Ex Parte AuthDownload PDFBoard of Patent Appeals and InterferencesAug 14, 200911008343 (B.P.A.I. Aug. 14, 2009) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte STEFAN AUTH ____________ Appeal 2009-000750 Application 11/008,343 Technology Center 3700 ____________ Decided: August 14, 2009 ____________ Before DONALD E. ADAMS, ERIC GRIMES, and RICHARD M. LEBOVITZ, Administrative Patent Judges. LEBOVITZ, Administrative Patent Judge. DECISION ON APPEAL This is a decision on the Patent Applicant’s appeal from the Patent Examiner’s rejection of claims 1-13. Jurisdiction for this appeal is under 35 U.S.C. § 6(b). We reverse. Appeal 2009-000750 Application 11/008,343 STATEMENT OF THE CASE The claims are directed to a self-drilling bone screw, alone, and in combination with a bone plate. The self-drilling screw is designed to be rapidly screwed into a bone or bone fragment while avoiding bending or breaking of the screw tip (Spec. 2:1-3). Claims 1-13 are appealed and stand rejected by the Examiner as follows: • Claims 1, 2, 4, 7, 8, and 10 under 35 U.S.C. § 102(b) as anticipated by Bechtel (U.S. Published Application No. 2003/0210970 A1, Nov. 13, 2003) (Ans. 3); • Claims 3, 5, 6, and 9 under 35 U.S.C. § 103(a) as obvious in view of Bechtel (Ans. 4); and • Claims 11-13 under 35 U.S.C. § 103(a) as obvious in view of Niiranen (U.S. Pat. No. 6,692,498 B1, Feb. 17, 2004), Bechtel, and Whitmore (U.S. Published Application No. 2005/0021036 A1, Jan. 27, 2005) (Ans. 4). Claims 1, 10, and 11 are representative and read as follows: 1. A self-drilling bone screw comprising: a head; and a shank extending from the head and having a thread with a pitch of approximately 0.7 to 1.0 mm, the shank having a tip with a tip angle selected such that a thread flank of a first flight of the thread adjacent to the tip is arranged at a distance of approximately 0.2 to 0.5 mm from the tip. 2 Appeal 2009-000750 Application 11/008,343 10. A self-drilling bone screw comprising: a head; a shank extending from the head to a distal end, the shank having a thread with a pitch of approximately 0.7 to 1.0 mm; and a tip disposed at the distal end of the shank with a tip angle of approximately 34 to 43º. 11. An implant system comprising: a self-drilling bone screw having a head and a shank extending from the head, the shank having a thread with a pitch of approximately 0.7 to 1.0 mm and a tip with a tip angle selected such that a thread flank of a first flight of the thread adjacent to the tip is arranged at a distance of approximately 0.2 to 0.5 mm from the tip; and a bone plate defining a bore and a recess disposed about the bore, the head of the bone screw adapted to rest in the recess and the shank of the bone screw adapted to penetrate the bore. ANTICIPATION BY BECHTEL Claims 1, 2, 4, 7, 8, and 10 stand rejected under 35 U.S.C. § 102(b) as anticipated by Bechtel. Statement of the Issues Claim 1 Independent claim 1 is directed to a self-drilling screw with a shank “having a thread with a pitch of approximately 0.7 to 1.0 mm” and a thread flank starting “at a distance of approximately 0.2 to 0.5 mm from the tip” (also known as the thread start distance). The Examiner contends that these limitations are met by the screw described in the Bechtel patent. Appellant contends that the Examiner erred in finding that Bechtel described a screw with the claimed thread pitch and thread start distance. The issue is whether Appellant established that the Examiner erred in these findings. 3 Appeal 2009-000750 Application 11/008,343 Claim 10 Independent claim 10 is directed to a self-drilling screw with a shank “having a thread with a pitch of approximately 0.7 to 1.0 mm” and a tip at the distal end of the shank “with a tip angle of approximately 34 to 43°.” The Examiner contends that these limitations are met by the screw described in the Bechtel patent. Appellant contends that the Examiner erred in finding that Bechtel described a screw with the claimed thread pitch and tip angle. The issue is whether Appellant established that the Examiner erred in these findings. Findings of Fact (“FF”) The Bechtel patent 1. Bechtel describes a thread-forming screw that forms threads as the screw advances into a body (¶ 3). 2. The thread start “S” occurs at a precise location relative to the distal tip of the shank (¶¶ 31 & 40). 3. Bechtel describes how S is calculated for a screw and discloses S values from 0.038 inches to 0.084 inches for exemplary screws (¶¶ 47 & 53). 4. 