first end of the shaft member;   a threaded shaft portion located along at least part of the central portion of the shaft member;   a transition portion of the shaft member located between the threaded shaft portion and the drill bit portion, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion;   a nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member, and the nut being located on the threaded shaft portion;   a sleeve located about the shaft member and at least part of the sleeve being located adjacent to the transition portion, the sleeve being capable of sliding along the shaft member for engaging the transition portion; and   a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member.   
   
   
       2 . The self-drilling anchor screw of  claim 1 , wherein the drill bit portion comprises a masonry bit. 
   
   
       3 . The self-drilling anchor screw of  claim 1 , wherein the drill bit portion comprises a tungsten carbide tip. 
   
   
       4 . The self-drilling anchor screw of  claim 1 , wherein the sleeve extends over and is adapted to slide over at least part of the threaded shaft portion. 
   
   
       5 . The self-drilling anchor screw of  claim 1 , wherein the shaft member comprises a sleeve-retention portion located adjacent to the transition portion and located between the transition portion and the threaded portion, wherein the sleeve is located about the shaft member at the sleeve-retention portion, and wherein the sleeve-retention portion comprises a sleeve-stop portion adapted to hinder the sleeve from moving past the sleeve-stop portion toward the threaded portion. 
   
   
       6 . The self-drilling anchor screw of  claim 5 , wherein the sleeve comprises a bump portion extending from an outside surface of the sleeve. 
   
   
       7 . The self-drilling anchor screw of  claim 1 , wherein the nut comprises a hexagonal portion and a flared portion, the flared portion having a larger diameter than a hexagonal portion. 
   
   
       8 . The self-drilling anchor screw of  claim 1 , wherein the drill bit portion comprises threaded flutes. 
   
   
       9 . The self-drilling anchor screw of  claim 8 , wherein the threaded flutes spiral in a first spiral direction, wherein the threaded portion of the shaft member spiral in a second spiral direction, and wherein the first spiral direction is opposite the second spiral direction. 
   
   
       10 . The self-drilling anchor screw of  claim 9 , wherein the drill bit portion is adapted to cut when rotating in a counter-clockwise direction, and wherein the first spiral direction is a reverse thread direction. 
   
   
       11 . The self-drilling anchor screw of  claim 8 , wherein the threaded flutes spiral in a first spiral direction, and wherein the threaded portion of the shaft member spiral in the first spiral direction. 
   
   
       12 . The self-drilling anchor screw of  claim 1 , further comprising a washer located about the central portion of the shaft member, wherein the washer is located between the nut and the sleeve. 
   
   
       13 . The self-drilling anchor screw of  claim 1 , wherein the nut stop portion has an elongated shape extending from the second end of the shaft member. 
   
   
       14 . The self-drilling anchor screw of  claim 1 , wherein the nut stop portion has a generally flattened shape. 
   
   
       15 . The self-drilling anchor screw of  claim 1 , wherein the sleeve comprises a longitudinal slit for allowing the sleeve to expand as it is pushed against the transition portion of the shaft member. 
   
   
       16 . A self-drilling anchor screw, comprising:
 a shaft member comprising a first end, second end, and a central portion extending between the first and second ends;   a masonry drill bit at the first end of the shaft member;   a threaded shaft portion located along at least part of the central portion of the shaft member;   a transition portion of the shaft member located between the threaded shaft portion and the masonry drill bit, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion;   a nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member,   wherein the nut is located on the threaded shaft portion, and
 wherein the nut comprises a hexagonal portion and a flared portion, the flared portion having a larger diameter than a hexagonal portion; 
   a sleeve located about the shaft member and located along part of the central portion between the nut and the transition portion, the sleeve being capable of sliding along the shaft member for engaging the transition portion, and the sleeve comprises a longitudinal slit for allowing the sleeve to expand as it is pushed against the transition portion of the shaft member; and   a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member.   
   
   
       17 . A method of attaching a first object to a second object using the self-drilling anchor screw of  claim 16 , comprising:
 engaging the nut with a socket wrench;   turning the socket wrench in a reverse or counter-clockwise direction while pressing the socket wrench against the nut toward a surface of a second object into which the self-drilling anchor screw will be installed so that the masonry bit is engaging the surface, wherein the nut engages the nut stop portion so that the nut drives the rotation of the shaft member;   drilling a hole into the second object using the masonry bit during the turning in the counter-clockwise direction, wherein part of the self-drilling anchor screw enters into the hole and into the second object during the drilling;   after the self-drilling anchor screw is drilled into the second object to a desired depth, turning the nut with the socket wrench in a forward or clockwise direction so that the nut presses the sleeve toward the transition portion of the shaft member, thereby expanding the sleeve at the transition portion of the shaft member as the longitudinal slit engages the transition portion and thereby anchoring the self-drilling anchor screw in the second object; and   tightening the nut further to attach the first object to the second object using the anchored self-drilling anchor screw.   
   
   
       18 . A method of attaching a first object to a second object using a self-drilling anchor screw, comprising:
 engaging a nut of the self-drilling anchor screw with a socket wrench, wherein the self-drilling anchor screw comprises
 a shaft member comprising a first end, second end, and a central portion extending between the first and second ends, 
 a drill bit portion at the first end of the shaft member, 
 a threaded shaft portion located along at least part of the central portion of the shaft member, 
 a transition portion of the shaft member located between the threaded shaft portion and the drill bit portion, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion, 
 the nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member, and the nut being located on the threaded shaft portion, 
 a sleeve located about the shaft member and at least part of the sleeve being located adjacent to the transition portion, the sleeve being capable of sliding along the shaft member for engaging the transition portion, and 
 a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member; 
   turning the socket wrench in a first direction while pressing the socket wrench against the self-drilling anchor screw toward a surface of a second object into which the self-drilling anchor screw will be installed so that the masonry bit is engaging the surface, wherein the nut engages the nut stop portion so that the nut drives the rotation of the shaft member;   drilling a hole into the second object using the masonry bit during the turning in the first direction, wherein part of the self-drilling anchor screw enters into the hole and into the second object during the drilling;   after the self-drilling anchor screw is drilled into the second object to a desired depth, turning the nut with the socket wrench in a second direction so that the nut presses the sleeve toward the transition portion of the shaft member, thereby expanding the sleeve at the transition portion of the shaft member as the sleeve engages the transition portion and thereby anchoring the self-drilling anchor screw in the second object, wherein the second direction is opposite the first direction; and   tightening the nut further to attach the first object to the second object using the anchored self-drilling anchor screw.   
   
   
       19 . The method of  claim 18 , wherein the first direction is a counter-clockwise direction and the second direction is a clockwise direction. 
   
   
       20 . The method of  claim 18 , wherein the first direction is a clockwise direction and the second direction is a counter-clockwise direction.