Ex Parte Sigler et al

Patent Trials and Appeals BoardMar 21, 2019

14673106 - (D) (P.T.A.B. Mar. 21, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE 14/673,106 03/30/2015 60770 7590 03/25/2019 General Motors Corporation c/o REISING ETHINGTON P.C. 755 W. Big Beaver Road Suite 1850 TROY, MI 48084 FIRST NAMED INVENTOR David R. Sigler UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www .uspto.gov ATTORNEY DOCKET NO. CONFIRMATION NO. P030467-RD-SDJ 8771 EXAMINER BAILLARGEON, JOSEPH M ART UNIT PAPER NUMBER 3761 NOTIFICATION DATE DELIVERY MODE 03/25/2019 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): stevens@reising.com USPTOmail@reising.com USPTOmail@gmx.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte DAVID R. SIGLER and BLAIRE. CARLSON Appeal 2018-003565 Application 14/673,106 1 Technology Center 3700 Before BIBHU R. MOHANTY, MICHAEL C. ASTORINO, and BEYERL Y M. BUNTING, Administrative Patent Judges. ASTORINO, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. Â§ 134(a), the Appellants appeal from the Examiner's decision rejecting claims 1-6 under 35 U.S.C. Â§ 103 as unpatentable over Urushihara et al. (US 7,951,465 B2, issued May 31, 2011) ("Urushihara") in view of Edwards, II (US 2016/0016252 Al, published Jan. 21, 2016) ("Edwards"). We have jurisdiction over the appeal under 35 U.S.C. Â§ 6(b). We REVERSE. 1 "The real parties in interest are the Appellant[s], GM Global Technology Operations LLC, and General Motors Company." Appeal Br. 2. Appeal2018-003565 Application 14/673,106 STATEMENT OF THE CASE Subject Matter on Appeal The Appellants' invention "relates generally to resistance spot welding and, more particularly, to resistance spot welding a steel workpiece and an aluminum alloy workpiece. " 2 Spec. ,r 1. Claim 1, the sole independent claim, is reproduced below. 1. A method of resistance spot welding a workpiece stack-up that includes steel workpiece and an aluminum alloy workpiece; the method comprising: providing a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece, the steel workpiece having a faying surface that overlies and contacts a faying surface of the aluminum alloy workpiece to establish a faying interface at a weld site; bringing a first welding electrode into electrical communication with the steel workpiece at the weld site; bringing a second welding electrode into electrical communication with the aluminum alloy workpiece at the weld site; passing a DC electrical current through the workpiece stack-up at the weld site and between the first and second welding electrodes to initiate and grow a molten aluminum alloy weld pool within the aluminum alloy workpiece, the DC electrical current assuming a conical flow pattern in which a path of current flow expands radially along a direction leading from the first welding electrode towards the second welding electrode such that a current density of the DC electrical current decreases along the direction within at least a portion of the workpiece stack-up spanning from within the steel workpiece, across the faying interface, and into the aluminum alloy workpiece. 2 "[S]teel has a relatively high melting point (-1500Â°C) and relatively high electrical and thermal resistivities, while the aluminum alloy material has a relatively low melting point (-600Â°C) and relatively low electrical and thermal resistivities," which "tend to complicate the spot welding process." Spec. ,r 5. 2 Appeal2018-003565 Application 14/673,106 ANALYSIS The Examiner's rejection relies on Urushihara's Figure 3 to teach substantially all of the steps of method claim 1. Final Act. 2-3. Urushihara's Figure 3 is illustrated below: FIG.3 7 -a Urushihara's Figure 3 shows "a spot welding process for fabricating a steel- aluminum welded material," having "steel material 1, an aluminum alloy sheet 2, a steel-aluminum welded material 3, a nugget 5, and electrodes 7 and 8." Urushihara, col. 5, 11. 60-61, col. 17, 11. 1-3 (emphasis omitted). Although it is not shown in Figure 3, Urushihara's "nugget 5 has a weld interface surface 6, namely, interface reaction layer, formed by spot welding." Id. at col. 6, 11. 