0.038 inches corresponds to 0.96 mm (Ans. 7); 0.084 inches corresponds to 2.13 mm (App. Br. 10). 5. Bechtel states that, in preferred embodiments, all screws are provided with 18 threads per axial inch of shaft to simplify manufacture (¶ 29) and that a screw with “a common number of threads per inch of screw length for various screw sizes” is an “advantage” of its “invention” (¶ 16). 6. 18 threads per axial inch corresponds to a thread pitch of 1.4 mm (Ans. 8; App. Br. 8). 4 Appeal 2009-000750 Application 11/008,343 7. Bechtel describes exemplary screws with S values that range from 0.038- 0.084 inch and which have a thread pitch of 18 threads per axial inch (¶¶ 42, 53 & 57). 8. Bechtel describes the taper angle from the shaft to the shaft tip to be 30º for all its screws (¶¶ 41 & 51). 9. A standard sized #4 screw is described by Bechtel to have 24 threads per inch or a thread pitch of 1.06 mm (¶ 6; Ans. 6). The Specification 10. The only tip to thread start distance range disclosed in the Specification is “approximately 0.2 to 0.5 mm” (Spec. 2:8-11), which is the same as the range recited in claim 1. 11. The only example of a thread start distance is of a screw with a thread start at “approximately 0.32 mm from the screw tip.” (Spec. 4:30-32; 5:7-8.) Analysis Claim 1 It is undisputed that Bechtel describes a screw with a thread start distance from 0.96 to 2.13 mm from the shank tip (FF2-4). The Examiner contends that “the axial distance from the tip of the screw to the thread start value of 0.96 millimeters is imprecise but fairly close to or approximately 0.2 millimeters to 0.5 millimeters” range recited in claim 1 (Ans. 7). Based on this finding, the Examiner concluded that Bechtel met the claim limitation of a screw with “a thread flank of a first flight of the thread adjacent to the tip is arranged at a distance of approximately 0.2 to 0.5 mm from the tip.” 5 Appeal 2009-000750 Application 11/008,343 The Examiner’s interpretation of “approximately 0.2 to 0.5 from the tip” to read on the 0.96 mm tip to thread start distance described in the Bechtel patent is not reasonable. The claimed thread start range spans 0.3 mm; this is the only range described in the Specification and there are no values disclosed outside of it (FF10-11; App. Br. 9). The difference between the claimed endpoint of 0.5 mm and Bechtel’s value of 0.96 mm is 0.46 mm, which is greater than 0.3 mm covered by the entire claimed range (0.5 mm- 0.2 mm). It is not reasonable to interpret “approximately” to read on a value that is almost double the endpoint of the claimed range (0.96 mm/0.5 mm = 1.92) and whose difference (0.96 mm-0.5 mm = 0.46 mm) between it and the range endpoint is greater than the breadth of the entire claimed range (0.3 mm). For this reason, we reverse the rejection of claim 1, and dependent claims 2, 4, 7, and 8, which incorporate all the limitations of claim 1. Claim 10 Claim 10 is to a self-drilling bone screw with a shank “having a thread with a pitch of approximately 0.7 to 1.0 mm” and a tip at the distal end of the shank “with a tip angle of approximately 34 to 43°.” Appellant does not dispute that Bechtel describes a screw which meets the tip angle recited in claim 10. The Examiner found that Bechtel disclosed in its background section a standard sized No. 4 screw with a thread pitch of 1.06 mm (Ans. 6; FF9), meeting the corresponding limitation of claim 10. Appellant contends that the Examiner erred in finding the thread pitch limitation met by Bechtel. According to Appellant, the pitch of the prior art No. 4 screw is 1.06 mm, but the pitch of Bechtel’s improved screw is 1.4 6 Appeal 2009-000750 Application 11/008,343 mm (App. Br. 8). Therefore, Appellant concludes Bechtel “fails to disclose a screw that combines a thread pitch of approximately 0.7 to 1.0 mm with a tip having a tip angle of from 34 to 43º” (App. Br. 11). The Examiner has not provided sufficient evidence that Bechtel describes a screw that meets the limitations of claim 10. Bechtel describes its invention as a screw with a thread pitch of 1.4 mm (FF5-7), which falls outside the claimed upper limit of 1.0 mm. The Examiner’s rationale for finding the upper claimed limit to have been met by Bechtel is that Bechtel describes a prior art screw with the thread pitch of 1.06 mm (FF9) – a value that is about 1 mm as recited in claim 1. However, the Examiner has not provided evidence that the prior art thread pitch of 1.06 mm was combined with the tip angle of 30º, a