DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restriction
Applicant’s election without traverse of invention I, claims 1-17 in the reply filed on 4 August 2026 is acknowledged.
Claims 18-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 4 August 2026.
Claim Objections
Claim 11 is objected to because of the following informalities:
Regarding claim 11, on line 2, the word “the” is missing before “mixture of electrolyte.”
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 5, 8, 9, and 14 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claim 5, the phrase "for example" renders the claim indefinite because it is unclear whether the limitation following the phrase is part of the claimed invention. See MPEP § 2173.05(d). Because claims are given the broadest reasonable interpretation during examination, the recitation of “at a position laterally spaced from the nozzle” will be interpreted as only exemplary of the preceding limitations.
Regarding claim 8, it is unclear whether the configuration of the device is to inject a compressed gas into the electrolyte flow path distinct from or the same as the gas injected into the electrolyte flow path as recited in claim 1. Because the specification does not disclose multiple points of gas injection to the electrolyte flow path, this configuration for compressed gas injection is interpreted as referring to the same gas injection configuration of claim 1.
Regarding claim 9, the phrase "for example" renders the claim indefinite because it is unclear whether the limitation following the phrase is part of the claimed invention. See MPEP §§ 2173.05(c) and (d). Because the recitation of “for example approximately 2 bar” is within the earlier recited range of 0.5-5 bar, it is not interpreted as imparting any further limitation on this range.
Regarding claim 14, the word "preferably" renders the claim indefinite because it is unclear whether the limitation following this word is part of the claimed invention. See MPEP § 2173.05(d). The claim will be interpreted as not requiring the ionic solvent having a conductivity of at least 8000 µS/cm.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-8 and 13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Liu et al. (CN 104959684 A, as previously attached).
Regarding claims 1-4, 8, and 13, Liu teaches an electrical machining device for machining a surface of a workpiece (Fig. 1), the electrical machining device comprising: a nozzle connectable to an electrolyte reservoir ([0013]; “Tool electrode”), the nozzle comprising an outlet port configured to dispense electrolyte towards a surface of a workpiece; and an electrolyte flow path for conveying electrolyte from an electrolyte reservoir to the nozzle (Fig. 1: arrow inside the “Tool electrode”). The nozzle is connected to the negative terminal of a power supply, equivalent to “configured to apply a voltage;” the workpiece is likewise connected to the positive terminal of the power supply ([0036]). This configuration necessarily applies a voltage to the surface electrolyte because the electrolyte undergoes an electrochemical reaction ([0008]). The electrolyte flow path comprises a gas inlet upstream of the outlet port of the nozzle (Fig. 1: “Gas or air supply system”). In use, the electrical machining device is configured to inject a gas into electrolyte flowing along the electrolyte flow path via the gas inlet so as to form gas bubbles in said electrolyte ([0036]). This gas may be compressed ([0016]: “the pressure of the gas is 0.01 MPa – 9 MPa”). The injected gas reduces the conductivity of the flowing electrolyte, enabling an electrical arc discharge to be generated ([0013]: “the conductivity of the atomized medium is controlled by adjusting the ratio of gas to electrolyte;” [0036]: atomizing medium from a mix of gas and electrolyte has low conductivity; [0024]: spark/arc and electrolytic discharge both occur). The pressure of the gas may be adjusted with the pressure control device (Fig. 1: labeled as such; [0025]: control of ratio of gas to electrolyte).
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Regarding claim 5, a conductive member is configured and arranged to electrically contact the surface electrolyte, so as to apply a voltage to surface electrolyte on a surface of a workpiece (Fig. 1, positive lead from pulsed power supply connects to workpiece).
Regarding claim 6, the power supply applies a voltage to the nozzle and to the electrolyte, via the conductive workpiece, to generate an electrical arc discharge ([0034]: as “electric spark discharge”).
Regarding claim 7, the nozzle is spaced apart from the surface of the workpiece as shown by the gap between the workpiece and tool electrode in Fig. 1.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (CN 104959684 A).