45--46 (emphasis omitted); see id. at Figs. 1, 2. The Examiner finds that nugget 5 is evidence that Urushihara teaches "passing a DC electrical current through the workpiece stack-up at the weld site and between the first and second welding electrodes to initiate and grow a molten aluminum alloy weld pool ... within the aluminum alloy 3 Appeal2018-003565 Application 14/673,106 workpiece," as recited in claim 1. See Final Act. 3. The Examiner also finds that Urushihara fails to teach the use of a conical flow pattern of the DC electrical current as called for by claim 1. See id. To remedy this deficiency, the Examiner relies on a teaching particular to Edwards. Id. (citing Edwards, Fig. 2). Edwards' Figure 2 is illustrated below: ~D HO -{ ~:-1--~~~~~~-........_..,:,~~ .~ .... p ~L~ :U 1Q: """""""'"""""""' flG. 2 Edwards' Figure 2 shows first and second welding tips 108, 110 contacting opposite sides of a stack of sheet metal 202 (i.e., sheets 210,212,214,216) and passing DC electrical current having a trapezoidal current density 228. See Edwards ,r,r 18, 19, 27. Additionally, Edwards teaches joining sheets 210, 212, 214, 216 together by creating nugget 414 through the interfaces of sheets 210,212,214,216. See Edwards, Figs. 4, 5. Edwards' Figure 4 is illustrated below: 4 Appeal2018-003565 Application 14/673,106 Ctme1,t 202 "\ 216 ...-~~"'I'--~ ......... 214_......._,,-- FIG.4 Edwards' Figure 4 shows "an exemplary current profile and a resulting welding nugget formation and growth in accordance with various embodiments." Id. ,r 11; see id. ,r,r 29--31. The Examiner concludes it would have been obvious to one of ordinary skill in the art to modify the method of resistance spot welding of Urushihara in view of Edwards' s teaching such that the DC electrical current assum[ es] a conical flow pattern in which a path of current flow expands radially along a direction leading from the first welding electrode towards the second welding electrode such that a current density of the DC electrical current decreases along the direction within at least a portion of the workpiece stack-up spanning from within the steel workpiece, across the faying interface, and into the aluminum alloy workpiece, to compensate for decreased resistance often in thinner sheets or varying materials. Final Act. 4 ( citing Edwards ,r 27). The Appellants argue that "[a] person of ordinary skill in the art would have had no reason to combine the teachings of Urushihara and Edwards as proposed by the Examiner" because Urushihara's process of 5 Appeal2018-003565 Application 14/673,106 joining "steel and aluminum materials 1, 2 together at their preserved interface through the weld nugget 5, which is accompanied by an interface reaction layer 6 comprised of complex reaction products" is fundamentally different than Edwards' welding process. Specifically, Appellants argue that Edwards' welding process joins steel sheets together that consumes the interfaces between multiple overlapping sheets 210,212,214,216 by "creat[ing] a single large weld nugget [ 414] that extends into or through each of the metal sheets 210,212,214,216 to fuse all of the sheets 210,212, 214, 216 together." See Appeal Br. 7-9 ( emphasis omitted). The Appellants' argument is persuasive. The Examiner's rationale is exemplified by the reason for the modification, i.e., "to compensate for decreased resistance often in thinner sheets or varying materials." Final Act. 4. This reason is particular to methods of joining metals together where a weld nugget crosses an interface layer between sheets of material, such as Edwards. Urushihara's process does not follow this teaching because the nugget 5 is limited to aluminum alloy sheet 2, i.e., it does not extend into steel material 1. We determine that the Examiner's rationale fails to adequately explain why Edwards' welding process, which creates a nugget in all sheets of material, would be implemented in Urushihara's process, where a weld nugget is limited to aluminum alloy sheet 2. Thus, we do not sustain the Examiner's rejection of independent claim 1 and dependent claims 2-6 as unpatentable over Urushihara in view of Edwards. 6 Appeal2018-003565 Application 14/673,106 DECISION We REVERSE the Examiner's decision rejecting claims 1---6. REVERSED 7