necessary finding to establish that all elements of claim 10 are described in Bechtel. Bechtel repeatedly states that its invention is a screw with a common number of threads for all screw sizes (FF5). This common number is stated to be 18 threads per inch or a thread pitch of 1.4 mm (FF5 & 7). In the examples, Bechtel refers to a screw of “the present design” (Bechtel, at ¶¶ 54-56) which would reasonably be understood to mean the 1.4 mm thread pitch in light of statements made before (id. at ¶¶ 16, 29, and 42) and after (id. at ¶ 57) characterizing this pitch as standard for its invention. Accordingly, since not all elements of claim 10 are described in the Bechtel patent, the rejection of claim 10 is reversed. OBVIOUSNESS IN VIEW OF BECHTEL Claims 3, 5, 6, and 9 stand rejected under 35 U.S.C. § 103(a) as obvious in view of Bechtel. 7 Appeal 2009-000750 Application 11/008,343 Claims 3, 5, 6, and 9 depend directly or indirectly on claim 1. The Examiner argued that limitations introduced in claims 3, 5, 6, and 9 were obvious in view of Bechtel’s teachings. However, Examiner did not provide any reasoning or evidence as to why it would have been obvious to modify Bechtel’s screw to have made a screw with a thread flank starting “at a distance of approximately 0.2 to 0.5 mm from the tip” as recited in claim 1, which we concluded is not taught by Bechtel. As claims 3, 5, 6, and 9 incorporate all the limitations in claim 1, we are therefore compelled to reverse the rejection. OBVIOUSNESS IN VIEW OF NIIRANEN, BECHTEL, AND WHITMORE Claims 11-13 stand rejected under 35 U.S.C. § 103(a) as obvious in view of Niiranen, Bechtel, and Whitmore. The Examiner stated that it would have been obvious to construct the system of Niiranen with a bone screw being self drilling, having a thread pitch of 1.05mm, and an axial distance from the tip of the screw to the start of the threads of approximately 0.451 to 0.5863 mm in view of Whitmore and Bechtel in order to eliminate the step of drilling a preliminary guide hole, to use a screw that is easier to manufacture, and to use a screw that has a optimized relationship between the insertion torque requirements and the strip-out resistance. (Ans. 6.) The Whitmore patent 12. Whitmore describes a self-drilling, self-tapping bone screw that has dual lead threads which form a spiral path from the cutting tip (¶¶ 18-19). 8 Appeal 2009-000750 Application 11/008,343 Analysis Claim 11 is to a bone plate and a bone screw with a shank “having a thread with a pitch of approximately 0.7 to 1.0 mm” and a thread flank starting “at a distance of approximately 0.2 to 0.5 mm from the tip.” Claim 13 is to a method of using a bone plate and bone screw with the same limitations as in claim 11. The Examiner has not provided sufficient evidence to establish that it would have been obvious to have made a screw with the claimed limitations. The absence of the 0.2 to 0.5 mm thread start limitation from the Bechtel screw has been addressed above. See supra at pp. 5-6. Whitmore describes a self-drilling, self-tapping bone screw with threads which form a spiral path from the cutting tip (FF12). The Examiner has not provided a reason as to why it would have been obvious to modify Whitmore or Bechtel’s screw to meet the claimed thread start distance. The values of 0.451 to 0.5863 mm cited by the Examiner in support of the rejection appear to be based on Appellant’s own Specification1, not the cited prior art. Conclusions of Law The Examiner erred in finding that Bechtel described or suggested a screw with a thread flank starting “at a distance of approximately 0.2 to 0.5 mm from the tip” as recited in claims 1, 11, and 13. The Examiner erred in finding that Bechtel described a screw with a shank “having a thread with a pitch of approximately 0.7 to 1.0 mm” and a 1 “When the factor of 0.451 is multiplied by the range diameter given in the specification [,] the range for the axial distance from the tip of the screw to the start of the threads is approximately 0.451 to 0.586 millimeters.” (Ans. 3.) 9 Appeal 2009-000750 Application 11/008,343 tip at the distal end of the shank “with a tip angle of approximately 34 to 43°” as recited in claim 10. Summary The anticipation rejection of claims 1, 2, 4, 7, 8, and 10 and the obviousness rejections of claims 3, 5, 6, 9, and 11-13 are reversed. REVERSED Ssc: HOWARD & HOWARD ATTORNEYS PLLC 450 WEST FOURTH STREET ROYAL OAK, MI 48067 10 Copy with citationCopy as parenthetical citation