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/Restrictions
Claims 1-9 withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected printhead or system comprising a printhead, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on April 7, 2026.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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(s) 10-16 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN 111391064) in view of Forgeron (US 2017/0043499).
Regarding claim 10, Zhang discloses a method comprising: flowing a primary fluid comprising a cementitious material into an inner bore of a printhead (cement-based material entering by main feed inlet 5, p. 4, annotated Fig. 1); flowing a secondary fluid into a pressure chamber surrounding at least a portion of the inner bore of the printhead (feed to material feeding port 6, p. 4-5, annotated fig. 1); flowing the secondary fluid from the pressure chamber into the inner bore of the printhead while the primary fluid flows within the inner bore of the printhead to mix the secondary fluid with the primary fluid within the inner bore of the printhead and form a cementitious composite material (material feeding port 6 feeding from a plurality of circumferentially arranged inlets, material mixed and flowing out of nozzle 4, p. 4-5, annotated Fig. 1); and discharging the cementitious composite material from the inner bore of the printhead (discharged through nozzle 4, p. 5).
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Annotated Fig. 1 of Zhang
Zhang teaches a method substantially as claimed. Zhang does not disclose flowing a secondary fluid comprising carbon dioxide, steam, or both.
However, in the same field of endeavor of preparing and discharging a cementitious material (abstract), Forgeron teaches flowing a secondary fluid comprising carbon dioxide, steam, or both ([0040] [0050], Fig. 1).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Zhang to insert Carbon dioxide with the secondary fluid because [0002] of Forgeron teaches the benefits of carbonation of cement and [0050] teaches doing so by introducing carbon dioxide at a suitable point in the mixing process, with Fig. 1 teaching to do so at what would be the same location as the injection of secondary fluid in Zhang.
Regarding claim 11, Zhang as modified teaches moving the printhead while discharging the cementitious composite material from the inner bore of the printhead (moving process of printer during printing, p. 2 and 4).
Regarding claim 12, Zhang as modified teaches wherein the secondary fluid is flowed from the pressure chamber into a convergent-divergent section of the inner bore of the printhead (as modified, injecting carbon dioxide, [0050] of Forgeron, with the secondary fluid at port 6 of Zhang, p. 4-5, annotated Fig. 1, flows the carbon dioxide into the chamber and into the convergent-divergent section, annotated Fig. 1 of Zhang).
Regarding claim 13, Zhang as modified teaches applying shear to the cementitious composite material within the inner bore of the printhead to homogenize the cementitious composite material (plurality of blades 32 perform this function, particularly in the section marked shearing section of annotated Fig. 1, Zhang p. 5).
Regarding claim 14, Zhang as modified teaches wherein the shear is applied to the cementitious composite material is applied by a shearing blade disposed within a shearing section of the inner bore of the printhead (plurality of blades 32 perform this function, including in the section marked shearing section of annotated Fig. 1, Zhang p. 5).
Regarding claim 15, Zhang as modified teaches wherein the shearing section of the inner bore of the printhead has a venturi shape with a converging cross-sectional flow area followed by a diverging cross-sectional flow area (annotated Fig. 1 of Zhang).
Regarding claim 16, Zhang as modified teaches wherein flowing the primary fluid into the inner bore of the printhead comprises flowing the primary fluid into a first inlet of the printhead (cement-based material entering by main feed inlet 5 of Zhang, p. 4, annotated Fig. 1).
Regarding claim 19, Zhang as modified teaches wherein the printhead comprises a plurality of venturi conduit linings spanning longitudinally along at least a portion of the convergent-divergent section of the inner bore of the printhead (effect of protrusions 2 of Zhang, p. 5, annotated Fig. 1).
Regarding claim 20, Zhang as modified teaches mixing, by the plurality of venturi conduit linings, the primary fluid and the secondary fluid within the convergent-divergent section of the inner bore of the printhead (Zhang p. 5, Fig. 1).
Allowable Subject Matter
Claims 17-18 objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 17 recites, “[the] method of claim 16, wherein the secondary fluid is flowed from the pressure chamber into the inner bore of the printhead through a secondary inlet extending from the pressure chamber to a convergent-divergent section of the inner bore.”
Zhang (CN 111391064) teaches flowing a primary cementitious fluid (p. 2) and flowing an auxiliary material through port 6. Other references, such as [0016] of Al-Khowaiter (US 2021/0189745; US 11,236,517), teach injecting steam/carbon dioxide downstream of a print head nozzle and just as the material leaves the print head. [0050] of Forgeron (US 2017/0043499; US 10,350,787) teaches introducing carbon dioxide at a pump that pumps concrete into the conduit, at or near the distal conduit, or elsewhere in the conduit. While “elsewhere in the conduit,” if applied as a modification to Zhang, could include inlet to the convergent-divergent section in annotated Fig. 1, doing so relies on an impermissible level of hindsight. Such a modification would essentially reimagine the printhead of Zhang beyond the teachings of Forgeron. The available prior art does not teach the inlet with steam and/or carbon dioxide as extending to a convergent-divergent section of the inner bore.
Claim 18 similarly recites allowable subject matter by depending from claim 17.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Li (Development of CO2-integrated printing concrete) teaches the benefits of carbonation for 3D printing concrete.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICHOLAS J CHIDIAC whose telephone number is (571)272-6131. The examiner can normally be reached 8:30 AM - 6:00 PM.
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/NICHOLAS J CHIDIAC/Examiner, Art Unit 1744
/XIAO S ZHAO/Supervisory Patent Examiner, Art Unit 1744
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