# US 8,540,755 B2 · Self-drilling self-tapping bone screw > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,755 B2 - Document ID: US8540755B2 - Status: Granted - Kind: B2 - Application number: 11/609,259 - Filed: 2006-12-11 - Published: 2007-07-12 - Granted: 2013-09-24 - Earliest claimed: 2003-07-21 - Applicants: Robin C. Whitmore - Inventors: Robin C. Whitmore - Web page: https://patentgrep.com/patent/US8540755B2 ## CPC - A61B 17/8625: {Shanks, i.e. parts contacting bone tissue} - A61B 17/863: {with thread interrupted or changing its form along shank, other than constant taper} - A61B 17/8635: {Tips of screws} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A self-drilling, self-tapping bone screw includes a body having a head at one end and a cutting end at an opposite end, the cutting end having a generally flat cutting surface supporting two symmetrical cutting edges which extend from the longitudinal centerline to diametrically opposed thread start points. A recess is formed in the head for receiving an end of an insertion tool. A dual lead thread extends outwardly from the body in a spiral path from the cutting end towards the head. The dual lead thread pitch is tapered towards the cutting end, and transitions to a straight or slightly tapered thread towards the head. ## Claims ### Claim 1 A self-drilling bone screw comprising: a body having: (a) a longitudinal centerline; (b) a head at a first end; and (c) a cutting end at a second end, the cutting end including a flat rectangular cutting surface oriented perpendicularly to the longitudinal centerline and having: (i) a first cutting edge which extends perpendicular from the longitudinal centerline to a first thread start point; and (iii) a second cutting edge which extends perpendicular from the longitudinal centerline to a second thread start point, the second cutting edge being parallel to the first cutting edge; and a dual lead thread extending outwardly from the body in a spiral path from the cutting end towards the head. ### Claim 2 (depends on 1) The bone screw of claim 1, wherein said dual lead thread is multi-pitched. ### Claim 3 (depends on 2) The bone screw of claim 2, wherein said dual lead thread is tapered towards the cutting end and transitions to a straight or slightly tapered thread towards the head. ### Claim 4 (depends on 1) The bone screw of claim 1, including a recess formed in the head configured to receive an end of an insertion tool. ### Claim 5 (depends on 1) The bone screw of claim 1, wherein said bone screw is comprised of a medical grade titanium alloy. ### Claim 6 (depends on 1) The bone screw of claim 1, wherein said bone screw is approximately 1.0 to 2.0 mm in diameter and approximately 3.0 to 6.0 mm in length. ### Claim 7 (depends on 1) The bone screw of claim 1, wherein the flat rectangular cutting surface is approximately 0.5 mm in length and 0.1 mm in width. ### Claim 8 A self-drilling bone screw, comprising: a body having: (a) a longitudinal centerline; (b) a head at a first end; and (c) cutting edge including a flat rectangular cutting surface at a second end, the flat rectangular cutting surface oriented perpendicularly to the longitudinal centerline and having: (i) a first cutting edge which extends perpendicular from the longitudinal centerline to a first thread start point; and (iii) a second cutting edge which extends perpendicular from the longitudinal centerline to a second thread start point, the second cutting edge being parallel to the first cutting edge; and a dual lead thread extending outwardly from the body in a spiral path from the cutting end towards the head, the dual lead thread being multi-pitched such that the pitch of the thread: (a) is tapered towards the cutting end; and (b) transitions to a straight or slightly tapered thread towards the head. ### Claim 9 (depends on 8) The bone screw of claim 8, including a recess formed in the head configured to receive an end of an insertion tool. ### Claim 10 (depends on 8) The bone screw of claim 8, wherein said bone screw is comprised of a medical grade titanium alloy. ### Claim 11 (depends on 8) The bone screw of claim 8, wherein said bone screw is approximately 1.0 to 2.0 mm in diameter and approximately 3.0 to 6.0 mm in length. ### Claim 12 (depends on 8) The bone screw of claim 8, wherein the flat rectangular cutting surface is approximately 0.5 mm in length and 0.1 mm in width. ### Claim 13 A self-drilling, self-tapping bone screw, comprising: a body comprised of medical grade titanium alloy of approximately 1.0 to 2.0 mm in diameter and approximately 3.0 to 6.0 mm in length, the body having: (a) a longitudinal centerline; (b) a head at a first end; and (c) a cutting end comprising a flat rectangular cutting surface at a second end oriented perpendicularly to the longitudinal centerline and having: (i) a first cutting edge which extends perpendicular from the longitudinal centerline to a first thread start point; and (iii) a second cutting edge which extends perpendicular from the longitudinal centerline to a second thread start point, the second cutting edge being parallel to the first cutting edge; a dual lead thread extending outwardly from the body in a spiral path from the cutting end towards the head, the dual lead thread being multi-pitched such that the pitch of the thread is: (a) tapered towards the cutting end; and (b) transitions to a straight to slightly tapered thread towards the head; and a recess formed in the head configured to receive an end of an insertion tool. ### Claim 14 (depends on 13) The bone screw of claim 13, wherein the flat rectangular cutting surface is approximately 0.5 mm in length and 0.1 mm in width.