Regarding claim 11, the amount of gas added to the mixture may be less than the amount of electrolyte present ([0038]). While not disclosed as “by volume,” the ratio of gas and electrolyte may be adjusted during the machining process to affect the efficiency and roughness of the machining ([0038]). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. It is therefore obvious to one skilled in the art to operate the device of Liu with any usable concentration including the claimed concentration ratio. See MPEP § 2144.05(II)(A).
Claims 9, 10, 12, and 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (CN 104959684 A) as applied to claims 1 and 8 above, and further in view of Wang et al. ("Fabrication of micro-dimple arrays by AS-EMM and EMM," Int J Adv Manuf Technol, 93:787-797, 2017, as attached by applicant).
Regarding claim 9, Liu teaches that the pressure of the gas of claim 8 is in the range of 0.01 MPa – 9 MPa, equivalent to 0.1 to 90 bar ([0016]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP §2144.05(I). The claimed range of 0.5-5 bar is therefore obvious.
In the alternative, Wang teaches that the pressure of the compressed gas in an electrochemical machining apparatus is 0.15 MPa, or 1.5 bar (Wang p. 791, table 2, “Gas pressure (Mpa)”), within the claimed range of 0.5-5 bar. It would have been obvious to one of ordinary skill in the art before the effective filing date to use this pressure in the electrochemical machining process taught by Liu, as it is within the range of gas pressures permitted, and was shown to be effective in machining micro-dimple arrays on a stainless steel workpiece (Wang Table 2, Fig. 10).
Regarding claim 10, Liu does not teach wherein the gas used in the machining process of claim 1 is selected from one or more of compressed air, argon, nitrogen, helium, neon, krypton, xenon, radon, and carbon dioxide. However, Wang teaches that the gas mixed into the electrolyte upstream of the nozzle outlet may be air (Fig. 7: air compressor).
It would have been obvious to one of ordinary skill in the art before the effective filing date to use compressed air in the machining process of Liu, because both air and oxygen are demonstrated as suitable for use in electrolytic machining.
Regarding claim 12, Liu does not teach wherein the gas inlet defines an area, and the size of said area is adjustable. However, Wang shows a flow control valve downstream of the gas source and upstream of the nozzle (Fig. 7: “Flow control valve”). The area of the gas inlet is therefore adjusted by the flow control valve because the valve may be at least either fully open or closed (p. 789, §2 Principle of the EMM and the AS-EMM: open or closed air valve results in different fluid behavior out of the nozzle).
It would have been obvious to one of ordinary skill in the art before the effective filing date to make the gas inlet area adjustable in the way taught by Wang. One of ordinary skill in the art would have been motivated to do so in order to achieve control over the ratio of gas and electrolyte mixing prior to exiting through the nozzle, as Liu teaches ([0039]). See also MPEP § 2144.04(V)(D) regarding the obviousness of making the prior art adjustable.
Regarding claims 14-17, Liu teaches that the electrolyte is a solution of the inorganic salts sodium chloride, nitrate, sulfate, or combinations thereof, but does not explicitly state that the solution comprises an ionic solvent such as water ([0020]).
However, Wang teaches that the electrolyte may be water-based (p. 791, §4.1 Experimental equipment: “aqueous electrolyte solution”), comprising 10% NaNO3 (p. 791, table 2). Water is well-known in the art as a polar solvent which can dissolve many ionic salts, thus reading on claim 15’s language of “an ionic solvent.”
It would have been obvious to one of ordinary skill in the art before the effective filing date to use an aqueous solution comprising NaNO3 as the electrolyte in the electrical machining device of Liu. One would be motivated to use this solution because it is within the disclosure of Liu, and electrolytes comprising aqueous solutions of ionic salts are common in the art due to their lower cost and reduced hazards compared to, e.g., molten salts or polar organic solvents.
Conclusion
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/CBF/
Examiner, Art Unit 1711
/MICHAEL E BARR/Supervisory Patent Examiner, Art Unit 1711
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